Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery
ISSN: 0284-4311 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/iphs19
Magnetic Resonance Imaging in the Assessment of Craniosynostosis Richard Hayward, William Harkness, Brian Kendall & Barry Jones To cite this article: Richard Hayward, William Harkness, Brian Kendall & Barry Jones (1992) Magnetic Resonance Imaging in the Assessment of Craniosynostosis, Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery, 26:3, 293-299, DOI: 10.3109/02844319209015274 To link to this article: http://dx.doi.org/10.3109/02844319209015274
Published online: 08 Jul 2009.
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Scrind J Plast Reconstr Hand Surg 26: 287-292, 1992
MELANOMA OF PALMS, SOLES, A N D NAIL-BEDS Liisa Tuominen’ and Liisa Strengell’ From the ’Division of Plastic Surgery, Toolo Hospital, University Central Hospital, Helsinki, and the ‘Department of Pathology, Hyvinkaa District Hospital, Hyvinkaa, Finland
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(Submitted for publication September 2, 1991)
Ahstruct. The clinical and histological characteristics of palmar, plantar, and subungual melanomas treated in the division of plastic surgery of Helsinki University Hospital between 1970 and 1984 were analysed. The peak incidence was during the seventh decade of life, and the mean delay between the onset of symptoms and the diagnosis was one year. The delay was as much the fault of the physician as of the patient. The observed and relative five-year-survival rates for all 31 patients were 60% and 67% and the 10-year-survival rates 39% and 49‘X, respectively. There were 15 cases of the acral lentiginous subtype, and the observed and relative five-year-survival rates were 65% and 71%. and the 10-year-survival rates 48% and 64%, respectively. For the nodular melanomas ( n = I I ) the survival rates were 53% and 60%1,and 39% and 53%, respectively. For the three superficial spreading melanomas they were 50%)and 52%, and 25% and 28%. respectively. Microstaging criteria (Breslow and Clark) were both good prognostic indicators. The series was too small for multivariate analysis. Kev words: palmar, plantar, and subungual melanoma; survival.
Melanomas on hair-bearing skin have been studied intensively, but melanomas on the hairless palmar. plantar, and subungual skin have received little attention. Clark et al. (5) and McGovern ( 14) divided melanomas into three morphological types: superficial spreading, lentigo maligna, and nodular. Arrington et al. (2) introduced the concept of acral lentiginous melanomas to denote those that arise on palmar, plantar, and subungual skin and have a histological radial growth phase similar to that of mucosal melanomas. This study was undertaken to characterise the clinical and histological findings, and analyse the prognosis of palmar, plantar, and subungual melanomas treated in the division of plastic surgery at Helsinki University Hospital.
PATIENTS A N D METHODS Between 1970 and 1984. 570 patients with melanoma were treated in this department, and the palmar, plantar, or subungual areas were affected in 31 (5.4%) of them. The following clinical data were recorded from the chart of each patient: age, sex, location of the lesion, duration of symptoms before diagnosis, time of onset of lesion, tumour, nodes, metastases (TNM) classification ( I I), primary treatment (surgical, irradiation, or chemotherapy) and survival time, which was calculated from the date of the biopsy to the time of the patient’s death or to the termination of the study (December 1988). Histological slides were reexamined and the following points were noted: confirmation of the diagnosis; subclassification into histological categories (superficial spreading, nodular, acral lentiginous, or unclassified); deepest level of invasion (Clark); thickness of lesion (Breslow); cell types; and whether ulceration was present. We used the histological criteria of Clark et al. ( 5 ) and Arrington et al. (2). Statistical analysis. The relative survival rates for patients were evaluated as the ratios of the observed and expected survival rates. The relative survival rates describe the population standardized survival of the patients when the effects of causes of death other than melanoma of the skin have been eliminated. The data were analysed on a Digital Equipment Corporation Vax computer with the Cancer Survival Packages of the Finnish Cancer Registry (10).
RESULTS Age. The mean age of the 31 patients was 57.5 years (59 for the 20 women and 57 for the 11 men). The peak incidence of these melanomas occurred during the seventh decade of life (Fig. 1). Location. The primary lesion was on the sole in 23 patients. One had a primary lesion of the palm and another on the ball of the thumb. There were six subungual melanomas, four on the toes and two on the fingers (Fig. 2). Symptoms. Eighteen patients had longstanding pigmented lesions at the sites where the melanomas Sccmd J Plust Reconstr Hand Surg 26
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L. Tuominen and L. Strengell Duration of the symptoms. The mean delay between the onset of symptoms and diagnosis was one year. Three lesions were treated as warts (Fig. 3), three as paronychia (subungual) (Fig. 4) and three as chronic ulcers. In these cases the delay was as much the fault of the physician as of the patient. TNM classiJication of palmar, plantar, and subungual melanomas. According to the TNM classification six melanomas were in Stage I, but most were in stages I1 (n = 14) and I11 ( n = 10). One patient had distant metastases at the time of diagnosis. Nodal diseuse. Disease was present in the lymph nodes in five cases, distant spread developed in six patients-in five ahnut a year later, and in one seven years later. Recurrences. Tumours recurred in the same extremity in five patients; in four cases they were
Number of
patients 10
8
6
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4
2
0
4.00
Five-year-survival (%)
10-year-survival (‘%)
Observed
Relative
Observed
Relative
1
100
103
3 16 II
I00 67
101
I00 100
106 122
30
34
37 20
46 28
No of patients (n = 31)
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74
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Melanoma of palms, soles, and nail-beds
plantar, and subungual melanomas, but only for those that meet the morphologic criteria established for this subtype (2). Melanomas located on the foot and hand have a poorer prognosis than melanomas of other sites (7). In several recent studies of prognosis (3,4,6, 7) the thickness of the lesion, the level of invasion and ulceration correlate closely with the prognosis. In our study the thickness of subungual, palmar, and plantar melanomas was more than 1.50 mm in 80% (25/31), which according to Breslow’s data (4) should have a poor prognosis. The relative (observed) five-year-survival rates for melanomas 1.504.00mm, o r more than 4.00mm thick, were 74?h (67%) and 34% (30%), respectively. Ten years later, however, the figures had dropped to 46% (37%), and 28% (20%). The level of microinvasion in these melanomas exceeded grade I11 in 87% of cases. A fifth of the melanomas included in this study were level V and the five-year-survival of these patients was 25%. The treatment of our patients varied greatly. The effects of elective lymph node dissection are controversial as are the effects of adjuvant chemotherapy and radiotherapy ( 17, 19,20). Therapeutic lymph node dissection was done at the time as primary excision in five cases, and later in six. Eight elective lymph node dissections were done by wide local excision o r amputation of the finger or toe. Paladugu et al. (IS) recommended wide local excision and elective lymph node dissection for subungual lesions that measured more than 1.00 mm and for those that showed severe regression, but two randomised trials have failed to show that this confers any benefit (17, 19). Two prospective randomised trials are now being conducted in North America and in Europe. Until the results of these trials are available, elective lymph node dissection should be considered in selected patients, in whom the risk : benefit ratio justifies it. Factors to be considered are intermediate tumour thickness, ulceration, and the risk of the operation for individual patients. Recurrences after primary treatment should be excised. Five patients who developed recurrences were treated with further wide local excision and one patient with excision around the extremity and skin grafting. Isolated limb perfusion for regional metastases has not been used in Finland.
