J Neurosurg 72:133-138, 1990
Acute presentations of syringomyelia Report of three cases ERIC L. ZAGER, M.D., ROBERT G. OJEMANN, M.D., AND CHARLES E. POLETTI, M.D. Neurosurgical Service, Massachusetts General Hospital and Harvard Medical School Boston, Massachusetts
v" Three unusual cases are reported in which communicating syringomyelia presented acutely. The first patient presented with paraplegia, the second with acute respiratory distress secondary to bilateral vocal cord paralysis, and the third with symptoms of acute brain-stem ischemia. Each patient had a communicating spinal cord syrinx associated with a posterior fossa and foramen magnum region anomaly (a huge posterior fossa arachnoid cyst in one and Chiari malformations in two). The mechanisms of craniospinal pressure dissociation and hindbrain herniation are discussed, along with other reported emergency presentations of syringomyelia. KEY WORDS
"
syringomyelia
-
T
HE traditional definition of syringomyelia is a chronic, progressive degenerative disorder of the spinal cord characterized by dissociated sensory loss and brachial a m y o t r o p h y with pathological evidence of central cord cavitation) In its most severe form, neuropathic joints and painless ulcers m a y develop. The clinical features of the syndrome are highly variable, usually with an insidious onset, a course of m a n y years, and an unpredictable pace of progression. In the most comprehensive discussion of this topic in the literature, Barnett, et al., 5 proposed the following broad classification: 1) communicating syringomyelia (also called "syringohydromyelia" by Ballantine, et al. 4) and 2) n o n c o m m u n i c a t i n g syringomyelia, each of these two contains several subtypes. The fundamental distinction between these two groups of disorders is the presence or absence of a communication between the cord cavity and the cerebrospinal fluid (CSF) pathways, Three unusual cases of communicating syringomyelia which were characterized by acute presentations requiring immediate intervention are reported. These cases serve to highlight the extreme variability in the clinical expression of this disease.
Case Reports Case 1
This 9-year-old girl first presented in July, 1964, at 7 weeks of age because of increasing head circumference. J. Neurosurg. / Volume 72/January, 1990
Chiari malformation
arachnoid cyst
Ventriculography showed marked obstructive hydrocephalus, with a huge midline arachnoid cyst of the posterior fossa that extended upward through an apparent tentorial defect and anteriorly to the pineal region, compressing the junction between the cerebral aqueduct and fourth ventricle. A ventriculoatrial shunt was placed which required several revisions over the first 3 years. The patient's subsequent childhood development was normal, with excellent school and athletic performance. A routine chest x-ray film in 1972 showed disconnection of the shunt tubing in the neck. The patient remained asymptomatic, and therefore no revision was undertaken. During the year prior to readmission the patient noted transient episodes of interscapular back pain following exercise. Four days prior to admission in December, 1973, after rope-climbing in gym class, she complained of a headache and midthoracic back pain. That night her gait was noted to be unsteady. Progressive bilateral leg weakness, urinary urgency, and persistent back pain a n d headache prompted emergency hospital admission. E x a m i n a t i o n . On neurological examination, the child's mental status was normal but bilateral papilled e m a was noted. Otherwise, cranial nerve function was intact. Motor and sensory examination of the upper extremities was remarkable only for slightly m o r e brisk deep-tendon reflexes in the right arm. She was just
133
E. L. Zager, R. G. Ojemann, and C. E. Poletti barely able to lift her legs off the bed, the left leg being weaker than the right. Deep-tendon reflexes were hyperactive in both lower extremities, with sustained ankle clonus bilaterally and extensor plantar responses. Proprioception was markedly impaired in the toes. The patient's lower-extremity weakness and spasticity continued to progress over several hours, and sensation was subjectively altered below the umbilicus. A Pantopaque myelogram demonstrated a complete block at T-6. Operation. The patient was taken immediately to the operating room where bilateral T-3 through T-8 laminectomies were performed. When the dura was opened, the spinal cord was noted to be abnormally pale and distended from the uppermost end of the exposure down to the T 5 - 6 level where the cord distention abruptly ended. When the patient was placed in a head-down position, the swollen cord collapsed; it refilled when the patient's head was elevated. A No. 25 needle was introduced into a cavity in the cord at a depth of 3 to 4 mm, and 10 to 12 cc of clear fluid was aspirated (protein 31 ms%). The dura was left open and the incision was closed. Still under general anesthesia, the patient was taken for computerized tomography (CT) of the brain: this demonstrated a large posterior fossa arachnoid cyst, mildly dilated occipital horns of the lateral ventricles, and normal frontal horns. She was then returned to the operating room for shunt exploration. The tubing was found to be disconnected at the valve; the ventricular end was patent (opening pressure 90 m m H20). A burr hole was made over the right posterior fossa, and a catheter was placed into the arachnoid cyst. The ventricular and cyst catheters were then both connected to a new high-pressure Hakim valve and atrial catheter.
Postoperative Course. The patient's papilledema disappeared, and her lower-extremity function progressiveIy improved to the point where she was able to walk aided by crutches with a mildly spastic gait at the time of discharge. Follow-up examination 6 months after surgery documented a normal neurological examination with the exception o f slightly increased ankle reflexes. Case 2 This 48-year-old w o m a n first noted tingling and numbness of the right hand in 1977 which progressed slowly up the arm to the shoulder and torso. Numbness of the left hand followed. Strength remained normal. A myelogram showed an enlarged cervical cord, and a pneumoencephalogram showed a "collapsed" cervical cord. The diagnosis of syringomyelia was made and, in October, 1978, she underwent a suboccipital craniectomy and C 1-4 laminectomy at another hospital. The cerebellar tonsils were noted to be herniated to the level of C- 1 and the cord was described as pale and atrophic. Dense arachnoidal adhesions in the region of the foramen magnum were divided. A muscle plug was placed 134
in the obex, and the dura was closed without a graft. The patient did well postoperatively and, except for some increase in numbness across the upper part of the chest and the development of mild difficulty with handwriting, her neurological symptoms stabilized. During the year prior to her present admission her voice was "raspy" at times and she occasionally noted mild dyspnea on exertion; she attributed these symptoms to smoking and allergic rhinitis.
