Artículo de revista
Atrofia monomiélica distal de extremidad superior. Caso clínico
Fecha
2021Registro en:
Revista Médica de Chile 2021; 149: 142-146
0034-9887
Autor
Matamala Capponi, José Manuel
Cea Muñoz, Gabriel
Salinas Ríos, Rodrigo
Vidal Téllez, Aarón
López, Ingeborg
Marileo, Roberto
Stuardo, Andrés
Institución
Resumen
Monomelic amyotrophy, also known as Hirayama disease, is a rare lower
motor neuron syndrome due to localized lower motor neuron loss in the spinal
cord at the cervical level. Clinically, monomelic amyotrophy is defined by the insidious
onset of unilateral atrophy and weakness involving the hand and forearm,
typically beginning in the second or third decade of life. We report 19-year-old
man with a two years history of slowly progressive unilateral weakness and
atrophy of his right-hand muscles. Neurological examination revealed weakness
and atrophy in his intrinsic hand muscles, with sparing of the abductor pollicis
brevis muscle. Also, mild atrophy of the ulnar aspect of the forearm was detected
with sparing of the brachioradialis muscle. Electromyography showed active and
chronic neurogenic changes affecting C8 and T1 myotomes, with mild chronic
neurogenic changes on C7 myotome. Magnetic resonance imaging of his cervical
spine revealed spinal cord atrophy involving C5 to C7 segments, associated with
forward displacement of the posterior wall of the dura in cervical spine flexion.
The clinical features associated with the imaging and electrophysiological findings
support the diagnosis of monomelic amyotrophy.