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Posterior fossa tension pneumocephalus
Posterior fossa ten&w pneumwephalus V.P. Singh and AK. ~~hapatra*
~sto~rative pne~~eph~us constitutes 3.7% of 295 cases of p~~~~~~s reviewed by Markham’ (1967). Postoperative tension pneumocephalus has been reported following intracranial or spinal surgery in the sitting positior~~~,following frontal cran~otomy’, foilowing puncture drainage of brain abscessa, following ventricular shunts9-” and following spinal CSF drainage done for the management of CSF fistula**.Bifrontal subdural pneumocephalus commonly follows surgery in the sitting position r3.We present a pa tient with tension pneu~~~~~s restricted to the posterior fossa fohowing surgery in sitting position.
A 17-yrs-old school boy presented with moderate grade, continuous fever of one month duration. He had progressively increasing generalized, throbbing headache associated with vomiting for the same duration. He was drowsy, hstless and unable to walk or sit uns~p~~ed for the past week. He had bilaterat chronic suppurative otitis media for 8 years and active pus discharge from the left ear for 4 months. Examination revealed a drowsy, disoriented, apathetic, undernourished individual who was
Frontal tension pne~~~~us is seen as a complication of surgery in the sitting position. A case of posterior fossa tension pneumocephalus occurring after operation for a posterior fossa abscess is presented. Key words: posterior fossa abscess, surgery in sitting position, tension pneum~phalus.
following commands ocasionally . Fundus examination was normal. He was uncooperative for a detailed neuro~o~c~ excitation but there was no obvious focal deficit. There were no signs of meningeal irritation. Otological examination revealed an attic cholesteatoma and a retracted tympanic membrane on the left side with active pus discharge. The right ear was dry. Hernato~o~~~ investi~tions revealed mild leucocytosis-other parameters being normal. Contrast enhanced CT scan revealed irregularly shaped, bilateral, infratentorial low attenuating lesions with enhancement of surrounding cortex. There was no ventricular dilatation (Fig. 1.). Patient was induced using thiopental, scoline & nitrous oxide and anesthesia maintained by muscle relaxants, analgesics and 66% nitrous oxide for 4 hrs. A midline suboccipitaf craniec-
* Department of Neurmurgery, Neuros&mxs Centre, All India institute of Medical Sciences, New Delhi - 110029, lndia Address for correspondence and reprint requests: Dr. A.K. Mahapatra, Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi - IItW29, India. Accepted 26.6.f989 Clin Neural Neurosurg 1990. Voi. 92-3
258
Fig. 1. Contrast uating. hilateral
enhanced posterior
tomy was done.
CT scan shows a large, low attenfossa lesion.
Cerebellum
was soft and fria-
Fig. 2. CT scan shows air restricted out any frontal air.
period.
Repeat
contrast
to posterior
enhanced
fossa with-
CT scan re-
ble. Thin, yellowish pus was encountered at a depth of 2 ems. The abscess was multiloculated
vealed an abscess cavity in the posterior fossa with a small extradural collection at the craniec-
and extended superiorly till the tentorium, anterolaterally to the petrous pyramids and was on both sides of the midline. The cavity was irrigated thoroughly after draining the pus and part of the abscess wall was excised. Pus culture grew Proteus mirabilis and patient was put on ap-
tomy site. There was no hydrocephalus. Reexploration of the wound was done and a small collection of extradural pus was drained. The abscess cavity did not contain any pus. Patient did not improve and died the next day.
