PubMed Health⌕ Search

Biomedical subjects

Marie Vidailhet

Publications and source records attributed to Marie Vidailhet.

At least 19 recordsLinked to original sources

Impaired modulation of motor cortex excitability by homonymous and heteronymous muscle afferents in focal hand dystonia.

A decrease of heteronymous median nerve-evoked inhibition of corticospinal projections to forearm extensor muscles was reported in a group of 10 dystonic patients by Bertolasi and colleagues in 2003. Here we tested the excitability of corticomotoneuronal connections to both wrist extensor (ECR) and flexor (FCR) muscles after conditioning stimulation of median and also radial nerve at rest in a group of 25 patients with focal hand dystonia compared to 20 healthy subjects. We also investigated the effect of the wrist dystonic posture, either in flexion or in extension, on the afferent modulation of ECR and FCR motor evolved potentials (MEPs). The heteronymous (median-induced) but also homonymous (radial-induced) inhibitions (interstimuli intervals 13-21 ms) of ECR MEP size observed in healthy subjects were decreased in patients. In addition, homonymous (median-induced) facilitation of FCR MEP size was also decreased in patients while heteronymous inhibition (radial-induced) was not. Neither the involvement of the target muscle in the dystonic posture nor the origin of the afferent volley (from a dystonic muscle) influenced the degree of impairment of afferent modulation of the MEP. These findings support the view that a global abnormal somatosensory coupling in focal hand dystonia may contribute to an inadequate motor command to wrist muscles.

Adolescent↗

Time-frequency analysis reveals decreased high-frequency oscillations in writer's cramp.

High-frequency oscillations (HFO) have been suggested to reflect the activity of thalamocortical and/or intracortical neurons bursting at high frequencies. These circuits seem to be involved in pathophysiological mechanisms of focal dystonia. In healthy subjects, we characterized the spectrotemporal properties of HFO patterns evoked by dominant-hand median-nerve stimulation, using magnetoencephalography coupled with time-frequency analysis. Then, we investigated HFO in patients with writer's cramp and found that HFO patterns are strongly decreased in power and disorganized in time. This supports the assumption that abnormal HFOs reflect pathophysiological mechanisms occurring in focal dystonia, possibly resulting from a dysfunction of somatosensory processing.

Adult↗

Long-term follow-up and adult outcome of 6-pyruvoyl-tetrahydropterin synthase deficiency.

Little information is available on the long-term course and adult outcome of patients with 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency. We describe the course of a 32-year-old woman with hypotonia, dystonia, choreoathetosis, mental retardation, behavioral disturbances, and incomplete puberty due to PTPS deficiency. From the age of 6 months she developed progressive hypotonia and choreoathtetoid movements despite good control of hyperphenylalaninemia. Tetrahydrobiopterin deficiency was diagnosed at age 3 years. She had a dramatic response to L-dopa, which persisted at a stable dose for 29 years. Reducing the L-dopa dose led to severe axial hypotonia and limb dystonia, and increasing it led to florid abnormal movements and behavioral disorders. This report illustrates the role of dopamine modulation in motor, psychiatric, and endocrine functions.

Adolescent↗

Psychogenic parkinsonism: a combination of clinical, electrophysiological, and [(123)I]-FP-CIT SPECT scan explorations improves diagnostic accuracy.

We evaluated the concordance between independent clinical, electrophysiological, and [(123)I]-FP-CIT SPECT scan explorations as a staged procedure for an accurate diagnosis in 9 patients referred with a diagnosis of suspected psychogenic parkinsonism. Three patients were reclassified as pure psychogenic parkinsonism (PP), 6 with a form of combined psychogenic parkinsonism and Parkinson's disease (PP + PD), and none with pure Parkinson's disease (PD). Electrophysiological recordings showed the characteristics of psychogenic tremor in 5 of 7 patients with tremor. In two of these 5, PD tremor was also recorded. SPECT scan results were abnormal in five of 9 patients. In one case of clinically suspected PP + PD, SPECT scan results were normal. Long-term follow-up supported the final diagnosis of PP (initial clinical misdiagnosis). Electrophysiology contributes to the clinical diagnosis of psychogenic tremor and may help confirm associated organic PD tremor. [(123)I]-FP-CIT SPECT is a robust test to ascertain dopaminergic denervation and increase the confidence of the clinical and electrophysiological diagnosis of associated PD. A combination of clinical, electrophysiological, and [(123)I]-FP-CIT SPECT scan explorations improves diagnostic accuracy in order to distinguish PP from PP + PD.

