Cortico-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): about two case reports characterized by a gap between the diagnosis of autoimmune thyroiditis and neurological disorders

Steroid-Responsive Encephalopathy Associated With Autoimmune Thyroiditis Presenting With Parkinsonism

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a rare condition defined as encephalopathy with a positive antithyroid antibody. We report the case of a 52-year-old woman who presented with Parkinsonism associated with Hashimoto's thyroiditis. A few similar cases have been reported. Our patient responded well to corticosteroids with a significant reduction in symptoms. Diagnosis can pose a significant challenge in SREAT cases because of its variable clinical presentation. Therefore, we recommend evaluating thyroid function and thyroid autoantibodies in the context of acute and subacute encephalopathy. In the elderly population, SREAT, as a cause of Parkinsonism, should not be forgotten because of its simple treatment and significant improvements in neurological symptoms.

Hashimoto's encephalopathy: Follow-up data from neuropsychology, lumbar puncture, and FDG-PET

Hashimoto's encephalopathy is a rare disease with nonspecific symptoms, associated with elevated levels of anti-TPO and/or anti-TG. It can be potentially fatal. However, it is responsive to steroid and treated in due time, it can be fully reversible.

Encephalopathy Associated with Autoimmune Thyroid Disease: A Potentially Reversible Condition

Autoimmune thyroid disease may occasionally associate with unspecific neurological symptoms, which are more commonly insidious, include cognitive or behavioural symptoms, and may associate with tremor, myoclonus, or ataxia. We report a 61-year-old female patient who presented with chronic headache, insidious mood, and cognitive disturbance which evolved in a few months to dementia associated with exuberant limb myoclonus. Diagnostic workup revealed high anti-thyroid peroxidase antibody titers and an inflammatory CSF profile, and it was negative for other possible etiologies. Treatment with steroids induced significant improvement. The diagnosis of encephalopathy associated with autoimmune thyroid disease is still controversial given the fact that the clinical presentation and diagnostic workup are unspecific, the pathophysiology is still undetermined, and the diagnosis is mostly of exclusion. No direct correlation is found between anti-thyroid antibody titers and clinical presentation, and it is currently speculated that other still unrecognized antibodies may be responsible for this clinical entity. It is extremely important to recognize this entity because it is potentially treatable with immunotherapies. It is also increasingly recognized that clinical improvement with first-line treatment with steroids may be absent or incomplete, and other immunotherapies as immunosuppressants, intravenous immunoglobulin, or plasma exchange must be attempted in the clinical suspicion of EEAT.

Steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT) in childhood

AIM

Steroid responsive encephalopathy with autoimmune thyroiditis (SREAT) is a clinically and electrographically heterogeneous steroid-responsive encephalopathy associated with thyroid autoantibodies. We report an adolescent with SREAT and review PubMed literature relating to childhood.

METHODS

A 14-year-old boy, without any preceding history of trauma, meningoencephalitis or seizures, was admitted in a comatose state. A similar episode of loss of consciousness 2 months prior with normal neuroimaging and electroencephalogram (EEG) had been followed by behavioral alterations. A year previously, during evaluation for increased appetite and poor weight gain, he was noted to have small goitre with thyroid-stimulating hormone (TSH) 7.26 mIU/L, T3 1.232 nmol/L, and T4 117.63 nmol/L. Routine hemogram, blood biochemistry, thyroid function tests including free hormone levels, ultrasonography thyroid and magnetic resonance imaging were normal. EEG showed diffuse slowing of all waves. Cerebrospinal fluid showed no pleocytosis and electrophoresis showed oligoclonal band. Viral studies and serum N-methyl-D-aspartate receptor antibody levels were negative. Anti-thyroid peroxidase (Anti-TPO) antibodies were raised. Intervention was with intravenous dexamethasone 4 mg every 6 h for 1 week followed by tapering schedule of oral prednisolone over 6 months.

RESULTS

He regained consciousness after the second dose of dexamethasone and was discharged on day 7 in a fully conscious and ambulant state on a tapering course of low dose prednisolone for 6 months. He remains euthyroid with normal sensorium and behavior at 18 months follow-up. Only 50 cases below 18 years age were identified amongst 300 PubMed articles up to 31 July 2013.

CONCLUSION

Prompt steroid therapy following early recognition by high clinical suspicion and measurement of antithyroid antibody titers can lead to a favorable prognosis in SREAT.

Hashimoto encephalopathy: a rare intricate syndrome

Recently, several patients have been reported with various signs of encephalopathy and high thyroid antibody levels together with good responsiveness to glucocorticoid therapy. Despite the various clinical presentations, these cases have been termed "Hashimoto encephalopathy" (HE). Although all of the pathogenic components have not yet been clearly elucidated, it is believed that brain vasculitis and autoimmunity directed against common brain-thyroid antigens represent the most likely etiologic pathway. The most common clinical signs include unexplained or epilepsy-like seizures resistant to anti-convulsive treatment, confusion, headaches, hallucinations, stroke-like episodes, coma, impairment of cognitive function, behavioral and mood disturbance, focal neurological deficits, disturbance of consciousness, ataxia, and presenile dementia, together with the presence of high thyroid antibody levels, especially against thyroperoxidase (TPOab). In most cases, the thyroid function is normal or decreased; the thyroid function is rarely increased. The examination of the cerebrospinal fluid, EEG, MRI, SPECT, and neuropsychological examinations are primarily used as diagnostic tools. Most cases showed neural symptoms for months before the acute onset; in some cases, a dramatic acute onset was described. Once the diagnosis is made, corticosteroid treatment usually provides a dramatic recovery. The authors also present a short review of literary cases reported in last decade.

Immune mediated diseases and immune modulation in the neurocritical care unit

This chapter will review the spectrum of immune-mediated diseases that affect the nervous system and may result in an admission to the neurological intensive care unit. Immunomodulatory strategies to treat acute exacerbations of neurological diseases caused by aberrant immune responses are discussed, but strategies for long-term immunosuppression are not presented. The recommendations for therapeutic intervention are based on a synthesis of the literature, and include recommendations by the Cochrane Collaborative, the American Academy of Neurology, and other key organizations. References from recent publications are provided for the disorders and therapies in which randomized clinical trials and large evidenced-based reviews do not exist. The chapter concludes with a brief review of the mechanisms of action, dosing, and side effects of commonly used immunosuppressive strategies in the neurocritical care unit.

Successful response to intravenous immunoglobulin as rescue therapy in a patient with Hashimoto's encephalopathy

The authors describe the case of a 61-year-old woman who was admitted to our intensive care unit (ICU) due to impaired consciousness associated with generalised seizures. Her cerebrospinal fluid, electrolytes, acid-base analysis, and common laboratory and toxicology tests were normal. An MRI ruled out the presence of stroke or haemorrhage but showed severe leukoencephalopathy. Parkinson's disease, Creuzfeld-Jacob disease, vascular alterations, cancer, and rheumatological and metabolic diseases were evaluated and excluded. In view of her history of hypothyroidism despite adequate hormonal replacement and clinical behaviour, Hashimoto's encephalopathy was considered. Anti-thyroperoxidase levels were above 3000 IU/ml. The patient received 5 g of methylprednisolone followed by prednisone, but after a favourable initial response, returned to a comatose state. However, after administration of intravenous immunoglobulin (IVIG) 2 g/kg, the patient recovered with resolution of neurological symptoms and was discharged from the ICU 4 days after finishing IVIG treatment.