Pneumocephalus at the cerebellopontine angle secondary to chronic otitis media Zeki Sekerci,
Nejat Akalan,
Celal Krhc; and Mustafa
Demirkazrk*.
Summary
Pneumatoceles arising from mastoid air cells are much less common than those arising in the frontal ethmoid region. Trauma to the paranasal sinuses and mastoid areas is the most common cause of pneumocephalus3,4. Tumors and infection are rarely reported to be responsible for this entity. Markham’s review of 295 cases’ revealed 218 (73.9%) secondary to trauma, 38 cases (8.8%) secondary to the infection and two cases with unknot cause. 42% of the cases secondary to infection were due to middle ear disease with 35% reported before the year
Intracranial air is usually asymptomatic but carries a potential risk of increased intracranial pressure or meningitis which require immediate therapy. Although pneumocephalus is quite common following trauma, especially with a fracture involving paranasal sinuses it is a rare manifestation of chronic otitis media. In this report, a case with a tension pneumocephalus at the cerebellopontine angle following a chronic mastoid infection is presented and the possibte mechanism, diagnostic measures and the surgical management is discussed. Key words: Pneumocephalus, computerised tomography, chronic otitis media.
1945’2.5.6,
S~ptomatic pneumocephalus localized at the pontocerebellar angle is a very rare condition’. In this report a case with pneumocephalus at the pontocerebellar angle due to chronic otitis media is presented. The literature on pneumocephalus at the pontocerebellar angle is reviewed and the possible mechanism, diagnostic measures and the treatment are discussed. Case report
A 28-year-old male with a history of chronic otitis media was admitted to the Neurosurgery Clinic of Ankara Numune Hospital with the complication of headache, nausea and vomit-
* Clinic of Neurosurgery, Address for correspondence
Ankara Numune Hospital, Ankara,
ing, drowsiness and drainage from the right ear. Previous history revealed that he had discharge from the right ear from time to time for the last 15 years and 20 days prior to admission to the neurosurge~ clinic, he was hospitalised with the diagnosis of meningitis. After the appropriate medical treatment, fever and the meningeal signs subsided while headache, nausea, vomitting and gait disturbance continued. When the patient was referred to the Neurosurgery clinic, physical examination revealed a perforated right tympanic membrane with purulant drainage. At neurological examination horizontal
Turkey.
and reprint requests: Zeki .$ekerci, Ankara Numune Hastanesi, N&o@&’
KIini& Ankara- Turkey.
Accepted 28.489 Clin Neurol Neurosurg 1990. Vol.92-2.
155
Fig. 1. Preoperative lateral skull film showing air at pontocerebellar angle is well outlined.
The patient was operated in sitting position with a right paramedian incision. After right occipital craniectomy, the dura was opened and cerebellar tissue was retracted to the left side. After retraction the escape of gas under pressure could be heard. Cerebellar tissue facing the cystic cavity showed no pathological changes while the overlying dura was defected with the free ends penetrating inside the destructed mastoid cells. The dura overlying the mastoid cells was repaired with duraplasty. Postoperative course was uneventful and the complaints of the patient subsided gradually. 2 weeks later the patient was transfered to the Otorhinolaryngology clinic for mastoidectomy. The follow-up examination at the end of 3 months revealed no neurological pathology except a mixed type hearing loss at the right side. At control radiographies no intracranial gas was seen. Discussion
Fig. 2. CT scan reveals air at right pontocerebellar angle which caused a distortion of posterior fossa contents.
