Electrophysiologic changes in patients with untreated primary hypothyroidism

Hypothyroidism: A Peculiar Presentation

Hypothyroidism constitutes a prevalent pathology, with up to 80% of afflicted individuals displaying associated muscular symptoms. However, these symptoms rarely appear as the first or only manifestation of hypothyroidism. We report the case of a previously healthy 21-year-old man, diagnosed with hypothyroid myopathy after experiencing intense myalgias and cramps, which were relieved by oral administration of levothyroxine. This case demonstrates the significance of considering thyroid-related conditions when patients present muscular symptoms as these can represent the only or initial indicator of hypothyroidism. Timely thyroxine supplementation leads to the gradual resolution of most neuromuscular symptoms.

Hoffmann's syndrome in the differential work-up of myopathic complaints: a case report

BACKGROUND

Hoffmann's syndrome is a rare form of hypothyroid myopathy in adults, which is mainly characterized by muscular weakness and muscular pseudohypertrophy.

CASE PRESENTATION

We report about a 61-year-old Western European man with myalgia, myxedema and pseudohypertrophy of the calf muscles. Laboratory tests revealed significantly elevated thyroid stimulating hormone (TSH) and creatine kinase (CK). Muscle MRI showed muscular hypertrophy of the lower limbs, but no signs of myositis or myopathy (no gadolinium enhancement, no edema, no fatty degeneration). In addition, electromyography (EMG) detected spontaneous activity. After the beginning of thyroxin-therapy it took six months until the muscle weakness improved and the myalgia regressed.

CONCLUSIONS

Here, we focus on diagnostic routines and typical findings to differentiate Hoffmann's syndrome from other myopathies. Clinical hallmarks of Hoffmann's syndrome are pseudohypertrophy and weakness of the calf muscles in combination with elevated CK and elevated TSH. EMG is well suited to detect the involvement of the muscles and muscle MRI helps to differentiate it from other myopathies. Hoffmann's syndrome is a rare myopathy due to hypothyroidism and plays a role in the differential diagnosis of myopathic complaints even if hypothyroidism has not been detected before.

Hashimoto's thyroiditis-related myopathy in a patient with SARS-CoV-2 infection: A case report and systematic literature review

RATIONALE

Hashimoto's thyroiditis (HT) is a common autoimmune disease. However, its presentation and management in the context of COVID-19 are unclear, and COVID-19-triggered HT, along with myopathy and persistent creatine kinase (CK) levels, have not been previously reported. Moreover, no literature review is currently available on HT in the context of COVID-19. This study is a case report and systematic review of the literature.

PATIENT CONCERNS

A 33-year-old man was admitted with acute-onset myalgia, anosmia, loss of taste, fever, and upper respiratory tract symptoms.

DIAGNOSES

He was diagnosed with coronavirus disease (COVID-19) during hospitalization and had abnormal CK levels. The elevated CK level persisted even after the resolution of COVID-19. After excluding myopathies and cardiac factors, HT was diagnosed.

INTERVENTIONS

CK levels did not decrease appreciably until 14 d after levothyroxine administration.

OUTCOMES

The patient was discharged from the hospital in good health. In the systematic literature review, 7 case reports on COVID-19-associated HT were observed, although no incidence of associated myopathy or persistent elevation of CK was noted.

LESSONS

This case report highlights the potential link between COVID-19 and autoimmune thyroid diseases. In particular, this study underscores the significance of recognizing new-onset autoimmune thyroid disease in COVID-19-positive patients with elevated CK levels that cannot be attributed to other factors. This systematic review offers additional perspectives for diagnosing and managing HT in COVID-19 settings. Overall, the findings of this study could have important clinical implications for the care of COVID-19 patients, as early identification and treatment of autoimmune thyroid disease could help prevent long-term complications. Additional research is essential to elucidate the fundamental correlations between COVID-19 and HT and assess the effectiveness of therapeutic approaches for autoimmune thyroid conditions related to COVID-19.