propriate antibiotics. Following surgery, the patient’s sensorium improved. On the 2nd postoperative day he became drowsy and had obtunded respiration. Lateral ventricle puncture through right frontal drill hole did not reveal dilated ventricles or raised pressure. Patient was intubated and ventilated. He improved partially, but a few hours later became unconscious. A plain CT scan revealed air restricted to the posterior fossa with an air fluid level (Fig. 2). There was no subfrontal or intraventricular air. A ventricular cannula was put into the cavity through the operative wound and air and a small amount of turbid fluid gushed out under pressure. Within 5 minutes the patient gained consciousness, opened eyes and was following commands. Artifical ventilation was continued for 12 hrs and he was extubated subsequently. Patient was then opening eyes, speaking a few words and taking small amounts of fluids orally. Patient deteriorated again on the 10th postoperative day. He became drowsy, developed a bilateral abducens paresis, a right facial LMN paresis and marked bilateral cerebellar signs. He was afebrile throughout the postoperative
Discussion Some amount of air invariably enters the intracranial cavity during surgery of the posterior fossa in the sitting position13. Factors contributing to this include dependant drainage of CSF, siphon effect of the shunt, use of Osmotic diuretics, decreased cerebral blood volume due to ventilation induced hypocarbia, resection of large tumor and the use of nitrous oxide during anesthesiah.‘4,‘h. Postoperatively, the reexpansion of the brain (as a result of eucarbia and rebound effect of osmotic diuretics), reaccumulation of CSF and post-operative edema cause compression of the air and a tension pneumocephalus may result”.“. This presents as neurological deterioration in the immediate postoperative period. In view of the commonly assumed supine position the air is found in the frontal region. Through there are several reports of bifrontal tension pneumocephalus following posterior fossa surgery in the sitting position’,“” there are very few reports of pneumocephalus occuring in the posterior fossa. Sharma & Kak’ (1988) reported a postoperative patient of cerebellopon259
tine (CP) angle meningioma who did not wake up fully from anesthesia and deteriorated further postoperatively. CT scan revealed a bifrontal and CP angle pneumocephalus. He had an increase in neurological deficit which improved by the 15th postoperative day. The pneumocephalus also resolved by the same time. A cerebellopontine angle tension pneumocephalus was also reported by Ganapathy & Govindam” (1985) - occuring 11 years following a mastoidectomy - the air had entered through a persistent craniodural fistula. The case reported here is unusual as he had a posterior fossa tension pneumocephalus following surgery in the sitting position. Surprisingly, he did not have frontal or intra-ventricular air. Localization of the intracranial air in this patient could be explained by the infratentorial subdural abscess obliterating the communication with the supratentorial subdural and subarachnoid spaces at the tentorial hiatus. Thus the air was restricted to the posterior fossa and did not go to the frontal subdural space even with assumption of the supine posture. The rapid clinical improvement in the patient’s condition after tapping the air suggested that the air was under tension and caused a pressure effect. Thus isolated posterior fossa tension pneumocephalus could occur after posterior fossa surgery in the sitting position and must be remembered as one of the causes of early post operative deterioration. Appropriate, simple management would give good results. References 1
2
260
JW. The clinical features of pneumocephalus based upon a survey of 284 cases with report of additional 11 cases. Acta Neurochir (Wien) 1967; 16:1-78. KITAHATA LM, KATZ JD. Tension pneumocephalus after MARKHAM
posterior fossa craniotomy, a complication of the stttinp position. Anaesthesiology 1976; 44:448-50. 3 HULLETI WB, LAING JW. Tension pneumocephalus in sitting position. Anaesthesiology 1976; 45578. 4 LUNSFORDLD,MAROONJD,StIEPTAKPE.AtBINSMS. Subdural tension pneumocephalus. report of three cases. J Neurosurg 1979; 50~525-27.
5
6
7
THIAGARAJAN
S, FROST
EAM,
SINGI, T. SUKMAN
K. Car-
diac arrest associated with tension pneumocephalus. Anaesthesiology 1982; 56:73-S. SHARMA Bs. KAK VK. Bifrontal (and cerebellopontine) tension pneumocephalus following posterior fossa surgery in sitting position. Report of three cases and review of literature. Neurology India 1988; 36:213-24. HAYMAN
LA,
ALDAMA-LEUBBERT
AE,
EVANS
RA.
