Congenital cervical spinal atrophy: an intrauterine hypoxic insult.

We present two patients with congenital cervical spinal atrophy who were born at 37 and 33 weeks of gestation. Both patients were unrelated and had no family history of neuromuscular diseases. They presented at birth with arthrogryposis multiplex and symmetrical severe muscle weakness and wasting confined to the upper extremities. There was no sensory or bulbar symptom. Electromyography showed polyphasic and fast-firing units in the proximal muscles of the upper extremities. With the evidence of chronic denervation and re-innervation, we speculate that this static condition is most likely due to circulatory insufficiency causing anterior horn cell ischemia during the latter part of the first trimester.