Adult↗

Clinical analysis in familial cortical myoclonic tremor allows differential diagnosis with essential tremor.

Familial cortical myoclonic tremor (FCMT) is a rare disorder often leading to a wrong clinical diagnosis of essential tremor. Electrophysiological data are usually considered to allow a correct diagnosis. We describe a FCMT French family with previously unreported clinical features such as sensitivity to glucose deprivation, vibration, repetitive visual patterns, and intense visual or auditory stimulation and contrasts. Electrophysiological studies of the propositus confirm the cortical reflex myoclonus elicited by photic stimulation and the absence of epileptic electroencephalographic discharges. We emphasize that a precise clinical analysis can lead to a correct diagnosis before electrophysiological confirmation. This is also the first-ever report of efficacy of levetiracetam in FCMT.

Adult↗

Lack of inhibitory interaction between somatosensory afferent inputs and intracortical inhibitory interneurons in focal hand dystonia.

We looked for an impaired interaction in the primary motor cortex between intracortical inhibitory circuits and circuits fed by somatosensory inputs in patients with writer's cramp. Short-interval intracortical inhibition (sICI) to wrist extensor carpi radialis muscle (ECR) was conditioned by stimulation of antagonist muscle afferents and sICI to first dorsal interosseus (FDI) muscle by homotopic cutaneous afferents stimulation. sICI was assessed at rest and during a tonic contraction of the target muscle. Eighteen patients with writer's cramp (10 having a wrist dystonic posture in flexion during writing and 8 in extension) were compared to 14 control subjects. Peripheral inputs decreased sICI in control subjects. This decrease was lost in patients in both FDI and ECR, regardless of the wrist dystonic posture. By contrast, contraction-induced depression of sICI appeared dependant on the dystonic status of the muscle: depression of sICI to ECR was abolished in patients with wrist dystonic posture in flexion, but not in patients with dystonic posture in extension, sICI even giving way to motor-evoked potential facilitation. Loss of interaction between interneurons mediating sICI and peripheral inputs probably belongs to the initial abnormalities underlying dystonia. Lack of peripherally induced sICI modulation may oppose wrist and/or hand muscles synergies.

Adolescent↗

Head tremor in Parkinson's disease.

Head tremor is a typical feature of essential tremor. Patients with sporadic Parkinson's disease can have tremor of the tongue, lip, or chin, but classically do not have head tremor. We describe five patients with Parkinson's disease and head tremor in whom clinical and neurophysiological findings suggested that head tremor was a manifestation of Parkinson's disease.

Head Movements↗

Interictal myoclonus with paroxysmal kinesigenic dyskinesia.

We report a new association between interictal myoclonus and paroxysmal kinesigenic dyskinesia (PKD) in 2 patients. By definition, PKD is transient, but the overexcitability of the neuronal system that induces these attacks may be permanent. Interictal myoclonus could be a manifestation of permanent overexcitability.

Adolescent↗

Bilateral deep-brain stimulation of the globus pallidus in primary generalized dystonia.

BACKGROUND: Severe forms of dystonia respond poorly to medical treatment. Deep-brain stimulation is a reversible neurosurgical procedure that has been used for the treatment of dystonia, but assessment of its efficacy has been limited to open studies. METHODS: We performed a prospective, controlled, multicenter study assessing the efficacy and safety of bilateral pallidal stimulation in 22 patients with primary generalized dystonia. The severity of dystonia was evaluated before surgery and 3, 6, and 12 months postoperatively during neurostimulation, with the use of the movement and disability subscores of the Burke-Fahn-Marsden Dystonia Scale (range, 0 to 120 and 0 to 30, respectively, with higher scores indicating greater impairment). Movement scores were assessed by a review of videotaped sessions performed by an observer who was unaware of treatment status. At three months, patients underwent a double-blind evaluation in the presence and absence of neurostimulation. We also assessed the patients' quality of life, cognition, and mood at baseline and 12 months. RESULTS: The dystonia movement score improved from a mean (+/-SD) of 46.3+/-21.3 before surgery to 21.0+/-14.1 at 12 months (P<0.001). The disability score improved from 11.6+/-5.5 before surgery to 6.5+/-4.9 at 12 months (P<0.001). General health and physical functioning were significantly improved at month 12; there were no significant changes in measures of mood and cognition. At the three-month evaluation, dystonia movement scores were significantly better with neurostimulation than without neurostimulation (24.6+/-17.7 vs. 34.6+/-12.3, P<0.001). There were five adverse events (in three patients); all resolved without permanent sequelae. CONCLUSIONS: These findings support the efficacy and safety of the use of bilateral stimulation of the internal globus pallidus in selected patients with primary generalized dystonia.