Examination. In May, 1987, nearly 9 years after her first operation, she noted a transient episode of noisy respirations with shortness of breath while walking. Two days later she became acutely short of breath, with stridulous respiration. She was admitted as an emergency to another hospital where laryngoscopic examination revealed bilateral vocal cord paralysis. A tracheostomy was placed, with resolution of her dyspnea and stridor. Neurological examination disclosed normal mental status and cranial nerve function with the exception of a hoarse voice with a talking tracheostomy in place and mild asymmetry of palate elevation. Intrinsic muscles of the hands were slightly weak bilaterally. There was hypalgesia over the posterior aspect of the scalp and neck, and over the shoulder and upper part of the chest, more marked on the left than the right. Light touch sensation was preserved. Proprioception was impaired in the toes and right hand (more than the left), and vibratory sensation was minimally diminished in the toes. There was mild appendicular ataxia bilaterally, reflexes were normal, and plantar responses were flexor. Operation. Magnetic resonance (MR) imaging demonstrated a well-decompressed Chiari type I malformation with a large syrinx cavity from C-l to T-2, possibly extending into the medulla (Fig. 1). She was taken to the operating room in July, 1987, where a bilateral T-1 laminectomy was performed. The spinal cord was distended. Needle aspiration produced clear fluid (protein 15 mg%). A myelotomy was made along the dorsal root entry zone and a K-shaped tube was placed into the cavity and drained to the subarachnoid space. The dura was closed with a paravertebral fascial graft. Postoperative Course. The patient improved neurologically, with diminished sensory findings. Followup laryngoscopic examination several weeks later revealed partial return o f vocal cord function, and the tracheostomy was removed. Case 3 This 32-year-old female nurse first noted left-arm pain after straining to lift a patient in October, 1987. Over the next several months the pain progressed slowly up to the left shoulder and neck, and severe shooting pains began in the left side of her face. When coughing she noted sharp pain in the upper section of the neck radiating up to the occiput. In January, 1988, she J. Neurosurg. / Volume 72/January, 1990
Acute presentations of syringomyelia a myelotomy was then made along the left dorsal root entry zone and a K-shaped tube was placed into the cervical syrinx draining into the subarachnoid space. Postoperative Course. There was improved sensation of pin prick in the left arm, decreased nystagmus, resolution of the dysmetria, improved swallowing and gag reflex, and resumption of normal voiding. At her 6-month follow-up examination, the patient showed persistent facial dysesthesia, left arm numbness, and intermittent neck pain. Discussion
FXG. 1. Case 2. Midsagittal magnetic resonance image demonstrating the Chiari type I malformation (previously decompressed) and the syrinx cavity extending throughout the cervical cord and into the upper thoracic cord.
acutely developed a sharp occipital headache, nausea and vomiting, paroxysmal vertigo, double vision, numbness of the left side of the face, and difficulty with swallowing and emptying her bladder. A referring neurologist suspected a subarachnoid hemorrhage and sent the patient to the emergency ward for a computerized tomography (CT) scan. Examination. The patient had counterclockwise rotary nystagmus, skew deviation of the left eye on downward gaze, decreased sensation of pin prick and cold on the left side of the face, decreased left palate elevation and gag reflex bilaterally, decreased left biceps strength and reflex, hypalgesia in the left C4-7 and T-1 distributions, and marked left upper-extremity dysmetria. Bladder catheterization revealed a post-void residual of 600 cc. A CT scan showed no intracranial hemorrhage and was interpreted as normal. Admission neurological diagnoses included ischemic lateral medullary syndrome, vertebral artery dissection, and multiple sclerosis. Over the next 24 hours there was marked improvement in her symptoms. Magnetic resonance imaging showed a Chiari type I malformation with a medullary and cervical spinal cord syrinx extending to C6-7. Operation. Suboccipital craniectomy and C-I laminectomy were performed. After the dura was opened, the cerebellar tonsils were seen extending to the C-1 level impacting the caudally displaced medulla and cervicomedullary junction. There were no constricting arachnoid bands. A decompressive dural graft was placed. Through a C-4 and inferior C-3 laminectomy, J. Neurosurg. / Volume 72/January, 1990
These three cases represent one end of a broad spectrum in the clinical expression of communicating syringomyelia. Although it has previously been noted that acute deterioration may occasionally punctuate the generally slowly progressive course of communicating syringomyelia, acute progression to 1) paraplegia, 2) respiratory failure, and 3) symptoms of lateral medullary compression are certainly rare occurrences. In each case the presumed acute expansion of the communicating syrinx cavities was related to posterior fossa developmental anomalies: an arachnoid cyst in Case 1, and a Chiari type I malformation in Cases 2 and 3. According to the hydrodynamic theory o f syringohydromyelia proposed by Gardner and coworkers, 9'~~ these posterior fossa anomalies obstructed the normal outflow of the fourth ventricle, which resulted in opening the communication between the fourth ventricle and the central canal of the lower medulla and spinal cord. In Case l, during infancy the arachnoid cyst apparently obstructed CSF flow at the junction of the fourth ventricle with the cerebral aqueduct, producing obstructive hydrocephalus. Subsequently, this obstruction cleared, as evidenced by the lack of symptomatic hydrocephalus in spite o f the shunt being disconnected for several years. Why did the syrinx in Case 1 present acutely with thoracic cord symptoms? Something must have caused acute obstruction o f the outflow from the fourth ventricle. The syrinx communicated with the cervical cord and fourth ventricle, as demonstrated intraoperatively by the response to the Trendelenburg position. It is possible that the stretching associated with rope-climbing may have triggered a sequence of events proposed by Williams: 27-29 a Valsalva maneuver, in which increased intrathoracic and intra-abdominal pressure is transmitted via the valveless veins in Batson's plexus to the spinal subarachnoid space, results in movement of CSF from the spinal to the intracranial subarachnoid space. The posterior fossa anomaly, functioning like a one-way valve, inhibits the free return of CSF to the spinal subarachnoid space, and the resulting craniospinal pressure dissociation is transmitted directly to the patent central canal, producing acute extension of the syrinx. In this patient, one can speculate that either the central canal of the thoracic cord was the site of least resistance to expansion or the thoracic cord was most susceptible to the effects of compression 135