29 1
CONCLUSIONS Melanomas located on palms, soles, and in nail-beds accounted for 5.4% of the primary cutaneous melanomas. The prognosis was related to the microstaging of the lesions according to Clark and Breslow. In view of the high incidence of nodal disease, it is important that the role of elective lymphadenopathy is further clarified in this aggressive subtype of melanoma.
REFERENCES 1. Ariel IM. Malignant melanoma. New York: AppletonCentery-Crofts, 1981 ; 365-377.
2 Arrington JH, Reed R, lchinose H, Krementz E. Plantar lentiginous melanoma: A distinctive variant of human cutaneous malignant melanoma. Am J Surg Pathol 1977; 1: 131-143. 3. Balch CM, Song S, Milton GW, et al. A comparison of prognostic factors and surgical results in 1786 patients with localized (Stage I) melanoma treated in Alabama USA and New South Wales Australia. Ann Surg 1982; 196: 677- 684. 4. Breslow A. Thickness, cross sectional areas and depth of invasion in the prognosis of cutaneous melanoma. Ann Surg 1970; 172: 902-908. 5. Clark WH Jr, From L, Bernandino EA, Mihm MC. The histogenesis and biologic behavior of primary human malignant melanoma of the skin. Cancer Res 1969; 29: 705-727. 6. Daly JM, Berlin R, Urmacher C. Subungual melanoma: A 25-year review of cases. J Surg Oncol 1987;35: 107-112. 7. Day C, et al. A multivariate analysis of prognostic factors for melanoma patients with lesions z 3.65mm in thickness. Ann Surg 1982; 195:44-49, 8. Feibleman CE, Stoll H, Maize JC. Melanomas of the palm sole and nail bed. Cancer 1980 46: 2492-2504. 9. Gutman M,Klausner JM, Inbar M, Skornik Y, Baratz M, Rozin RR. Acral (volarsubungual) melanoma. Br J Surg 1985;72: 610-613. 10. Hakulinen T,Abeywickrama K. A computer program package for relative survival analysis. Comp Progr Biomed 1985; 19: 197-207. I I . International Union Against Cancer TNM Classification of Malignant Tumors. 4th ed 1987. 12. Jimbow K, Ikeda S, Takahashi H, Kukita A, Miura S. Biological behavior and natural course of acral malignant melanoma. Am J Dermatopathol 1984;6: 43-53. 13. Kerl H, Hod1 S, Stettner H. In: Ackerman AB, ed. Pathology of malignant melanoma: Acral lentiginous melanoma. Masson Monographs in Dermatopathology. USA: Masson Pub1 Inc. 1981; 1: 217-242. 14. McGovern VJ. The classification of melanomas and its relationship with prognosis. Pathology 1970;2: 85-98. 15. Paladugu RR, Winberg CD, Yonemoto RH. Acral lentiginous melanoma. Cancer 1983; 52: 161 - 168. Scund J Plusr Reconstr Hand Surg 26
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16. Shaw JHF, Koea JB. Acral (volar-subungual) melanoma in Auckland, New Zealand. Br J Surg 1988; 75: 69-72. 17. Sim FH, Taylor WF, Pritchard DJ, Soule EH.
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Lymphadenectomy in the management of stage I malignant melanoma: a prospective randomized study. Mayo Clin Proc 1986; 61: 697-705. 18. Sodergaard K, Olsen G. Histological type and biological behavior of primary cutaneous malig-
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nant melanoma. Virchows Arch 1983; 401: 333343. 19. Veronesi U. et al. Inefficacy of immediate node dissec-
tion in stage I melanoma of the limbs. N Engl J Med 1977; 297: 627-630. 20. Veronesi U. et al. A randomized trial of adju-
vant chemotherapy and immunotherapy in cutaneous melanoma. N Engl J Med 1982; 307: 913916.
se;mcl.J Plast Reconstr Hand Surg 26: 293-299, 1992
MAGNETIC RESONANCE IM-AGING IN THE ASSESSMENT OF CRANIOSYNOSTOSIS Richard Hayward, William Harkness, Brian Kendall and Barry Jones From the Craniofacial Unit, The Hospital for Sick Children, London WClN JJH, England
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(Submitted for publication July 12, 1991)
Abstract. Modern interest in craniosynostosis began when clinicians, regardless of their individual specialty but united in their interest in the problems raised by patients with this condition, first realised that if treatment was confined simply to opening up the fused sutures of the skull vault, success in terms of both function and the restoration of a more normal appearance was likely to be limited. Indeed, the grouping together of such specialists into formal craniofacial units was tacit recognition of this, as was the acceptance that many affected children had evidence of clinical problems that could not be explained on simple mechanical grounds alone. It is not surprising, therefore, that the advent of any new method of investigation has been welcomed by craniofacial surgeons eager to learn anything that might lead to an improvement in management, particularly of the more complex syndromes.
following the installation of our own MRI scanner, we decided to study other cases of craniosynostosis that presented to our craniofacial unit. It is our intention in this paper to draw attention to the range of abnormalities that can be demonstrated by MR scanning and to show how such a facility can assist in the management of these cases. For this reason some of the results are dealt with in rather general terms, and more detailed information (regarding the fine anatomy of herniation of the hindbrain, for example) reserved for an appropriate specialist publication.
Key words: craniosynostosis, magnetic resonance imaging.
Our first 30 cases form the basis of this report. Their clinical details are given below, under RESULTS. These patients are a selected group. It was necessary to limit MRI to those children with the most severe clinical problems, that is, those presenting with hydrocephalus, with obvious respiratory difficulties, and with the worst craniofacial deformities. Children presenting with “simple” craniosynostosis (such as premature fusion of the sagittal, or one coronal suture, for example) are therefore underrepresented in this series (a fact whose implications are dealt with in the discussion). All the scans, with three exceptions, were carried out on a 1.5 T Siemens Magnetom. Axial, coronal, and sagittal sections were attempted in all cases although factors unrelated to the scanning technique (such as a failure of sedation) meant that some studies were incomplete.
