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L Vercueil

Publications and source records attributed to L Vercueil.

18 recordsLinked to original sources
PubMed2001

Deep brain stimulation of the corpus luysi (subthalamic nucleus) and other targets in Parkinson's disease. Extension to new indications such as dystonia and epilepsy.

Chronic high frequency (130 Hz) stimulation (HFS) of the thalamic target Vim, first used in our group in 1987 as a treatment of tremor of various origins, has been used over the last ten years in 137 patients. Since 1993, this method has been extended to two other targets (subthalamic nucleus (STN): 137 patients and the medial pallidum (GPi): 12 patients), based on recent experimental data in rats and monkeys. STN appears to be a target of major interest, able to control the three cardinal symptoms and to allow the decrease or suppression of levodopa treatment, which then also suppresses levodopa induced dyskinesias. The stereotactic technique is based on the determination of the target using ventriculography, MRI and electrophysiology, with both microrecording of single neuron activity and microstimulation inducing therapeutic symptom suppression and side effects. Chronic electrodes are then placed bilaterally at the best physiologically defined location and then connected to implantable stimulators (either 2 Itrel II or the new double channel Kinetra), operated at 130-185 Hz, 60 ms pulse width, 2.5 to 3.5 volts. There was no operative mortality and permanent morbidity was observed in 3 patients. The mechanisms of action of HFS are not fully understood, but are definitely related to high frequency and are probably different depending on the target. Inhibition of cellular activity or of neural network functions could be induced, by jamming of a retroactive loop for tremor, or by shutdown of neurotransmitter release in STN. Mechanisms within an individual target are also probably different for tremor or for other symptom alleviation. All cardinal symptoms are alleviated from tremor to akinesia and rigidity. This strong improvement allows the decrease of the drug dosage to approximately 30% of the preoperative level, which suppresses the levodopa-induced dyskinesias. The off period dystonias are also suppressed as well as freezings and falls. The effects remain stable over more than 5 years and in the same period, the off stimulation-off medication UPDRS remains stable and does not increase at the usual rate The low rate of permanent complications, the minor side effects and their immediate reversibility, the possibility of bilateral implantation in one session and the long-term persistence of symptom relief are strong arguments which support chronic HFS of STN as the method of choice when a surgical procedure is indicated for the treatment of Parkinson's disease and even more when a bilateral procedure is necessary. Recent data show that STN stimulation could be useful in the treatment of dystonia as well as some forms of epilepsy. It is therefore possible that DBS in STN as well as in other targets could become a potent therapeutic tool in the near future for neurological disorders.

Dystonia↗
PubMed2001

Deep brain stimulation in the treatment of severe dystonia.

A retrospective study of a consecutive series of 19 patients with medically intractable dystonia treated with uni- or bilateral deep brain stimulation (DBS) is reported. A minimal follow-up of 6 months was available, up to eleven years in one patient. The first twelve consecutive patients (4 with primary and 8 with secondary dystonia) were treated with chronic stimulation of the posterior part of the ventrolateral thalamic nucleus (VLp). In this group global functional outcome was improved in 8 patients, although dystonia movement and disability scale scores did not show significant improvement. Of the 12 patients treated first by VLp DBS, three (1 primary and 2 secondary dystonia) underwent pallidal (GPi) DBS after the VLp DBS failed to improve their symptoms. The last seven consecutive patients (5 primary and 2 secondary dystonia) were treated directly with GPi DBS. Extracranial infection prevented chronic GPi DBS in one patient. In another GPi patient, preliminary negative tests with the electrodes discouraged implantation of the stimulators, and the patient was not treated with chronic DBS. In the remaining group of eight patients including those previously treated with VLp DBS, chronic GPi DBS resulted in a significant improvement in the dystonia movement scale and disability scores. Although this is a retrospective study dealing with dystonia of heterogeneous etiology, the results strongly suggest that GPi DBS has a better outcome than VLp DBS.

Adolescent↗
PubMed2001

[Myoclonus in the adult: diagnostic approach].

Myoclonus, defined as shock-like involuntary movement, may be physiological or caused by a very wide variety of hereditary and acquired conditions. Because myoclonus can originate from different disorders and lesions affecting quite varied levels of the central and peripheral nervous systems, it represents from many points of view a diagnostic challenge. Moreover, new entities have been recently individualized, such as cortical tremor, which deserve renewed attention. The aim of this review is to propose a rationale for a diagnostic approach based on clinical and electrophysiological grounds. In this setting, we successively address 1) the clinical features allowing a positive diagnosis of myoclonus; 2) the clinical clues to the etiology; 3) the relevance of the clinical context to the diagnosis; and 4) the contribution of neurophysiology. Differentiating myoclonus from tics, spasm, chorea and dystonia can be difficult, and a careful reappraisal of clinical features allowing precise identification is presented. Moreover, the topographical distribution of myoclonus, the temporal pattern of muscle recruitment, the condition of occurrence and the rhythm of the event, may provide clinical clues relevant to the diagnosis. Myoclonus without associated epilepsy, myoclonus with epilepsy, myoclonus with encephalopathy, parkinsonism and/or dementia represent overlapping clinical categories, although they remain useful for the diagnostic approach. Using electrophysiology (including back-averaging EEG, MEG, SEP, C-reflex studies) to determine the origin of myoclonus may not allow us to focus on the underlying condition. Indeed, in many instances, the myoclonus is cortical in origin, but the pathology is found elsewhere.