Adolescent↗

Dystonia and parkinsonism in GM1 type 3 gangliosidosis.

GM1 gangliosidosis is due to beta-galactosidase deficiency. Only patients with type 3 disease survive into adulthood and develop movement disorders. Clinical descriptions of this form are rare, particularly in non-Japanese patients. We describe four new patients and systematically analyze all previous reports found by a literature search and contacts with the authors for additional information. Generalized dystonia remained the predominant feature throughout the disease course and was often associated with akinetic-rigid parkinsonism. GM1 gangliosidosis must be considered as a cause of early-onset generalized dystonia, particularly in patients with short stature and skeletal dysplasia.

Adolescent↗

Effects of internal clock and memory disorders on duration reproductions and duration productions in patients with Parkinson's disease.

Patients with Parkinson's disease (PD) exhibit deficits in perceptual and motor timing as well as impairments in memory and attentional processes that are related to dysfunction of dopaminergic systems in the basal ganglia. The aim of the present study was to assess the relationships existing between impaired duration judgments and defective memory and attention in PD patients. We compared time performance of medicated PD patients and control subjects on a duration reproduction task that is highly memory-dependent, and on a duration production task that could reveal effects of changes in the speed of internal time-keeping mechanisms. Each task was performed in a control counting condition and in a condition requiring divided attention between the temporal task and a concurrent reading task. Moreover, PD patients and control subjects were assessed on memory and attention using a battery of neuropsychological tests. The results revealed that in the concurrent reading condition of the reproduction task, duration judgments tended to be more variable in PD patients than in control subjects. Moreover, variability of duration reproductions was correlated with both measures of memory and of disease severity. In the concurrent reading condition of the production task, duration judgments were significantly shorter in PD patients than in control subjects, and accuracy of duration productions was correlated with scores on sub-tests of short-term memory. The findings suggest that the administration of dopamine did not entirely remove the memory deficits in PD patients. Moreover, DA treatment would have abnormally accelerated the rate of the internal clock leading to shorter duration productions in PD patients. The whole results indicate that dopamine administration in patients might have overshadowed the slowing rate of the internal clock usually reported in non medicated PD patients, without entirely restoring all of the memory functions.

Aged↗

REM sleep behavior disorder and REM sleep without atonia in patients with progressive supranuclear palsy.

STUDY OBJECTIVE: To compare sleep characteristics, rapid eye movement (REM) sleep without atonia, and REM sleep behavior disorder (RBD) in patients with progressive supranuclear palsy (tauopathy), patients with Parkinson's disease (a synucleinopathy), and control subjects. DESIGN: Sleep interview, overnight polysomnography, and Multiple Sleep Latency Tests. PATIENTS: Forty-five age- and sex-matched patients with probable progressive supranuclear palsy, (n=15, aged 68 +/- 8 years, 7 men), patients with Parkinson disease (n=15), and control subjects (n=15). SETTINGS: Tertiary-care academic hospital. INTERVENTION: N/A. RESULTS: Compared to the 2 other groups, patients with progressive supranuclear palsy had a longer duration of wakefulness after sleep onset and twice as much sleep fragmentation and percentage of stage 1 sleep but had similar apnea-hypopnea indexes, periodic leg movements indexes, and mean daytime sleep latencies. REM sleep percentage was as low in patients with progressive supranuclear palsy (8% +/- 6% of total sleep time) as in patients with Parkinson disease (10% +/- 4%), versus 20% +/- 6% in controls (analysis of variance, P < .0001). Interestingly, patients with progressive supranuclear palsy had percentages of REM sleep without atonia (chin muscle activity: 33% +/- 36% of REM sleep) similar to those of patients with Parkinson disease (28% +/- 35%) and dramatically higher than those of controls (0.5% +/- 1%, analysis of variance, P = .008). Four (27%) patients with progressive supranuclear palsy had more than 50% REM sleep without atonia (as did a similar number of patients with Parkinson disease), and 2 of them (13%, vs 20% of patients with Parkinson disease) had clinical RBD. The four patients with progressive supranuclear palsy with excessive daytime sleepiness slept longer at night than the 11 patients with progressive supranuclear palsy who were alert (442 +/- 14 minutes vs 312 +/- 74 minutes, student t tests, P = .004), suggesting a primary nonnarcoleptic hypersomnia. CONCLUSION: REM sleep without atonia and RBD were as frequent in patients with progressive supranuclear palsy as in patients with Parkinson disease. It suggests that the downstream cause of parkinsonism, rather than its primary neuropathology (synucleinopathy vs tauopathy), is a key factor for REM sleep behavior disorder.