E. L. Zager, R. G. Ojemann, and C. E. Poletti because of the smaller spinal cord diameter and a blood supply less adequate than that of the cervical cord. There are other reported cases in which relatively minor trauma, sometimes associated with a Valsalva maneuver, resulted in acute neurological deterioration in patients with syringomyelia. Barnett, et al., 5 in their series of 100 cases, presented seven patients who exhibited initial or aggravated symptoms in association with relatively minor trauma. One patient developed sudden facial numbness after sneezing; another had the onset of arm pain, weakness, and numbness after coughing and later developed dysarthria, palatal weakness, and an abnormal gait after osteopathic manipulation of the neck. Stretching over the back of a car seat produced sudden weakness and numbness of the hands in one patient, and a fall on the back of the head resulted in severe neck pain and mild spastic quadriparesis in another patient. Similarly, Bertrand 6 reported a case of a 20-year-old woman who noted the sudden onset of sharp upper back and neck pain while carrying a heavy tray of meat, causing her to drop the tray. She developed immediate left-arm weakness and numbness and (over several days) ataxia, diplopia, dysphagia, and nasal regurgitation o f fluid. Syringomyelia with bulbar extension of the syrinx was documented intraoperatively. Williams 29 described a similar case. Bertrand 6 mentioned another patient who developed sudden arm weakness with paresthesias while swimming. Schlesinger, e t a / . , 24 briefly mentioned several patients who reported increased neurological deficits immediately after coughing or sneezing. Another patient in their series reported marked deterioration after accidental falls. There have been other similar cases reported. ~6 A cough or sneeze associated with headaches and even syncope (see below) are fairly commonly described in patients with Chiari malformation without syrinx; the CSF pressure dissociation mechanism proposed by Williams may explain these phenomena as well. Williams and T u r n e r 3~ reported a case in which relatively minor trauma (in this case a short fall from a tree) resulted in immediate hand weakness in a 7-yearold girl; the hand weakness later progressed to wasting, dissociated sensory loss, and hyporeflexia. At surgery 3 years later, bloody fluid was found in the syrinx and hemosiderin staining was found in the syrinx wall. Although not discussed by the authors, this was evidently a case of Gowers' syringal hemorrhage which has been described as a rare, dramatic presentation of bleeding into a syringal cavity. Gowers 1~described four such cases in 1904, but only one was verified pathologically: this was a man who spontaneously developed ascending paralysis and died 5 weeks later. Postmortem examination disclosed a syrinx which extended from cervical through lumbar vertebral segments with hemorrhage throughout. We have found only two other reports of dramatic neurological deterioration associated with documented syringal hemorrhage: a patient reported by Perot, et al.,2~ developed acute monoplegia following a fall with violent neck extension, and another 336
patient described by Schenk 23 was a hemophiliac who spontaneously developed neck pain, acute paraplegia, and later quadriplegia. In both of these cases, the hemorrhages were documented intraoperatively, and the latter case was confirmed post mortem. Sedzimir, et al., 25 and Barnett, et al., 5 described patients who also had evidence o f syringal hemorrhages, but neither patient presented acutely. Pathological studies by Netsky TM demonstrated several cases in which abnormal, hyalinized vessels were found in the gliotic walls of syrinx cavities. He proposed that thrombosis and infarction may be involved in cavity formation; perhaps, in addition, these abnormal vessels are responsible for Gowers' syringal hemorrhages. The acute deterioration in our second patient occurred during a relatively quiescent clinical period nearly 9 years after bone but not dural decompression of the foramen magnum and insertion of a muscle plug in the obex. There was no apparent precipitating event. The muscle plug that had earlier been placed at the obex and had been tagged with a metallic clip was identified in our intraoperative x-ray film: it had migrated to a position inferior to the obex. We assume that the migration of the muscle plug had no significant influence on the patient's clinical course. Presumably, one vocal cord had become paralyzed at some point during the year prior to admission, accounting for her "raspy" voice and intermittent dyspnea on exertion. It is difficult to be certain whether the bilateral vocal cord palsy is attributable to syringobulbia or to the Chiari malformation; both situations have been described. Willis and Weaver 3~ reported a patient who developed acute respiratory distress secondary to bilateral flaccid abductor vocal cord paralysis. As in our case, this patient had findings typical of syringomyelia. Rhoton 2j also reported a case o f acute respiratory distress due to bilateral vocal cord paralysis, but he stated that this patient had only a Chiari malformation with no hydromyelia. Five cases of symptomatic laryngeal palsy in association with hydrocephalus and a probable Chiari malformation (the latter was demonstrated directly in only two of the five cases) were reported by Kirsch, et al. 14 Abductor vocal cord paralysis in these cases was attributed to increased intracranial pressure (ICP), and stridor was relieved in four o f the five cases by reduction of ICP by ventricular drainage. These four patients were infants with myelomeningocele, and therefore only the fifth patient, a 15-year-old girl with minimal hydrocephalus and without myelomeningocele, may be comparable to the patients in this report. This girl's symptoms were relieved by suboccipital craniectomy and upper cervical laminectomy. None of the patients in Kirsch's report was investigated for the presence of a syrinx. Weakness of the larynx in syringobulbia is usually due to a cleft arising from the floor of the fourth ventricle which extends ventrolaterally and damages the tractus solitarius, nucleus tractus solitarii, nucleus J. Neurosurg. / V o l u m e 7 2 / J a n u a r y , 1990
