ABSTRACT
The present study was undertaken to determine whether impairment of sensory conduction in the auditory pathway is one of the contributory factors of performance in children with borderline intelligence. The study was conducted on children having borderline intelligence (IQ 71-84). The functional integrity of the central auditory pathway was assessed using Auditory Evoked Responses i.e. Auditory Brainstem response (ABR), Mid Latency Response (MLR) and Slow Vertex Response (SVR). The recordings were done using a computerized evoked potential recorder by 10–20 electrode placement system. There was no significant difference in the absolute peak latencies, the interpeak latencies and amplitude of ABR in the subjects as compared to controls. There was prolongation of the latency of MLR and SVR waves in subjects though not statistically significant indicating no conduction abnormality in the auditory pathway of the study subjects. Electrophysiological methods reveal underlying immaturity or abnormal brainstem timing and may serve as reliable tool in individuals with learning difficulties.
ABSTRACT
Objectives: Attention Deficit/Hyperactivity Disorder (AD/HD) is one of the childhood disorder characterized by lack of sustained attention, hyperactivity and impulsivity. Children with AD/HD have functional impairment occurring at multiple levels. Sensory neural processing of visual information can be one of the contributory factors. The present study was undertaken to examine the integrity and function of visual pathway by means of Visual Evoked Potential (VEP). Method: Twenty AD/HD children and twenty controls were taken for the study and Pattern reversal Visual Evoked Potential was recorded on computerized evoked potential recorder using 10-20 system of electrode placement. The statistical analysis for the comparison between controls and AD/HD children was done using unpaired Student’s t test. Results: The latencies of N75, P100 and N145 were increased but could not reach the level of significance. Conclusion: Our finding indicates that the sensory processing is not involved in children with AD/HD alone without any other disorders like Reading Disability, Learning disability etc.
Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Child , Evoked Potentials, Visual , Sensation Disorders , Visual PerceptionABSTRACT
Hypothyroidism is known to be associated with mental retardation, motor dysfunction, memory deficits and hearing impairment. In the present study, the functional integrity of the thalamocortical projections to the primary auditory cortex and association cortex has been assessed by using Auditory Evoked Responses i.e Auditory Brainstem (ABR), Mid Latency Response (MLR) and Slow Vertex Response (SVR). Thirty newly diagnosed hypothyroid patients and thirty healthy controls were taken for the study and ABR, MLR and SVR were recorded on computerized evoked potential recorder using 10-20 system of electrode placement. The second recordings for the hypothyroid patients were done 3 months after treatment with attainment of euthyroid states. The present study revealed a slight increase in absolute latency of wave III of ABR in hypothyroid patients and significant decrease in absolute latency of wave III and interpeak latency of I-III after treatment. There was a significant decrease in amplitude of wave V in hypothyroid patients and significant increase in amplitudes of ABR wave I and wave V after treatment. There was a significant increase in latency of wave Na of MLR and wave P2 of SVR in hypothyroid patients. The latencies of waves Na, Pa, Nb of MLR and waves PI and N2 of SVR showed significant improvement with thyroid hormone treatment. The results of the present study indicates that in hypothyroid state there might be slow conduction at the periphery and with treatment there is better recruitment of neuronal pool of the generators of the waves of ABR in the brainstem. We can also conclude that the thalamocortical projections of the auditory pathways are adversely affected in the hypothyroid state and this improves after treatment.