A study of transcranial magnetic stimulation in older (>3 years) patients of malnutrition

Transcranial magnetic stimulation was performed in 40 subjects. Twenty patients in the age group of 3 to 8 years and having different grades of malnutrition were included in the 'study group' whereas 20 normal children having no complaints comprised the 'control group'. The coil of the magnetic stimulator was applied tangentially over the vertex to stimulate the cortex. The motor evoked potential (MEP) was obtained using root stimulation by applying the coil at the cervical and lumbosacral spines. Recordings were made from the abductor pollicis brevis (APB) and extensor digitorum brevis (EDB) muscles of both sides. Cortical threshold, latency and amplitude of motor evoked potential and central conduction time were recorded. Malnourished children showed significantly increased cortical threshold, prolonged cortical latency and central conduction time and reduction in amplitude of MEP. Observed delay in central motor conduction in malnourished children suggests asymptomatic involvement of corticospinal pathways.