Acute presentations of syringomyelia ambiguus, and/or the exiting nerves to the larynx. ~9 However, syringobulbia has probably been overdiagnosed. Williams has cautioned: " . . . complex cranial nerve deficiencies m a y occur in response to the deformities of the nerves following downward dislocation of the hindbrain hernia. The occurrence of voice, swallowing, hearing or palatal difficulties does not necessarily indicate a cavity within the cord, nor a cleft leading out from the fourth ventricle to the bulbar area. ''27 Reimpaction of the hindbrain at the foramen m a g n u m after posterior fossa decompression has been described. 26 There are, however, several indications that in our second case syringobulbia rather than the Chiari malformation was responsible for the vocal cord palsy. The patient had already undergone what appeared on M R imaging to be an adequate posterior fossa decompression, with vii'tual arrest of her clinical progression. There were no associated headaches. The M R study suggested a cavity in the medulla, although it is difficult to be certain o f this. Most convincing is the fact that after syringosubarachnoid shunting there was clinical improvement including partial recovery of vocal cord function. In addition to vocal cord paralysis, other mechanisms for acute respiratory failure have been reported in patients with syringomyelia. Bokinsky, et aL, 8 described an 18-year-old m a n with a Chiari malformation and syringomyelia who presented with bilateral p n e u m o n i a and profound hypoxia, but a remarkable absence of hyperventilation. The p u l m o n a r y mechanics in that patient were evaluated and found to be adequate. On testing, he had a normal hyperventilatory response to hypercapnia, but no hyperventilation with hypoxia. In association with his lower cranial nerve palsies, it was postulated that syringobulbia had damaged the afferent connections f r o m the peripheral chemoreceptor to the medullary respiratory centers. Rodman, et al., 22 presented a similar case o f a young m a n with syringomyelia who was evaluated for episodes of somnolence. He was found to be insensitive to hypercapnia. Bleck and Shannon 7 reported a patient who complained of dysphagia and, in the course of an upper gastrointestinal series, aspirated b a r i u m and developed pneumonitis. He progressively lost his gag reflex, and required intubation and feeding jejunostomy. A CT scan demonstrated a syrinx cavity involving the pons and medulla in addition to the cervical cord. After shunting of the syrinx, the patient recovered normal swallowing and respiratory function. There are cases in other reported series o f syringomyelic patients in which respiratory arrest may be attributable to acute hydrocephalus, with or without associated vocal cord paralysis. 3,5,~~Kelly 13 reported a patient with bilateral vocal cord palsy who did not present acutely but rather complained only of recent dyspnea on exertion. In the series of Schlesinger, et al., 24 several patients presented with stridor and eight patients at some point exhibited involvement of the ninth and 10th cranial nerves; however, further clinical details in these cases were not provided. J. Neurosurg. / V o l u m e 7 2 / J a n u a r y , 1990
Another important m o d e of acute presentation in patients with syringomyelia and Chiari malformation is syncope. This has been more c o m m o n l y reported than the presentations discussed earlier, in particular in association with a Valsalva maneuver. 2,5,j2~5,17,19 Syncope in these cases is most likely due to the associated posterior fossa anomaly, usually a Chiari type I malformation, with acute cerebellar tonsillar impaction in the foramen magnum. Williams and coworkers ~2'29 have argued persuasively that the craniospinal CSF pressure dissociation, as measured in these cases, is responsible for hindbrain impaction in the foramen magnum. Either ischemia or mechanical distortion of the brain stem results in interference with the medullary baroreceptor reflex center a n d / o r the midbrain reticular activating system. Less frequently, extension of the syrinx to involve the intermediolateral cell column in the upper thoracic cord could result effectively in a sympathectomy with postural hypotension, z Nogu6s, et al., w have demonstrated that normal cardiovascular reflexes are often impaired in patients without syncope who have syringomyelia, most c o m m o n l y if there is evidence of syringobulbia as well. Therefore, patients with syringobulbia such as our Case 2 are at risk of developing postural hypotension and possible syncope. Somewhat atypically, our Case 3 with acute medullary compression developed headache, stiff neck, nausea and vomiting, diplopia, dysphagia, and dysmetria - - a syndrome suggesting an acute subarachnoid hemorrhage with lateral medullary dysfunction. The symptoms proved to be largely reversible following decompression of the foramen m a g n u m . The role of shunting the syrinx in this case is unclear. In this disorder M R imaging has become an invaluable diagnostic tool. This is particularly true in cases with atypical presentations, such as those presented here. Acknowledgment
The authors acknowledge the help of Dr. Ernest Picard, the neurologist who took care of several of the patients. References
1. Adams RD, Victor M" Principles of Neurology, ed 3. New York: McGraw-Hill, 1985, pp 665-698 2. Aminoff M J, Wilcox CS: Autonomic dysfunction in syringomyelia. Postgrad Med J 48:113-115, 1972 3. Appleby A, Bradley WG, Foster JB, et al: Syringomyelia due to chronic arachnoiditis at the foramen magnum. J Neurol Sci 8:451-464, 1969 4. Ballantine HT, Ojemann RG, Drew JH: Syringohydromyelia. Prog Neurol Surg 4:227-245, 1971 5. Barnett JHM, Foster JB, Hudgson P: Syringohydromyelia. London: WB Saunders, 1973 6. Bertrand G: Dynamic factors in the evolution of syringomyelia and syringobulbia. Clin Neurosurg 20:322-333, 1972 7. Bleck TP, Shannon KNI: Disordered swallowing due to a syrinx: correction by shunting. Neurology 34:1497-1498, 1984 8. Bokinsky GE, Hudson LD, Weil JV: Impaired peripheral 137
E. L. Zager, R. G. Ojemann, and C. E. Poletti
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15. 16. 17. 18. 19. 20. 21.
