[Juvenile amyotrophic lateral sclerosis. Apropos of a case].

INTRODUCTION: There are scanty reports on juvenile forms of amyotrophic lateral sclerosis, specially amyotrophic lateral sclerosis and deafness, and it is known as Madras pattern of motor neurone disease.

CLINICAL CASE: We describe an sporadic case of juvenile amyotrophic lateral sclerosis with deafness in a young person who started with hearing loss at 21 years old, loss of strength in upper limbs and muscular atrophy. He was seen by a neurologist when he was 25 years old, there were evident generalized fasciculation activity in proximal and distal muscles in the four limbs and the tongue, with swallowing troubles, and increased tendon reflexes in lower limbs with abnormal plantar extensor responses. All the paraclinical test were normal, except the electromyogram, showing a classical pattern of lower motor neuron disease, and the auditory brain stem response with absence of the main components of this evoked response, as expression of VIII cranial nerve damage.

DISCUSSION: Patients like this one were first described in Madras (India), and the evolution of this kind of juvenile form of amyotrophic lateral sclerosis is chronically progressive and relative benign, in relation to the classical form of amyotrophic lateral sclerosis and other forms of motor neurone disease which begin in childhood, adolescence or young adulthood.

CONCLUSION: Its recognition is very important in order to diminish misleading therapies in these patients.