Journal of Endocrinological Investigation

, Volume 19, Issue 10, pp 670–677 | Cite as

Evaluation of central motor conduction in hypothyroid and hyperthyroid patients

  • M. Ozata
  • A. Ozkardes
  • H. Dolu
  • A. Çorakçi
  • M. Yardim
  • M. A. Gundogan


Deficiency or excess of thyroid hormones is associated with central nervous system (CNS) disturbances. Although the CNS involvement either in hypothyroidism or in hyperthyroidism have previously been shown on the basis of visual, auditory and somatosensory evoked potentials studies, less is known about the function of central motor pathways in both disorders. We studied the motor evoked potentials (MEPs) following the magnetic stimulation of the motor cortex and spinal roots in 20 patients with hypothyroidism and in 19 patients with hyperthyroidism both before treatment and after they became euthyroid and compared with findings in 20 age-, sex- and height-matched control subjects. Disease duration (expressed as time from diagnosis of diseases to the time of neurological testing) is less than one month in both disorders. Central motor conduction time (CMCT) was determined as the differences between MEPs latencies after cortical and spinal stimulation. The mean CMCTs before treatment in hypothyroid patients (8.31±1.52 msec,) and in hyperthyroid patients (7.92±1.06 msec,) were significantly prolonged as compared to those in normal controls (6.82±0.83 msec, p=0.002 and p=0.004, respectively). Four of the 20 (20.0%) hypothyroid patients and 2 of 19 (10.5%) hyperthyroid patients had abnormal CMCT (values exceeding mean + 2.5 SD of normal control). The mean CMCT values in both groups were not significantly decreased after euthyroidism was achieved, although a tendency of the decrease in CMCT was observed. Improvement of CMCT abnormalities was observed in 1 of 4 hypothyroid patients and in one of 2 patients with hyperthyroidism, who had CMCT abnormalities before treatments, after they became euthyroid. No correlation was found between CMCT and free T3, free T4, or TSH levels as well as the onset age, the severity of the diseases or the disease duration in both disorders. We conclude that abnormal CMCT could be documented in few patients in both disorders. However, these alterations could not be improved completely after restoration of euthyrodism. Thus, it remains to be determined if long-term treatment would completely improve CMCT abnormalities in both disorders. Since abnormal CMCT values in both disorders were observed only in few patients, our results also suggest that CMCT measurement does not have, at present time, a clinical usefulness to assess the peripheral action of thyroid hormones. Thus, the data obtained need a more extensive evaluation.