Selected musculoskeletal disorders in patients with thyroid dysfunction, diabetes, and obesity

Many medical conditions affect the skeletal system and constitute independent risk factors for fractures. The action of thyroid hormones is necessary to maintain adequate development, mineralization, and bone strength. Untreated hyperthyroidism can lead to a decrease in bone mineral density (BMD), osteoporosis, and pathological fractures. In hypothyroidism, the changes in the quality of bone structure lead to an increase in the frequency of fractures. Excessive body weight negatively impacts fracture risk, increases the risk of osteoarthritis and accelerates the development of rheumatoid arthritis and osteoporosis. Type 1 and type 2 diabetes are associated with an increased risk of bone fractures despite different etiopathogenesis due to the duration of the disease and the pro-inflammatory state, the incorporation of advanced glycation end products (AGEs) into the bone matrix, and microvascular disorders. This study summarizes the current literature on the influence of thyroid dysfunction, obesity, and diabetes on the skeletal system.

An atypical presentation of hypothyroidism with extremely exaggerated functional impairment

Key Clinical Message

Myopathy-related symptoms are rare manifestations of hypothyroidism. Clinicians should consider hypothyroid myopathy as one of the possible diagnoses for patients with proximal weaknesses.

Abstract

Myopathy-related symptoms are rare manifestations of hypothyroidism. Clinicians should consider hypothyroid myopathy as one of the possible diagnoses for patients with proximal weaknesses. We report a 34-year-old woman, presenting with a new atypical musculoskeletal manifestation of hypothyroidism mimicking polymyositis.

Sympathetic skin responses and electromyographic reaction times in chronic autoimmune thyroiditis: An overlooked electrodiagnostic study

Objectives

This study aims to evaluate peripheral nerve functions, sympathetic skin responses (SSRs), and electromyographic (EMG) reaction times in hypothyroid patients and to compare them to healthy individuals.

Patients and methods

Between January 2007 and September 2007, a total of 54 patients with Hashimoto’s thyroiditis including 35 euthyroid (3 males, 32 females; mean age: 45.2±10.2 years; range, 35 to 60 years) and 19 with subclinical hypothyroidism (2 males, 17 females; mean age: 43.2±12.6 years; range, 40 to 65 years) were included in the study. The control group consisted of 35 healthy individuals (5 males, 30 females; mean age: 39.1±9.3 years; range, 29 to 52 years). Nerve conduction studies (NCSs), SSRs of the hand and foot obtained by stimulation of the contralateral median nerve, and EMG reaction times of the extensor indicis proprius muscle were performed in all subjects.

Results

There was no significant difference in peripheral NCSs and SSRs between patients and the control group. However, reaction times were longer in the AIT patients compared to the healthy individuals suggesting alterations in cognitive function related to the primary disease process in AIT.

Conclusion

Electrodiagnosis of autonomic nervous system involvement and cognitive impairment can be challenging in AIT. However, EMG reaction times and SSRs are practical and useful tools that are often overlooked. On the other hand, SSRs may be combined with more quantitative tests, such as sudomotor axon reflex testing, to allow us to better determine the extent of involvement of the autonomic nervous system in AIT.

Replication of epidemiological associations of carpal tunnel syndrome in a UK population-based cohort of over 400,000 people

Introduction

Several phenotypic factors are associated in the literature with an increased risk of carpal tunnel syndrome (CTS). Along with female sex and older age, certain systemic diseases show an association with CTS, with varying degrees of evidence.

Methods

This study was performed using the UK Biobank resource – a cohort study of over 500,000 participants who have allowed linkage of phenotypic data with their medical records. We calculated the prevalence of CTS and a sex-specific prevalence ratio and compared the body mass index (BMI) between cases and controls. We performed a series of nested case-control studies to compute odds ratios for the association between CTS and three systemic diseases.

Results

There were 12,312 CTS cases within the curated UK Biobank dataset of 401,656 (3.1% prevalence), and the female:male ratio was 1.95:1. CTS cases had, on average, a BMI > 2.0 kg/m² greater than controls. Odds ratios for the association with CTS for three systemic diseases were 2.31 (95% CI 2.17–2.46) for diabetes, 2.70 (95% CI 2.44–2.99) for rheumatoid arthritis, and 1.47 (95% CI 1.38–1.57) for hypothyroidism. Adjusted for BMI, these odds ratios fell to 1.75 (95% CI 1.65–1.86), 2.43 (95% CI 2.20–2.69), and 1.35 (95% CI 1.26–1.43), respectively.

Discussion

We harnessed the size and power of UK Biobank to provide robust replication of evidence for the associations between CTS and female sex, raised BMI, and three systemic diseases, which are only mediated in part by raised BMI.

