Peripheral Neuropathy in Subclinical Hypothyroidism

Abstract

Alterations in peripheral nerves are well documented in overt myxedema but not in subclinical hypothyroidism. We performed electrophysiologic studies to investigate such abnormalities in patients with normal serum total T4 and hyperresponsiveness of TSH to TRH, either with normal or high levels of basal circulating TSH. Subjects were divided in three groups: (i) Hypothyroidism Stage I (group () (n = 17, mean age = 39 +/- 34 years), T4 = 9 +/- 0.7 micrograms/dL, TSH = 4.3 +/- 0.4 microU/mL, sTSH post-TRH (peak value) = 37.6 +/- 1.6 microU/mL; (ii) Hypothyroidism Stage II (group II) (n = 10, mean age: 43 +/- 6 years), T4 = 7.7 +/- 0.8 microgram/dL, TSH = 20 +/- 5 microU/mL, TSH post-TRH > 50 microU/mL; (iii) Control Group (n = 20, mean age 41 +/- 5 years), healthy subjects. All patients and controls were women. TRH test consisted in the i.v. injection of 200 micrograms TRH (normal peak value up to 25 microU/mL, normal basal TSH < 5.5 microU/mL. None of the patients had carpal tunnel syndrome or any other neurological or metabolic disturbances. We studied the distal motor latencies, motor and sensory amplitudes, and nerve conduction velocities. The motor parameters were measured in the median and external sciatic popliteal (ESP) nerves, and the sensory parameters in the median and sural nerves. In most cases values were obtained from both right and left nerves. Motor parameters: no differences were found between all groups for conduction velocities (CV).(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral and Central Nervous System Alterations in Hypothyroidism: Electrophysiological Findings

“…The electrophysiological abnormalities such as slowing of motor and sensory nerve conduction velocities have been reported in overt hypothyroidism [6][7][8][25][26][27]. Misiunas et al [28] and Ozata et al [11] recorded no significant differences between patients with subclinical hypothyroidism and a control group in distal latencies and motor conduction velocities of peripheral nerves. In the present study, the PNS was affected in 52% of the cases, entrapment neuropathy was the commonest (35%), which may be due to mucinous deposits that cause nerve compression.…”

Clinical Profile of Subclinical Hypothyroidism:A Retrospective Study

“…[13] Though fatty liver was present, none of the subjects had any evidence of cardiac disease or other sequelae of atherosclerosis.Nerve conduction studies had demonstrated presence of peripheral neuropathies in individuals with subclinical hypothyroidism. [15] Painful neuropathies and neuromuscular abnormitieswere reported to be relieved with hormone replacement therapies. [16,26] The most frequent presenting complaint in this study was body pains.…”

“…[13] Increased rate of residual myocardial ischemia is also seen in patients with clinical hypothyroidism. [14] In the neuromuscular system subclinical hypothyroidism may cause peripheral neuropathies [15,16] muscular weakness and low exercise tolerance. [17] Reviews have also stated a significant prevalence of subclinical hypothyroidism among patients with bipolar mood disorders.…”

Subclinical hypothyroidism: Comparison of adhesion molecule levels before and after levothyroxine therapy

“…neurological and psychiatric or psychological, and coagulopathies. 10,[12][13][14][15] Atherosclerosis is a chronic process involving both cellular and humoral responses. In atherogenesis, leucocytes are involved in the early phase of atherosclerosis and maintain their activity during plaque formation, during which time sICAM-1 and sVCAM-1 first co-ordinate leucocyte adhesion, then their transendothelial migration.…”