Aged↗

Motor execution and imagination networks in post-stroke dystonia.

Reorganization of motor execution and imagination networks was studied in six patients with unilateral dystonia secondary to a subcortical stroke and compared with seven control subjects using fMRI. Patients performed imagined and real auditory-cued hand movements. Movements of the dystonic hand resulted in overactivity in bilateral motor, premotor, and prefrontal cortex, insula, precuneus, and cerebellum, in parietal areas and the striatum contralateral to the lesion. Movements of the unaffected hand resulted in overactivity in bilateral preSMA, prefrontal, and parietal areas, insula and cerebellum, the ipsilateral premotor cortex and the contralateral striatum to the lesion. Mental representation of movements with each hand resulted in overactivity in bilateral parietal, premotor and prefrontal areas. These results suggest that execution and mental representation of movement are altered in these patients.

Adult↗

Globus pallidus internus stimulation in primary generalized dystonia: a H215O PET study.

Globus pallidus internus (GPi) deep brain stimulation (DBS) increasingly shows promising efficacy in the treatment of severe primary generalized dystonia. Functional imaging studies have shown previously that dystonia could be related to abnormal cortical activation during voluntary movement. In the present study, the effects of GPi DBS on regional cerebral blood flow (rCBF) during a motor task were studied in patients with primary generalized dystonia. rCBF was measured using H215O and PET in eight control subjects and six patients with dystonia treated with bilateral GPi DBS. Subjects were scanned at rest and while performing joystick movements. Dystonic patients were tested in two conditions: 'OFF' (stimulator bilaterally switched off) and 'ON' (unilateral stimulation). In the 'OFF' condition, compared with rest, motor activation of the most dystonic hand was associated with overactivity in the contralateral dorsolateral prefrontal cortex, gyrus frontalis medialis, superior frontal gyrus (area 10), frontoorbital cortex and thalamus. In the 'ON' condition, GPi DBS contralaterally to the most dystonic hand induced a decrease of the overactivation in the same areas, as well as the putamen. According to the present study, generalized dystonia is associated with prefrontal overactivation which can be reversed by effective GPi DBS.

Adolescent↗

Myoclonus and generalized digestive dysmotility in triple A syndrome with AAAS gene mutation.

We report on the case of a 25-year-old woman with triple A syndrome and gene mutation, who, during the long follow-up period of 23 years, developed myoclonus of the face and the upper limbs (with normal brain magnetic resonance spectroscopy) and widespread digestive dysmotility, involving small bowels and gall bladder. These features, not previously described, illustrate an extension of the cerebral and digestive neurological involvement in this syndrome.

Adrenal Gland Diseases↗

How much phenotypic variation can be attributed to parkin genotype?

To establish phenotype-genotype correlations in early-onset parkinsonism, we have compared the phenotype of a large series of 146 patients with and 250 patients without parkin mutations. Although no single sign distinguished the groups, patients with mutations had significantly earlier and more symmetrical onset, dystonia more often at onset and hyperreflexia, slower progression of the disease, and a tendency toward a greater response to levodopa despite lower doses. After forward stepwise multiple logistic regression analysis, dystonia at onset and brisk reflexes were not longer significantly different but were correlated with age at onset rather than the presence of the parkin mutation. Age at onset in carriers of parkin mutations varied as did the rate of progression of the disease: the younger the age at onset the slower the evolution. The genotype influenced the phenotype: carriers of at least one missense mutation had a higher United Parkinson's Disease Rating Scale motor score than those carrying two truncating mutations. The localization of the mutations was also important because missense mutations in functional domains of parkin resulted in earlier onset. Patients with a single heterozygous mutation had significantly later and more asymmetrical onset and more frequent levodopa-induced fluctuations and dystonia than patients with two mutations.

Adolescent↗

Myoclonus in spinal dysraphism.

Two cases of segmental myoclonus occurring in association with spinal dysraphism are described. In one, myoclonus of paralysed legs arose below a region of spinal cord lacking any normal function, illustrating the capacity of the isolated spinal cord to generate and maintain rhythmic activity independent of supraspinal influences.

Adolescent↗