Nerve Conduction study and Evoked potentials in Visually Challenged Persons

Sadeesh Kumar, V (2013) Nerve Conduction study and Evoked potentials in Visually Challenged Persons. Masters thesis, Madras Medical College, Chennai.


Download (1MB) | Preview


INTRODUCTION: The development and refinement of instrumentation has been a great asset in the diagnosis of neurologic diseases. First available study was in 1951 by GALLEGO A.1 Peripheral nerve conduction study is an extension of neurological examination. Data are available for normal persons and how it gets changed in diseases process. From 1975 onward numerous studies are published regarding normal data, techniques, methods and origin of waves etc. Peripheral nerve conduction studies are done in very few of the visually challenged. PubMed advanced search of “Somatosensory Evoked Potentials” and “visually challenged persons” yields no available data. AIM OF THE STUDY: 1. To study the peripheral nerve conduction in visually challenged persons. 2. To study auditory and somatosensory evoked potentials in visually challenged persons. 3. Comparison of previous available data with our control population. MATERIALS AND METHODS: The study was conducted on the patient attenders in neurology services at the institute of neurology, Madras Medical College and Rajiv Gandhi Government general Hospital from May 2011 to march 2013. Institutional ethical committee is applied and the committee approved the study. Informed consent was obtained from the participants. In the control group a volunteer read the information sheet and consent form are visually challenged persons are got by means of thumb impression. Visually challenged persons are chosen from a government blind school. Twenty five persons from school and twenty five persons of age matched controls are chosen. Inclusion and Exclusion criteria: Those who are visually challenged since childhood are selected Persons with other associated diseases are excluded. Participants age, sex, visual acuity and height are measured and documented. METHODS: Patients are advised to avoid applying oil after head bath on the day of test. His test is done in the sitting position with comfortable neck muscle relaxation or in the lying posture according to the patients relaxation. CONCLUSION: 1. The central conduction time is significantly short in the visually challenged persons using Braille reading. It favours that visually deprived persons uses the touch information in a efficient manner which help them for coping with their surroundings. 2. The fast conduction decreases with decreasing usage of braille reading. 3. Brainstem auditory evoked response is normal in visually challenged persons. 4. Brainstem auditory evoked response not faster when they are using recorded voice lesson learning. 5. Peak central conduction time does not correlate with age. 6. In Braille reading persons, sensory nerve conduction latency, amplitude, velocities are normal while the central conduction is short indicating faster conduction. 7. The faster central conduction is of significance in visually challenged as they rely on touch for their locomotion and many other day to day activities. Hence it may be better if they continue to use Braille which helps better touch perception. Where as when they switch to auditory learning the central conduction in somatosensory pathway slows to that of normal people, which may be a disadvantage to the visually challenged who has to "feel" the world that they cannot see. So we recommend that Braille usage to be continued in older visually challenged persons even though they may also use auditory learning.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Evoked potentials, Visually Challenged Persons, Nerve Conduction study.
Subjects: MEDICAL > Neurology
Depositing User: Subramani R
Date Deposited: 27 Mar 2020 08:05
Last Modified: 27 Mar 2020 08:05

Actions (login required)

View Item View Item