DIAGNOSIS OF SMALL FIBRE NEUROPATHIES–THE NEED TO GET THE BASICS RIGHT

• Published in: Journal of neurology, neurosurgery and psychiatry Vol. 84; no. 11; p. e2
• Main Authors: Johnston, Michael, Gosal, David Yunus
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd 01.11.2013; BMJ Publishing Group LTD
• Subjects: PARKINSON'S DISEASE; STROKE
• ISSN: 0022-3050; 1468-330X
• DOI: 10.1136/jnnp-2013-306573.201

This retrospective study characterised 98 patients with a clinical diagnosis of small fibre neuropathy and assessed how they were investigated against predefined internal standards, which were devised from literature search and determined to be those examinations and investigations that individuals with idiopathic small fibre neuropathy should have as a minimum. The internal standards devised were: all patients should have a documented thorough alcohol history, a full sensory examination, quantitative sensory threshold studies (thermal thresholds) and blood tests (oral glucose tolerance test, anti–nuclear antibodies, and serum protein electrophoresis at the very least). It was also recommended that all patients should have a confirmatory skin biopsy, however this service was not available and for practical reasons not included in the analysis. Patients were included if they had a history and examination consistent with SFN in the setting of normal nerve conduction studies. Only 21% of patients screened were investigated to the predefined standard. Only 71% had a documented alcohol history; 92% had a documented sensory examination; 83% had quantitative sensory tests; 36% of patients were tested with an oral glucose tolerance test and only 62% had a glucose test of any kind; 63% were tested for antinuclear antibodies and 59% were tested for protein electrophoresis. This data was reflected in the observation that a causative factor was only identified in 40% of patients diagnosed which seemed lower than most other reported patient cohorts. Conclusions Cases of suspected small fibre neuropathies need to be investigated in a more thorough manner and ideally in a specialist setting. Whereas ideally all patients diagnostic skin biopsy with estimation of the intraepidermal nerve fibre density should be performed, it is equally important to get the very basics right.