Small-Fiber Neuropathy in Pompe Disease: First Reported Cases and Prospective Screening of a Clinic Cohort
Lisa D. Hobson-Webb, Stephanie L. Austin, Sneha Jain, Laura E. Case, Karla Greene, Priya S. Kishnani
(Department of Neurology, Division of Neuromuscular Medicine, Duke University Medical Center, Durham, NC, USA)
Am J Case Rep 2015; 16:196-201
Prior autopsy reports demonstrate glycogen deposition in Schwann cells of the peripheral nerves in patients with infantile and late-onset Pompe disease (LOPD), but little is known about associated clinical features.
Case Report: Here, we report the first confirmed cases of small-fiber neuropathy (SFN) in LOPD and present the results of a first attempt at screening for SFN in this patient population.
After confirming small-fiber neuropathy in 2 LOPD patients, 44 consecutive Pompe patients (iOPD=7, LOPD n=37) presenting to the Duke University Glycogen Storage Disease Program between September 2013 and November 2014 were asked to complete the 21-item Small-Fiber Neuropathy Screening List (SFNSL), where a score of ≥11 is considered to be a positive screen.
Fifty percent of patients had a positive SFN screen (mean score 11.6, 95% CI 9.0–14.2). A modest correlation between the SFNSL score and current age was seen (r=0.38, p=0.01), along with a correlation with duration of ERT (r=0.31, p=0.0495). Trends toward correlation with forced vital capacity and age at diagnosis were also present. Women had a higher mean SFNSL score (14.2) than men (8.2, p=0.017).
Conclusions: SFN may occur in association with Pompe disease and precede the diagnosis. Further studies are needed to determine its true prevalence and impact.
Keywords: Child, Age Factors, Cohort Studies, Erythromelalgia - etiology, Female, Glycogen Storage Disease Type II - complications, Humans, Male, Middle Aged, Questionnaires, Risk Factors, Sex Factors, Vital Capacity