Our own interest in the use of magnetic resonance imaging ( MRI) in the assessment of craniosynostosis was aroused by finding, in a scan performed in October 1987, a severe degree of hindbrain herniation in a 5 year old child with a cloverleaf skull syndrome associated with Pfeiffer’s syndrome (as was also reported by Venes, 1988). Another finding-obvious enough in restrospect although to us at the time unexpected-was the dramatic demonstration of the anatomy of the airway. The patient suffered from severe upper respiratory tract obstruction for which a Le Fort 111 extracranial midface advancement had been carried out (with modest success) when she was just under 4 years old. The MRI showed clearly the degree of oropharyngeal obstruction caused by adenoidal hypertrophy. This led directly to her referral for tonsillectomy and adenoidectomy, a procedure that provided her with excellent symptomatic relief. (This patient is illustrated in Figs. 3a, b). Encouraged by our success with this case, and
METHOD
RESULTS The diagnoses of the patients studied are shown in Table I. The scans were analysed first for evidence of abnormalities of the hindbrain and craniocervical junction. Herniation of the hindbrain varied from simple descent of the cerebellar tonsils to just below the Scand J Plast Reconstr Hand Surg 26
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Table 1. Clinical diagnoses in patients studied Diagnosis
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Crouzon’s syndrome Saethre-Chotzen syndrome Pfeiffer’s syndrome: (with cloverleaf skull) (without cloverleaf skull) Apert’s syndrome “Simple” craniosynostosis: Bicoronal (non-syndromic) Lambdoid Bicoronal + sagittal Metopic Total
No. of patients
9 3 6
3 3 5 1
3 2 1
1
30
foramen magnum, to herniation to the level of the second cervical vertebra together with kinking of the lower brainstem and downward shift of the pontinemedullary junction. (Examples are iHustrated in Figs. 1-5.) Detailed information concerning herniation of the hindbrain is to be published elsewhere but the results may be summarized as follows:
Some degree of herniation of the hindbrain was seen in a total of 19 cases (Table 11). In general, the more severe degrees of herniation of the hindbrain-that is. those cases with the greatest descent of the cerebellar tonsils, buckling of the brainstem and displacement of the pontinemedullary junction-were associated with the most severe craniofacial abnormalities-for example, the cloverleaf skull syndrome. In one patient (with Apert’s syndrome) the tonsillar herniation was associated with syringomyelia for which decompression of the foramen magnum was required. All these abnormalities are customarily grouped under the title of the Chiari I malformation-the Chiari I1 malformation (or Arnold-Chiari malformation), which is typically associated with spina bifida aperta and in which there is also herniation upwards through the tentorial hiatus (and possibly represents a primary malformation of the brainstem) was not seen in this series. Hydrocephalus. For the purpose of this paper, we have defined hydrocephalus as ventricular enlargement associated with a rise in intracranial pressure sufficient to require the insertion of a shunt. Altogether there were 12 cases of hydrocephalus in this series, and all 12 were associated with herniation of the hindbrain. Assessment of the airway. Analysis of the MR images of the airway allowed assessment of the following: The configuration and length of the palate, the size of the nasopharyngeal space, the Table 11. Diagnoses in patients who had some degree of herniation of the hindbrain Diagnosis
Fig. 1. This (normal) sagittal MRI of a child with metopic synostosis will allow comparisons to be made with subse-
quent illustrations. There is no evidence of herniation of the hindbrain and the medulla of the brainstem is not deformed. The junction between the pons and the medulla of the brainstem can be seen (arrow) and is in a normal position. Note also the normal pattern of the turbinates and the horizontal orientation of the palate. There is a generous oral airway. Srand J Plasr Reconslr Hand Surg 26
Crouzon’s syndrome Saethre-Chotzen syndrome Pfeiffer’s syndrome: (with cloverleaf skull) (without cloverkaf skull) Apert’s syndrome - ~ i ~ craniosynostosis: ~ l ~ ” Bicoronal ~non-syndromic) Lambdoid Total
No. of cases 5 1 6
3 3 4
3
I 2 19
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Fig. 2. ((I) Crouzon’s syndrome. There is synostosis ofthe sagittal as well as the coronal sutures, and the maxilla is hypoplastic. ( h ) The MRI shows herniation of the ccrebellar tonsils (/urge urrow) but no deformation of the medulla. The pontomedullary junction is low ( s n d l orrow). There is a high arched palate that contributes to the obstruction of the nasal airway and the soft palate is orientated more closely to the vertical than the horizontal. Hypoplasia of the mandible is also seen clearly.
degree of obstruction caused by adenoidal hypertrophy, the anatomy of the nasal airway, the size of the tongue in relation to the oral cavity, and the size of the oropharynx. Examples of abnormalities in all these areas are also illustrated in Figs. 1-5. “Abnormalities” oJ’ cerebral white matter. Many children with craniosynostosis have evidence of neurodevelopmental delay for which an obvious explanation (for example, hydrocephalus or raised intracranial pressure as a result of restricted cranial volume) is present in only a certain proportion of cases. MRI allows assessment of the progress of cerebral myelination in the child’s brain to be made as delay in this process is a factor that might be associated with developmental problems. Such abnormalities were seen in four patients; once each in cases of lambdoid synostosis, nonsyndromic bicoronal synostosis, Crouzon’s syn--
drome and Saethre-Chotzen syndrome. All showed signs of moderate developmental delay, but the appropriate sequences for analysing the stage of cerebral myelination were not routinely employed in this series. DISCUSSION The advent of a sophisticated new investigational technique can lead to alterations in our thinking about a subject in a variety of ways. Clearly, the clinical management of that condition may be altered but, in addition to this, there can be changes in our understanding, the immediate applications of which are less obvious even though the knowledge itself seems t o be of great interest. We will discuss the results of introducing MRI into the assessment of our patients with craniosynostosis with these two aspects in mind. Smnd J Plusr Reconsrr Hand Surg 26
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Fig. 3. (a) Pfeiffer’s syndrome in an infant with cloverleaf skull deformity. (b) MRI of the same patient four years later.
Hydrocephalus can be recognised by the enlargement o f the third ventricle. There is pronounced cerebellar tonsillar herniation with kinking of the brainstem anteriorly over the odontoid peg at the level of the pontomedullary junction (small arrow). In addition to the abnormalities of the ainvay already seen in Fig. 2a, there is also adenoidal hypertrophy (large arrow) causing obstruction of the oropharynx.
Anomalies of the hindbrain in patients with craniosynostosis. Our results show that there is a high
incidence of herniation of the hindbrain in our patients with craniosynostosis (18 of 30), but rt should be emphasised that it is not possible from this series to make any useful assessment about the incidence of the association. Our patients were usually imaged because of the severity of their condition, but sometimes they were selected because they were known from previous investigations, computed tomography, for example, to have hydrocephalus or some other neurological complication. The association seems to be more obvious in the more severe cases, however, as no evidence of herniation of the hindbrain was seen in the non-syndromic patients though it was present in all patients with the cloverleaf skull syndrome. The advent of the MR scanning has allowed us to diagnose neurological abnormalities that result from Scund J Plust Reconstr
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compression of the brainstem at the foramen magnum. These include various degrees of ataxia that had previously been unexplained. One child with Saethre-Chotzen syndrome had drop attacks unassociated with any loss of consciousness and required a decompression of the foramen magnum (Fig. 4a, b). Two of the children with cloverleaf skulls also have longstanding problems caused by their ataxia that have not, so far, been sufficiently severe to justify a decompression. The recognition of herniation of the hindbrain also provides us with a possible explanation for any central component to the respiratory dysfunction that so often complicates the management of the more complex cases of craniosynostosis. A further category of clinical conditions that could be attributed to the herniation of the hindbrain seen in our patients is related to the obstruction to the passage of cerebrospinal fluid around the foramen magnum. If the effects of this predominate
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Fig. 4. (a)A 4 year old girl with Saethre-Chotzen syndrome who was operated on (frontal cranioplasty) at 6 months. She presented again with drop attacks. ( b) Her MRI scan shows a modest degree of cerebellar tonsillar herniation through the foramen magnum (arrow). She has had no further drop attacks since decompression of the faramen magnum.