Severe Hypothyroidism Complicated by Myopathy and Neuropathy with Atypical Demyelinating Features

Autoimmune hypothyroidism may result in a wide range of neuromuscular disorders. The frequently observed neurological manifestations of acquired hypothyroidism include mild to moderate myopathy and sensorimotor neuropathy, which usually resolve by clinical and electrophysiological criteria, in adults treated with thyroid hormone replacement. We report a case of a 30-year-old male with severe hypothyroidism secondary to chronic autoimmune thyroiditis who presented with a 2-year history of progressive fatigue, upper and lower limb weakness, myalgia, and intermittent paraesthesia. His neurological exam demonstrated proximal and distal muscle weakness, lower limb areflexia, and relatively intact sensory modalities. The patient's biochemistry revealed unusually and profoundly raised the thyroid stimulating hormone (TSH) level of 405.5 mIU/L (reference range (RR): 0.27–4.2 mIU/L) and creatine kinase (CK) level of 20,804 U/L (RR: 45–250 U/L), while his nerve conduction studies (NCS) demonstrated severe sensorimotor polyneuropathy with both axonal and demyelinating features. Thyroid hormone replacement therapy over the first 3 months resulted in biochemical normalization of his extremely deranged thyroid function tests (TFTs) and CK levels. At 12 months, despite maintaining euthyroidism and noticeable improvement in strength, his nerve conduction studies (NCS) demonstrated the continued absence of distal motor and sensory responses in his lower limbs with only partial improvement in sensory amplitudes and conduction velocities in his upper limbs. This report highlights the potential for severe neuromuscular consequences from advanced and chronic autoimmune hypothyroidism. The patient's myopathy has resolved over a period of three months with prompt normalization of CK levels. Concerningly, the patient achieved significant but incomplete recovery from his mixed axonal and demyelinating neuropathy with residual mild distal weakness and areflexia in his lower limbs and persistent motor and sensory impairments on his NCS. The severity and incomplete resolution of our patient's neurological manifestations emphasize the importance of early diagnosis and the need for prompt therapeutic intervention for hypothyroidism.

A Smart Tendon Hammer System for Remote Neurological Examination

The deep tendon reflex exam is an important part of neurological assessment of patients consisting of two components, reflex elicitation and reflex grading. While this exam has traditionally been performed in person, with trained clinicians both eliciting and grading the reflex, this work seeks to enable the exam by novices. The COVID-19 pandemic has motivated greater utilization of telemedicine and other remote healthcare delivery tools. A smart tendon hammer capable of streaming acceleration measurements wirelessly allows differentiation of correct and incorrect tapping locations with 91.5% accuracy to provide feedback to users about the appropriateness of stimulation, enabling reflex elicitation by laypeople, while survey results demonstrate that novices are reasonably able to grade reflex responses. Novice reflex grading demonstrates adequate performance with a mean error of 0.2 points on a five point scale. This work shows that by assisting in the reflex elicitation component of the reflex exam via a smart hammer and feedback application, novices should be able to complete the reflex exam remotely, filling a critical gap in neurological care during the COVID-19 pandemic.

Myocardial ischaemia reperfusion injury and cardioprotection in the presence of sensory neuropathy: Therapeutic options

During the last decades, mortality from acute myocardial infarction has been dramatically reduced. However, the incidence of post-infarction heart failure is still increasing. Cardioprotection by ischaemic conditioning had been discovered more than three decades ago. Its clinical translation, however, is still an unmet need. This is mainly due to the disrupted cardioprotective signalling pathways in the presence of different cardiovascular risk factors, co-morbidities and the medication being taken. Sensory neuropathy is one of the co-morbidities that has been shown to interfere with cardioprotection. In the present review, we summarize the diverse aetiology of sensory neuropathies and the mechanisms by which these neuropathies may interfere with ischaemic heart disease and cardioprotective signalling. Finally, we suggest future therapeutic options targeting both ischaemic heart and sensory neuropathy simultaneously. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.23/issuetoc.