IIItDl-
cranial diverticulum of the frontal sinus as a complication of frontal craniotomy, case report. J. Neurosurg 1979; 5 1870-7I x VAOUERO _I,MARTINEZ R. Tension pneumocephalus in brain abscess after simple puncture drainage. Acta Neurochir (Wien) 1984; 71:225-7. 9 LITTLEJR,MAcCARTYCS.~~~IS~OII pneumocephalusafter insertion of ventriculoperitoneal shunt for aqueductal stenosis, case report. J. Neurosurg 1976; 44:383-5. I” IKEDA K, NAKANO M, TANI E. Tension pneumocephalus complicating ventriculoperitoneal shunt for CSF rhinorrhea, case report. J. Neural Neurosurg. Psychiatry 1978; 41:319-22. II PIrrs LH, WILSON CB, DEDO HH, WEYAND K. Pneumocephalus following ventriculoperitoneal shunt, case report J. Neurosurg 1975; 43:631-3. ‘* CiaAr c‘J, GROSS CE, BECK Dw. Complications of spinal drainage in the management of cerebrospinal fistula. J. Neurosurg 1981; 54:392-5. 13 DILORENZON.cARUSO R,FLORIS R,GuERRISIV,BOZZAO L, FORTUNA A. Pneumocephalus & tension pneumocephalus after posterior fossa surgery in the sitting position, a prospective study. Acta Neurochir (Wien) 1986; 83:112-5. 13 FRIEDMAN GA, NORFLEET EA, BEDFORD RF. Discontinuation of nitrous oxide does not prevent pneumocephalus. Anaesthesia Analgesia (Paris) 1981; 6057-8. Is ARTRU A. Nitrous oxide plays a direct role in the development of tension pneumocephaius intraoperatively. Anaesthesiology 1982; 5759-61. ” MACGILLIVRAY RG. Pneumocephalus as a complication of posterior fossa surgery in sitting position. Anaesthesia 1982; 371722-S. ” GANAPATHY K, GOVINDAN R. Cerebellopontine pneumocephalus acting as a space occupying lesion: CT demonstration. J. Comput Assist Tomog 1985; 9407-12.
~sto~rative pne~~eph~us constitutes 3.7% of 295 cases of p~~~~~~s reviewed by Markham’ (1967). Postoperative tension pneumocephalus has been reported following intracranial or spinal surgery in the sitting positior~~~,following frontal cran~otomy’, foilowing puncture drainage of brain abscessa, following ventricular shunts9-” and following spinal CSF drainage done for the management of CSF fistula**.Bifrontal subdural pneumocephalus commonly follows surgery in the sitting position r3.We present a pa tient with tension pneu~~~~~s restricted to the posterior fossa fohowing surgery in sitting position.
A 17-yrs-old school boy presented with moderate grade, continuous fever of one month duration. He had progressively increasing generalized, throbbing headache associated with vomiting for the same duration. He was drowsy, hstless and unable to walk or sit uns~p~~ed for the past week. He had bilaterat chronic suppurative otitis media for 8 years and active pus discharge from the left ear for 4 months. Examination revealed a drowsy, disoriented, apathetic, undernourished individual who was
Frontal tension pne~~~~us is seen as a complication of surgery in the sitting position. A case of posterior fossa tension pneumocephalus occurring after operation for a posterior fossa abscess is presented. Key words: posterior fossa abscess, surgery in sitting position, tension pneum~phalus.
following commands ocasionally . Fundus examination was normal. He was uncooperative for a detailed neuro~o~c~ excitation but there was no obvious focal deficit. There were no signs of meningeal irritation. Otological examination revealed an attic cholesteatoma and a retracted tympanic membrane on the left side with active pus discharge. The right ear was dry. Hernato~o~~~ investi~tions revealed mild leucocytosis-other parameters being normal. Contrast enhanced CT scan revealed irregularly shaped, bilateral, infratentorial low attenuating lesions with enhancement of surrounding cortex. There was no ventricular dilatation (Fig. 1.). Patient was induced using thiopental, scoline & nitrous oxide and anesthesia maintained by muscle relaxants, analgesics and 66% nitrous oxide for 4 hrs. A midline suboccipitaf craniec-
* Department of Neurmurgery, Neuros&mxs Centre, All India institute of Medical Sciences, New Delhi - 110029, lndia Address for correspondence and reprint requests: Dr. A.K. Mahapatra, Department of Neurosurgery, All India Institute of Medical Sciences, New Delhi - IItW29, India. Accepted 26.6.f989 Clin Neural Neurosurg 1990. Voi. 92-3
258
Fig. 1. Contrast uating. hilateral
enhanced posterior
tomy was done.
