Abstract
Dysfunction of the central nervous system (CNS) is an important consequence of thyroid hormone deficiency. Evoked potentials like visual evoked potentials (VEP) provide a reliable and objective measure of function in related sensory system and tracts. In this study pattern-shift VEP (PVEP) recordings were performed on 48 newly diagnosed hypothyroid patients. Twenty-four had sub-clinical and 24 had overt hypothyroidism. None of the patients had clinical symptoms or signs referable to CNS dysfunction. Their mean age was 44±12 yr. The response to pattern stimulation on the normal control subjects was a triphasic response with a prominent positive wave (P100) with a peak latency of 84–105 (mean:96±4) milliseconds (ms). In patients with hypothyroidism mean P100 latency was (mean: 97±6) ms and the difference between the 2 groups was not statistically significant. (p>0.05) Delays above the average latency ±2.5 SD of the mean of the control subjects was defined as a criteria for an abnorm ality. According to defined criteria 6 (12.5%) patients demonstrated abnormal PVEP at least on one tested side. Previous studies conducted on small patient populations stated there is high percentage of VEP abnormalities in hypothyroid patients. However, this fact was not confirmed by our study. We believe abnormalities of PVEP will be more prominent in untreated patients in the advanced stage of the disease, or in patients who have a neurological involvement; such as apathy, impaired memory or cerebellar dysfunction. Consecutive studies, in a more clearly defined and selected patient population, are needed to confirm and settle this issue. (J. Endocrinol. Invest. 25: 955–958, 2002)
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References
Boyages S.C. The neuromuscular system and brain in hypothyroidism. In: Braverman L.E., Utiger R.D. (Eds.), The thyroid. A fundamental and clinical text. Lippincott Williams & Wilkins, Philadelphia, 2000, p.806.
Utiger R.D. The Thyroid: Physiology, Thyrotoxicosis, Hypothyroidism, and the Painful Thyroid. In: Felig P., Frohman L.A. (Eds.), Endocrinology & Metabolism. Mc Graw-Hill Companies, USA, 2001, p.261.
Beghi E., Delovici M., Graziella B. et al. Hypothyroidism and polyneuropathy. J. Neurol. Neurosurg. Psychiatry 1989, 52: 1420–1423.
Ladenson P.W., Stakes J.W., Ridgway E.C. Reversible alteration of the visual evoked potential in hypothyroidism. Am. J. Med. 1984, 77: 1010–1014.
Tamburini G., Tacconi P., Ferringo P. et al. Visual evoked potentials in hypothyroidism: a long-term evaluation. Electromyogr. Clin. Neurophysiol. 1998, 38: 201–205.
Nuwer M., Packwood J.W., Myers L.W., Ellison G.W. Evoked potentials predict the clinical changes in multiple sclerosis drug study. Neurology 1987, 37: 1754–1761.
Douglas S- Ross. Subclinical hypothyroidism. In: Bravermar L.E, Utiger R.D. (Eds.), The thyroid. A fundamental and clinical text. Lippincott Williams & Wilkins, Philadelphia, 2000, p. 1001.
Avramides A., Papamargaritis K., Mavromitis I., Saddic G., Vyzantiadis A., Milanos I. Visual evoked potentials in hypothyroid and hyperthyroid patients before and after achievement of euthyroidism J. Endocrinol. Invest. 1992, 15: 749–753.
Osterweil D., Syndulko K., Cohen S.N. et al. Cognitive function in non-demented older adults with hypothyroidism. J. Am. Geriatr. Soc. 1992, 40: 325–335.
Dugbartey A.T. Neurocognitive aspects of hypothyroidism. Arch. Intern. Med. 1998, 158: 1413–1418.
Özkardes A., Özata M., Beyhan Z. et al. Acute hypothyroidism leads to reversible alterations in central nervous system as revealed by somotosensory evoked potentials. Electroenceph. Clin. Neurophysiol. 1996, 100: 500–504.
Bongers-Schokking C.J., Colon E.J., Hoogland R.A., Groot C., Brande L.V. Somotosensory evoked potentials in neonates with primary congenital hypothyroidism during the first week of therapy. Pediatric Research 1991, 30: 31–36.
Chan Y.W., Mc Leod J.G., Tuck R.R., Walsh J.C., Pa F. Visual evoked potential responses in chronic alcoholics. J. Neurol. Neurosurg. Psychiatr. 1986, 49: 945–950.
Khedr E.M., El Toony L.F., Tarkhan M.N., Abdella G. Peripheral and central nervous system alterations in hypothyroidism: electrophysiolgical findings. Neuropsychobiology 2000, 41: 88–94.
Abbott R.J., Malley B.P.O., Barnett D.B., Timson L., Rosenthal F.D. Central and peripheral nerve conduction in thyroid dysfunction: the influence of L-thyroxine therapy compared with warming upon the conduction abnormalities of primary hypothyroidism. Clin. Sci. 1983, 64: 617–622.
Mastaglia F.L., Black J.L., Collins D.W., Gutterridge D.H., Yuen R.W.M. Slowing of conduction in visual pathway in hypothyroidism. Lancet 1978, 1: 387–388.
Misra S., Sinha R.S., Jain D.C., Chakravorty B. Visual evoked potential (VEP) — Dependable marker for CNS affection in thyroid diseases. J. Assoc. Physicians India 1996, 44: 123–126.
Holder G.E., Condon J.R. Pattern visual evoked potentials and pattern electroretinograms in hypothyroidism. Documenta Ophthalmol. 1989, 73: 127–131.
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Nazliel, B., Akbay, E., Irkeç, C. et al. Pattern visual evoked potential (PVEP) evaluation in hypothyroidism. J Endocrinol Invest 25, 955–958 (2002). https://doi.org/10.1007/BF03344067
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DOI: https://doi.org/10.1007/BF03344067