Causes of neuropathy in patients referred as "idiopathic neuropathy"

Muscle Nerve. 2016 Jun;53(6):856-61. doi: 10.1002/mus.24969. Epub 2015 Dec 29.


Introduction: The etiology of neuropathy was idiopathic in 20%-30% of patients despite thorough investigation, based on results from the 1980s and 1990s. Since then, new etiologies have been recognized, and skin biopsy has been used to confirm small-fiber neuropathy.

Methods: The authors reviewed the charts of 373 patients with idiopathic neuropathy who were referred to a neuropathy center between 2002 and 2012.

Results: Among the 284 eligible patients, 93 (32.7%) remained idiopathic. The most common cause was impaired glucose metabolism (72 patients, 25.3%), including diabetes in 26 and prediabetes in 46. Other etiologies were chronic inflammatory demyelinating polyneuropathy (CIDP) in 57 (20%) and monoclonal gammopathy in 20 (7%), as well as toxic, Sjögren disease, celiac disease, other immune-mediated diseases, vitamin B12 deficiency, amyloidosis, vitamin B1 and B6 deficiency, vasculitis, hypothyroidism, hereditary, Lyme disease, and anti-sulfatide antibody.

Conclusions: The major causes of undiagnosed neuropathies were impaired glucose metabolism, CIDP, and monoclonal gammopathies. Despite thorough evaluation 32.7% remained idiopathic. Muscle Nerve 53: 856-861, 2016.

Keywords: CIDP; MGUS; diabetes; idiopathic; neuropathy; prediabetes.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Male
  • Middle Aged
  • Paraproteinemias / complications*
  • Peripheral Nervous System Diseases / diagnosis*
  • Peripheral Nervous System Diseases / etiology*
  • Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / complications*
  • Retrospective Studies
  • Young Adult