venerdì 5 ottobre 2007
Remote cerebellar hemorrhage
Figure 1, Figure 2, and Figure 3: Three axial brain CT sections reveal subarachnoid hemorrhage in the perimesencephalic, interpeduncular and ambient cisterns. There is also evidence of a right pterional craniotomy. Evidence of a cerebellar hemorrhage is apparent (Figure 2 and Figure 3), remote from the site of aneurysm clipping.
Figure 4: Single axial brain CT on bone windows reveals that the patient is status post a right pterional craniotomy/cranioplasty.
Diagnosis: Remote cerebellar hemorrhage
Remote cerebellar hemorrhage is a self-limited complication of supratentorial craniotomy. Approximately 100 cases have been reported in the literature. Remote cerebellar hemorrhage usually comes to clinical attention post-operatively when brain CT is performed to evaluate altered mental status, new motor deficits or ataxia. The finding may also be incidentally noted on routine postcraniotomy imaging.
Remote cerebellar hemorrhage may occur ipsilateral or contralateral to the craniotomy site. Friedman et al2 studied 43 case of remote cerebellar hemorrhage and concluded that it may accompany supratentorial craniotomies which require access to the ventricular system or basal cisterns. This, in turn, results in loss of cerebrospinal fluid with cerebellar sagging, with occlusion of posterior fossa bridging veins and subsequent hemorrhagic venous infarction.
Other groups3,4 concluded that remote cerebellar hemorrhage was related to the degree of postoperative CSF drainage. This CSF overdrainage results in shifting of the cerebellum caudally with tearing of the superior cerebellar vein and its tributaries, resulting in cerebellar parenchymal hemorrhage. Potential modifiable risk factors associated with remote cerebellar hemorrhage include preoperative aspirin use, perioperative hypertension and male sex.
Management of remote cerebellar hemorrhage is conservative. The hemorrhage is usually self-limiting and does not require intervention. Ventriculostomy may be necessary if hydrocephalus occurs.