Impaired peripheral somatosensory function in children with Prader-Willi syndrome.
The Prader-Willi syndrome (PWS) is associated with a tendency to self-injury and a reduced sensitivity to painful stimuli. Somatosensory functions were studied in 5 children aged 11-13 years with PWS. Tactual perception in the hands (stereognosis) was apparently normal in 4 of them. Sensory nerve conduction velocities in the median nerve and latencies for sensory evoked potentials were similar in the PWS subjects and in 10 healthy controls indicating a preserved myelinisation of sensory nerve fibers in PWS. Sensory nerve action potential amplitudes in the PWS group were on an average only 40-50% of normal size (p = 0.03), suggesting a reduced number of normal axons in the median nerve. The results may be relevant for the impaired pain sensitivity in PWS because similar neurographic findings and a low density of peripheral nerve fibers have been reported in patients with hereditary or congenital insensitivity to pain.
Brandt
B R
BR
Center of Child and Youth Habilitation, Lund, Sweden.
Rosén
I
I
D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D006987:Hypesthesia / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D009431:Neural Conduction / Q000502:physiology; D017288:Pain Threshold / Q000502:physiology; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000503:physiopathology*; D011218:Prader-Willi Syndrome / Q000150:complications / Q000503:physiopathology*; D016728:Self-Injurious Behavior / Q000209:etiology* / Q000503:physiopathology; D013236:Stereognosis / Q000502:physiology