Cutaneous silent periods in patients with Fabry disease

• Published in: Muscle & nerve Vol. 23; no. 8; pp. 1179 - 1186
• Main Authors: Syed, Nadir Ali, Sandbrink, Friedhelm, Luciano, Carlos A., Altarescu, Gheona, Weibel, Thais, Schiffmann, Raphael, Floeter, Mary Kay
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 01-08-2000; Wiley
• Subjects: Action Potentials - physiology; Adolescent; Adult; Biological and medical sciences; Cold Temperature; Electric Stimulation; Electromyography; Errors of metabolism; Fabry disease; Fabry Disease - diagnosis; Fabry Disease - physiopathology; Foot - innervation; Hand - innervation; Humans; Lipids (lysosomal enzyme disorders, storage diseases); Male; Medical sciences; Metabolic diseases; Middle Aged; Neural Conduction - physiology; Neural Inhibition - physiology; Neurons, Afferent - physiology; quantitative sensory testing; Reaction Time - physiology; reflexes; Sensory Thresholds - physiology; silent period; small fiber neuropathy; spinal circuitry; Sural Nerve - physiology; Vibration; Threshold detection; Suppression; Fabry disease; Cardiovascular disease; Peripheral neuropathy; Enzymopathy; Vascular disease; Nerve conduction; Electrodiagnosis; Electromyography; X-Chromosome; Lipoidosis; Human; Nervous system diseases; Enzyme; Metabolic diseases; Silent period; Striated muscle; Thermal sensibility; Genetic disease; α-Galactosidase; Glycosidases; Detection threshold; Hydrolases; Sensory nerve; O-Glycosidases
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/1097-4598(200008)23:8<1179::AID-MUS4>3.0.CO;2-7

We assessed the cutaneous silent period (CSP) in 24 patients with Fabry disease with small‐fiber sensory neuropathy and 12 normal subjects to test the hypothesis that small‐diameter afferents are responsible for producing the CSP. Sensory nerve conduction studies and quantitative sensory testing for cold and vibration detection thresholds were also measured. Overall, Fabry patients had impaired thermal, but not vibration, detection thresholds, with greatest impairment in the feet. In the upper extremity, CSP latencies, duration, and suppression of electromyographic activity (EMG) did not differ. In the lower extremity, patients had reduced suppression of EMG during the CSP compared to normal controls. CSP durations exhibited a bimodal distribution in patients, including a subset of seven patients with durations shorter than all controls. This subset had profound loss of thermal sensation in the feet, but this was also true of some patients who had normal CSPs. Patients with shortened CSPs had modestly elevated vibration thresholds and reduced sensory potentials in comparison to patients with normal CSPs. Reduced CSPs in Fabry patients are associated with, but not entirely explained by, the severity of small‐fiber neuropathy as measured by quantitative sensory testing. The possibility that large‐diameter fibers provide a minor contribution to producing the CSP should be considered. © 2000 John Wiley & Sons, Inc. Muscle Nerve 23: 1179–1186, 2000