in the head then hydrocephalus will result (see below). Obstruction of the normal ingress and egress of cerebrospinal fluid across the foramen magnum itself during such normal activities as coughing and straining, for example, is one of the commonest causes of syringomyelia. One case of Apert’s syndrome in this series had syringomyelia and required a decompression of the foramen magnum (which was performed at another hospital). Herniation of the hindbrain can also produce abnormalities of eye movement (particularly downbeat nystagmus) and difficulties with swallowing and articulation (dysarthria). No examples of these were recorded in this series. The discovery of an association between craniosynostosis and abnormalities at the cranio-cervical junction also allows new theories concerning the development of this complex region to be formulated-a subject of continuing debate among neurologists, neurosurgeons, radiologists, geneticists and anatomists (among others) -and this topic is also to be discussed in a further publication. Hydrocephalus and craniosynostosis. Though the association of hydrocephalus with craniosynostosis
is well known its aetiology remains mysterious. In the absence of any obvious structural abnormality-such as aqueduct stenosis-or a preceding history of an illness, such as meningitis, that can lead to obstruction of the cerebrospinal fluid (CSF) pathways, investigators have concentrated on the possible effects of the bony abnormality at the base of the skull. This has been thought of either as providing a mechanical obstruction to CSF flow or (in a less direct way) as interfering with the venous drainage from the intracranial compartment through the jugular foramina, and thus raising the pressure against which the CSF has to be absorbed. Herniation of the hindbrain is an accepted cause of hydrocephalus in conditions such as spina bifida aperta, and as it has been found in all cases of hydrocephalus complicating craniosynostosis in our series, we would suggest that there is probably a strong aetiological connection. This is not to say that other factors may not have a part to play in the pathogenesis. There are changes in venous pressure across the skull base as well as possible alterations in CSF production rates in some children with craniosynostosis (one of our children, Scund J PIasr Reconstr Hund Surg 26
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Fig. 5. ( u ) Pfeiffer’s syndrome with cloverleaf skull deformity. The reservoir of the shunt system that was needed for
treatment of her hydrocephalus can be seen (arrow). (h) Her MRI scan shows residual enlargement of the third ventricle. There is herniation of the cerebellar tonsils and the medulla of the brdinstem is kinked at the level of the foramen magnum (urrow). The nasal airway is reduced by a combination of maxillary hypolasia and arching of the hard palate. The soft palate is close to the vertical and this contributes to obstruction of the oropharynx.
aged 4 years, with Pfeiffer’s syndrome, produced approximately 700ml of CSF each day while on lumbar drainage). Assessment of the airway. Severe cases of craniosynostosis may be complicated by airway obstruction affecting any part of the respiratory pathways, but it is particularly the abnormalities within the upper respiratory tract (the nose and velopharynx) that can, during the first few months of life when children are preferential nose breathers, sometimes be life threatening. Episodes of sleep apnoea are not uncommon and affected babies may die suddenly of respiratory obstruction. A narrowed airway also predisposes the child to upper respiratory tract infections which, by producing mucosal, tonsillar, and adenoidal hypertrophy, further compound the problem. Respiratory obstruction raises the intracranial pressure and this, together with the feeding and nutritional problems (resulting in failure to thrive) Scund J Pbsr Reconstr Hand Surg 26
so often seen in these children, may contribute to their neurodevelopmental delay. MRI provides excellent images in various planes, particularly of the soft tissue component of the airway. The varying contributions of maxillary hypoplasia, naso-pharyngeal volume, palatal anatomy, relative tongue size, and tonsillar and adenoidal hypertrophy can all be assessed and judgements made about the likely effect of any operation. For example, a n advancement of the middle third of the face is unlikely to improve the patient’s airway problems if a preceding MRI has shown that, in addition t o the restriction of space within the nasopharynx, there are sites of obstruction elsewhere-in the nasal cavity or low in the oropharynx, for example. As can be seen from the illustrations, MRI provides a unique method for viewing many of the components of the upper airways at the same time,
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and allows an assessment to be made of the relative offer parents a more accurate prognosis concerning contribution that an abnormality of any of them their child's likely developmental progress. might be making to the final degree of respiratory MRI can also provide information about the obstruction. Our images show how the high, arched anatomy of the brain surface-the shape and size of palate further reduces the volume of the nasal air- the gyri together with the degree of distortion to way and demonstrate how-although the soft palate which they have been subjected by the abnormal seems to be of normal length even in cases with a skull shape, for example-all of which may be of severe deformity-the reduced volume of the relevance in the determination of any eventual neuoropharynx ensures that it must now be disposed rological or intellectual deficit. The presence of other vertically as opposed to horizontally, and provide intracranial abnormalities that may be associated both a fixed and dynamic obstruction to airflow with neurodevelopmental delay -agenesis of the through this region. corpus callosum, for example-can also be demonIn order to obtain the most complete information strated clearly. about the airway, in terms of imaging techniques, it is necessary to combine MRI with computed tomogCONCLUSION raphy (using bone windows, and preferably with three-dimensional reconstructions) to define the MRI has established itself as a regular part of our anatomy of both the bony and soft tissue elements. assessment of patients with craniosynostosis. Not This is particularly important in the assessment of only has it provided us with important new information about this whole group of patients, but it is also stenosis or atresia at choanal level. helping from day to day in the management of Assessment of brain myelination. It is not possible individual children, in particular by permitting a from our present observations to comment on either more accurate anatomical assessment of the airway the rate or the degree of myelination that MRI can as well as by allowing us to diagnose those problems demonstrate in craniosynostosis. Nevertheless, all caused by herniation of the hindbrain that, with the clinicians-and in particular, paediatricians-inexception of hydrocephalus, our previous routine volved in the care of these patients must be only too aware of the frequent discrepancy between delay in investigations such as computed tomography had an affected child's developmental progress and the not led us to suspect. existence of any obvious anatomical abnormality that could be responsible. A particularly good example of REFERENCES this can be seen in Apert's syndrome and it may be 1. Venes JL. Arnold-Chiari malformations in an infant that MRI, by providing information about the speed with Kleeblattschadel: an acquired malformation? Neurosurgery 1988; 23: 360-362. and stage of cerebral myelination, will enable us to
Scund J Plust Reconstr Hand Surg 26
ISSN: 0284-4311 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/iphs19
Magnetic Resonance Imaging in the Assessment of Craniosynostosis Richard Hayward, William Harkness, Brian Kendall & Barry Jones To cite this article: Richard Hayward, William Harkness, Brian Kendall & Barry Jones (1992) Magnetic Resonance Imaging in the Assessment of Craniosynostosis, Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery, 26:3, 293-299, DOI: 10.3109/02844319209015274 To link to this article: http://dx.doi.org/10.3109/02844319209015274
Published online: 08 Jul 2009.
