Effect of cerebellar stimulation on EEG power spectra in the acute model of epilepsy.

Experiments were performed to investigate the effects of cerebellar stimulation on epilepsy induced by parenteral administration of penicillin, in rats without or with the lesion of sensorimotor cortex. There were no differences in the EEG activity of the same experimental animal after the first and subsequent penicillin treatments (at least 7 days later). The electrical stimulation (duration of 5-10 min) of the lateral cerebellar nucleus was applied repetitively 135-315 min after penicillin administration, when the EEG power spectra markedly increased. The cerebellar stimulation evoked the decrease of the mean total EEG power spectra, but the effects were temporary. The EEG power spectra were significantly lower (P < 0.05) during the period of 150-330 min after penicillin treatment in experimental sessions with applied cerebellar stimulation in comparison to the experimental sessions without such stimulation. The residual effects (if any) of cerebellar stimulation on the EEG activity in the later period, 345-600 after penicillin treatment were not significant (P > 0.05). Cerebellar stimulation had the same effect among unlesioned animals and animals with prior cortical lesion in the acute model of epilepsy.

Unilateral ataxia following herpes zoster of spinal C4 segment.

Focal lesions of central nervous system are extremely rare following cutaneous herpes zoster. A 55 year old male developed cerebellar speech, right sided ataxia and intention tremor, three weeks after herpes zoster of right spinal C4 segment. Clinical examination and investigations confirmed a focal vascular lesion in the midbrain suggestive of granulomatous angiitis which can cause focal neurological defect after herpes zoster.