Alzheimer Disease↗
PubMed2001

Review of the functional surgical treatment of dystonia.

A review of functional surgery for dystonia is presented. Recently renewed interest in stereotaxy for dystonia has followed the resurgence of pallidotomy and the introduction of deep brain stimulation (DBS) in Parkinson's disease (PD) in the early 1990s. However, even since the 1950s, small series of patients treated with ablative surgery have been carefully studied, providing useful information, notably regarding the tolerability of surgery. In the setting of dystonia, thalamotomy was first performed with substantial benefits, but some authors outlined the great variability in outcome, and the high incidence of operative side-effects. In the 'modern' era of functional surgery for movement disorders, the globus pallidus internus (GPi) has emerged to be currently the best target for dystonia, based on small series of patients published in the last few years. Both bilateral posteroventral pallidotomy (PVP) and bilateral pallidal stimulation, performed by several teams, have benefited a variety of patients with severe dystonia, the most dramatic improvements being seen in primary dystonia with a mutation in the DYT1 gene. Whereas patients with secondary dystonia have often shown a lesser degree of improvement, some publications have nevertheless reported major benefit. There is today a strong need for carefully controlled studies comparing secondary and primary dystonia, DYT1 and non-DYT1 dystonia, ablative surgery and DBS, with additional assessment of neuropsychological changes, especially in children treated with bilateral pallidal procedures.

Dystonia↗
PubMed2000

Hyperkinesia contralateral to acute hemiplegia: relevance of previous frontal lesions.

Two patients with a hyperkinetic syndrome contralateral to acute hemiplegia are presented. One patient showed a right-sided hemiplegia associated with abnormal movements of the left upper limb. In the other patient hemiplegia was localised on the left side while abnormal movements involved the right lower limb. Brain imaging showed acute infarctions (respectively left middle cerebral artery area and right lacunar infarctions) associated with a pre-existing contralateral infarction involving anterior non-primary motor areas. Hyperkinetic syndromes in stroke are mainly related to acute lesion of the contralateral subcortical areas. In our patients, the acute lesions were located ipsilateral to the hyperkinetic body part while the pre-existing lesions were located contralateral to the hyperkinetic side. We speculated that these pre-existing lesions might play a role in the pathophysiology of this clinical syndrome.

Journal Article↗
PubMed2000

Pallido-Luysio-Nigral atrophy revealed by rapidly progressive hemidystonia: a clinical, radiologic, functional, and neuropathologic study.

Pallido-luysio-nigral atrophy (PLNA) is a rare neurodegenerative disease in which the clinical and radiologic correlates have not yet been clearly established. A 62-year-old man insidiously developed dystonic postures, choreoathetoid movements, slowness, and stiffness, which initially affected the right hand and foot and progressively spread to the entire right side. T2-weighted magnetic resonance imaging showed increased signal intensity in both left and right medial pallida and in the left substantia nigra. Tests using HMPAO-SPECT and FDG-PET demonstrated left cortical hyperperfusion and hypermetabolism, whereas the left lenticular nucleus was slightly hypometabolic. At age 65, abnormal movements and postures involved all four limbs and the axis causing major gait disturbances, and facial and bulbar muscles atrophied resulting in dysarthria, dysphagia, and impaired breathing. Diffuse amyotrophy and fasciculations also appeared. Death occurred at age 66, 4 years after onset. At autopsy, severe bilateral neuronal loss and gliosis restricted to the pallidum, the subthalamic nucleus, the substantia nigra, and the hypoglossal nucleus were noted, accounting for the diagnosis of PLNA with lower motor neuron involvement. Progressive hemidystonia with adult onset represents an unusual clinical presentation for this disorder. Moreover, this observation indicates that a diagnosis of PLNA should be considered for specific magnetic resonance imaging, SPECT, and/or PET data, and suggests that in PLNA, pallidal dysfunction might play a key role in the dystonic presentation.

Age of Onset↗
PubMed2000

Reply.

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Editorial↗
PubMed2000

[Clinical diagnostic criteria in Parkinson's disease and parkinsonian syndromes: review of the literature].