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Date: 23 April 2016, At: 03:09
Scrind J Plast Reconstr Hand Surg 26: 287-292, 1992
MELANOMA OF PALMS, SOLES, A N D NAIL-BEDS Liisa Tuominen’ and Liisa Strengell’ From the ’Division of Plastic Surgery, Toolo Hospital, University Central Hospital, Helsinki, and the ‘Department of Pathology, Hyvinkaa District Hospital, Hyvinkaa, Finland
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(Submitted for publication September 2, 1991)
Ahstruct. The clinical and histological characteristics of palmar, plantar, and subungual melanomas treated in the division of plastic surgery of Helsinki University Hospital between 1970 and 1984 were analysed. The peak incidence was during the seventh decade of life, and the mean delay between the onset of symptoms and the diagnosis was one year. The delay was as much the fault of the physician as of the patient. The observed and relative five-year-survival rates for all 31 patients were 60% and 67% and the 10-year-survival rates 39% and 49‘X, respectively. There were 15 cases of the acral lentiginous subtype, and the observed and relative five-year-survival rates were 65% and 71%. and the 10-year-survival rates 48% and 64%, respectively. For the nodular melanomas ( n = I I ) the survival rates were 53% and 60%1,and 39% and 53%, respectively. For the three superficial spreading melanomas they were 50%)and 52%, and 25% and 28%. respectively. Microstaging criteria (Breslow and Clark) were both good prognostic indicators. The series was too small for multivariate analysis. Kev words: palmar, plantar, and subungual melanoma; survival.
Melanomas on hair-bearing skin have been studied intensively, but melanomas on the hairless palmar. plantar, and subungual skin have received little attention. Clark et al. (5) and McGovern ( 14) divided melanomas into three morphological types: superficial spreading, lentigo maligna, and nodular. Arrington et al. (2) introduced the concept of acral lentiginous melanomas to denote those that arise on palmar, plantar, and subungual skin and have a histological radial growth phase similar to that of mucosal melanomas. This study was undertaken to characterise the clinical and histological findings, and analyse the prognosis of palmar, plantar, and subungual melanomas treated in the division of plastic surgery at Helsinki University Hospital.
PATIENTS A N D METHODS Between 1970 and 1984. 570 patients with melanoma were treated in this department, and the palmar, plantar, or subungual areas were affected in 31 (5.4%) of them. The following clinical data were recorded from the chart of each patient: age, sex, location of the lesion, duration of symptoms before diagnosis, time of onset of lesion, tumour, nodes, metastases (TNM) classification ( I I), primary treatment (surgical, irradiation, or chemotherapy) and survival time, which was calculated from the date of the biopsy to the time of the patient’s death or to the termination of the study (December 1988). Histological slides were reexamined and the following points were noted: confirmation of the diagnosis; subclassification into histological categories (superficial spreading, nodular, acral lentiginous, or unclassified); deepest level of invasion (Clark); thickness of lesion (Breslow); cell types; and whether ulceration was present. We used the histological criteria of Clark et al. ( 5 ) and Arrington et al. (2). Statistical analysis. The relative survival rates for patients were evaluated as the ratios of the observed and expected survival rates. The relative survival rates describe the population standardized survival of the patients when the effects of causes of death other than melanoma of the skin have been eliminated. The data were analysed on a Digital Equipment Corporation Vax computer with the Cancer Survival Packages of the Finnish Cancer Registry (10).
RESULTS Age. The mean age of the 31 patients was 57.5 years (59 for the 20 women and 57 for the 11 men). The peak incidence of these melanomas occurred during the seventh decade of life (Fig. 1). Location. The primary lesion was on the sole in 23 patients. One had a primary lesion of the palm and another on the ball of the thumb. There were six subungual melanomas, four on the toes and two on the fingers (Fig. 2). Symptoms. Eighteen patients had longstanding pigmented lesions at the sites where the melanomas Sccmd J Plust Reconstr Hand Surg 26
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L. Tuominen and L. Strengell Duration of the symptoms. The mean delay between the onset of symptoms and diagnosis was one year. Three lesions were treated as warts (Fig. 3), three as paronychia (subungual) (Fig. 4) and three as chronic ulcers. In these cases the delay was as much the fault of the physician as of the patient. TNM classiJication of palmar, plantar, and subungual melanomas. According to the TNM classification six melanomas were in Stage I, but most were in stages I1 (n = 14) and I11 ( n = 10). One patient had distant metastases at the time of diagnosis. Nodal diseuse. Disease was present in the lymph nodes in five cases, distant spread developed in six patients-in five ahnut a year later, and in one seven years later. Recurrences. Tumours recurred in the same extremity in five patients; in four cases they were
Number of
patients 10
8
6
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4
2
0
4.00
Five-year-survival (%)
10-year-survival (‘%)
Observed
Relative
Observed
Relative
1
100
103
3 16 II
I00 67
101
I00 100
106 122
30
34
37 20
46 28
No of patients (n = 31)
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74
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Melanoma of palms, soles, and nail-beds
plantar, and subungual melanomas, but only for those that meet the morphologic criteria established for this subtype (2). Melanomas located on the foot and hand have a poorer prognosis than melanomas of other sites (7). In several recent studies of prognosis (3,4,6, 7) the thickness of the lesion, the level of invasion and ulceration correlate closely with the prognosis. In our study the thickness of subungual, palmar, and plantar melanomas was more than 1.50 mm in 80% (25/31), which according to Breslow’s data (4) should have a poor prognosis. The relative (observed) five-year-survival rates for melanomas 1.504.00mm, o r more than 4.00mm thick, were 74?h (67%) and 34% (30%), respectively. Ten years later, however, the figures had dropped to 46% (37%), and 28% (20%). The level of microinvasion in these melanomas exceeded grade I11 in 87% of cases. A fifth of the melanomas included in this study were level V and the five-year-survival of these patients was 25%. The treatment of our patients varied greatly. The effects of elective lymph node dissection are controversial as are the effects of adjuvant chemotherapy and radiotherapy ( 17, 19,20). Therapeutic lymph node dissection was done at the time as primary excision in five cases, and later in six. Eight elective lymph node dissections were done by wide local excision o r amputation of the finger or toe. Paladugu et al. (IS) recommended wide local excision and elective lymph node dissection for subungual lesions that measured more than 1.00 mm and for those that showed severe regression, but two randomised trials have failed to show that this confers any benefit (17, 19). Two prospective randomised trials are now being conducted in North America and in Europe. Until the results of these trials are available, elective lymph node dissection should be considered in selected patients, in whom the risk : benefit ratio justifies it. Factors to be considered are intermediate tumour thickness, ulceration, and the risk of the operation for individual patients. Recurrences after primary treatment should be excised. Five patients who developed recurrences were treated with further wide local excision and one patient with excision around the extremity and skin grafting. Isolated limb perfusion for regional metastases has not been used in Finland.
