Jean Perret

Long-term suppression of tremor by chronic stimulation of the ventral intermediate thalamic nucleus

The usefulness of high-frequency stimulation of the ventral intermediate nucleus (Vim) as the first neurosurgical procedure in disabling tremor was assessed in 26 patients with Parkinsons disease and 6 with essential tremor. 7 of these patients had already undergone thalamotomy contralateral to the stimulated side, and 11 others had bilateral Vim stimulation at the same time. Chronic stimulating electrodes connected to a pulse generator were implanted in the Vim. Tremor amplitude at rest, during posture holding, and during action and intention manoeuvres was assessed by means of accelerometry. Of the 43 thalami stimulated, 27 showed complete relief from tremor and 11 major improvement (88%). The improvement was maintained for up to 29 months (mean follow-up 13 [SD 9] months). Adverse effects were mild and could be eradicated by reduction or cessation of stimulation. This reversibility and adaptability, allowing control of side-effects, make thalamic stimulation preferable to thalamotomy, especially when treatment of both sides of the brain is needed.

Effect on parkinsonian signs and symptoms of bilateral subthalamic nucleus stimulation

In monkeys rendered parkinsonian, lesions and electrical stimulation of the subthalamic nucleus reduce all major motor disturbances. The effect of electrical stimulation of the subthalamic nucleus was assessed in three patients with disabling akinetic-rigid Parkinsons disease and severe motor fluctuations. Quadripolar electrodes connected to a pulse generator were implanted in the subthalamic nuclei on both sides. Patients were evaluated with the unified Parkinsons disease rating scale and timed motor tests. 3 months after surgery, activities of daily living scores had improved by 58-88% and motor scores by 42-84%. This improvement was maintained for up to 8 months in the first patient operated upon. One patient was confused for 2 weeks after surgery, and another developed neuropsychological impairment related to a thalamic infarction which improved over 3 months. In one patient, stimulation could induce ballism that was stopped by reduction of stimulation. This is the first demonstration in human beings of the part played by the subthalamic nuclei in the pathophysiology of Parkinsons disease.

European Stroke Initiative Recommendations for Stroke Management

This article summarises recommendations for acute management of stroke by the European Stroke Initiative (EUSI), on behalf of the European Stroke Council (ESC), the European Neurological Society (ENS), and the European Federation of Neurological Societies (EFNS).

Hospital Admission and Acute Stroke Units

Cerebrovascular diseases are medical emergencies. Hospital admission rates for stroke vary from 40 to 80% depending on the country. The burden of stroke in terms of hospital expenditures and health co

Relationship between Levodopa Independent Symptoms and Central Atrophy Evaluated by Magnetic Resonance Imaging in Parkinson’s Disease

Thirty patients with Parkinsons disease were studied for the purpose of investigation relations between motor symptoms and cerebral atrophy evaluated by magnetic resonance imaging (MRI). Axial symptoms (gait disorder, postural instability and difficulty in arising from a chair), assessed at the time of maximum clinical improvement, were significantly correlated with frontal atrophy, while no correlation was found between the basal parkinsonian disability score and cerebral atrophy. It is suggested that frontal atrophy observed by MRI is linked with axial motor symptoms resulting from non-dopaminergic lesions. The origin of this atrophy is unknown.

Effects of tiapride in tardive dyskinesia

Tiapride, a selective D2 dopaminergic receptor blocking agent from the substituted benzamide class, was evaluated in a blind video-controlled trial in 10 psychiatric patients with tardive dyskinesia. There was a significant decrease in dyskinesia with a parallel increase in parkinsonism. This relationship between two opposite effects on movement suggests a common pathophysiological basis lying on a reciprocal hyper- and hypoactivity of the dopaminergic striatal system. Nevertheless, other mechanisms may be involved, for the evolution of individual parkinsonian and dyskinesia scores is not necessarily opposite: the tiapride-induced parkinsonism was generally acceptable and in two cases, the dyskinesia scores were reduced without an increase in parkinsonism. Therefore, more dyskinetic patients have to be evaluated in long-term studies with tiapride, before this drug could be recommended in tardive dyskinesia, when dyskinetic movements become intolerable.