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Neurophysiological correlates of senile dementia: II. The somatosensory evoked response

Published online by Cambridge University Press:  09 July 2009

Raymond Levy
Affiliation:
Academic Department of Psychiatry, Middlesex Hospital Medical School;
Anthony Isaacs
Affiliation:
Academic Department of Psychiatry, Middlesex Hospital Medical School;
Joan Behrman
Affiliation:
Cane Hill Hospital and Bethlem Royal and Maudsley Hospitals

Synopsis

Specific cortical somatosensory evoked responses were recorded in nine patients suffering from senile dementia and eight elderly depressed patients. The results were as follows. (1) The latencies of each peak were longer in the demented than in the depressed group but this difference was significant only for peak 3 (the second negative deviation). (2) The late negative deviation (peak 5) was either absent or very flat in demented patients. The ratio of the amplitude of this late wave to that of the first peak discriminated between demented and non-demented patients at the 0·5% level. (3) The value of this ratio combined with that of the latency of peak 3 could be used to classify all but one patient into the correct diagnostic group. The results are discussed in the light of the relevant literature. It is suggested that slowing of conduction in the nervous system may be a very basic disturbance associated with cognitive impairment in old age and that measurements of this kind may come to assist in the diagnosis of dementia.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1971

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References

REFERENCES

Bickford, R. G., Jacobson, J. L., and Cody, D. T. R. (1964). The nature of averaged evoked responses to sound and other stimuli in man. Annals of the New York Academy of Sciences, 112, 204218.CrossRefGoogle Scholar
Blessed, G., Tomlinson, B. E., and Roth, M. (1968). The association between quantitative measures of dementia and senile changes in the cerebral grey matter of elderly subjects. British Journal of Psychiatry, 117, 797812.CrossRefGoogle Scholar
Bradley, P. B., Eayrs, J. T., and Richards, N. M. (1964). Factors influencing potentials in normal and cretinous rats. Electroencephalography and Clinical Neurophysiology, 17, 308313.CrossRefGoogle ScholarPubMed
Dawson, G. D. (1947). Cerebral responses to electrical stimulation of peripheral nerve in man. Journal of Neurology, Neurosurgery and Psychiatry, 10, 137140.Google ScholarPubMed
Dawson, G. D. (1954). A summation technique for the detection of small evoked potentials. Electroencephalography and Clinical Neurophysiology, 6, 6587.CrossRefGoogle ScholarPubMed
Ertl, J. P., and Schafer, E. W. P. (1969). Brain response correlates of psychometric intelligence. Nature, 223, 421422.CrossRefGoogle ScholarPubMed
Giblin, D. R. (1964). Somatosensory evoked potentials in healthy subjects and in patients with lesions of the nervous system. Annals of the New York Academy of Sciences, 112, 93142.CrossRefGoogle ScholarPubMed
Levy, R., and Poole, E. W. (1966). Peripheral motor nerve conduction in elderly demented and non-demented psychiatric patients. Journal of Neurology, Neurosurgery and Psychiatry, 29, 362366.Google ScholarPubMed
Levy, R. (1969). The neurophysiology of dementia. British Journal of Hospital Medicine, 2, 688690.Google Scholar
Levy, R., Isaacs, A., and Hawks, G. (1970). Neurophysiological correlates of senile dementia. I. Motor and sensory nerve conduction velocity. Psychological Medicine, 1, 4047.CrossRefGoogle ScholarPubMed
Nishitani, H., and Kooi, K. A. (1968). Cerebral evoked responses in hypothyroidism. Electroencephalography and Clinical Neurophysiology, 27, 554560.CrossRefGoogle Scholar
Rhodes, L. E., Dustman, R. E., and Beck, E. C. (1969). The visual evoked response: a comparison of bright and dull children. Electroencephalography and Clinical Neurophysiology, 27, 364372.CrossRefGoogle Scholar
Shagass, C., Schwartz, M., and Amadeo, M. (1962). Some drug effects on evoked cerebral potentials in man. Journal of Neuropsychiatry, 3, Suppl. 1, 4958.Google Scholar
Shagass, C., and Schwartz, M. (1965). Age, personality and somatosensory cerebral evoked responses. Science, 148, 13591361.CrossRefGoogle ScholarPubMed
Straumanis, J. J., Shagass, C. and Schwartz, M. (1965). Visually evoked response changes associated with chronic hrain syndromes and aging. Journal of Gerontology, 20, 298506.Google Scholar
Sutton, S., Braren, M., Zubin, J., and John, E. R. (1965). Evoked-potential correlates of stimulus uncertainty. Science. 150, 11871188.CrossRefGoogle ScholarPubMed
Wang, H. S., Obrist, W. D., and Busse, E. W. (1970). Neuro-physiological correlates of the intellectual function of elderly persons living in the community. American Journal of Psychiatry, 126, 12051212.CrossRefGoogle Scholar
Williamson, P. D., Goff, W. H., Matsumiya, Y., and Allison, T. (1970). Somatosensory evoked potentials in patients with unilateral cerebral lesions. Electroencephalography and Clinical Neurophysiology, 28, 91.CrossRefGoogle ScholarPubMed