29 1
CONCLUSIONS Melanomas located on palms, soles, and in nail-beds accounted for 5.4% of the primary cutaneous melanomas. The prognosis was related to the microstaging of the lesions according to Clark and Breslow. In view of the high incidence of nodal disease, it is important that the role of elective lymphadenopathy is further clarified in this aggressive subtype of melanoma.
REFERENCES 1. Ariel IM. Malignant melanoma. New York: AppletonCentery-Crofts, 1981 ; 365-377.
2 Arrington JH, Reed R, lchinose H, Krementz E. Plantar lentiginous melanoma: A distinctive variant of human cutaneous malignant melanoma. Am J Surg Pathol 1977; 1: 131-143. 3. Balch CM, Song S, Milton GW, et al. A comparison of prognostic factors and surgical results in 1786 patients with localized (Stage I) melanoma treated in Alabama USA and New South Wales Australia. Ann Surg 1982; 196: 677- 684. 4. Breslow A. Thickness, cross sectional areas and depth of invasion in the prognosis of cutaneous melanoma. Ann Surg 1970; 172: 902-908. 5. Clark WH Jr, From L, Bernandino EA, Mihm MC. The histogenesis and biologic behavior of primary human malignant melanoma of the skin. Cancer Res 1969; 29: 705-727. 6. Daly JM, Berlin R, Urmacher C. Subungual melanoma: A 25-year review of cases. J Surg Oncol 1987;35: 107-112. 7. Day C, et al. A multivariate analysis of prognostic factors for melanoma patients with lesions z 3.65mm in thickness. Ann Surg 1982; 195:44-49, 8. Feibleman CE, Stoll H, Maize JC. Melanomas of the palm sole and nail bed. Cancer 1980 46: 2492-2504. 9. Gutman M,Klausner JM, Inbar M, Skornik Y, Baratz M, Rozin RR. Acral (volarsubungual) melanoma. Br J Surg 1985;72: 610-613. 10. Hakulinen T,Abeywickrama K. A computer program package for relative survival analysis. Comp Progr Biomed 1985; 19: 197-207. I I . International Union Against Cancer TNM Classification of Malignant Tumors. 4th ed 1987. 12. Jimbow K, Ikeda S, Takahashi H, Kukita A, Miura S. Biological behavior and natural course of acral malignant melanoma. Am J Dermatopathol 1984;6: 43-53. 13. Kerl H, Hod1 S, Stettner H. In: Ackerman AB, ed. Pathology of malignant melanoma: Acral lentiginous melanoma. Masson Monographs in Dermatopathology. USA: Masson Pub1 Inc. 1981; 1: 217-242. 14. McGovern VJ. The classification of melanomas and its relationship with prognosis. Pathology 1970;2: 85-98. 15. Paladugu RR, Winberg CD, Yonemoto RH. Acral lentiginous melanoma. Cancer 1983; 52: 161 - 168. Scund J Plusr Reconstr Hand Surg 26
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16. Shaw JHF, Koea JB. Acral (volar-subungual) melanoma in Auckland, New Zealand. Br J Surg 1988; 75: 69-72. 17. Sim FH, Taylor WF, Pritchard DJ, Soule EH.
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Lymphadenectomy in the management of stage I malignant melanoma: a prospective randomized study. Mayo Clin Proc 1986; 61: 697-705. 18. Sodergaard K, Olsen G. Histological type and biological behavior of primary cutaneous malig-
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nant melanoma. Virchows Arch 1983; 401: 333343. 19. Veronesi U. et al. Inefficacy of immediate node dissec-
tion in stage I melanoma of the limbs. N Engl J Med 1977; 297: 627-630. 20. Veronesi U. et al. A randomized trial of adju-
vant chemotherapy and immunotherapy in cutaneous melanoma. N Engl J Med 1982; 307: 913916.
se;mcl.J Plast Reconstr Hand Surg 26: 293-299, 1992
MAGNETIC RESONANCE IM-AGING IN THE ASSESSMENT OF CRANIOSYNOSTOSIS Richard Hayward, William Harkness, Brian Kendall and Barry Jones From the Craniofacial Unit, The Hospital for Sick Children, London WClN JJH, England
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(Submitted for publication July 12, 1991)
Abstract. Modern interest in craniosynostosis began when clinicians, regardless of their individual specialty but united in their interest in the problems raised by patients with this condition, first realised that if treatment was confined simply to opening up the fused sutures of the skull vault, success in terms of both function and the restoration of a more normal appearance was likely to be limited. Indeed, the grouping together of such specialists into formal craniofacial units was tacit recognition of this, as was the acceptance that many affected children had evidence of clinical problems that could not be explained on simple mechanical grounds alone. It is not surprising, therefore, that the advent of any new method of investigation has been welcomed by craniofacial surgeons eager to learn anything that might lead to an improvement in management, particularly of the more complex syndromes.
following the installation of our own MRI scanner, we decided to study other cases of craniosynostosis that presented to our craniofacial unit. It is our intention in this paper to draw attention to the range of abnormalities that can be demonstrated by MR scanning and to show how such a facility can assist in the management of these cases. For this reason some of the results are dealt with in rather general terms, and more detailed information (regarding the fine anatomy of herniation of the hindbrain, for example) reserved for an appropriate specialist publication.
Key words: craniosynostosis, magnetic resonance imaging.
Our first 30 cases form the basis of this report. Their clinical details are given below, under RESULTS. These patients are a selected group. It was necessary to limit MRI to those children with the most severe clinical problems, that is, those presenting with hydrocephalus, with obvious respiratory difficulties, and with the worst craniofacial deformities. Children presenting with “simple” craniosynostosis (such as premature fusion of the sagittal, or one coronal suture, for example) are therefore underrepresented in this series (a fact whose implications are dealt with in the discussion). All the scans, with three exceptions, were carried out on a 1.5 T Siemens Magnetom. Axial, coronal, and sagittal sections were attempted in all cases although factors unrelated to the scanning technique (such as a failure of sedation) meant that some studies were incomplete.
