[A case of idiopathic brain stone presenting as psychomotor epilepsy].

A rare case of idiopathic brain stone with psychomotor epilepsy is reported. On December 9, 1982, a 29-year-old man with 18 years' history of psychomotor epilepsy was admitted to our neurosurgical service. He had no history of neonatal asphyxia, trauma or other neurological diseases. No neurological deficit was disclosed. Skull x-ray films and plain CT scan demonstrated a calcified mass in the right temporal lobe. No contrast enhancement was noted. Despite an extensive search, the etiology of the calcified mass was not revealed. Conventional EEG showed focal spike discharges in the right anterior temporal lead and telemetered EEG monitoring for 24 hours disclosed sharp wave burst in the right temporal lobe. In spite of appropriate medication, seizures persisted. At surgery, electrocorticogram and stereo-electrocorticogram showed paroxysmal epileptiform events in the right temporal lobe. Anterior temporal lobectomy with excision of calcified mass was done. Histopathological examination demonstrated thick collagen fibers and gliosis around the stone, and diagnosis of idiopathic brain stone was made. We reviewed five previously reported cases. We also emphasized an epileptogenicity of idiopathic brain stone and indication of surgical excision which may result in an excellent control of epilepsy.