[A case of complex brain anomaly with arachnoid cyst treated well by cyst-cisternal shunt]

A rare case of complex anomaly, composed of schizencephaly, polymicrogyria, heterotopic gray matter, agenesis of the septum pellicidi and arachnoid cyst at the right middle cranial fossa was encountered. A 38-year old man, complaining of epileptic seizure, was admitted to our department. His past history included cerebral palsy. Plain skull roentgenogram showed protrusion of the right temporal bone and thinning of the ipsilateral sphenoidal wing. CT revealed arachnoid cyst and parietal crest surrounded by cortical layer on the right side. MRI also demonstrated the arachnoid cyst, parietal crest and agenesis of septum pellicidi. MRI, especially proton density weighted image, well demonstrated cortical layer surrounding the parietal crest, right opercular polymicrogyria and left heterotopic gray matter. The crest was diagnosed as schizencephaly. The arachnoid cyst was treated by cyst-cisternal shunt with a silicone tube (Sapporo shunt) after fenestrating the cyst. The tube was inserted into the sylvian fissure from the cyst and sutured to the inner wall of the cyst. Despite slight intratumoral hemorrhage in the CT at 1.5 months after the operation, the cyst markedly decreased in size. As to the diagnosis of the brain anomaly, MRI gives extremely useful information. Particularly for the diagnosis of anomalies of migration of neuronal cells, MRI, especially proton density weighted image, has been regarded as an indispensable examination. In the operation of subarachnoid cyst, to maintain the flow between the inside of its cyst and the basal cistern, cyst-cisternal shunt with a silicone tube had satisfactory results.(ABSTRACT TRUNCATED AT 250 WORDS)