Complication Of Posterior Fossa Surgery Research Articles

Paraplegia due to spinal subdural hematoma as a complication of posterior fossa surgery: Case report and review of the literature

Although blood contamination of cerebrospinal fluid (CSF) after an intracranial operation is possible, development of a symptomatic spinal hematoma after a posterior fossa surgery has never been reported. A 43-year-old woman underwent a posterior fossa tumor removal in the prone position with no intraoperative difficulty. On the second postoperative day, she complained of severe epigastric pain and developed a rapid onset of paraplegia with anesthesia below the thoracic 5 spinal level. The emergency cranial and spinal MRIs revealed a spinal extramedullary hemorrhage spreading to the whole spinal regions, just sparing the cauda equina area. There was a prominent localized hematoma formation surrounding and compressing the spinal cord at the upper thoracic levels, which was evacuated via an urgent laminectomy. The patient showed partial neurological recovery after the decompression. Development of the spinal hematoma was explained by the movement of blood from the tumor bed into the spinal canal under the effect of gravity, during or after the operation. A 30° head elevation might facilitate the accumulation of blood. Localization of the hematoma formation may be caused by the fact that the upper thoracic levels constitute the apex of the kyphosis. We conclusively suggest that a spinal hematoma should be taken into consideration as a rare but potentially severe complication of a posterior fossa surgery. Meticulous hemostasis and isolation of the surgical area from the spinal spaces are essential. Overdrainage of CSF should be abandoned. Postoperatively, patients should be monitored for spinal findings as well as cranial signs.

Visual disturbance associated with postoperative cerebellar mutism

Cerebellar mutism is an uncommon complication of posterior fossa surgery. Manifestations include disturbances of articulation, prosody, and pitch, and, if severe, complete mutism. Symptoms are independent of recognizable cortical or brainstem injury, and recovery is variable, with permanent deficits frequently observed. Cerebellar dysfunction is commonly invoked as an etiology, although controversy remains concerning the mechanism. Visual impairment has been reported only once before in the setting of this disorder. We report a confirmatory case of sudden, severe visual loss in association with cerebellar mutism after resection of a midline medulloblastoma in a 7-year-old.

Tumour type and size are high risk factors for the syndrome of “cerebellar” mutism and subsequent dysarthria

OBJECTIVE“Cerebellar mutis” and subsequent dysarthria (MSD) is a documented complication of posterior fossa surgery in children. In this prospective study the following risk factors for MSD were assessed: type, size...

Somatosensory evoked potential monitoring during positioning of the patient for posterior fossa surgery in the semisitting position.

Midcervical flexion myelopathy is a rare but well-known complication of posterior fossa surgery. To reduce the risk, we routinely used somatosensory evoked potential (SSEP) monitoring during positioning of the patient. Fifty-five consecutive patients were operated on for posterior fossa lesions in the semisitting position via a median (5 patients) or a lateral (50 patients) suboccipital approach. During positioning, monitoring of SSEPs by stimulation of the tibial nerve (T-SSEP) as well as by stimulation of the median nerve (M-SSEP) was established. In the case of pronounced SSEP changes, the head was repositioned. Surgery was started after SSEP recordings were unchanged as compared to the baseline investigation. Effective monitoring was possible in all cases. Whereas M-SSEP recordings showed no changes while placing patients in the sitting position, T-SSEP recordings were altered in 14 cases (25%). In cases using the midline approach, SSEP changes were never so pronounced to require repositioning of the head. Head flexion and rotation resulted in significant changes of T-SSEP recordings in eight patients (14.5%), requiring repositioning. In two cases, an amplitude loss was noted. In only two of these eight patients were M-SSEP recordings markedly changed. SSEP recordings after repositioning disclosed recovery of spinal cord function. In no patient were clinical signs of myelopathy observed postoperatively. We observed a high incidence of pronounced changes of T-SSEP recordings when the patient's head was flexed and rotated for lateral suboccipital craniotomy in the semisitting position. Despite the low specificity monitoring of T-SSEPs during positioning of the patient for posterior fossa surgery, the semisitting position is strongly recommended.

Middle Ear Mucocele: An Unusual Complication of the Tranlabyrinthine Approach to Acoustic Neuroma

The complications of posterior fossa surgery continue to decrease in incidence as our collective experience broadens. Most complications are seen in the immediate postoperative period and the minimized by careful attentiveness to subtle changes in mental status, vital signs, and cranial nerve examination. Long-term follow-up is necessary to identify tumor recurrence, but strict imaging protocols as yet do not exist to facilitate the early identification of recurrent disease, as recurrence is very rare. We report the first case of secondary mucocele formation in the middle ear cleft following translabyrinthine excision of an intracanalicular acoustic neuroma. This complication was found in the fourth postoperative year on routine magnetic resonance imaging, which itself followed previously normal contrasted magnetic resonance imaging in the second postoperative year. The genesis of this complication and possible treatment options are discussed.

Midcervical Flexion Myelopathy after Posterior Fossa Surgery in the Sitting Position: Case Report

Midcervical Quadriplegia is a well-known complication of posterior fossa surgery performed with the patient in the sitting position. The case of a 24-year-old man with a fourth ventricular choroid plexus papilloma is described. The patient developed reversible quadriparesis after surgery in the sitting position; postoperative magnetic resonance imaging demonstrated a hyperintense area within the cervical cord at C5-C6 on T2-weighted images, which was considered to represent "midcervical flexion myelopathy." It is suggested that the prolonged stretch and compression of the cervical cord is the pathogenesis of this serious complication.

Tension pneumocephalus following posterior fossa surgery in sitting position: A report of 2 cases

Tension pneumocephalus is a rare complication of posterior fossa surgery in sitting position. We encountered 2 patients with this complication amongst 60 patients operated during the past 2 years. All 60 patients had some amount of intracranial air at the end of surgery. The causative factors of tension pneumocephalus are briefly reviewed. Prompt recognition of this complication is very important. Diagnosis and management are discussed.

Subdural tension pneumocephalos

✓ Two patients developed subdural tension pneumocephalus after undergoing posterior fossa surgery performed in the sitting position. The mechanism for entry of air into the intracranial compartment is analogous to the entry of air into an inverted soda-pop bottle. As the fluid pours out, air bubbles to the top of the container. We have thus referred to this as the “inverted pop-bottle syndrome.” Computerized tomography provided prompt diagnosis and confirmed brain displacement. Twist-drill aspiration of the air resulted in improvement in both patients, although one patient subsequently died from an intracerebellar hemorrhage. Tension pneumocephalus appears to be another potential complication of posterior fossa surgery in the sitting position. This condition is easily diagnosed and treated, and should be considered whenever a patient fails to recover as expected following posterior fossa surgery.

NORMAL PRESSURE HYDROCEPHALUS: COMPLICATION OF POSTERIOR FOSSA SURGERY IN CHILDREN

The occurrence of symptomatic normal pressure hydrocephalus in children as a complication of posterior fossa surgery is recorded here. Diagnosis of this exceedingly treatable condition is essential since its syndrome can be confused with brain stem or cortical injury attributed to surgery. All cases responded to shunting with marked improvement.