nystagmus at right lateral gaze, cerebellar dysfunction at the right side with a slight right-sided hemiparesia was found. The plain skull films revealed a chronic mastoid disease at the right side with a decreased density area resembling air at the right pontocerebellar angle (Fig. 1). At computerised tomography (CT) scanning a low-density lesion, with an attenuation value similar to air, was detected at the right pontocerebellar angle, with rim enhancement without perifocal edema, which caused a distortion at the posterior fossa contents (Fig. 2). 156
Trauma is responsible for 75 to 90 percent of pneumocephalus5T8. Especially in cases with fracture of paranasal sinus of the base of the skull, pneumocephalus is evident in about S9.7% of the head injuries2,4,5. Despite the relatively high incidence of occurrence, the presence of intracranial air was often neglected prior to CP’,‘,*. Apart from the fact that the plain radiographic findings of this entity is elusive, the course is often asymptomatic519. The recognition of the presence of air within the cranial cavity ma be of serious clinical significance because of complications such as a rapid enlargement causing a mass effect or a potential risk of meningitis via the same route as air entry5,6,7,10.By means of CT scan, as little as 0.5 cc intracranial air can readily be identified, as well as detect its serious complications. Whatever the underlying pathology is, a defect in the cranium and dura mater with a pressure gradient extra- and intracranially makes pneumocephalus possible’“. There are two main hypotheses to explain the entry of air into the cranial cavity. A ball-valve mechanism is suggested, where intracranial contents may act as a ball-valve, that allows air to enter through a fistula, especially at coughing, sneezing and straining ‘J . Air is entrapped inside by the tamponade of the intracranial contents to the dural
tear. At cases where CSF leakage is present, the entrance of air is also suggested to occur by the mechanism of simple replacement of the loss of CSF volume, compensating for the negative pressure caused by the leakage’. In the case presented, the probable explanation of pneumocephalus at the cerebello-pontine angle is that the chronic otitis media preceeded by mastoiditis and bony erosion caused a dural defect that allowed the air enter to the subdural space via the defective t~panic membrane. Also previous lumbar punctures may have caused air to be drawn into the subdural space due to intracranial hypotension. While a great variety of clinical signs and symptoms have been reported in cases of pneumocephalus they do not differ from those caused by any space occupying lesion intracranially. Also in our case, the neurological signs and symptoms suggested the presence of a lesion located infratento~ally such as a cerebellar abcess as a complication of suppurative otitis media. Although plain X-ray examination revealed the presence of gas in an area of right retropetrous portion, CT disclosed the fact that a pneumocephalus at the right cerebella-pontine angle was responsible for the clinical picture. Although most of the cases are asymptomatic depending on the extent and localisation, pneumocephalus may require immediate surgical intervention. Surgical therapy for pneumocephalus consists of relieving the tension within the cavity and closure of the dural tear. In our case, exploration of the right pontocerebellar angle
with evacuation of air and repairment of dural defect over the petrous bone resulted with immediate regression of the symptoms. It is evident that by means of a CT scan the accurate diagnosis of a wide variety of intracranial lesions including rare conditions such as pneumocephalus is possible, as shows the case presented. This rare and potentially serious complication was rapidly identified by CT, facilitating appropriate surgical intervention. References FRANKEL,FAHEYD,ALKERG.O~O~~II~C pneumatocephalus secondary to chronic otitis media. Arch Otolaryngol 1980; 106:437-9. MARKHAM w. The clinical features of pneumoceph~us based upon a survey of 284 cases with report of 11 additional cases. Acta Neurochir 1967; 16:1-78. STAVASJ,MCGEACHIEE,TURNER
DA,
NELSONMJ.SyIIlp-
tomatic intracranial pneumatocele from mastoid sinus of spontaneous origin. J Neurosurg 1987; 67:773-5. STUDEL WI, HACKER N. Prognosis, incidence and management of acute traumatic intracr~i~ pneumocephahis. Acta Neurochi~rgi~ 1986; 80:93-9. BETZ H, PRAGER P. Spontaneous pneumatoceie during radiation of a giant meningosarcoma. Neuroradiology 1981; 22159-61. MARLEYTP,HETHERINGTONRF. Traumaticcerebrospinal fluid rhinorrhea and otorrhea, pneumocephalus and meningitis. Surg Gynecol Obstet 1957; 104:88-98. OSBORN
AG, DAINES JH, WING
SD, ANDERSON
RE. in-
tracranial air on computerised tomography. J Neurosurg 1978; 48:355-359. MENDELSOHNDB,HERTZANUY. Intracerebralpneumatoceles following facial trauma: CT findings. Radiology 1985; 154:115-8. BHIMANI
S, VIRAPONGSE
C, SABSHIN JK, SARWAR
Jr. Intracerebrai pneumat~ele: ings. Neuroradiology 1985; 154:111-4. PETERSON RH
AZAR-KIA B, SARWAR
M, BATNIZKY
M,
CT find-
S, SCHECHTER
MM.
Radiology of intracranial gas. AJR 1975; 124:315-23.
