source: Johns Hopkins Medicine summary/abstract:
Disorders of peripheral nerves are the most common neurological complications of systemic amyloidosis; an illness where a protein called amyloid is deposited in tissues and organs. Amyloidosis can affect peripheral sensory, motor or autonomic nerves and deposition of amyloid lead to degeneration and dysfunction in these nerves.
The typical symptoms of amyloid neuropathy are due to sensory and autonomic dysfunction. Patients may experience painful paresthesias (unusual sensations), numbness and balance difficulties due to sensory dysfunction and persistent nausea, vomiting, diarrhea, constipation, incontinence, sweating abnormalities or sexual dysfunction due to autonomic nerve involvement.
Diagnosis of amyloid neuropathies is based on history, clinical examination and supporting laboratory investigations. These include electromyography with nerve conduction studies, skin biopsies to evaluate cutaneous nerve innervation, and nerve and muscle biopsies for histopathological evaluation. In cases of familial amyloidosis, genetic testing in the blood may be useful.