The clinical, radiologic and EEG features of three children with dysplastic gangliocytoma of the cerebral hemispheres and drug resistant partial seizures are described from the Comprehensive Epilepsy Center and Department of Neurology, Miami Children's Hospital, Miami, FL. A two year old girl had recurrent right-sided focal motor seizures that began within hours of birth; a 15 year old boy had habitual left-sided sensory seizures and infrequent grand mal attacks beginning at age three; and an eight month old boy was hospitalized following an episode of head trauma with unconsciousness and apnea followed by recurrent seizures consisting of staring, eye blinking and left versive head movement. None of the cases manifested a mass effect and the EEG findings lateral ized to one hemisphere. Following cortical resection, two became seizure free and the third was almost seizure free. The authors consider that dysplastic gangliocytoma may be an important and surgically remedial cause of very early malignant partial seizures. 
COMMENT. Gangliocytomas are usually localized to the cerebellum and those originating in the cerebral hemispheres are much less common but may be epileptogenic. CT demonstrates hyperdense noncontrast enhancing regions and MRI's reveal medium intensity regions in the T-l weighted and proton density images. The authors consider that subdural electrode recording can facilitate early surgical intervention by localizing epileptogenic regions and defining cortical regions of functional significance. The use of subdural electrodes to study the EEG features of simple partial seizures in seven patients is described in an additional article in this same issue of Neurology.