[Carpal tunnel syndrome: Rare causes and associated forms behind a common and stereotyped affection]

Carpal tunnel syndrome (CTS) is too common a condition not to daily interact with the practitioner, if only because of its entanglement to other pathologies, causal or chance association. The typical symptomatology, with hand paresthesia and morning pain upon waking, is related to a median nerve injury in the confined space of the carpal tunnel, more often by local inflammation and tenosynovitis of the finger flexors (repetitive activity of the hands). SCC may be secondary to situations (pregnancy) or conditions (edema, hypothyroidism…), which exaggerate the ordinary pathophysiology or cause deposits in the channel (amyloidosis, mucopolysaccharidoses, etc.). Otherwise, SCC is favored by all neuropathies that cause nerve fragility (especially diabetes). It is sometimes the first sign of these various affections of which it can allow early diagnosis. Electroneuromyographic examination (ENMG) is a key examination to confirm the diagnosis (slowing of sensitive and motor conduction of the median nerve through the carpal tunnel, due to local demyelination), to look for a predisposing neuropathy and for signs of seriousness (amplitude reduction of electrophysiological signals) that indicate axonal loss. In SCC forms with only slowed conduction without sign of seriousness, a splint or infiltration treatment may be attempted. If this medical treatment does not bring healing, or if there are signs of seriousness or unbearable pains, a decompression surgery is indicated. Whether it is performed traditionally or endoscopically, it provides fast relief, even immediate.

Toxic and Endocrine Myopathies

PURPOSE OF REVIEW

This article discusses the clinical features, pathophysiology, and management of toxic and endocrine myopathies.

RECENT FINDINGS

Early detection and expeditious correction of metabolic disturbances in endocrinopathies such as Cushing syndrome, thyroid and parathyroid diseases, and acromegaly can minimize and prevent neurologic complications including myopathy. Recently proposed mechanisms of injury in patients with critical illness myopathy include inhibition of protein synthesis, mitochondrial dysfunction, disruption of the ubiquitin-proteasome system, oxidative stress, and disruption of intramuscular calcium homeostasis, which can cause a myosin-loss myopathy. Mechanisms underlying toxic myopathies include myosin loss; damage to cellular structures, including myofibrils and organelles such as lysosomes and mitochondria; inflammation; and necrosis. Presentations range anywhere from acute, painful, and necrotic myopathies, as can occur in statin myopathy, to more insidious presentations such as steroid myopathy.

SUMMARY

Endocrinopathies known to cause myopathy include thyroid and parathyroid diseases, disorders of the adrenal axis such as Cushing syndrome, and acromegaly. Patients in the intensive care unit are at risk for developing critical illness myopathy, also known as myosin-loss myopathy, which should be considered if intensive care unit acquired weakness develops. The most common toxic agents associated with myopathy include statins and other lipid-lowering medications, corticosteroids, colchicine, amiodarone, hydroxychloroquine, and chloroquine.

Investigation of Nerve Conduction Studies of Carpal Tunnel Syndrome Cases With Different Risk Factors: An Electrodiagnostic Study

PURPOSE

The aim of this study was to determine whether there are electrodiagnostic differences between carpal tunnel syndrome (CTS) patients with diabetes mellitus, CTS + hypothyroidism (HT), CTS + fibromyalgia syndrome, CTS + rheumatoid arthritis (RA), and idiopathic CTS cases, by comparing nerve conduction studies.

METHODS

This research examined electrophysiologic studies of 47 untreated HT + CTS, 47 diabetes mellitus + CTS, 49 RA + CTS, 52 fibromyalgia syndrome + CTS, 50 idiopathic CTS cases, and a healthy control group of 50 individuals (a total of 293 patients and 433 hands with CTS).

RESULTS

There were no significant differences between the groups in terms of sex and age. There was no significant difference between the CTS groups-in terms of numbers-with mild, moderate, and severe CTS. When the CTS groups were compared with the control group, in all CTS groups on both left and right hands, there was a significant prolongation in median motor latency and median sensory latency (in the 3rd finger); also a significant decrease in median sensory velocity in the 3rd finger. In diabetes mellitus, HT, and RA groups, the median motor amplitudes in both hands were significantly decreased compared with the idiopathic group. There was a moderate significant negative correlation between disease duration and median motor amplitudes (of both right and left sides) in RA (right; P = 0.028, r = 0.761, left; P = 0.041, r = 0.694) and HT groups (right; P = 0.035, r = 0.637, left; P = 0.049, r = 0.697).

