Auditory brain-stem responses in the fragile X syndrome.
Auditory brain-stem responses (ABRs) were recorded from a group of 12 mentally retarded males with the fragile X (fra[X]). The responses were analyzed in terms of ABR thresholds, absolute latencies, and interpeak latencies. One patient had increased ABR thresholds, indicating hearing impairment. Five fra(X) subjects had prolonged I-V interpeak latencies. Comparisons between the fra(X) group (excluding one possible hard-of-hearing subject) and a control group of age-matched males with normal intelligence showed that the fra(X) group's interpeak latencies were significantly prolonged for the III-V and I-V but not for the I-III. This pattern of prolongation of interpeak latencies suggests that central, as opposed to peripheral, nervous-system dysfunction predominates in many patients having this syndrome. In addition, frequently observed prolongation of the transmission time may indicate that brain-stem white-matter functioning is also apt to be involved in this syndrome.
Arinami
T
T
Ibaraki Prefectural Colony Hospital, Japan.
Sato
M
M
Nakajima
S
S
Kondo
I
I
D000293:Adolescent; D000328:Adult; D001309:Auditory Threshold; D001933:Brain Stem / Q000503:physiopathology*; D005072:Evoked Potentials, Auditory; D005600:Fragile X Syndrome / Q000235:genetics / Q000503:physiopathology*; D006801:Humans; D008297:Male; D011930:Reaction Time; D012729:Sex Chromosome Aberrations / Q000503:physiopathology*