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chemosensitivity and acute respiratory failure in ArnoldChiari malformation and syringomyelia. N Engl J Med 288:947-948, 1973 Gardner WJ: Hydrodynamic mechanism of syringomyelia: its relationship to myelocele. J Neurol Neurosurg Psychiatry 28:247-259, 1965 Gardner WJ, Abdullah AF, McCormack LJ: The varying expressions of embryonal atresia of the fourth ventricle in adults. Arnold-Chiari malformation, Dandy-Walker syndrome, "arachnoid" cyst of the cerebellum, and syringomyelia. J Neurosurg 14:591-607, 1957 Gowers WR: Lectures on diseases of the nervous system, 2nd series. Lecture VIII. Syringal Haemorrhage into the Spinal Cord. London: J & A Churchill, 1904, p 250 Hampton F, Williams B, Loizou LA: Syncope as a presenting feature of hindbrain herniation with syringomyelia. J Neurol Neurosurg Psychiatry 45:919-922, 1982 Kelly DB: Bilateral abductor laryngeal palsy in syringomyelia. Br Med J 2:655-656, 1947 Kirsch WM, Duncan BR, Black FO, et al: Laryngeal palsy in association with myelomeningocele, hydrocephalus, and the Arnold-Chiari malformation. J Neurosurg 28: 207-214, 1968 Larson SJ, Sances A Jr, Baker JB, et at: Herniated cerebellar tonsils and cough syncope. J Neurosurg 40: 524-528, 1974 McIlroy WJ, Richardson JC: Syringomyelia: a clinical review of 75 cases. Can Med Assoc J 93:731-734, 1965 Mullan S, Raimondi AJ: Respiratory hazards of the surgical treatment of the Arnold-Chiari malformation. J Neurosurg 19:675-678, 1962 Netsky MG: Syringomyelia. A clinicopathologic study. Arch Neurol Psychiatry 70:741-777, 1953 Nogurs MA, Newman PK, Male VJ, et al: Cardiovascular reflexes in syringomyelia. Brain 105:835-849, 1982 Perot P, Feindel W, Lloyd-Smith D: Hematomyelia as a complication of syringomyelia: Gowers' syringal hemorrhage. Case report. J Neurosnrg 25:447-451, 1966 Rhoton AL Jr: Microsurgery of Arnold-Chiari malformation in adults with and without hydromyelia. J Neurosurg 45:473-483, 1976
22. Rodman T, Resnick ME, Berkowitz RD, et al: Alveolar hypoventilation due to involvement of the respiratory center by obscure disease of the central nervous system. Am J Med 32:208-217, 1962 23. Schenk VWD: Haemorrhages in spinal cord with syringomyelia in a patient with haemophilia. Acta Neuropathol 2:306-308, 1963 24. Schlesinger EB, Antunes JL, Michelsen WJ, et al: Hydromyelia: clinical presentation and comparison of modalities of treatment. Neurosurgery 9:356-365, 1981 25. Sedzimir CB, Roberts JR, Occleshaw JV, et al: Gowers' syringal haemorrhage. J Neurol Neurosurg Psychiatry 37: 312-315, 1974 26. Williams B: A critical appraisal of posterior fossa surgery for communicating syringomyelia. Brain 101:223-250, 1978 27. Williams B: Progress in syringomyelia. Neurol Res 8: 130-145, 1986 28. Williams B: Simultaneous cerebral and spinal fluid pressure recordings. 1. Technique, physiology, and normal results. Acta Neurochir 58:167-185, 198 l 29. Williams B: Simultaneous cerebral and spinal fluid pressure recordings. 2. Cerebrospinal dissociation with lesions at the foramen magnum. Acta Neurochir 59:123-142, 1981 30. Williams B, Turner E: Communicating syringomyelia presenting immediately after trauma. A case description and some theoretical concepts. Acta Neurochir 24: 97-106, 1971 31. Willis WH, Weaver DF: Syringomyelia with bilateral vocal cord paralysis. Report of a case. Arch Otolaryngol 87:468-470, 1968
Manuscript received May 4, 1989. This work was supported in part by National Institutes of Health Grant NS23357 to Dr. Poletti. Address reprint requests to: Eric L. Zager, M.D., Division of Neurosurgery, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.
J. Neurosurg. / Volume 72/January, 1990
Acute presentations of syringomyelia Report of three cases ERIC L. ZAGER, M.D., ROBERT G. OJEMANN, M.D., AND CHARLES E. POLETTI, M.D. Neurosurgical Service, Massachusetts General Hospital and Harvard Medical School Boston, Massachusetts
v" Three unusual cases are reported in which communicating syringomyelia presented acutely. The first patient presented with paraplegia, the second with acute respiratory distress secondary to bilateral vocal cord paralysis, and the third with symptoms of acute brain-stem ischemia. Each patient had a communicating spinal cord syrinx associated with a posterior fossa and foramen magnum region anomaly (a huge posterior fossa arachnoid cyst in one and Chiari malformations in two). The mechanisms of craniospinal pressure dissociation and hindbrain herniation are discussed, along with other reported emergency presentations of syringomyelia. KEY WORDS
"
syringomyelia
-
T
HE traditional definition of syringomyelia is a chronic, progressive degenerative disorder of the spinal cord characterized by dissociated sensory loss and brachial a m y o t r o p h y with pathological evidence of central cord cavitation) In its most severe form, neuropathic joints and painless ulcers m a y develop. The clinical features of the syndrome are highly variable, usually with an insidious onset, a course of m a n y years, and an unpredictable pace of progression. In the most comprehensive discussion of this topic in the literature, Barnett, et al., 5 proposed the following broad classification: 1) communicating syringomyelia (also called "syringohydromyelia" by Ballantine, et al. 4) and 2) n o n c o m m u n i c a t i n g syringomyelia, each of these two contains several subtypes. The fundamental distinction between these two groups of disorders is the presence or absence of a communication between the cord cavity and the cerebrospinal fluid (CSF) pathways, Three unusual cases of communicating syringomyelia which were characterized by acute presentations requiring immediate intervention are reported. These cases serve to highlight the extreme variability in the clinical expression of this disease.
Case Reports Case 1
This 9-year-old girl first presented in July, 1964, at 7 weeks of age because of increasing head circumference. J. Neurosurg. / Volume 72/January, 1990
Chiari malformation
arachnoid cyst
Ventriculography showed marked obstructive hydrocephalus, with a huge midline arachnoid cyst of the posterior fossa that extended upward through an apparent tentorial defect and anteriorly to the pineal region, compressing the junction between the cerebral aqueduct and fourth ventricle. A ventriculoatrial shunt was placed which required several revisions over the first 3 years. The patient's subsequent childhood development was normal, with excellent school and athletic performance. A routine chest x-ray film in 1972 showed disconnection of the shunt tubing in the neck. The patient remained asymptomatic, and therefore no revision was undertaken. During the year prior to readmission the patient noted transient episodes of interscapular back pain following exercise. Four days prior to admission in December, 1973, after rope-climbing in gym class, she complained of a headache and midthoracic back pain. That night her gait was noted to be unsteady. Progressive bilateral leg weakness, urinary urgency, and persistent back pain a n d headache prompted emergency hospital admission. E x a m i n a t i o n . On neurological examination, the child's mental status was normal but bilateral papilled e m a was noted. Otherwise, cranial nerve function was intact. Motor and sensory examination of the upper extremities was remarkable only for slightly m o r e brisk deep-tendon reflexes in the right arm. She was just
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E. L. Zager, R. G. Ojemann, and C. E. Poletti barely able to lift her legs off the bed, the left leg being weaker than the right. Deep-tendon reflexes were hyperactive in both lower extremities, with sustained ankle clonus bilaterally and extensor plantar responses. Proprioception was markedly impaired in the toes. The patient's lower-extremity weakness and spasticity continued to progress over several hours, and sensation was subjectively altered below the umbilicus. A Pantopaque myelogram demonstrated a complete block at T-6. Operation. The patient was taken immediately to the operating room where bilateral T-3 through T-8 laminectomies were performed. When the dura was opened, the spinal cord was noted to be abnormally pale and distended from the uppermost end of the exposure down to the T 5 - 6 level where the cord distention abruptly ended. When the patient was placed in a head-down position, the swollen cord collapsed; it refilled when the patient's head was elevated. A No. 25 needle was introduced into a cavity in the cord at a depth of 3 to 4 mm, and 10 to 12 cc of clear fluid was aspirated (protein 31 ms%). The dura was left open and the incision was closed. Still under general anesthesia, the patient was taken for computerized tomography (CT) of the brain: this demonstrated a large posterior fossa arachnoid cyst, mildly dilated occipital horns of the lateral ventricles, and normal frontal horns. She was then returned to the operating room for shunt exploration. The tubing was found to be disconnected at the valve; the ventricular end was patent (opening pressure 90 m m H20). A burr hole was made over the right posterior fossa, and a catheter was placed into the arachnoid cyst. The ventricular and cyst catheters were then both connected to a new high-pressure Hakim valve and atrial catheter.
