Biomedical subjects

Christophe Vial

Publications and source records attributed to Christophe Vial.

5 recordsLinked to original sources

PubMed2007

Granulomatous myositis: a clinical study of thirteen cases.

Granulomatous myositis (GM) is a rare condition that has generally been described in association with sarcoidosis. In the absence of sarcoidosis or other underlying disease, a diagnosis of isolated GM is considered. Only one study has focused on the clinical difference between isolated GM and sarcoid myopathy (SM). We report 13 cases of symptomatic GM; 8 had sarcoidosis. All patients with sarcoidosis had predominantly proximal, symmetrical lower-limb weakness, and 3 subsequently developed upper-limb or distal involvement. Three of the five patients with isolated GM had predominantly distal muscle involvement, and two had dysphagia. Corticosteroid treatment was followed by prolonged improvement in only one patient with sarcoidosis. One patient had acute sarcoid myositis and benefited from methotrexate; other immunosuppressants and etanercept proved ineffective in chronic sarcoid myopathy. Three of the five patients with isolated GM responded to corticosteroid treatment. When last examined, three patients with sarcoidosis had severe disability, whereas patients with isolated GM showed milder weakness. Thus, SM was frequently associated with severe disability and rarely improved after corticosteroid treatment, whereas most patients with isolated GM improved.

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PubMed2006

Cold extends electromyography distinction between ion channel mutations causing myotonia.

OBJECTIVE: Myotonias are inherited disorders of the skeletal muscle excitability. Nondystrophic forms are caused by mutations in genes coding for the muscle chloride or sodium channel. Myotonia is either relieved or worsened by repeated exercise and can merge into flaccid weakness during exposure to cold, according to causal mutations. We designed an easy electromyography (EMG) protocol combining repeated short exercise and cold as provocative tests to discriminate groups of mutations. METHODS: Surface-recorded compound muscle action potential was used to monitor muscle electrical activity. The protocol was applied on 31 unaffected control subjects and on a large population of 54 patients with chloride or sodium channel mutations known to cause the different forms of myotonia. RESULTS: In patients, repeated short exercise test at room temperature disclosed three distinct abnormal patterns of compound muscle action potential changes (I-III), which matched the clinical symptoms. Combining repeated exercise with cold exposure clarified the EMG patterns in a way that enabled a clear correlation between the electrophysiological and genetic defects. INTERPRETATION: We hypothesize that segregation of mutations into the different EMG patterns depended on the underlying pathophysiological mechanisms. Results allow us to suggest EMG guidelines for the molecular diagnosis, which can be used in clinical practice.

Action Potentials↗

PubMed2006

SIMPLE mutation analysis in dominant demyelinating Charcot-Marie-Tooth disease: three novel mutations.

Charcot-Marie-Tooth disease type 1C (CMT1C) is caused by mutations in the small integral membrane protein of the lysosome/late endosome (SIMPLE). We analyzed the coding sequence of SIMPLE in DNA of 53 unrelated cases of dominant demyelinating CMT disease with no mutations in PMP22, GJB1, MPZ, EGR2, and NEFL genes. Four different missense mutations were observed in six families. The mutation Gly112Ser was found in two families confirming its frequent occurrence in SIMPLE mutations. Three novel mutations were also identified: Ala111Gly (two families), Pro135Ser, and Pro135Thr. Familial studies revealed that all carriers of mutations (n = 38), aged from 1 to 78 years, were symptomatic, notably children under 10 years (n = 8). Motor conduction velocities in the median nerve ranked from 16.4 to 32.8 m/s (n = 20). In our series of 968 unrelated dominant demyelinating CMT cases (1992-2005), the percentage of SIMPLE mutations was 0.6 (6/968).

Adolescent↗

PubMed2006

Long-term functional results of selective peripheral neurotomy for the treatment of spastic upper limb: prospective study in 31 patients.