Our own interest in the use of magnetic resonance imaging ( MRI) in the assessment of craniosynostosis was aroused by finding, in a scan performed in October 1987, a severe degree of hindbrain herniation in a 5 year old child with a cloverleaf skull syndrome associated with Pfeiffer’s syndrome (as was also reported by Venes, 1988). Another finding-obvious enough in restrospect although to us at the time unexpected-was the dramatic demonstration of the anatomy of the airway. The patient suffered from severe upper respiratory tract obstruction for which a Le Fort 111 extracranial midface advancement had been carried out (with modest success) when she was just under 4 years old. The MRI showed clearly the degree of oropharyngeal obstruction caused by adenoidal hypertrophy. This led directly to her referral for tonsillectomy and adenoidectomy, a procedure that provided her with excellent symptomatic relief. (This patient is illustrated in Figs. 3a, b). Encouraged by our success with this case, and
METHOD
RESULTS The diagnoses of the patients studied are shown in Table I. The scans were analysed first for evidence of abnormalities of the hindbrain and craniocervical junction. Herniation of the hindbrain varied from simple descent of the cerebellar tonsils to just below the Scand J Plast Reconstr Hand Surg 26
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Table 1. Clinical diagnoses in patients studied Diagnosis
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Crouzon’s syndrome Saethre-Chotzen syndrome Pfeiffer’s syndrome: (with cloverleaf skull) (without cloverleaf skull) Apert’s syndrome “Simple” craniosynostosis: Bicoronal (non-syndromic) Lambdoid Bicoronal + sagittal Metopic Total
No. of patients
9 3 6
3 3 5 1
3 2 1
1
30
foramen magnum, to herniation to the level of the second cervical vertebra together with kinking of the lower brainstem and downward shift of the pontinemedullary junction. (Examples are iHustrated in Figs. 1-5.) Detailed information concerning herniation of the hindbrain is to be published elsewhere but the results may be summarized as follows:
Some degree of herniation of the hindbrain was seen in a total of 19 cases (Table 11). In general, the more severe degrees of herniation of the hindbrain-that is. those cases with the greatest descent of the cerebellar tonsils, buckling of the brainstem and displacement of the pontinemedullary junction-were associated with the most severe craniofacial abnormalities-for example, the cloverleaf skull syndrome. In one patient (with Apert’s syndrome) the tonsillar herniation was associated with syringomyelia for which decompression of the foramen magnum was required. All these abnormalities are customarily grouped under the title of the Chiari I malformation-the Chiari I1 malformation (or Arnold-Chiari malformation), which is typically associated with spina bifida aperta and in which there is also herniation upwards through the tentorial hiatus (and possibly represents a primary malformation of the brainstem) was not seen in this series. Hydrocephalus. For the purpose of this paper, we have defined hydrocephalus as ventricular enlargement associated with a rise in intracranial pressure sufficient to require the insertion of a shunt. Altogether there were 12 cases of hydrocephalus in this series, and all 12 were associated with herniation of the hindbrain. Assessment of the airway. Analysis of the MR images of the airway allowed assessment of the following: The configuration and length of the palate, the size of the nasopharyngeal space, the Table 11. Diagnoses in patients who had some degree of herniation of the hindbrain Diagnosis
Fig. 1. This (normal) sagittal MRI of a child with metopic synostosis will allow comparisons to be made with subse-
quent illustrations. There is no evidence of herniation of the hindbrain and the medulla of the brainstem is not deformed. The junction between the pons and the medulla of the brainstem can be seen (arrow) and is in a normal position. Note also the normal pattern of the turbinates and the horizontal orientation of the palate. There is a generous oral airway. Srand J Plasr Reconslr Hand Surg 26
Crouzon’s syndrome Saethre-Chotzen syndrome Pfeiffer’s syndrome: (with cloverleaf skull) (without cloverkaf skull) Apert’s syndrome - ~ i ~ craniosynostosis: ~ l ~ ” Bicoronal ~non-syndromic) Lambdoid Total
No. of cases 5 1 6
3 3 4
3
I 2 19
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Fig. 2. ((I) Crouzon’s syndrome. There is synostosis ofthe sagittal as well as the coronal sutures, and the maxilla is hypoplastic. ( h ) The MRI shows herniation of the ccrebellar tonsils (/urge urrow) but no deformation of the medulla. The pontomedullary junction is low ( s n d l orrow). There is a high arched palate that contributes to the obstruction of the nasal airway and the soft palate is orientated more closely to the vertical than the horizontal. Hypoplasia of the mandible is also seen clearly.
degree of obstruction caused by adenoidal hypertrophy, the anatomy of the nasal airway, the size of the tongue in relation to the oral cavity, and the size of the oropharynx. Examples of abnormalities in all these areas are also illustrated in Figs. 1-5. “Abnormalities” oJ’ cerebral white matter. Many children with craniosynostosis have evidence of neurodevelopmental delay for which an obvious explanation (for example, hydrocephalus or raised intracranial pressure as a result of restricted cranial volume) is present in only a certain proportion of cases. MRI allows assessment of the progress of cerebral myelination in the child’s brain to be made as delay in this process is a factor that might be associated with developmental problems. Such abnormalities were seen in four patients; once each in cases of lambdoid synostosis, nonsyndromic bicoronal synostosis, Crouzon’s syn--
drome and Saethre-Chotzen syndrome. All showed signs of moderate developmental delay, but the appropriate sequences for analysing the stage of cerebral myelination were not routinely employed in this series. DISCUSSION The advent of a sophisticated new investigational technique can lead to alterations in our thinking about a subject in a variety of ways. Clearly, the clinical management of that condition may be altered but, in addition to this, there can be changes in our understanding, the immediate applications of which are less obvious even though the knowledge itself seems t o be of great interest. We will discuss the results of introducing MRI into the assessment of our patients with craniosynostosis with these two aspects in mind. Smnd J Plusr Reconsrr Hand Surg 26
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Fig. 3. (a) Pfeiffer’s syndrome in an infant with cloverleaf skull deformity. (b) MRI of the same patient four years later.
Hydrocephalus can be recognised by the enlargement o f the third ventricle. There is pronounced cerebellar tonsillar herniation with kinking of the brainstem anteriorly over the odontoid peg at the level of the pontomedullary junction (small arrow). In addition to the abnormalities of the ainvay already seen in Fig. 2a, there is also adenoidal hypertrophy (large arrow) causing obstruction of the oropharynx.