Postoperative Course. The patient's papilledema disappeared, and her lower-extremity function progressiveIy improved to the point where she was able to walk aided by crutches with a mildly spastic gait at the time of discharge. Follow-up examination 6 months after surgery documented a normal neurological examination with the exception o f slightly increased ankle reflexes. Case 2 This 48-year-old w o m a n first noted tingling and numbness of the right hand in 1977 which progressed slowly up the arm to the shoulder and torso. Numbness of the left hand followed. Strength remained normal. A myelogram showed an enlarged cervical cord, and a pneumoencephalogram showed a "collapsed" cervical cord. The diagnosis of syringomyelia was made and, in October, 1978, she underwent a suboccipital craniectomy and C 1-4 laminectomy at another hospital. The cerebellar tonsils were noted to be herniated to the level of C- 1 and the cord was described as pale and atrophic. Dense arachnoidal adhesions in the region of the foramen magnum were divided. A muscle plug was placed 134
in the obex, and the dura was closed without a graft. The patient did well postoperatively and, except for some increase in numbness across the upper part of the chest and the development of mild difficulty with handwriting, her neurological symptoms stabilized. During the year prior to her present admission her voice was "raspy" at times and she occasionally noted mild dyspnea on exertion; she attributed these symptoms to smoking and allergic rhinitis.
Examination. In May, 1987, nearly 9 years after her first operation, she noted a transient episode of noisy respirations with shortness of breath while walking. Two days later she became acutely short of breath, with stridulous respiration. She was admitted as an emergency to another hospital where laryngoscopic examination revealed bilateral vocal cord paralysis. A tracheostomy was placed, with resolution of her dyspnea and stridor. Neurological examination disclosed normal mental status and cranial nerve function with the exception of a hoarse voice with a talking tracheostomy in place and mild asymmetry of palate elevation. Intrinsic muscles of the hands were slightly weak bilaterally. There was hypalgesia over the posterior aspect of the scalp and neck, and over the shoulder and upper part of the chest, more marked on the left than the right. Light touch sensation was preserved. Proprioception was impaired in the toes and right hand (more than the left), and vibratory sensation was minimally diminished in the toes. There was mild appendicular ataxia bilaterally, reflexes were normal, and plantar responses were flexor. Operation. Magnetic resonance (MR) imaging demonstrated a well-decompressed Chiari type I malformation with a large syrinx cavity from C-l to T-2, possibly extending into the medulla (Fig. 1). She was taken to the operating room in July, 1987, where a bilateral T-1 laminectomy was performed. The spinal cord was distended. Needle aspiration produced clear fluid (protein 15 mg%). A myelotomy was made along the dorsal root entry zone and a K-shaped tube was placed into the cavity and drained to the subarachnoid space. The dura was closed with a paravertebral fascial graft. Postoperative Course. The patient improved neurologically, with diminished sensory findings. Followup laryngoscopic examination several weeks later revealed partial return o f vocal cord function, and the tracheostomy was removed. Case 3 This 32-year-old female nurse first noted left-arm pain after straining to lift a patient in October, 1987. Over the next several months the pain progressed slowly up to the left shoulder and neck, and severe shooting pains began in the left side of her face. When coughing she noted sharp pain in the upper section of the neck radiating up to the occiput. In January, 1988, she J. Neurosurg. / Volume 72/January, 1990
Acute presentations of syringomyelia a myelotomy was then made along the left dorsal root entry zone and a K-shaped tube was placed into the cervical syrinx draining into the subarachnoid space. Postoperative Course. There was improved sensation of pin prick in the left arm, decreased nystagmus, resolution of the dysmetria, improved swallowing and gag reflex, and resumption of normal voiding. At her 6-month follow-up examination, the patient showed persistent facial dysesthesia, left arm numbness, and intermittent neck pain. Discussion
FXG. 1. Case 2. Midsagittal magnetic resonance image demonstrating the Chiari type I malformation (previously decompressed) and the syrinx cavity extending throughout the cervical cord and into the upper thoracic cord.
