RESUMEN
Occlusion of vertebro-basilar artery and its branches can produce massive cerebellar lesion with edematous swelling from ischemia and accompanying hemorrhage. Recognition of this massive cerebellar lesion is essential, because it compresses the brain stem and rapidly leads to coma and death unless immediate surgical decompression of posterior fossa is performed. However, surgery might not be beneficial if the arterial occlusion had simultaneously produced and extensive infarction in the brain stem. The clinical and radiological findings are important in determining the optimum therapy and indication for decompressive surgery. CT scan was the most useful diagnostic test. Prompt and correct diagnosis of this illness is required to ensure adequate therapy. We are presenting two cases of cerebellar infarction, which have quite different clinical pictures and courses. One case has progressive headache for 2 months, which was misdiagnosed as tumorous condition and suboccipital craniectomy was performed but died due to brain swelling. The other one has acute course with compression of brain stem 24hr after onset of sudden headache and suboccipital decompressive surgery was performed and the patient recovered successfully.