Neurologic manifestations of myxedema

Complete recovery after severe myxoedema coma complicated by status epilepticus

We report a case of life-threatening myxoedema presenting with hypothermia, hypotension, bradycardia, pericardial effusion and deep coma. The condition was complicated by prolonged status epilepticus. The optimal treatment strategy has been debated over the years and the literature is briefly reviewed. Treatment with l-thyroxine (LT4) monotherapy without initial loading dose and with no l-triiodothyronine (LT3) treatment was successful with full recovery after hospitalisation for more than a month. Myxoedema coma is a rare, reversible condition with a high mortality and should be considered as a differential diagnosis in medical emergencies.

Hashimoto encephalopathy presenting as progressive myoclonus epilepsy syndrome

We report an 11 year old girl with multi-focal spontaneous myoclonus, generalized seizures and behavioural changes. She was found to have sub-clinical hypothyroidism and elevated anti-thyroid peroxidase antibodies. A diagnosis of Hashimoto encephalopathy (or Steroid Responsive Encephalopathy with Autoimmune Thyroiditis) was made in view of consistent clinical and laboratory features. The patient showed and maintained significant improvement with valproate, clonazepam and long term prednisolone. Other findings included mild cerebral cortical grey matter atrophy on brain magnetic resonance imaging and intermittent slowing with generalized poly-spike-and-wave discharges on electroencephalography. Other causes of progressive myoclonus epilepsy (PME) syndrome including subacute sclerosing panencephalitis, Lafora body disease, Juvenile Neuronal Ceroid Lipofuscinosis, Late onset gangliosidosis, Sialidosis, mitochondrial disorders and coeliac disease were ruled out by appropriate investigations. No other auto-immune abnormality was detected. This case emphasizes that Hashimoto encephalopathy should be considered in the etiologies of PME syndrome in adolescents since it is a treatable entity.

Encephalopathy associated with Hashimoto thyroiditis: pediatric perspective

In recent years, neuropsychiatric symptoms associated with Hashimoto thyroiditis have been increasingly recognized in both adult and pediatric patients. This neurologic complication has been termed "Hashimoto encephalopathy," and it can begin abruptly, in the form of seizures or agitation, with or without other neurologic complaints, or it can develop gradually, in a relapsing-remiting manner, including, among others, cognitive deterioration and psychiatric illness. The occurrence of Hashimoto encephalopathy is unrelated to the patient's thyroid function status. Although the pathogenesis of this encephalopathy is not fully understood, evidence for both autoimmune and vasculitic mechanisms exists. Owing to a low index of suspicion, this encephalopathy is very likely underdiagnosed in children. The diagnosis of Hashimoto encephalopathy is based on detecting antithyroid antibodies in these patients, although there is no correlation between antibody levels and the severity of the illness. Cerebrospinal fluid analysis, electroencephalography, and neuroimaging studies do not show consistent findings to support the diagnosis. Physicians' awareness of this complication is of great importance because most patients respond dramatically to corticosteroid therapy. Moreover, early recognition might also avoid an expensive diagnostic work-up in patients with unexplained encephalopathy (J Child Neurol 2006;21:1-5).

Low headache prevalence amongst women with high TSH values

The aim of this large cross-sectional population-based study was to examine a possible positive or negative association between thyroid dysfunction and headache. Between 1995 and 1997, all 92 566 adults in Nord-Trøndelag County in Norway were invited to participate in a health survey. A total of 51 383 (56%) responded to a headache questionnaire, whereof thyroid-stimulating hormone (TSH) was measured in 28 058 individuals. These included 15 465 women and 8019 men above 40 years of age, 1767 randomly selected individuals between 20 and 40 years of age, and 2807 (97%) with thyroid dysfunction. Associations between thyroid dysfunction and headache were assessed in multivariate analyses, estimating prevalence odds ratios (OR) with 95% confidence intervals (CIs). High TSH values were associated with low prevalence of headache. This was most evident amongst women with no history of thyroid dysfunction. Amongst these, headache was less probable (OR=0.5, 95% CI 0.3-0.7) if TSH > or = 10 mU/l than in women with normal TSH (0.2-4 mU/l). In all age groups between 40 and 80 years, TSH was lower amongst headache sufferers, especially migraineurs, than in those without headache complaints.

Headache etiology in children: a retrospective study of 125 cases

BACKGROUND

To determine the headache etiology in children in the middle Anatolia region of Turkey.