acutely developed a sharp occipital headache, nausea and vomiting, paroxysmal vertigo, double vision, numbness of the left side of the face, and difficulty with swallowing and emptying her bladder. A referring neurologist suspected a subarachnoid hemorrhage and sent the patient to the emergency ward for a computerized tomography (CT) scan. Examination. The patient had counterclockwise rotary nystagmus, skew deviation of the left eye on downward gaze, decreased sensation of pin prick and cold on the left side of the face, decreased left palate elevation and gag reflex bilaterally, decreased left biceps strength and reflex, hypalgesia in the left C4-7 and T-1 distributions, and marked left upper-extremity dysmetria. Bladder catheterization revealed a post-void residual of 600 cc. A CT scan showed no intracranial hemorrhage and was interpreted as normal. Admission neurological diagnoses included ischemic lateral medullary syndrome, vertebral artery dissection, and multiple sclerosis. Over the next 24 hours there was marked improvement in her symptoms. Magnetic resonance imaging showed a Chiari type I malformation with a medullary and cervical spinal cord syrinx extending to C6-7. Operation. Suboccipital craniectomy and C-I laminectomy were performed. After the dura was opened, the cerebellar tonsils were seen extending to the C-1 level impacting the caudally displaced medulla and cervicomedullary junction. There were no constricting arachnoid bands. A decompressive dural graft was placed. Through a C-4 and inferior C-3 laminectomy, J. Neurosurg. / Volume 72/January, 1990
These three cases represent one end of a broad spectrum in the clinical expression of communicating syringomyelia. Although it has previously been noted that acute deterioration may occasionally punctuate the generally slowly progressive course of communicating syringomyelia, acute progression to 1) paraplegia, 2) respiratory failure, and 3) symptoms of lateral medullary compression are certainly rare occurrences. In each case the presumed acute expansion of the communicating syrinx cavities was related to posterior fossa developmental anomalies: an arachnoid cyst in Case 1, and a Chiari type I malformation in Cases 2 and 3. According to the hydrodynamic theory o f syringohydromyelia proposed by Gardner and coworkers, 9'~~ these posterior fossa anomalies obstructed the normal outflow of the fourth ventricle, which resulted in opening the communication between the fourth ventricle and the central canal of the lower medulla and spinal cord. In Case l, during infancy the arachnoid cyst apparently obstructed CSF flow at the junction of the fourth ventricle with the cerebral aqueduct, producing obstructive hydrocephalus. Subsequently, this obstruction cleared, as evidenced by the lack of symptomatic hydrocephalus in spite o f the shunt being disconnected for several years. Why did the syrinx in Case 1 present acutely with thoracic cord symptoms? Something must have caused acute obstruction o f the outflow from the fourth ventricle. The syrinx communicated with the cervical cord and fourth ventricle, as demonstrated intraoperatively by the response to the Trendelenburg position. It is possible that the stretching associated with rope-climbing may have triggered a sequence of events proposed by Williams: 27-29 a Valsalva maneuver, in which increased intrathoracic and intra-abdominal pressure is transmitted via the valveless veins in Batson's plexus to the spinal subarachnoid space, results in movement of CSF from the spinal to the intracranial subarachnoid space. The posterior fossa anomaly, functioning like a one-way valve, inhibits the free return of CSF to the spinal subarachnoid space, and the resulting craniospinal pressure dissociation is transmitted directly to the patent central canal, producing acute extension of the syrinx. In this patient, one can speculate that either the central canal of the thoracic cord was the site of least resistance to expansion or the thoracic cord was most susceptible to the effects of compression 135
E. L. Zager, R. G. Ojemann, and C. E. Poletti because of the smaller spinal cord diameter and a blood supply less adequate than that of the cervical cord. There are other reported cases in which relatively minor trauma, sometimes associated with a Valsalva maneuver, resulted in acute neurological deterioration in patients with syringomyelia. Barnett, et al., 5 in their series of 100 cases, presented seven patients who exhibited initial or aggravated symptoms in association with relatively minor trauma. One patient developed sudden facial numbness after sneezing; another had the onset of arm pain, weakness, and numbness after coughing and later developed dysarthria, palatal weakness, and an abnormal gait after osteopathic manipulation of the neck. Stretching over the back of a car seat produced sudden weakness and numbness of the hands in one patient, and a fall on the back of the head resulted in severe neck pain and mild spastic quadriparesis in another patient. Similarly, Bertrand 6 reported a case of a 20-year-old woman who noted the sudden onset of sharp upper back and neck pain while carrying a heavy tray of meat, causing her to drop the tray. She developed immediate left-arm weakness and numbness and (over several days) ataxia, diplopia, dysphagia, and nasal regurgitation o f fluid. Syringomyelia with bulbar extension of the syrinx was documented intraoperatively. Williams 29 described a similar case. Bertrand 6 mentioned another patient who developed sudden arm weakness with paresthesias while swimming. Schlesinger, e t a / . , 24 briefly mentioned several patients who reported increased neurological deficits immediately after coughing or sneezing. Another patient in their series reported marked deterioration after accidental falls. There have been other similar cases reported. ~6 A cough or sneeze associated with headaches and even syncope (see below) are fairly commonly described in patients with Chiari malformation without syrinx; the CSF pressure dissociation mechanism proposed by Williams may explain these phenomena as well. Williams and T u r n e r 3~ reported a case in which relatively minor trauma (in this case a short fall from a tree) resulted in immediate hand weakness in a 7-yearold girl; the hand weakness later progressed to wasting, dissociated sensory loss, and hyporeflexia. At surgery 3 years later, bloody fluid was found in the syrinx and hemosiderin staining was found in the syrinx wall. Although not discussed by the authors, this was evidently a case of Gowers' syringal hemorrhage which has been described as a rare, dramatic presentation of bleeding into a syringal cavity. Gowers 1~described four such cases in 1904, but only one was verified pathologically: this was a man who spontaneously developed ascending paralysis and died 5 weeks later. Postmortem examination disclosed a syrinx which extended from cervical through lumbar vertebral segments with hemorrhage throughout. We have found only two other reports of dramatic neurological deterioration associated with documented syringal hemorrhage: a patient reported by Perot, et al.,2~ developed acute monoplegia following a fall with violent neck extension, and another 336
