Distal Acquired Demyelinating Symmetric (DADS) Neuropathy without Gammopathy: A Case Report and Comprehensive Review of the Literature

Abstract

Distal acquired demyelinating symmetric (DADS) neuropathy is a subtype of chronic inflammatory demyelinating polyneuropathy (CIDP) with characteristic clinical and electrophysiological features. It usually progresses more slowly than typical CIDP and is frequently associated with an IgM paraprotein. We report a rare case of DADS neuropathy without a paraprotein. A 26-year-old Caucasian woman from South Africa visited our neurological clinic because of subacute symmetric numbness and mild weakness of distal limbs. Nerve conductive study showed sensorimotor polyneuropathy, demyelinating type with a markedly reduced terminal latency index. CSF examination showed elevated protein (148 mg/dL) without significant pleocytosis. Detailed examinations following hospitalization, including hematology, infection, autoimmune, biochemistry, malignancy, paraprotein and endocrine studies, were unremarkable. The patient responded poorly to corticosteroid treatment, but intravenous immunoglobulin (IVIG) 0.4 g/kg/day for five days improved her symptoms. The effect of IVIG lasted for about six months, followed by slow progression of numbness and mild weakness in distal limbs. The patient received steroid pulse therapy but in vain; she then returned to South Africa. She was diagnosed with DADS neuropathy from the characteristic clinical and electrophysiological features. Striking demyelination with a markedly reduced terminal latency index identified by nerve conduction study and symmetric sensory symptoms with minimal distal weakness are the main features of this rare treatable neuropathy.