6. Amyloidosis affecting nervus radialis. Case report

Background Polyneuropathy due to amyloidosis (a symmetric distal sensitive and motoric polyneuropathy with frequent pain) is being described as a possible cause of systemic amyloidosis in literature. Actually, neurologists see this relatively rarely. Impairment of single nerve caused by amyloidosis is even rarer. That’s why we devote our case report to this unusual condition. We report about 55 year old woman, who has been experiencing gradually progressive sensitive and motoric impairment caused by affected nervus radialis on right upper extremity for 7 years. EMG (done in 2/2010) verified chronic syndrome of partial denervation of m. extensor digit. comm. and m. brachioradialis on right upper extremity, and no SNAP on r. superficialis n. radialis and blockade in motoric fibres of n. radialis on upper right extremity. MR showed spindle expansion 6 centimetres long in the course of n. radialis of right upper extremity. Neurofibroma was mentioned in differential diagnosis. An operation was done in May 2010 and some formation was removed from the nerve. During second operation there was performed a substitution with graft from n. suralis. Histologically was proven amyloidosis. Subsequently, a complete internal investigation focusing on amyloidosis was performed, including rectal, liver, bucal mucosal membrane and bone marrow biopsy, everything was negative for amyloidosis. Patient now is recovering and rehabilitating with gradual improving of her condition and is being observed by neurologist, internal physician, neurosurgeon and EMG specialist. No signs of polyneuropathy or systemic amyloidosis have yet shown. EMG is in gradual regression. Conclusion N. radialis is most frequently affected by trauma, or by inner or outer pressure, iatrogenous or by benign tumour. Local affecting by amyloidosis is extremely rare.