METHODS

The clinical and laboratory findings of 125 patients, who were followed up after a diagnosis of headache in our hospital, were reviewed retrospectively. The criteria defined by the International Headache Society (IHS) were used in the classification of patients. The patients were divided into two subgroups according to age intervals: (i) group 1, 5-10 years of age; and (ii) group II, 11-16 years of age.

RESULTS

There were 62 males and 63 females in the study. The patients' ages ranged from 5 to 16 years (mean (+/- SD) age 10.67+/-2.72 years). Headache was more commonly noted between 11 and 16 years of age. While headache was more frequent in male children in group I, there was female predominance in group II. However, there was no significant difference between the groups with respect to age and gender (P>0.05). The most frequent cause of headache was migraine and the remaining causes, in decreasing order, included sinusitis (no. 11 according to IHS criteria) and tension-type and psychosomatic headaches (no. 13 according to IHS criteria). Of the 125 patients in the study, 85 (68%) had acute headache and 40 (32%) had chronic headache; 44 (35.2%) patients had acute localized-type headache, 39 (31.2%) suffered from acute recurrent-type headache, 38 (30.4%) had chronic non-progressive headache and acute generalized and chronic progressive-type headache were diagnosed in two (1.6%) patients. Computed tomography (CT) and magnetic resonance imaging (MRI) of the brain were performed in 50 and seven patients, respectively; there were abnormal findings in six patients on CT examiniation and in two patients following MRI.

CONCLUSIONS

In conclusion, we stress that the most frequent cause of headache in childhood is migraine and the remaining causes, in decreasing order of frequency, were sinusitis and tension-type and psychosomatic headaches. Neuroimaging studies, such as CT or MRI, need to be performed, especially in patients with complicated symptoms.

Encephalopathy as the presenting symptom of Hashimoto's thyroiditis

In recent years, encephalopathy has increasingly been recognized as a complication of Hashimoto's thyroiditis. It can begin abruptly as a stroke-like event, acute seizures, or confusion, or as an insidious decline in cognitive function. Most reported cases have been on adult patients, although this encephalopathy does affect children as well. This form of encephalopathy should be considered in the differential diagnosis of children and adults with unexplained neurologic deterioration. We describe the case of a child in whom acute encephalopathy was the presenting symptom of Hashimoto's thyroiditis.

Hashimoto's myoclonic encephalopathy: an underdiagnosed treatable condition?

We report two patients with subacute diffuse encephalopathy characterized by confusion, myoclonic encephalopathy, and mild akineto-rigid extrapyramidal signs in one case and by apathy, memory deficit, and partial complex seizures in the other. Hashimoto's thyroiditis with high titers of anti-thyroglobulin antibodies was diagnosed in both patients, who were unresponsive to anticonvulsant medication, but showed rapid neurological improvement following steroid treatment. On neuropsychological examination, predominant frontotemporal dysfunction was noted. Electroencephalographic activity was remarkable for its rhythmical delta activity, unresponsive to, or even paradoxically increased by, anticonvulsant treatment. On magnetic resonance imaging, atrophy with temporal predominance was found. These observations support the idea that this potentially treatable dementia and movement disorder should be classified as a separate clinical entity.

Neurologic complications of thyroid and parathyroid disease

Common thyroid and parathyroid disorders present with reversible neurologic signs and symptoms affecting the central and peripheral nervous system, musculature, and mental function. Patients with thyrotoxicosis may have myopathy, spasticity, seizures, and multiple psychiatric symptoms. A deficiency of thyroid hormone also causes muscle weakness and may be accompanied by reversible muscle hypertrophy or movement disorders. The chronic hypercalcemia that develops secondary to hyperparathyroidism produces many psychiatric and cognitive symptoms, as well as a reversible myopathy. Calcium deficiency leads to neuromuscular irritability, paresthesias, and tetany. Psychiatric disorders are also common in this disorder.

Thyroid function in patients with chronic headache

Headache is one of the neurological manifestations of hypothyroidism but it is unknown whether there is a relationship between hyperthyroidism and chronic headache. Thyroid function tests were performed in 30 patients with chronic headache. Six were found to have hyperthyroidism and none had hypothyroidism. Thyroid testing may be useful for differential diagnosis of chronic headache, and indicates that headache could be caused by hyperthyroidism.