CONCLUSIONS

Electrodiagnostic results showed both demyelinating injury and axonal damage in diabetes mellitus, HT, and RA patients with CTS, in these patients during treatment for CTS. Early treatment planning should include the risk factor diseases.

A Randomized Prospective Comparison of Ultrasound-Guided and Landmark-Guided Steroid Injections for Carpal Tunnel Syndrome

PURPOSE

The aim of this study was to compare the clinical and electrodiagnostic efficacy of ultrasound (US)-guided versus landmark (LM)-guided steroid injections in patients with carpal tunnel syndrome (CTS).

METHODS

This randomized clinical trial included 47 patients (60 affected hands) with moderate CTS (30 hands in each group). All clinically suspected patients with CTS who met the inclusion criteria confirmed by electrodiagnostic tests were enrolled. The subjects received 40 mg of methylprednisolone either with the US-guide or the LM-guided injection technique. They were evaluated using the Boston Carpal Tunnel Questionnaire (symptom/function/total) and 6 electrodiagnostic findings at the baseline and 12 weeks after injection.

RESULTS

Symptom severity scores and functional status scores and electrodiagnostic parameters were significantly improved within each group at week 12 after treatment (P < 0.05), except for compound muscle action potential amplitude and motor nerve conduction velocity (P > 0.05). The improvement in symptom severity scores and functional status scores in the US-guided group was more than in the LM-guided group after 12 weeks, but there was no statistically significant difference (P = 0.79 and 0.64). The mean changes in electrodiagnostic parameters were also not different between groups except for the higher sensory nerve action potential amplitude in LM-guided group (P = 0.003).

CONCLUSIONS

Both US-guided and LM-guided steroid injections were effective in reducing the symptoms, improving the function and electrodiagnostic findings of CTS. Although there was better symptomatic improvement with US-guided injections and better increase in sensory nerve action potential amplitude with LM-guided injection, a significant difference was not generally observed between US-guided and LM-guided CTS injections.

Hypothyroid myopathy: A peculiar clinical presentation of thyroid failure. Review of the literature

Abnormalities in thyroid function are common endocrine disorders that affect 5-10 % of the general population, with hypothyroidism occurring more frequently than hyperthyroidism. Clinical symptoms and signs are often nonspecific, particularly in hypothyroidism. Muscular symptoms (stiffness, myalgias, cramps, easy fatigability) are mentioned by the majority of patients with frank hypothyroidism. Often underestimated is the fact that muscle symptoms may represent the predominant or the only clinical manifestation of hypothyroidism, raising the issue of a differential diagnosis with other causes of myopathy, which sometimes can be difficult. Elevated serum creatine kinase, which not necessarily correlates with the severity of the myopathic symptoms, is certainly suggestive of muscle impairment, though it does not explain the cause. Rare muscular manifestations, associated with hypothyroidism, are rhabdomyolysis, acute compartment syndrome, Hoffman's syndrome and Kocher-Debré-Sémélaigne syndrome. Though the pathogenesis of hypothyroid myopathy is not entirely known, proposed mechanisms include altered glycogenolytic and oxidative metabolism, altered expression of contractile proteins, and neuro-mediated damage. Correlation studies of haplotype, muscle gene expression and protein characterization, could help understanding the pathophysiological mechanisms of this myopathic presentation of hypothyroidism.

Cross-sectional area of the median nerve is increased in primary autoimmune hypothyroidism and decreases upon treatment with thyroxine

BACKGROUND

The purpose of this study was to assess changes in the cross-sectional area (CSA) of nervus medianus by ultrasound in newly diagnosed primary hypothyroid patients after thyroxine replacement treatment.

PATIENTS AND METHODS

The cohort comprised 30 patients with newly diagnosed primary autoimmune hypothyroidism. These were subsequently compared with 30 controls, matched for sex, BMI and age. Ultrasound evaluation, including measurement of CSA at the level of the pisiform bone or tunnel inlet was performed at baseline and after 3months. A CSA threshold of more than 10mm(2) was considered pathological.

