Spinal charcot-marie-tooth disease: A reappraisal
ABSTRACT Introduction: Distal hereditary motor neuropathy (dHMN) is characterized by isolated distal muscle atrophy without sensory deficit. Nevertheless, clinical sensory loss has been reported despite preserved sensory nerve conduction in a few patients, thus differentiating these cases from the classical type 2 Charcot-Marie-Tooth disease (CMT2). Methods: We report 4 patients who presented with clinical sensory and motor neuropathy and normal peripheral sensory nerve conduction studies and were investigated with complete electrophysiological studies, including somatosensory evoked potentials (SEP). Results: These patients had a clinical presentation of classical CMT with isolated axonal motor neuropathy suggestive of dHMN. Interestingly, tibial nerve SEPs showed abnormalities suggestive of proximal involvement of dorsal roots that may explain the clinical somatosensory disturbances. Conclusions: These cases support the concept of spinal CMT that should be recognized as an intermediate form between dHMN and CMT2. SEP recording was helpful in defining a more precise phenotype of spinal CMT. Muscle Nerve 46: 603-607, 2012.
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ABSTRACT: Amyotrophic lateral sclerosis (ALS) is a degenerative disease which prognosis is poor. Early diagnosis permits to set up immediately adapted treatment and cares. Available diagnostic criteria are based on the detection of both the central and peripheral motor neuron injury in bulbar, cervical, thoracic and lumbar regions. Electromyographic study is the key tool to identify peripheral motor neuron involvement. Conduction velocities are systematically performed to rule out differential diagnosis. Needle examination records abnormal activities at rest and looks for neurogenic pattern during muscle contraction. Motor unit potentials morphology is modified primary to recruitment. Motor evoked potentials remain the test of choice to identify impairment of central motor neurons. For the monitoring of ALS patients, the MUNE technique (motor unit number estimation) seems the most interesting.La Presse Médicale 04/2014; · 1.17 Impact Factor
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ABSTRACT: Motor neuron diseases (MNDs) are an etiologically heterogeneous group of disorders of neurodegenerative origin, which result in degeneration of lower (LMNs) and/or upper motor neurons (UMNs). Neurodegenerative MNDs include pure hereditary spastic paraplegia (HSP), which involves specific degeneration of UMNs, leading to progressive spasticity of the lower limbs. In contrast, spinal muscular atrophy (SMA) involves the specific degeneration of LMNs, with symmetrical muscle weakness and atrophy. Amyotrophic lateral sclerosis (ALS), the most common adult-onset MND, is characterized by the degeneration of both UMNs and LMNs, leading to progressive muscle weakness, atrophy, and spasticity. A review of the comparative neuroanatomy of the human and zebrafish motor systems showed that, while the zebrafish was a homologous model for LMN disorders, such as SMA, it was only partially relevant in the case of UMN disorders, due to the absence of corticospinal and rubrospinal tracts in its central nervous system. Even considering the limitation of this model to fully reproduce the human UMN disorders, zebrafish offer an excellent alternative vertebrate model for the molecular and genetic dissection of MND mechanisms. Its advantages include the conservation of genome and physiological processes and applicable in vivo tools, including easy imaging, loss or gain of function methods, behavioral tests to examine changes in motor activity, and the ease of simultaneous chemical/drug testing on large numbers of animals. This facilitates the assessment of the environmental origin of MNDs, alone or in combination with genetic traits and putative modifier genes. Positive hits obtained by phenotype-based small-molecule screening using zebrafish may potentially be effective drugs for treatment of human MNDs.Progress in Neurobiology 04/2014; 118. DOI:10.1016/j.pneurobio.2014.03.001 · 10.30 Impact Factor
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DESCRIPTION: accepté pour publication (NCCN) Summary Somatosensory evoked potentials (SSEPs) are increasingly performed for the assessment of peripheral neuropathies, but no practical guidelines have been established in this specific application. For this purpose, a survey was conducted among the French-speaking practitioners having an experience of SSEP recording in the context of peripheral neuropathies. The objectives were to determine the relevant indication criteria and technical settings for SSEP recording in this condition. From this survey, SSEPs appeared to be a second-line test when electroneuromyographic investigation was not enough conclusive, providing complementary and valuable information on peripheral proximal conduction and central conduction in the somatosensory pathways. Guidelines for a standardized recording protocol, including the various variables to measure, are proposed. This consensus statement is an important step in the process to recognize the value of this technique in assessing peripheral neuropathies in clinical practice. Keywords: diagnosis; evoked potentials; indication; parameters; peripheral neuropathies; technique.