Selective suppression of neurofilament antigen expression in the hypothyroid rat cerebral cortex

As an integral component of the cytoskeleton neurofilaments play a central role in the establishment and maintenance of neuronal form. In particular, high neurofilament concentrations are characteristic of many classes of axons in the central nervous system. Isolated neurofilaments from rat brain consist of 3 distinct polypeptides with apparent molecular weights 210K, 160K and 68K. A murine monoclonal antibody, mabN210, has been produced which specifically recognizes an epitope associated with the high molecular weight subunit and this antibody has been used to explore the regulation of neurofilament expression during brain development. It has been shown that in the rat cerebellar cortex, the expression of mabN210-immunoreactivity in basket cell axons is severely suppressed in hypothyroidism while neurofilament antigen expression in other cerebellar axons seems not to require thyroid hormones. In view of the well-known cortical deficits in hypothyroidism, these studies have now been extended to include the developing rat cerebral cortex and selected cortical afferent and efferent axons. In hypothyroid rats there is a marked suppression of mabN210-immunoreactivity in the cerebral cortex and corpus callosum and, to a lesser extent, there is a reduction in staining in the internal capsule. By contrast, hypothyroidism did not reduce mabN210-immunoreactivity in the lateral olfactory tract or the stria medullaris. In rats, serum thyroid hormone starts to rise to adult levels on postnatal day 4. It appears that axons that have attained their mature distribution prior to the onset of thyroid hormone expression are not affected by hypothyroidism whereas mabN210-immunoreactivity is suppressed in those axonal tracts that reach a mature distribution after P4.

Organic delusions: phenomenology, anatomical correlations, and review

Organic delusions are common, but have received little systematic study. Review of the literature reveals that they occur most commonly in toxic-metabolic processes and in disorders affecting the limbic system and basal ganglia. A prospective study of 20 consecutive patients with organic delusions revealed four general types of false beliefs: simple persecutory delusions, complex persecutory delusions, grandiose delusions, and those associated with specific neurological defects (anosognosia, reduplicative paramnesia). Simple delusions responded best to treatment, and complex delusions were more resistent. Acting on delusional beliefs was not unusual, and treatment of the delusions was an important aspect of management of the patient.

Reversible alteration of the visual evoked potential in hypothyroidism

The pattern-shift evoked potential was measured in 19 hypothyroid patients before treatment, and after short- (one week) and long-term (12 to 24 weeks) thyroid hormone replacement therapy. Before treatment, nine patients had an abnormally prolonged visual evoked potential latency, more than 115 msec. After one week of therapy with 50 micrograms per day of L-triiodothyronine, the mean visual evoked potential latency for the entire group was unchanged, 114 +/- 8 to 114 +/- 7 msec. However, long-term therapy with 100 to 200 micrograms per day of L-thyroxine significantly shortened the visual evoked potential latency to 105 +/- 1 msec (p less than 0.001). In eight of the nine patients with initially abnormal results, the visual evoked potential latency was completely restored to normal. The visual evoked potential amplitude was also significantly changed by long-term L-thyroxine, 4.8 +/- 0.7 to 9.0 +/- 1.0 microV (p less than 0.01). It is concluded that the visual evoked potential is reversibly altered in hypothyroidism. This neurophysiologic parameter permits quantitation of the effects of hypothyroidism on the central nervous system and the extent and rate of response to thyroid hormone replacement therapy.

Multiple sclerosis co-existent with myxedema. An autopsy case report

A 64-year-old woman developed impaired consciousness and vision, sensorimotor paresis, hypothermia, bradycardia, and edema. Symptoms fluctuated with seasonal exacerbations in winter and terminated in coma with respiratory insufficiency at age 69. High CSF protein content and low serum T4 and TSH levels were noted. Treatment with prednisolone and thyroxin considerably improved her consciousness and edema. The patient suddenly expired of pulmonary embolism. Postmortem examination revealed a marked atrophy of pituitary and thyroid glands, while multiple demyelinating plaques were disclosed in the optic tract and cervical cord. A review of the literature indicates that this is the first report of the co-existence of two such disorders.

Episodic encephalopathy associated with thyroid disorders

Two patients with a thyroid disorder and an associated episodic encephalopathy are reported. The relationship between Hashimoto's thyroiditis, myxoedema, and neurological disease is considered, and the evidence for such disorders being due either to an underlying autoimmune process or that the encephalopathy is a direct result of the thyroid disorder is discussed.