157
Nejat Akalan,
Celal Krhc; and Mustafa
Demirkazrk*.
Summary
Pneumatoceles arising from mastoid air cells are much less common than those arising in the frontal ethmoid region. Trauma to the paranasal sinuses and mastoid areas is the most common cause of pneumocephalus3,4. Tumors and infection are rarely reported to be responsible for this entity. Markham’s review of 295 cases’ revealed 218 (73.9%) secondary to trauma, 38 cases (8.8%) secondary to the infection and two cases with unknot cause. 42% of the cases secondary to infection were due to middle ear disease with 35% reported before the year
Intracranial air is usually asymptomatic but carries a potential risk of increased intracranial pressure or meningitis which require immediate therapy. Although pneumocephalus is quite common following trauma, especially with a fracture involving paranasal sinuses it is a rare manifestation of chronic otitis media. In this report, a case with a tension pneumocephalus at the cerebellopontine angle following a chronic mastoid infection is presented and the possibte mechanism, diagnostic measures and the surgical management is discussed. Key words: Pneumocephalus, computerised tomography, chronic otitis media.
1945’2.5.6,
S~ptomatic pneumocephalus localized at the pontocerebellar angle is a very rare condition’. In this report a case with pneumocephalus at the pontocerebellar angle due to chronic otitis media is presented. The literature on pneumocephalus at the pontocerebellar angle is reviewed and the possible mechanism, diagnostic measures and the treatment are discussed. Case report
A 28-year-old male with a history of chronic otitis media was admitted to the Neurosurgery Clinic of Ankara Numune Hospital with the complication of headache, nausea and vomit-
* Clinic of Neurosurgery, Address for correspondence
Ankara Numune Hospital, Ankara,
ing, drowsiness and drainage from the right ear. Previous history revealed that he had discharge from the right ear from time to time for the last 15 years and 20 days prior to admission to the neurosurge~ clinic, he was hospitalised with the diagnosis of meningitis. After the appropriate medical treatment, fever and the meningeal signs subsided while headache, nausea, vomitting and gait disturbance continued. When the patient was referred to the Neurosurgery clinic, physical examination revealed a perforated right tympanic membrane with purulant drainage. At neurological examination horizontal
Turkey.
and reprint requests: Zeki .$ekerci, Ankara Numune Hastanesi, N&o@&’
KIini& Ankara- Turkey.
Accepted 28.489 Clin Neurol Neurosurg 1990. Vol.92-2.
155
Fig. 1. Preoperative lateral skull film showing air at pontocerebellar angle is well outlined.
The patient was operated in sitting position with a right paramedian incision. After right occipital craniectomy, the dura was opened and cerebellar tissue was retracted to the left side. After retraction the escape of gas under pressure could be heard. Cerebellar tissue facing the cystic cavity showed no pathological changes while the overlying dura was defected with the free ends penetrating inside the destructed mastoid cells. The dura overlying the mastoid cells was repaired with duraplasty. Postoperative course was uneventful and the complaints of the patient subsided gradually. 2 weeks later the patient was transfered to the Otorhinolaryngology clinic for mastoidectomy. The follow-up examination at the end of 3 months revealed no neurological pathology except a mixed type hearing loss at the right side. At control radiographies no intracranial gas was seen. Discussion
Fig. 2. CT scan reveals air at right pontocerebellar angle which caused a distortion of posterior fossa contents.
