[MOTOR NEUROPATHY PRECEDING PRIMARY SYSTEMIC AMYLOIDOSIS]

Primary (AL) systemic amyloidosis is an uncommon disorder in which immunoglobulin light chains are deposited in the tissues as amyloid, resulting in organ dysfunction. The initial symptoms are frequent fatigue and weight loss, and common manifestations include nephrotic syndrome, cardiomyopathy, peripheral neuropathy or hepatomegaly. Histological examination reveals some degree of amyloid deposition in virtually every organ system except the central nervous system (CNS). In contrast to the absence of CNS involvement, peripheral neuropathy is present in 17-36% of AL cases. The typical presentation of AL neuropathy is numbness in the feet, burning and aching pains with lancinating electrical sensations and loss of pain and thermal sensation in the distal limbs. Carpal tunnel syndrome may also co-exist in up to 21% of AL amyloidosis patients. A predominant effect of the disease on small-diameter sensory fibers is consistent with painful and autonomic symptoms. We present a unique case of clinical motor axonal neuropathy predating systemic amyloidosis. The patient provided his informed consent to the study.