Cerebral‐cerebellar paroxysmal activity in experimental focal seizures

Focal seizures were induced in 14 monkeys by injection of 25,000 units of penicillin into area 4 of the right cerebral motor cortex. Prior to and throughout the development and propagation of the seizures, bipolar recording of the surface electrical activity was obtained from an array of four pairs of platinum electrodes over the right precentral gyrus of the cerebral cortex and a similar array over the paravermal area of the lobulus simplex and the anterior lobe of the left cerebellar cortex. There was a very close correlation between the initial and subsequent rhythmic spike activity from the right cerebral to the left cerebellar cortices, as evidenced by: (1) an identical time of onset of spike activity in 11 of 14 monkeys, as recorded by the ink‐writing equipment; (2) a comparable increase in frequency and complexity of waveform with progression of paroxysmal activity; and (3) an appropriate and simultaneous somatotopic representation of initiation and progression of the paroxysmal activity along the motor strip of the right motor cortex and the left paravermal area of the cerebellar cortex. The activity in both was consonant with that from electromyograms of the left face, arm, and leg.