RESULTS

CSA was increased in patients compared with controls (9.8±0.7mm(2) vs 7.2±1.1mm(2); P<0.001). Thyroxin substitution increased fT4 levels (baseline, 11.0±0.6pmol/L vs 15.5±0.4pmol/L; P<0.001) and decreased TSH (baseline, 23.9±6.0mIU/L vs 2.7±0.2mIU/L; P<0.001). Thyroxine treatment decreased CSA to 8.4mm(2)±0.3mm(2) (P=0.033). Before treatment, four patients experienced distal paresthesia in the median nerve distribution area. Increased CSA pathognomonic for carpal tunnel syndrome found in two symptomatic patients normalized after 3months. No clinical symptoms were observed after 3months. A positive correlation was found between TSH and CSA (R=0.155, P=0.05) before treatment.

CONCLUSION

Our study demonstrates that increase in median nerve CSA caused by primary autoimmune hypothyroidism can be fully reversible after achieving target levels of TSH and fT4.

Rheumatic and autoimmune thyroid disorders: a causal or casual relationship?

A number of dysfunctions may affect the thyroid gland leading either to hyper- or hypothyroidism which are mediated by autoimmune mechanisms. Thyroid abnormalities may represent an isolated alteration or they may be the harbinger of forthcoming disorders as is the case of well-characterized polyendocrine syndromes. Also, they may precede or follow the appearance of rheumatic manifestations in patients affected with connective tissue diseases or rheumatoid arthritis. The mechanisms by which autoimmune thyroid disorders may be linked to systemic autoimmune diseases have not been fully unraveled yet, however alterations of common pathways are suggested by shared genetic variants affecting autoantigen presentation and regulation of the immune response. On the other hand, the higher prevalence of autoimmune thyroid disorders over rheumatic diseases compels the chance of a mere causal concomitancy in the same patient. The aim of our paper is to provide an overview of available data on thyroid involvement in different rheumatic diseases and to go over the main rheumatic manifestations in the context of autoimmune thyroid diseases.

Neurologic complications of nondiabetic endocrine disorders

PURPOSE OF REVIEW

This article provides an overview of the neurologic complications found in the various endocrine disorders affecting adult patients. Specifically, disorders in pituitary hormones (prolactin, growth hormone, vasopressin, and oxytocin), thyroid hormones, adrenal hormones (glucocorticoids), and sex hormones (estrogen and testosterone) will be covered, with an emphasis on identifying the signs and symptoms in addition to diagnosing and managing these disorders.

RECENT FINDINGS

Hyperthyroidism in the young was found to increase the risk for ischemic stroke in a recent prospective case-cohort study. The cognitive effects of hormonal therapy in postmenopausal women remain controversial, but a recent study found no benefit or risk in cognitive function when treating younger (50 to 55 years of age) postmenopausal women with hormonal therapy.

SUMMARY

Endocrine disorders can cause various neurologic complications, from insidious myopathy to acute encephalopathy. Diagnosing the endocrine disorder as the cause of the neurologic impairment is essential, as treating the underlying hormonal dysfunction will often rapidly reverse the neurologic symptoms. Ongoing research is needed to further clarify the role of hormonal dysfunction in neurologic disorders.

[Hypothyroid polyneuropathy in a patient with autoimmune polyglandular syndrome type 2: case report]

The incidence of polyneuropathy in patients with hypothyroidism is not precisely known, but some studies report that about 25% to 42% of patients may show neuropathic clinical signs. We report a case of autoimmune poliglandular syndrome type 2 (APS-2), whose initial presentation was hypothyroid polyneuropathy. A 41-year-old man complained of slowly progressive paresthesias and weakness affecting all four limbs, and associated with frequent drowsiness, weakness, cold intolerance, dizziness, nausea, and craving for salt. General physical examination showed hyperpigmentation of skin and mucous membranes, and hypotension. Neurological examination showed global, deep, and symmetrical hyporeflexia with slight signs of superficial hypoesthesia in the limbs. Electrodiagnostic studies (ENMG) together with laboratory tests, confirmed the suspicion of Hashimoto's thyroiditis associated with Addison's disease featuring the picture of APS-2. The patient was treated with fludrocortisone 0.05 mg/day and levothyroxine 100 mcg/day, and showed gradual and complete resolution of complaints. Changes were found in general physical and neurological examinations. ENMG repeated six months later showed complete resolution of neuropathy. This report shows a rare case of APS-2 presented as polyneuropathy hypothyroidism, and reinforces the importance of dosing thyroid hormone in polyneuropathy syndromes. Levothyroxine replacement was shown to be effective in reversing clinical and electrophysiologic neuropathy.