patient described by Schenk 23 was a hemophiliac who spontaneously developed neck pain, acute paraplegia, and later quadriplegia. In both of these cases, the hemorrhages were documented intraoperatively, and the latter case was confirmed post mortem. Sedzimir, et al., 25 and Barnett, et al., 5 described patients who also had evidence o f syringal hemorrhages, but neither patient presented acutely. Pathological studies by Netsky TM demonstrated several cases in which abnormal, hyalinized vessels were found in the gliotic walls of syrinx cavities. He proposed that thrombosis and infarction may be involved in cavity formation; perhaps, in addition, these abnormal vessels are responsible for Gowers' syringal hemorrhages. The acute deterioration in our second patient occurred during a relatively quiescent clinical period nearly 9 years after bone but not dural decompression of the foramen magnum and insertion of a muscle plug in the obex. There was no apparent precipitating event. The muscle plug that had earlier been placed at the obex and had been tagged with a metallic clip was identified in our intraoperative x-ray film: it had migrated to a position inferior to the obex. We assume that the migration of the muscle plug had no significant influence on the patient's clinical course. Presumably, one vocal cord had become paralyzed at some point during the year prior to admission, accounting for her "raspy" voice and intermittent dyspnea on exertion. It is difficult to be certain whether the bilateral vocal cord palsy is attributable to syringobulbia or to the Chiari malformation; both situations have been described. Willis and Weaver 3~ reported a patient who developed acute respiratory distress secondary to bilateral flaccid abductor vocal cord paralysis. As in our case, this patient had findings typical of syringomyelia. Rhoton 2j also reported a case o f acute respiratory distress due to bilateral vocal cord paralysis, but he stated that this patient had only a Chiari malformation with no hydromyelia. Five cases of symptomatic laryngeal palsy in association with hydrocephalus and a probable Chiari malformation (the latter was demonstrated directly in only two of the five cases) were reported by Kirsch, et al. 14 Abductor vocal cord paralysis in these cases was attributed to increased intracranial pressure (ICP), and stridor was relieved in four o f the five cases by reduction of ICP by ventricular drainage. These four patients were infants with myelomeningocele, and therefore only the fifth patient, a 15-year-old girl with minimal hydrocephalus and without myelomeningocele, may be comparable to the patients in this report. This girl's symptoms were relieved by suboccipital craniectomy and upper cervical laminectomy. None of the patients in Kirsch's report was investigated for the presence of a syrinx. Weakness of the larynx in syringobulbia is usually due to a cleft arising from the floor of the fourth ventricle which extends ventrolaterally and damages the tractus solitarius, nucleus tractus solitarii, nucleus J. Neurosurg. / V o l u m e 7 2 / J a n u a r y , 1990
Acute presentations of syringomyelia ambiguus, and/or the exiting nerves to the larynx. ~9 However, syringobulbia has probably been overdiagnosed. Williams has cautioned: " . . . complex cranial nerve deficiencies m a y occur in response to the deformities of the nerves following downward dislocation of the hindbrain hernia. The occurrence of voice, swallowing, hearing or palatal difficulties does not necessarily indicate a cavity within the cord, nor a cleft leading out from the fourth ventricle to the bulbar area. ''27 Reimpaction of the hindbrain at the foramen m a g n u m after posterior fossa decompression has been described. 26 There are, however, several indications that in our second case syringobulbia rather than the Chiari malformation was responsible for the vocal cord palsy. The patient had already undergone what appeared on M R imaging to be an adequate posterior fossa decompression, with vii'tual arrest of her clinical progression. There were no associated headaches. The M R study suggested a cavity in the medulla, although it is difficult to be certain o f this. Most convincing is the fact that after syringosubarachnoid shunting there was clinical improvement including partial recovery of vocal cord function. In addition to vocal cord paralysis, other mechanisms for acute respiratory failure have been reported in patients with syringomyelia. Bokinsky, et aL, 8 described an 18-year-old m a n with a Chiari malformation and syringomyelia who presented with bilateral p n e u m o n i a and profound hypoxia, but a remarkable absence of hyperventilation. The p u l m o n a r y mechanics in that patient were evaluated and found to be adequate. On testing, he had a normal hyperventilatory response to hypercapnia, but no hyperventilation with hypoxia. In association with his lower cranial nerve palsies, it was postulated that syringobulbia had damaged the afferent connections f r o m the peripheral chemoreceptor to the medullary respiratory centers. Rodman, et al., 22 presented a similar case o f a young m a n with syringomyelia who was evaluated for episodes of somnolence. He was found to be insensitive to hypercapnia. Bleck and Shannon 7 reported a patient who complained of dysphagia and, in the course of an upper gastrointestinal series, aspirated b a r i u m and developed pneumonitis. He progressively lost his gag reflex, and required intubation and feeding jejunostomy. A CT scan demonstrated a syrinx cavity involving the pons and medulla in addition to the cervical cord. After shunting of the syrinx, the patient recovered normal swallowing and respiratory function. There are cases in other reported series o f syringomyelic patients in which respiratory arrest may be attributable to acute hydrocephalus, with or without associated vocal cord paralysis. 3,5,~~Kelly 13 reported a patient with bilateral vocal cord palsy who did not present acutely but rather complained only of recent dyspnea on exertion. In the series of Schlesinger, et al., 24 several patients presented with stridor and eight patients at some point exhibited involvement of the ninth and 10th cranial nerves; however, further clinical details in these cases were not provided. J. Neurosurg. / V o l u m e 7 2 / J a n u a r y , 1990
Another important m o d e of acute presentation in patients with syringomyelia and Chiari malformation is syncope. This has been more c o m m o n l y reported than the presentations discussed earlier, in particular in association with a Valsalva maneuver. 2,5,j2~5,17,19 Syncope in these cases is most likely due to the associated posterior fossa anomaly, usually a Chiari type I malformation, with acute cerebellar tonsillar impaction in the foramen magnum. Williams and coworkers ~2'29 have argued persuasively that the craniospinal CSF pressure dissociation, as measured in these cases, is responsible for hindbrain impaction in the foramen magnum. Either ischemia or mechanical distortion of the brain stem results in interference with the medullary baroreceptor reflex center a n d / o r the midbrain reticular activating system. Less frequently, extension of the syrinx to involve the intermediolateral cell column in the upper thoracic cord could result effectively in a sympathectomy with postural hypotension, z Nogu6s, et al., w have demonstrated that normal cardiovascular reflexes are often impaired in patients without syncope who have syringomyelia, most c o m m o n l y if there is evidence of syringobulbia as well. Therefore, patients with syringobulbia such as our Case 2 are at risk of developing postural hypotension and possible syncope. Somewhat atypically, our Case 3 with acute medullary compression developed headache, stiff neck, nausea and vomiting, diplopia, dysphagia, and dysmetria - - a syndrome suggesting an acute subarachnoid hemorrhage with lateral medullary dysfunction. The symptoms proved to be largely reversible following decompression of the foramen m a g n u m . The role of shunting the syrinx in this case is unclear. In this disorder M R imaging has become an invaluable diagnostic tool. This is particularly true in cases with atypical presentations, such as those presented here. Acknowledgment
The authors acknowledge the help of Dr. Ernest Picard, the neurologist who took care of several of the patients. References
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Manuscript received May 4, 1989. This work was supported in part by National Institutes of Health Grant NS23357 to Dr. Poletti. Address reprint requests to: Eric L. Zager, M.D., Division of Neurosurgery, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, Pennsylvania 19104.
J. Neurosurg. / Volume 72/January, 1990