This paper reviews the validity of clinical diagnostic criteria developed for Parkinson's disease and parkinsonian syndromes. Proposed criteria are predominantly empirical. There are only a few studies with neuropathological verifications. For Parkinson's disease and Progressive Supranuclear Palsy clinicopathological studies have been performed and led to pathologically based criteria. In this context, the specificity and sensitivity of clinical criteria could be assessed. Reliability however has seldom been tested. In contrast, the proposed criteria for the clinical diagnosis of Multiple System Atrophy and Corticobasal atrophy have not been pathologically evaluated.

Humans↗
PubMed1999

Breathing pattern in patients with Parkinson's disease.

The improvement in motor performance resulting from levodopa administration in patients with Parkinson's disease (PD) provides the opportunity to investigate ventilatory changes brought about by the disease. The aim of this study has been to investigate these changes in order to specify the mechanisms of the impairment in breathing in PD. Breathing patterns at rest were investigated in 11 patients with idiopathic PD both before (OFF) and after (ON) administration of levodopa at a dose improving their motor performance by at least 30%. Airflow (Fleisch head mounted on a mask), rib cage and abdomen movements (inductance plethysmography) were recorded in the OFF condition 1 h after subjects woke up. Subjects then received levodopa and a new set of recordings was obtained 1 h later, in the ON condition. Breath-by-breath processing of recordings was carried out, and tidal volume (VT), inspiratory (TI) and expiratory (TE) durations were measured. The main finding was a lengthening of TI resulting in a decrease in ventilation and in VT/TI, and an increase in TI/TTOT in the ON compared to the OFF condition. In the ON condition abnormal rib cage-abdomen plots patterns were found in four out of six subjects. A hypothesis on the effect of PD on breathing is proposed on grounds of normal diaphragmatic activity but impaired activity of the other respiratory muscles and more specifically the intercostal muscles.

Aged↗
PubMed1999

Basal ganglia involvement in rotational seizures.

Body rotation during partial epileptic seizures remains a poorly understood clinical feature, possibly related to the ictal involvement of specific cortical areas (e.g. vestibular cortex). However, there are both experimental and clinical arguments which support the hypothesis of basal ganglia asymmetric activation during such complex motor behavior. We report a patient exhibiting rotational seizures which proved to arise from right anterior temporal lobe structures and the orbito-cingular cortex, as demonstrated during stereotactic EEG recordings. An ictal 99mTc-ECD-SPECT study was performed during an electrically induced seizure, similar to the seizures usually experienced by the patient but without a rotatory component, showing a marked increase of cerebral blood flow in the lenticular nucleus, ipsilaterally to the epileptogenic area. This finding suggests that lenticulate involvement might be necessary to produce an ictal circling behavior. As circling behavior can be observed during epileptic seizures originating from areas widely distributed in the cortex, one may postulate that the basal ganglia involvement is the "final common pathway" underlying the rotational part of the clinical symptomatology.

Basal Ganglia↗
PubMed1998

High-frequency stimulation of the subthalamic nucleus suppresses absence seizures in the rat: comparison with neurotoxic lesions.

High-frequency electrical stimulation of deep brain structures has recently been developed for the surgical approach of neurologic disorders. Applied to the thalamus in tremors or to the subthalamic nucleus in Parkinson's disease, high-frequency stimulation has been demonstrated to exert a local inhibiting influence, leading to symptoms alleviation. In the present study, bilateral high-frequency stimulations (130 Hz) of the subthalamic nuclei suppressed ongoing spontaneous absence seizures in rats. This effect was dissociated from motor side-effects and appears specific to the subthalamic nucleus. Bilateral excitotoxic lesions of the subthalamic nuclei only partially suppressed absence-seizures. These results confirm the involvement of the basal ganglia system in the control of generalized seizures and suggest that high-frequency stimulations could be used in the treatment of some forms of seizures.

Animals↗
PubMed1998

The role of basal ganglia in the control of generalized absence seizures.

During the last two decades, evidence has accumulated to demonstrate the existence, in the central nervous system, of an endogenous mechanism that exerts an inhibitory control over different forms of epileptic seizures. The substantia nigra and the superior colliculus have been described as key structures in this control circuit; inhibition of GABAergic neurons of the substantia nigra pars reticulata results in suppression of seizures in various animal models of epilepsy. The role in this control mechanism of the direct GABAergic projection from the striatum to the substantia nigra and of the indirect pathway, from the striatum through the globus pallidus and the subthalamic nucleus, was examined in a genetic model of absence seizures in the rat. In this model, pharmacological manipulations of both the direct and indirect pathways resulted in modulation of absence seizures. Activation of the direct pathway or inhibition of the indirect pathway suppressed absence seizures through disinhibition of neurons in the deep and intermediate layers of the superior colliculus. Dopamine D1 and D2 receptors in the nucleus accumbens, appear to be critical in these suppressive effects. Along with data from the literature, our results suggest that basal ganglia circuits play a major role in the modulation of absence seizures and provide a framework to understand the role of these circuits in the modulation of generalized seizures.

Animals↗