Motor evoked potentials hypothyroidism hyperthyroidism 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    DeLong G.R., Adams R.D. Neuromuscular system and brain in thyrotoxicosis. In: Braverman L.E., Utiger R.D. (Eds), Werner and Ingbar’s, The Thyroid, 6th ed. JB Lippincott Co., Philadelphia, 1991, p. 793.Google Scholar
  2. 2.
    DeLong G.R., Adams R.D. Neuromuscular system and brain in hypothyroidism. In: Braverman L.E., Utiger R.D. (Eds), Werner and Ingbar’s, The Thyroid, 6th ed. Lippincott Co., Philadelphia, 1991, p. 1027.Google Scholar
  3. 3.
    Swanson J.W., Kelly J.J., McConahey W.M. Neurologic aspects of thyroid dysfunction. Mayo Clin. Proc. 56: 504, 1981.PubMedGoogle Scholar
  4. 4.
    Braverman L.E., Utiger R.D. Introduction to hypothyroidism. In: Braverman L.E., Utiger R.D. (Eds), Werner and Ingbar’s, The Thyroid, 6th ed. JB Lippincott Co., Philadelphia, 1991, p. 919.Google Scholar
  5. 5.
    Osterweil D., Syndulko K., Cohen S.N., Pettier-Jennings P.D., Hershman J.M., Cummings J.L., Tourtellotte W.W., Solomon D.H. Cognitive function in non-demented older adults with hypothyroidism. J. Am. Geriatr. Soc. 40: 325, 1992.PubMedGoogle Scholar
  6. 6.
    Klein I., Trzepacz P., Roberts M., Levey G.S. Symptom rating scale for assessing hyperthyroidism. Arch. Intern. Med. 148: 387, 1988.PubMedCrossRefGoogle Scholar
  7. 7.
    Ladenson P.W., Stakes J.W., Ridgway E.C. Reversible alteration of the visual evoked potentials in hypothyroidism. Am. J. Med. 77: 1010, 1984.PubMedCrossRefGoogle Scholar
  8. 8.
    Avramides A., Papamargaritis K., Mavromatis I., Saddic G., Vyzantiadis A., Milonas I. Visual evoked potentials in hypothyroid and hyperthyroid patients before and after achievement of euthyroidism. J. Endocrinol. Invest. 15: 749, 1992.PubMedCrossRefGoogle Scholar
  9. 9.
    Himmelfarb M., Lakretz T., Gold S., Shanon E. Auditory brainstem responses in thyroid dysfunction. J. Laryngol. Otol. 95: 679, 1981.CrossRefGoogle Scholar
  10. 10.
    Bongers-Schokking J.J., Colon E.J., Mulder P.G.H., Hoogland R.A., De Groot C.J., Brande J.L.W. Somatosensory evoked potentials in neonates with primary congenital hypothyroidism during the first week of therapy. Pediatric Res. 30: 34, 1991.CrossRefGoogle Scholar
  11. 11.
    Torres C.F., Moxley R.T. Hypothyroid neuropathy and myopathy: Clinical and electrodiagnostic longitudinal findings. J. Neurol. 237: 271, 1990.PubMedCrossRefGoogle Scholar
  12. 12.
    Nemni R., Bottacchi E., Fazio R., Mamoli A., Corbo M., Camerlingo M., Galardi G., Erenbourg L., Canal N. Polyneuropathy in hypothyroidism: clinical, electrophysiological and morphological findings in four cases. J. Neurol. Neurosurg. Psychiatr. 50: 1454, 1987.PubMedCentralPubMedCrossRefGoogle Scholar
  13. 13.
    Beghi E., Delodovici M., Bogliun G., Crespi V., Paleari F., Gamba F., Capra M., Zarrelli M. Hypothyroidism and polyneuropathy. J. Neurol. Neurosurg. Psychiatr. 52: 1420, 1989.PubMedCentralPubMedCrossRefGoogle Scholar
  14. 14.
    Dick D.J., Nogues M.A., Lane R.J.M., Fawcett P.R.W. Polyneuropathy in occult hypothyroidism. Postgrad. Med. J. 59: 518, 1989.CrossRefGoogle Scholar
  15. 15.
    Rao S.N., Katiyar C., Nair K.R.P., Misra S. Neuromuscular status in hypothyroidism. Acta Neurol. Scand. 61: 167, 1980.PubMedCrossRefGoogle Scholar
  16. 16.
    Sozay S., Gökce-Kutsal Y., Celiker R., Erbas S., Basgoze O. Neuroelectrophysiological evaluation of untreated hyperthyroid patients. Thyroid Clin. Exp. 6: 55, 1994.Google Scholar
  17. 17.
    Berlit P., Mahlberg U., Usadel K.H. Polyneuropathy in hyperthyroidism-a clinical neurophysiologic study. Schweiz. Arch. Neurol. Psychiatr. 143: 81, 1992.PubMedGoogle Scholar
  18. 18.
    Tramutoli R., Rinaldi R., Poggio P., Guglielmi R., Panunzi C., Petrucci L., Innamorato V., Pisicchio G., Papini E. Motor nerve conduction velocity (MNCV) changes in thyrotoxic patients before and after treatment. Preliminary report. Proceeding of the 77th Annual Meeting of the Endocrine Society. Abstract no. P3-470, 1995.Google Scholar
  19. 19.
    Barker A.T., Jalinous R., Freeston I.L. Non-invasive magnetic stimulation of the motor cortex. Lancet 2: 1106, 1985.CrossRefGoogle Scholar
  20. 20.
    Murray N.M.F. Magnetic stimulation of cortex: Clinic applications. J. Clin. Neurophysiol. 8: 66, 1991.PubMedCrossRefGoogle Scholar
  21. 21.
    Murray N.M.F. The clinical usefulness of magnetic cortical stimulation. Electroenceph. Clin. Neurophysiol. 85: 81, 1992.PubMedCrossRefGoogle Scholar
  22. 22.
    Chiappa K.H. Transcranial motor evoked potentials. Electromyogr. Clin. Neurophysiol. 34: 15, 1994.PubMedGoogle Scholar
  23. 23.
    Hess C.W., Mills K.R., Murray N.M.F., Schriefer T.N. Magnetic brain stimulation: Central motor conduction studies in multiple sclerosis. Ann. Neurol. 22: 744, 1987.PubMedCrossRefGoogle Scholar
  24. 24.
    Eisen A., Shytbel W., Murphy K., Hoirch M. Cortical stimulation in amytrophic lateral sclerosis. Muscle Nerve 13: 146, 1990.PubMedCrossRefGoogle Scholar
  25. 25.
    Abbruzzese G., Schenone A., Scramuzza G., Caponnetto C., Gasparetto B., Adezati L., Abbruzzese M., Viviani G.L. Impairment of central motor conduction in diabetic patients. Electroenceph. Clin. Neurophysiol. 89: 335, 1993.PubMedCrossRefGoogle Scholar
  26. 26.
    Andersen H., Nielsen J.F., Poulsen P.L., Mogensen C.E., Jakobsen J. Motor pathway function in normoalbuminuric IDDM patients. Diabetologia 38: 1191, 1995.PubMedCrossRefGoogle Scholar
  27. 27.
    Dratman M.B., Crutchfield F.L., Gordon J.T., Jennings A.S. Iodothyronine homeostasis in rat brain during hypo and hyperthyroidism. Am. J. Physiol. 245: E185, 1983.PubMedGoogle Scholar
  28. 28.
    Brabant G., Radam C., Johannes S., Münte T.F. Cognitive functions as determined by event related brain potential but not behavioural measures are altered in experimentally induced hyperthyroidism in healthy men. Proceeding of 77th Annual Meeting ofthe Endocrine Society, Abstract no: P3-448, 1995.Google Scholar
  29. 29.
    Mastaglia F.L., Black J.L., Collins D.W.K., Gutteridge D.H., Yuen R.W.M. Slowing of conduction in visual pathway in hypothyroidism. Lancet 1: 387, 1978.PubMedCrossRefGoogle Scholar

Copyright information

© Italian Society of Endocrinology (SIE) 1996

Authors and Affiliations

  • M. Ozata
    • 1
  • A. Ozkardes
    • 2
  • H. Dolu
    • 2
  • A. Çorakçi
    • 1
  • M. Yardim
    • 2
  • M. A. Gundogan
    • 1
  1. 1.Department of Endocrinology and MetabolismGulhane School of MedicineEtlik-AnkaraTurkey
  2. 2.Department of NeurologyGulhane School of MedicineEtlik-AnkaraTurkey

Personalised recommendations