Long‐term thalamic stimulation in Parkinson's disease

Abstract

Parkinsonian tremor may be suppressed by thalamic stimulation. For an equivalent clinical efficacy, its obvious advantage over micro-thalamotomy is its reversibility. This patient experienced postural tremor at the age of 44 years and akineto-rigid syndrome 8 years later. At the age of 60 years, intrathalamic stimulation was applied over a long-term period of 43 months until death and was efficient on tremor with low stimulation. This case is the first with anatomic verification. The extent of the lesion provoked by the electrode is very small. The location of the stimulation site was in the medio-inferior part of the intermedius complex at the entrance of cerebello-thalamic fibers. The stimulation of the cerebellar afferent axons could be the cause of the clinical effect. The stimulation site corresponds to the thalamic source of the precentral and accessory motor cortex, which correlates with changes observed in our PET study showing a regional cerebral blood flow decrease in cerebellar nuclei and also in precentral and accessory motor cortex. The places and mechanisms of the effects of stimulations and lesions could be different.

Deep brain stimulation in the subthalamic area is more effective than nucleus ventralis intermedius stimulation for bilateral intention tremor

“…Similar observations have been made in postmortem studies performed after ventralis intermedius stimulation [12,18].…”

Morphological differences in Parkinson’s disease with and without rest tremor

“…A strong argument in favor of a contribution of the cerebellum and its projections to the thalamus in the pathogenesis of rest tremor comes from experience with stereotactic surgery. The thalamic targets, Vim [5,10,44,46,47] and the cerebello-thalamic projections [11], have proven efficacious in the suppression of rest tremor and Vim was even postulated to a better target than the ventro-oralis posterior nucleus (Vop) receiving pallidal afferents [61]. The fact that Vim receives cerebellar afferents, but none from the basal ganglia [34], implies that rest tremor originates from either a cerebellar generator [61] or an interaction of the basal ganglia-and cerebellothalamo-cortical circuits in the cerebral cortex, where those segregated circuits converge [16].…”

Evaluation of surgery for Parkinson’s disease

“…No damage attributable to stimulation was observed. 45 The real advantage of DBS of the thalamus becomes apparent when bilateral procedures are employed. Bilateral thalamotomies have a complication rate of up to 25%.…”

“…14, Of the 38 articles identified for DBS of the thalamus, 16 articles met criteria. [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] The review of DBS of the globus pallidus consisted of all 10 articles identified, [56][57][58][59][60][61][62][63][64][65] and DBS of the subthalamic nucleus was based on all 6 articles identified. 62,[66][67][68][69][70] There were 52 articles for adrenal medullary transplantation, but the review includes only the 9 that met criteria.…”