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Published on: March 4, 2014
Central motor conduction in brachial monomelic amyotrophy
Pramod K Pal1, Nalini Atchayaram, Gaurav Goel
1Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India. palpramod@hotmail.com
Neurology India
|January 8, 2009
Summary
Subclinical motor pathway dysfunction occurs in Brachial Monomelic Amyotrophy (BMMA). This central motor conduction time (CMCT) impairment affects both affected and unaffected limbs, worsening with voluntary contraction.
Area of Science:
- Neurology
- Neurophysiology
Background:
- Brachial Monomelic Amyotrophy (BMMA) is a clinical diagnosis.
- The subclinical involvement of motor pathways in BMMA remains uncharacterized.
Purpose of the Study:
- To investigate the prevalence of subclinical central motor pathway involvement in BMMA patients.
- Utilize transcranial magnetic stimulation (TMS) to assess motor pathway function.
Main Methods:
- A prospective case-control study involving 17 BMMA patients and 10 healthy controls.
- Central motor conduction time (CMCT) was measured using the 'F' wave method.
- Motor evoked potentials were recorded from the first dorsal interosseous muscle in affected and unaffected limbs at rest and during contraction.
Main Results:
- BMMA patients exhibited significantly prolonged CMCT in affected limbs compared to controls, both at rest and during contraction.
- Subclinical dysfunction was detected in 29.4% of affected limbs and 6.25% of unaffected limbs at rest.
- During voluntary contraction, CMCT was prolonged in 47.1% of affected and 23.5% of unaffected limbs.
Conclusions:
- Central motor pathway dysfunction is present in some BMMA patients, affecting both limbs.
- This dysfunction is exacerbated by voluntary muscle contraction.
- Further research with larger cohorts is recommended to confirm these findings.
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