OBJECT: To manage refractory upper-limb spasticity, selective peripheral neurotomy (SPN) is proposed when the spastic muscles to be treated are under the control of a single or a few peripheral nerves. The aim of this study was to assess prospectively the long-term effects of SPN. METHODS: Thirty-one patients with disabling upper-limb spasticity were selected by a multidisciplinary team using clinical, analytical, and functional scales as well as nerve block tests for assessment. Sixty-four SPNs were performed at the level of the musculocutaneous (15 SPNs), the median (25 SPNs), and the ulnar (24 SPNs) nerves. Results of a long-term follow up (mean 4.5 years) showed statistically significant improvement on 1) analytical assessment (p < 0.01): resting position, active amplitude, and motor strength; 2) Ashworth Scale scoring (p < 0.01); 3) hand function assessment (p < 0.01); and 4) rating of daily activities. Four patients with severe painful spasticity experienced complete pain relief after surgery. On the basis of a Visual Analog Scale ranging from 0 to 100, the mean degree of patient satisfaction was 61.5. Complications occurred in five patients (15%): two postoperative hematomas, one (temporary) hypesthesia, and one transient paresia of the wrist and finger flexors. CONCLUSIONS: Selective peripheral neurotomy leads to long-term satisfactory improvement in function and/or comfort with a low morbidity rate in appropriately selected patients suffering from severe harmful spasticity of the upper limb that has been refractory to conservative therapy. Patients must be selected after complete assessment by a multidisciplinary team.

Adolescent↗

PubMed2002

Paraneoplastic peripheral neuropathy associated with anti-Hu antibodies. A clinical and electrophysiological study of 20 patients.

Although paraneoplastic subacute sensory neuronopathy is the most frequent presentation of peripheral neuropathy in patients with anti-Hu antibodies, other neuropathies have been reported. In order to investigate the clinical and electrophysiological manifestations of neuropathies associated with anti-Hu antibodies, we conducted a retrospective study of 20 patients. For the electrophysiological study, each nerve was classified as normal, demyelinating, axonal/neuronal or axonal/demyelinating. Peripheral neuropathy was the presenting symptom in 95% of patients. CNS and autonomic neuropathy were present in 40% and 30% of patients, respectively. The course of the neuropathy was acute, mimicking Guillain-Barré syndrome in one patient (5%), and subacute (55%) or progressive (40%) in the others. Clinically, the neuropathy was sensory (70%), sensorimotor (25%) or motor (5%). At onset, symptoms were symmetrical (65%), asymmetrical (25%) or multifocal (10%). Pain was a predominant manifestation (80%). Amyotrophia and fasciculations were rare. The median Rankin's score was 2, three patients having an indolent form. Electrophysiology showed the axonal/neuronal pattern to be the most frequent (46.9% of studied nerves); an axonal/demyelinating or demyelinating pattern being seen in 18.3% and 4.9% of nerves, respectively. The axonal/neuronal pattern was more frequent in sensory nerves and the mixed axonal/demyelinating pattern more frequent in motor nerves (P < 0.01). A higher proportion of abnormal nerves correlated with a progressive course (P < 0.05) or a Rankin's score between 3 and 5 (P < 0.01). In patients with sensory neuropathy, 88.5% of sensory nerves were abnormal, mostly with an axonal/neuronal pattern. In addition, 47% of motor nerves were abnormal so that only four out of 14 patients with a clinically pure sensory neuropathy (28.6%) had an electrophysiological pattern typical of sensory neuronopathy. In patients with a sensorimotor neuropathy, 96.6% of sensory and 71% of motor nerves were abnormal. The only statistical difference between sensory and sensorimotor neuropathies was that patients with sensorimotor neuropathy had more frequent motor nerve involvement (P < 0.05) without differences concerning the distribution of the abnormal patterns. Needle neuromyography showed only limited evidence of motor neurone degeneration in both sensory and sensorimotor neuropathy. The present work shows that the typical clinical and electrophysiological pattern of subacute sensory neuronopathy is rarely encountered in patients with anti-Hu antibody and that motor nerve involvement is frequently seen, even in the absence of a motor deficit. In addition to their potential pathophysiological involvement in the mechanism of the paraneoplastic neuropathy, these findings have practical consequences for the diagnosis of the disorder.

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