Anomalies of the hindbrain in patients with craniosynostosis. Our results show that there is a high
incidence of herniation of the hindbrain in our patients with craniosynostosis (18 of 30), but rt should be emphasised that it is not possible from this series to make any useful assessment about the incidence of the association. Our patients were usually imaged because of the severity of their condition, but sometimes they were selected because they were known from previous investigations, computed tomography, for example, to have hydrocephalus or some other neurological complication. The association seems to be more obvious in the more severe cases, however, as no evidence of herniation of the hindbrain was seen in the non-syndromic patients though it was present in all patients with the cloverleaf skull syndrome. The advent of the MR scanning has allowed us to diagnose neurological abnormalities that result from Scund J Plust Reconstr
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compression of the brainstem at the foramen magnum. These include various degrees of ataxia that had previously been unexplained. One child with Saethre-Chotzen syndrome had drop attacks unassociated with any loss of consciousness and required a decompression of the foramen magnum (Fig. 4a, b). Two of the children with cloverleaf skulls also have longstanding problems caused by their ataxia that have not, so far, been sufficiently severe to justify a decompression. The recognition of herniation of the hindbrain also provides us with a possible explanation for any central component to the respiratory dysfunction that so often complicates the management of the more complex cases of craniosynostosis. A further category of clinical conditions that could be attributed to the herniation of the hindbrain seen in our patients is related to the obstruction to the passage of cerebrospinal fluid around the foramen magnum. If the effects of this predominate
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Fig. 4. (a)A 4 year old girl with Saethre-Chotzen syndrome who was operated on (frontal cranioplasty) at 6 months. She presented again with drop attacks. ( b) Her MRI scan shows a modest degree of cerebellar tonsillar herniation through the foramen magnum (arrow). She has had no further drop attacks since decompression of the faramen magnum.
in the head then hydrocephalus will result (see below). Obstruction of the normal ingress and egress of cerebrospinal fluid across the foramen magnum itself during such normal activities as coughing and straining, for example, is one of the commonest causes of syringomyelia. One case of Apert’s syndrome in this series had syringomyelia and required a decompression of the foramen magnum (which was performed at another hospital). Herniation of the hindbrain can also produce abnormalities of eye movement (particularly downbeat nystagmus) and difficulties with swallowing and articulation (dysarthria). No examples of these were recorded in this series. The discovery of an association between craniosynostosis and abnormalities at the cranio-cervical junction also allows new theories concerning the development of this complex region to be formulated-a subject of continuing debate among neurologists, neurosurgeons, radiologists, geneticists and anatomists (among others) -and this topic is also to be discussed in a further publication. Hydrocephalus and craniosynostosis. Though the association of hydrocephalus with craniosynostosis
is well known its aetiology remains mysterious. In the absence of any obvious structural abnormality-such as aqueduct stenosis-or a preceding history of an illness, such as meningitis, that can lead to obstruction of the cerebrospinal fluid (CSF) pathways, investigators have concentrated on the possible effects of the bony abnormality at the base of the skull. This has been thought of either as providing a mechanical obstruction to CSF flow or (in a less direct way) as interfering with the venous drainage from the intracranial compartment through the jugular foramina, and thus raising the pressure against which the CSF has to be absorbed. Herniation of the hindbrain is an accepted cause of hydrocephalus in conditions such as spina bifida aperta, and as it has been found in all cases of hydrocephalus complicating craniosynostosis in our series, we would suggest that there is probably a strong aetiological connection. This is not to say that other factors may not have a part to play in the pathogenesis. There are changes in venous pressure across the skull base as well as possible alterations in CSF production rates in some children with craniosynostosis (one of our children, Scund J PIasr Reconstr Hund Surg 26
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Fig. 5. ( u ) Pfeiffer’s syndrome with cloverleaf skull deformity. The reservoir of the shunt system that was needed for
treatment of her hydrocephalus can be seen (arrow). (h) Her MRI scan shows residual enlargement of the third ventricle. There is herniation of the cerebellar tonsils and the medulla of the brdinstem is kinked at the level of the foramen magnum (urrow). The nasal airway is reduced by a combination of maxillary hypolasia and arching of the hard palate. The soft palate is close to the vertical and this contributes to obstruction of the oropharynx.
aged 4 years, with Pfeiffer’s syndrome, produced approximately 700ml of CSF each day while on lumbar drainage). Assessment of the airway. Severe cases of craniosynostosis may be complicated by airway obstruction affecting any part of the respiratory pathways, but it is particularly the abnormalities within the upper respiratory tract (the nose and velopharynx) that can, during the first few months of life when children are preferential nose breathers, sometimes be life threatening. Episodes of sleep apnoea are not uncommon and affected babies may die suddenly of respiratory obstruction. A narrowed airway also predisposes the child to upper respiratory tract infections which, by producing mucosal, tonsillar, and adenoidal hypertrophy, further compound the problem. Respiratory obstruction raises the intracranial pressure and this, together with the feeding and nutritional problems (resulting in failure to thrive) Scund J Pbsr Reconstr Hand Surg 26
so often seen in these children, may contribute to their neurodevelopmental delay. MRI provides excellent images in various planes, particularly of the soft tissue component of the airway. The varying contributions of maxillary hypoplasia, naso-pharyngeal volume, palatal anatomy, relative tongue size, and tonsillar and adenoidal hypertrophy can all be assessed and judgements made about the likely effect of any operation. For example, a n advancement of the middle third of the face is unlikely to improve the patient’s airway problems if a preceding MRI has shown that, in addition t o the restriction of space within the nasopharynx, there are sites of obstruction elsewhere-in the nasal cavity or low in the oropharynx, for example. As can be seen from the illustrations, MRI provides a unique method for viewing many of the components of the upper airways at the same time,
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and allows an assessment to be made of the relative offer parents a more accurate prognosis concerning contribution that an abnormality of any of them their child's likely developmental progress. might be making to the final degree of respiratory MRI can also provide information about the obstruction. Our images show how the high, arched anatomy of the brain surface-the shape and size of palate further reduces the volume of the nasal air- the gyri together with the degree of distortion to way and demonstrate how-although the soft palate which they have been subjected by the abnormal seems to be of normal length even in cases with a skull shape, for example-all of which may be of severe deformity-the reduced volume of the relevance in the determination of any eventual neuoropharynx ensures that it must now be disposed rological or intellectual deficit. The presence of other vertically as opposed to horizontally, and provide intracranial abnormalities that may be associated both a fixed and dynamic obstruction to airflow with neurodevelopmental delay -agenesis of the through this region. corpus callosum, for example-can also be demonIn order to obtain the most complete information strated clearly. about the airway, in terms of imaging techniques, it is necessary to combine MRI with computed tomogCONCLUSION raphy (using bone windows, and preferably with three-dimensional reconstructions) to define the MRI has established itself as a regular part of our anatomy of both the bony and soft tissue elements. assessment of patients with craniosynostosis. Not This is particularly important in the assessment of only has it provided us with important new information about this whole group of patients, but it is also stenosis or atresia at choanal level. helping from day to day in the management of Assessment of brain myelination. It is not possible individual children, in particular by permitting a from our present observations to comment on either more accurate anatomical assessment of the airway the rate or the degree of myelination that MRI can as well as by allowing us to diagnose those problems demonstrate in craniosynostosis. Nevertheless, all caused by herniation of the hindbrain that, with the clinicians-and in particular, paediatricians-inexception of hydrocephalus, our previous routine volved in the care of these patients must be only too aware of the frequent discrepancy between delay in investigations such as computed tomography had an affected child's developmental progress and the not led us to suspect. existence of any obvious anatomical abnormality that could be responsible. A particularly good example of REFERENCES this can be seen in Apert's syndrome and it may be 1. Venes JL. Arnold-Chiari malformations in an infant that MRI, by providing information about the speed with Kleeblattschadel: an acquired malformation? Neurosurgery 1988; 23: 360-362. and stage of cerebral myelination, will enable us to
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