nystagmus at right lateral gaze, cerebellar dysfunction at the right side with a slight right-sided hemiparesia was found. The plain skull films revealed a chronic mastoid disease at the right side with a decreased density area resembling air at the right pontocerebellar angle (Fig. 1). At computerised tomography (CT) scanning a low-density lesion, with an attenuation value similar to air, was detected at the right pontocerebellar angle, with rim enhancement without perifocal edema, which caused a distortion at the posterior fossa contents (Fig. 2). 156
Trauma is responsible for 75 to 90 percent of pneumocephalus5T8. Especially in cases with fracture of paranasal sinus of the base of the skull, pneumocephalus is evident in about S9.7% of the head injuries2,4,5. Despite the relatively high incidence of occurrence, the presence of intracranial air was often neglected prior to CP’,‘,*. Apart from the fact that the plain radiographic findings of this entity is elusive, the course is often asymptomatic519. The recognition of the presence of air within the cranial cavity ma be of serious clinical significance because of complications such as a rapid enlargement causing a mass effect or a potential risk of meningitis via the same route as air entry5,6,7,10.By means of CT scan, as little as 0.5 cc intracranial air can readily be identified, as well as detect its serious complications. Whatever the underlying pathology is, a defect in the cranium and dura mater with a pressure gradient extra- and intracranially makes pneumocephalus possible’“. There are two main hypotheses to explain the entry of air into the cranial cavity. A ball-valve mechanism is suggested, where intracranial contents may act as a ball-valve, that allows air to enter through a fistula, especially at coughing, sneezing and straining ‘J . Air is entrapped inside by the tamponade of the intracranial contents to the dural
tear. At cases where CSF leakage is present, the entrance of air is also suggested to occur by the mechanism of simple replacement of the loss of CSF volume, compensating for the negative pressure caused by the leakage’. In the case presented, the probable explanation of pneumocephalus at the cerebello-pontine angle is that the chronic otitis media preceeded by mastoiditis and bony erosion caused a dural defect that allowed the air enter to the subdural space via the defective t~panic membrane. Also previous lumbar punctures may have caused air to be drawn into the subdural space due to intracranial hypotension. While a great variety of clinical signs and symptoms have been reported in cases of pneumocephalus they do not differ from those caused by any space occupying lesion intracranially. Also in our case, the neurological signs and symptoms suggested the presence of a lesion located infratento~ally such as a cerebellar abcess as a complication of suppurative otitis media. Although plain X-ray examination revealed the presence of gas in an area of right retropetrous portion, CT disclosed the fact that a pneumocephalus at the right cerebella-pontine angle was responsible for the clinical picture. Although most of the cases are asymptomatic depending on the extent and localisation, pneumocephalus may require immediate surgical intervention. Surgical therapy for pneumocephalus consists of relieving the tension within the cavity and closure of the dural tear. In our case, exploration of the right pontocerebellar angle
with evacuation of air and repairment of dural defect over the petrous bone resulted with immediate regression of the symptoms. It is evident that by means of a CT scan the accurate diagnosis of a wide variety of intracranial lesions including rare conditions such as pneumocephalus is possible, as shows the case presented. This rare and potentially serious complication was rapidly identified by CT, facilitating appropriate surgical intervention. References FRANKEL,FAHEYD,ALKERG.O~O~~II~C pneumatocephalus secondary to chronic otitis media. Arch Otolaryngol 1980; 106:437-9. MARKHAM w. The clinical features of pneumoceph~us based upon a survey of 284 cases with report of 11 additional cases. Acta Neurochir 1967; 16:1-78. STAVASJ,MCGEACHIEE,TURNER
DA,
NELSONMJ.SyIIlp-
tomatic intracranial pneumatocele from mastoid sinus of spontaneous origin. J Neurosurg 1987; 67:773-5. STUDEL WI, HACKER N. Prognosis, incidence and management of acute traumatic intracr~i~ pneumocephahis. Acta Neurochi~rgi~ 1986; 80:93-9. BETZ H, PRAGER P. Spontaneous pneumatoceie during radiation of a giant meningosarcoma. Neuroradiology 1981; 22159-61. MARLEYTP,HETHERINGTONRF. Traumaticcerebrospinal fluid rhinorrhea and otorrhea, pneumocephalus and meningitis. Surg Gynecol Obstet 1957; 104:88-98. OSBORN
AG, DAINES JH, WING
SD, ANDERSON
RE. in-
tracranial air on computerised tomography. J Neurosurg 1978; 48:355-359. MENDELSOHNDB,HERTZANUY. Intracerebralpneumatoceles following facial trauma: CT findings. Radiology 1985; 154:115-8. BHIMANI
S, VIRAPONGSE
C, SABSHIN JK, SARWAR
Jr. Intracerebrai pneumat~ele: ings. Neuroradiology 1985; 154:111-4. PETERSON RH
AZAR-KIA B, SARWAR
M, BATNIZKY
M,
CT find-
S, SCHECHTER
MM.
Radiology of intracranial gas. AJR 1975; 124:315-23.
157
![[Acute otitis media complicated with pneumocephalus and pneumococcal meningitis].](/assets/img/hold.png)