Asymptomatic myotonia congenita unmasked by severe hypothyroidism

Myotonia congenita is an inherited muscle disorder sustained by mutations in the skeletal muscle chloride channel gene CLCN1. Symptoms vary from mild to severe and generalized myotonia and worsen with cold, stressful events and hormonal fluctuations. Here we report the case of a young woman who sought medical attention because of subacute onset of diffuse and severe limb myotonia. CLCN1 gene sequencing showed a heterozygous transversion (T550M), two polymorphisms and one silent mutation. Thyroid function screening revealed severe hypothyroidism. She was placed on l-thyroxine replacement therapy which dramatically improved myotonia. We conclude that hypothyroidism unmasked a genetically determined, clinically asymptomatic chloride channelopathy. Diagnostic work-up in patients with clinically isolated myotonia should not be limited to genetic screening of non-dystrophic or dystrophic myotonias. Considering the high prevalence of hypothyroidism in females, systematic thyroid function screening by looking for additional hypothyroid symptoms and serum TSH levels measurement is mandatory in these patients.

Goiter and laryngeal sensory neuropathy

Objective. Examining the prevalence of laryngeal sensory neuropathy (LSN) in goiter patients versus a control group. Study Design. Cross-sectional study. Methods. 33 Goiter patients were enrolled versus 25 age-matched controls. TSH levels, size of thyroid gland, and presence or absence of thyroid nodules were reported. Subjects were asked about the presence or absence of any of the following symptoms: cough, globus pharyngeus, and/or throat clearing that persistented for more than 6 weeks. The presence of one or more of these symptoms for at least six weeks in the absence of LPRD, allergy, asthma, ACE inhibitor intake, and psychogenic disorder was defined as LSN. Results. For goitrous patients mean age (years) was (41.73 ± 9.47) versus (37.44 ± 10.89) for controls. 82% goitrous patients had known nodules and 27% carried a simultaneous diagnosis of hypothyroidism. Among those with documented size (61%), mean total thyroid volume was 26.996 ± 14.852 cm³, with a range from 9.430 to 67.022 cm³. The overall prevalence of LSN among goitrous patients was 42% versus 12% among controls (P = 0.0187). There was no correlation between LSN, size of thyroid gland, and TSH level. Conclusion. The prevalence of LSN in goitrous patients is significantly higher than that in a nongoitrous population.

[Metabolic neuropathies: overview in 2011]

Metabolic diseases constitute a frequent etiologic group of axonal and small-fiber neuropathies. Recent works in this field are dominated by diabetic neuropathy (clinical presentation, prognostic factors) because of its prevalence. Vitamin B12 deficiency aroused several studies in 2011. This renewed interest for this well known entity ensues from the lack of sensibility of its biological markers underestimating its prevalence, its clinical spectrum and therefore, access to its therapy. Finally, 2011 highlighted the growing interest of the measure of the intra-epidermic nerve fibers density by skin biopsy for some metabolic disorders such as infra-clinical hypothyroïdism, chronic renal failure or Fabry disease.

Severe oligozoospermia in a patient with myxedema coma

A case of severe oligozoospermia with myxedema coma is herein presented. The patient was referred to a male infertility clinic with a 5-year history of primary infertility. Decreased serum testosterone and elevated serum prolactin without abnormal MRI findings in the hypothalamus, and decreased semen volume and sperm motility were noted. A GnRH test revealed a decreased luteinizing hormone response, whereas the HCG test showed a normal testosterone increase. Because a urinalysis after ejaculation indicated retrograde ejaculation, imipramine administration was started. However, the semen quality deteriorated, so the patient was referred to an ART clinic. Twenty-one months from the initial visit, the patient developed a loss of consciousness and edema due to myxedema coma, a life-threatening state of hypothyroidism. The patient recovered after 1 month of thyroid hormone replacement therapy (HRT) with corticosteroids. Three months after the myxedema coma, a semen analysis showed a decreased semen volume (0.2 mL) and severe oligozoospermia (two spermatozoa/ejaculate). Elevated prolactin and decreased testosterone levels were still present. These parameters gradually improved after restoration of euthyroidism by HRT. In conclusion, physicians should confirm the thyroid function in the management of male infertility, especially in patients with elevated prolactin levels.