[Primary hyperparathyroidism, a differential diagnosis of motor neuron diseases]. / Hyperparathyroïdie primitive, un diagnostic différentiel des maladies du motoneurone.

INTRODUCTION: Motor neuron diseases are always lethal. Other curable causes of neurologic disorders have to be sought. We report an example. EXEGESIS: A 72-year-old man presented a distal weakness and atrophy of the upper extremities. Electromyography showed thenar and hypothenar denervation, without fasciculation. Hypercalcemia led to the discovery of a primary hyperparathyroidism. Five months after parathyroid surgery, there was no worsening. CONCLUSION: Von Recklinghausen and Vical were the first to describe neuromuscular involvement in primary hyperparathyroidism. Faced with symptoms mimicking motor neuron diseases, calcium and phosphorus levels have to be measured because hyperparathyroidism can be cured and neurologic disorders disappear after surgery.