CT scan shows a large, low attenfossa lesion.
Cerebellum
was soft and fria-
Fig. 2. CT scan shows air restricted out any frontal air.
period.
Repeat
contrast
to posterior
enhanced
fossa with-
CT scan re-
ble. Thin, yellowish pus was encountered at a depth of 2 ems. The abscess was multiloculated
vealed an abscess cavity in the posterior fossa with a small extradural collection at the craniec-
and extended superiorly till the tentorium, anterolaterally to the petrous pyramids and was on both sides of the midline. The cavity was irrigated thoroughly after draining the pus and part of the abscess wall was excised. Pus culture grew Proteus mirabilis and patient was put on ap-
tomy site. There was no hydrocephalus. Reexploration of the wound was done and a small collection of extradural pus was drained. The abscess cavity did not contain any pus. Patient did not improve and died the next day.
propriate antibiotics. Following surgery, the patient’s sensorium improved. On the 2nd postoperative day he became drowsy and had obtunded respiration. Lateral ventricle puncture through right frontal drill hole did not reveal dilated ventricles or raised pressure. Patient was intubated and ventilated. He improved partially, but a few hours later became unconscious. A plain CT scan revealed air restricted to the posterior fossa with an air fluid level (Fig. 2). There was no subfrontal or intraventricular air. A ventricular cannula was put into the cavity through the operative wound and air and a small amount of turbid fluid gushed out under pressure. Within 5 minutes the patient gained consciousness, opened eyes and was following commands. Artifical ventilation was continued for 12 hrs and he was extubated subsequently. Patient was then opening eyes, speaking a few words and taking small amounts of fluids orally. Patient deteriorated again on the 10th postoperative day. He became drowsy, developed a bilateral abducens paresis, a right facial LMN paresis and marked bilateral cerebellar signs. He was afebrile throughout the postoperative
Discussion Some amount of air invariably enters the intracranial cavity during surgery of the posterior fossa in the sitting position13. Factors contributing to this include dependant drainage of CSF, siphon effect of the shunt, use of Osmotic diuretics, decreased cerebral blood volume due to ventilation induced hypocarbia, resection of large tumor and the use of nitrous oxide during anesthesiah.‘4,‘h. Postoperatively, the reexpansion of the brain (as a result of eucarbia and rebound effect of osmotic diuretics), reaccumulation of CSF and post-operative edema cause compression of the air and a tension pneumocephalus may result”.“. This presents as neurological deterioration in the immediate postoperative period. In view of the commonly assumed supine position the air is found in the frontal region. Through there are several reports of bifrontal tension pneumocephalus following posterior fossa surgery in the sitting position’,“” there are very few reports of pneumocephalus occuring in the posterior fossa. Sharma & Kak’ (1988) reported a postoperative patient of cerebellopon259
