Brachial amyotrophic diplegia associated with a novel SOD1 mutation (L106P).

Brachial amyotrophic diplegia (BAD) is a subtype of sporadic lower motor neuron disease (LMND) presenting with adult onset, mainly in men, and remaining largely restricted to proximal arm and shoulder girdle muscles without involvement of the lower limbs or appearance of pyramidal signs. 1,2 Mutations in the cop-per/zinc superoxide dismutase (SOD1) gene have been described in familial cases of ALS and occurring in sporadic cases of ALS, 3-4 but not in patients with BAD. We describe here a patient with BAD syndrome associated with a novel SOD1 mutation. Case report. A 77-year-old man was referred to our clinic for a 12-month history of bilateral painless arm weakness and wasting. The patient did not have a history of diabetes. Weakness began in the left arm and progressed to the proximal right arm 2 months later. Family history was unremarkable for neuromuscular disorders and entrapment neuropathies. There were no symptoms in the lower limbs or sphincter disturbances. Neurologic examination showed a peculiar posture of the " man in the barrel " with both hands hanging loosely at his sides (figure). Severe atrophy and weakness of both upper limb muscles were present, mainly in proximal areas (Medical Research Council score 1/5 for shoulder abductor and flexor muscles, supraspinatus, infraspinatus, del-toid, biceps brachii, and pectoralis major; 2/5 for elbow extensor, flexor, and wrist extensor muscles; 3/5 for wrist flexor and hand muscles). There was no atrophy or weakness in the bulbar or neck muscles or in the lower limbs and no scapular winging. Fascicula-tions were evident only in the upper limb muscles. Tendon reflexes were absent in the upper limbs and normal at the knees and ankles. Plantar responses were flexor. Sensory examination was normal, and no other neurologic signs were found. Needle electromyography showed denervation potentials with reduced recruitment in all upper limb muscles but normal facial, tongue, neck, and lower limb muscles. Nerve conduction studies in the upper limbs showed lower amplitude of compound muscle action potentials of the median, ulnar, and radial nerves, bilaterally, with normal motor and sensory nerve conduction velocities and without evident conduction blocks. Nerve conduction studies in the lower limbs were normal. A wide screening was otherwise normal, including brain and spinal cord MR images, CSF examination , and blood studies (cell counts, erythrocyte sedimentation rate, immunoelectrophoresis, creatine kinase, vitamin B 12 , ␤-hexosaminidase, thyroid function, research for tumor markers, antinuclear antibodies, anti-GM1 and anti-asialo GM1 antibod-ies). …