Impairment of parietal cortical functions associated with episodic prolonged spike-and-wave discharges.

A case of a 16-year-old girl who showed selective impairment of higher cortical functions and very slight lowering of initiative activity without overt disturbance of consciousness, during prolonged generalized spike-and-wave discharges with a parietal predominance, is reported. Neuropsychological investigations during the episode revealed a disturbance of parietal cortical functions, such as constructional apraxia, ideational or ideomotor apraxia, finger agnosia, acalculia, right-left disorientation, disturbance of visual-spatial orientation, and agraphia. The transient impairment of parietal cortical functions associated with the parietal-dominant spike-and-wave discharges was suggested as a principal pathophysiology of the clinical picture. Emphasis is placed on the importance of neurophysiological assessment in such a case.