tine (CP) angle meningioma who did not wake up fully from anesthesia and deteriorated further postoperatively. CT scan revealed a bifrontal and CP angle pneumocephalus. He had an increase in neurological deficit which improved by the 15th postoperative day. The pneumocephalus also resolved by the same time. A cerebellopontine angle tension pneumocephalus was also reported by Ganapathy & Govindam” (1985) - occuring 11 years following a mastoidectomy - the air had entered through a persistent craniodural fistula. The case reported here is unusual as he had a posterior fossa tension pneumocephalus following surgery in the sitting position. Surprisingly, he did not have frontal or intra-ventricular air. Localization of the intracranial air in this patient could be explained by the infratentorial subdural abscess obliterating the communication with the supratentorial subdural and subarachnoid spaces at the tentorial hiatus. Thus the air was restricted to the posterior fossa and did not go to the frontal subdural space even with assumption of the supine posture. The rapid clinical improvement in the patient’s condition after tapping the air suggested that the air was under tension and caused a pressure effect. Thus isolated posterior fossa tension pneumocephalus could occur after posterior fossa surgery in the sitting position and must be remembered as one of the causes of early post operative deterioration. Appropriate, simple management would give good results. References 1
2
260
JW. The clinical features of pneumocephalus based upon a survey of 284 cases with report of additional 11 cases. Acta Neurochir (Wien) 1967; 16:1-78. KITAHATA LM, KATZ JD. Tension pneumocephalus after MARKHAM
posterior fossa craniotomy, a complication of the stttinp position. Anaesthesiology 1976; 44:448-50. 3 HULLETI WB, LAING JW. Tension pneumocephalus in sitting position. Anaesthesiology 1976; 45578. 4 LUNSFORDLD,MAROONJD,StIEPTAKPE.AtBINSMS. Subdural tension pneumocephalus. report of three cases. J Neurosurg 1979; 50~525-27.
5
6
7
THIAGARAJAN
S, FROST
EAM,
SINGI, T. SUKMAN
K. Car-
diac arrest associated with tension pneumocephalus. Anaesthesiology 1982; 56:73-S. SHARMA Bs. KAK VK. Bifrontal (and cerebellopontine) tension pneumocephalus following posterior fossa surgery in sitting position. Report of three cases and review of literature. Neurology India 1988; 36:213-24. HAYMAN
LA,
ALDAMA-LEUBBERT
AE,
EVANS
RA.
IIItDl-
cranial diverticulum of the frontal sinus as a complication of frontal craniotomy, case report. J. Neurosurg 1979; 5 1870-7I x VAOUERO _I,MARTINEZ R. Tension pneumocephalus in brain abscess after simple puncture drainage. Acta Neurochir (Wien) 1984; 71:225-7. 9 LITTLEJR,MAcCARTYCS.~~~IS~OII pneumocephalusafter insertion of ventriculoperitoneal shunt for aqueductal stenosis, case report. J. Neurosurg 1976; 44:383-5. I” IKEDA K, NAKANO M, TANI E. Tension pneumocephalus complicating ventriculoperitoneal shunt for CSF rhinorrhea, case report. J. Neural Neurosurg. Psychiatry 1978; 41:319-22. II PIrrs LH, WILSON CB, DEDO HH, WEYAND K. Pneumocephalus following ventriculoperitoneal shunt, case report J. Neurosurg 1975; 43:631-3. ‘* CiaAr c‘J, GROSS CE, BECK Dw. Complications of spinal drainage in the management of cerebrospinal fistula. J. Neurosurg 1981; 54:392-5. 13 DILORENZON.cARUSO R,FLORIS R,GuERRISIV,BOZZAO L, FORTUNA A. Pneumocephalus & tension pneumocephalus after posterior fossa surgery in the sitting position, a prospective study. Acta Neurochir (Wien) 1986; 83:112-5. 13 FRIEDMAN GA, NORFLEET EA, BEDFORD RF. Discontinuation of nitrous oxide does not prevent pneumocephalus. Anaesthesia Analgesia (Paris) 1981; 6057-8. Is ARTRU A. Nitrous oxide plays a direct role in the development of tension pneumocephaius intraoperatively. Anaesthesiology 1982; 5759-61. ” MACGILLIVRAY RG. Pneumocephalus as a complication of posterior fossa surgery in sitting position. Anaesthesia 1982; 371722-S. ” GANAPATHY K, GOVINDAN R. Cerebellopontine pneumocephalus acting as a space occupying lesion: CT demonstration. J. Comput Assist Tomog 1985; 9407-12.