Cerebellar and thalamic stimulation treatment for epilepsy

Abstract

The present chapter describes the most important available experimental and clinical evidence on the role of electrical stimulation of the cerebellum or the thalamus in the control of epilepsy. Cerebellum serves as an integrator of sensory information and regulator of motor coordinating and training. The sole output of the cerebellum is inhibitory Purkinje cell projections to deep cerebellar nuclei in the brainstem. Cerebellar stimulation in animal models of epilepsy has given mixed results. Nevertheless, more than 130 epileptic patients have been subjected to cerebellar stimulation and the results from uncontrolled studies have been encouraging. The anterior thalamic nucleus (ATN) is part of the Papez circuit, a group of limbic structures with demonstrated role in epilepsy. The centromedian thalamic nucleus (CMN) is considered part of the thalamic reticular system. Stimulation of either of these nuclei in experimental animals has been associated with considerable antiepileptic effects. On the basis of the research evidence, numerous studies have been done on humans, which gave promising results. Currently, a multicenter trial on stimulation of the ATN, the SANTE trial is in progress in the USA. On the basis of the reported studies, the authors aim to provide insights into how the electrical stimulation of the above structures exerts an antiepileptic effect and also provide suggestions regarding the future progress in this field.

Cerebellar stimulation in the management of medically intractable epilepsy: a systematic and critical review

“…34 The previously proposed theory that stimulation of the Purkinje cells may intensify the inhibitory cerebellar output to the thalamic neuronal network, and subsequently weaken its excitatory output to the cerebral cortex, cannot be supported by the histopathological findings of several animal and human reports. These reports described significantly decreased populations of Purkinje cells in epileptic patients.…”

“…9,18,54 It has been proven that stimulation of the cerebellar cortex resulted in further degeneration and population decrease of Purkinje cells. 34 In addition, Dow et al…”

“…In an attempt to summarize the results of these series, Krauss and Koubeissi 34 found that a total of 36 patients had been reported to have undergone cortical CS for their epilepsy. 4,14 The seizure frequency was found to be reduced in 33 (91.6%) of the 36 patients, whereas 12 (33.3%) had become seizure free.…”

Deep Brain Stimulation for the Treatment of Epilepsy: Circuits, Targets, and Trials

“…A pooled analysis of prior small series has recently been published by Krauss and Koubeissi [56], demonstrating a seizure freedom rate of 27 % (31/115 patients) and at minimum a reduction of seizures in 76 % (87/115 patients) in the prior, heterogeneous case series. More rigorously controlled studies across 17 patients found none seizure free and 5/17 with reduced seizures.…”

Possible new avenues in epilepsy treatment: the stimulation techniques deep brain stimulation, vagal nerve stimulation, transcranial magnetic stimulation

“…Only 2 patients out of 17 benefited from this procedure [37]. However, a recent study reported that stimulation of the superior-mesial cerebellar cortex in 5 patients with generalised tonicoclonic seizures (4 patients also with tonic seizures), led to a reduction but not complete suppression of tonicoclonic or clonic seizures after 24 months [38].…”