Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We recorded ABR in 65 infants and children with developmental retardation and analyzed the relationship between the incidence of abnormal findings and the degree of mental retardation, which was confirmed by follow-up observation and formal intelligence tests. There were 3 cases for whom no response could be obtained. In the 21 retardates with specific causes of retardation or complications, peripheral abnormalities were noted in 13 (62%) and central abnormalities in 11 (52%). The 41 cases of idiopathic retardates were divided into three categories according to the degree of mental retardation. Of 15 cases who were ascertained to be normal or borderline retardates, 3 (20%) showed some abnormal findings. Of 13 cases who were proven to be suffering from mild to moderate mental retardation, 5 (38%) showed abnormal findings. Of 13 cases who were confirmed to be suffering from severe to profound mental retardation, 5 (39%) showed central abnormalities. The high incidence of ABR abnormalities in retardates compared to in normal controls suggests that ABR measurement is a useful tool for evaluating infants who have possible developmental delay. It seems that disturbance of acoustic information processing can disturb language acquisition, and such a consideration is necessary for the education of children who show significant elevation of the response threshold.
 ...
PMID:Auditory brain stem responses(ABR) in developmentally retarded infants and children. 242 72

Latency compensation analysis (LCA) was applied to single trial samples of the auditory brain-stem evoked response (ABR, IV-V complex). By this means it was possible to characterize properties of temporal variability in the ABR, including certain cases of temporal outliners. A lagged cross-correlogram analysis provided information for each trial that included the largest r2 and associated lead/lag value. The distribution of lag values (based on all trials) was statistically different when ABRs were evoked by stimuli differing by 5 dB. Recomputing the ABR by eliminating temporal outliers, and by adjusting for temporal variability, showed a range of individual patterns of increased amplitude. However, a comparison of Down syndrome (DS) and non-retarded individuals showed a significantly greater amplitude increase in the DS group after LCA. This suggests that certain forms of mental retardation may be characterized by reduced stability in a neural system that is thought to depend upon 'synaptically secure' neurons.
 ...
PMID:Latency compensation analysis of the auditory brain-stem evoked response. 620 2

We examined the clinical picture of eight patients with severe intellectual and motor disabilities, who had experienced prolonged and severe neonatal jaundice, and showed localized lesions in the globus pallidus, subthalamic nuclei and hippocampus on MRI. All patients had athetoid tetraplegia, and five patients showed disturbed ocular movements and seven showed dysphagia. Five patients could communicate with others or utter words, and all showed mental retardation. Auditory brainstem responses were abnormal in seven, and the percentage of REM sleep on all-night polysomnography was reduced in three. Neither CT nor T1-weighted MR images could detect any changes in the pallidum or subthalamic nuclei, while T2-weighted MR images disclosed bilateral high signals in the pallidum, especially in the internal segment, in all patients. Five of the 7 patients, in whom coronal T2-weighted MR imagings were obtained, showed high signals in the subthalamic nuclei. The hippocampus showed atrophy and/or T2-prolongation in seven patients. In one autopsy case, these MRI changes were concordant with pathological lesions. In patients with athetoid cerebral palsy, brainstem dysfunctions, and abnormal ABR, localization of MRI lesions to the pallidum and subthalamic nuclei is evidence for neonatal bilirubin encephalopathy.
 ...
PMID:[Localized lesions on MRI in the globus pallidus, subthalamic nuclei and hippocampus in patients with severe intellectual and motor disabilities]. 939 98

This is believed to be the first report on estimating hearing loss in Hurler's disease, based on the correlation between ABR and temporal bone pathology. ABR findings revealed hearing loss to be about 70 dB or more as result of peripheral mixed impairment. A histological study of the temporal bones revealed almost all pathological findings in the conductive system, except for the hyperplastic arachnoid in the internal auditory canal. In the middle ear cavity, otitis media, residual mesenchyme and deformity of ossicles were found. We explain the conductive component to be due to otitis media and poor ossicular connection. However, the etiology of the sensorineural component remains speculative. In Hurler's disease, hearing loss with mental retardation is often found at infantile age. Therefore, assessing the extent of hearing loss exactly was difficult, for example, the severity. the etiology and incidence of sensorineural impairment. We emphasize the need for not only well-described pathological studies but also for more objective functional investigations, at least ABR.
 ...
PMID:ABR and temporal bone pathology in Hurler's disease. 957 28