Steroid-responsive encephalopathy associated with autoimmune thyroiditis presenting with diffusion MR imaging changes

MRI Findings of Two Patients With Hashimoto Encephalopathy

Hashimoto encephalopathy (HE), also known as steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), is a rare type of autoimmune encephalitis that typically presents with cognitive and neuropsychiatric symptoms that resolve with steroids. Positive neuroimaging findings of HE are rarely reported in the literature. We present two cases of HE with abnormal MRI findings, including signal abnormalities in the claustrum, cerebral white matter, and mesial temporal lobes. HE and other forms of autoimmune encephalopathies can often be misdiagnosed as viral encephalopathies. As such detection of subtle neuroimaging findings in the context of suspicious clinical history should prompt further investigations to ensure accurate and timely diagnosis.

Brain Diffusion Tensor Imaging Findings in Hashimoto's Thyroiditis

BACKGROUND AND PURPOSE

Hashimoto's thyroiditis (HT) is a type of autoimmune thyroid disease. Diffusion tensor imaging (DTI) can evaluate microstructural brain involvement in various diseases. We aimed to investigate whether there were any DTI differences in patients with HT, and the relationship between DTI values and disease duration time and thyroid peroxidase antibodies (TPOAb) levels.

METHODS

We prospectively included 36 patients with HT (mean age 41.6 ± 13.8 years, range 18-64 years) and 18 age and sex-matched healthy control subjects (mean age 41.6 ± 13.1 years, range 18-63 years). All patients were euthyroid at the time of imaging. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) values of 15 distinct neuroanatomical locations were measured and compared.

RESULTS

FA values of the patients with HT were lower in cingulum, globus pallidus (GP), cerebellar white matter (CWM) than the control (P = .019, .002, and <.001, respectively). MD values of the CWM in patients were higher than the control (P = .008). AD values of patients with HT were lower in the cingulum, posterior limbs of the internal capsule, GP, and putamen (P = .038, .038, .030, and .045, respectively). RD values of cingulum and CWM in HT were higher than controls (P <.001 and P = .011, respectively). There was a negative relationship between the FA values of PLIC and a positive relationship between the MD values of the corona radiata and TPOAb levels were detected.

CONCLUSIONS

The current DTI study presented microstructural changes in the neurocognitive-related areas that may be related to accompanying neurological findings in HT.

Acute cerebellar ataxia: differential diagnosis and clinical approach

Cerebellar ataxia is a common finding in neurological practice and has a wide variety of causes, ranging from the chronic and slowly-progressive cerebellar degenerations to the acute cerebellar lesions due to infarction, edema and hemorrhage, configuring a true neurological emergency. Acute cerebellar ataxia is a syndrome that occurs in less than 72 hours, in previously healthy subjects. Acute ataxia usually results in hospitalization and extensive laboratory investigation. Clinicians are often faced with decisions on the extent and timing of the initial screening tests, particularly to detect treatable causes. The main group of diseases that may cause acute ataxias discussed in this article are: stroke, infectious, toxic, immune-mediated, paraneoplastic, vitamin deficiency, structural lesions and metabolic diseases. This review focuses on the etiologic and diagnostic considerations for acute ataxia.

Hashimoto Encephalopathy as a Complication of Autoimmune Thyroiditis

OBJECTIVE

To present a case of Hashimoto encephalopathy as a complication of autoimmune thyroiditis.

CLINICAL PRESENTATION AND INTERVENTION

A previously healthy 56-year-old female presented with rapidly progressive cognitive decline and visual hallucinations. Being a diagnosis of exclusion, Hashimoto encephalopathy required an extensive laboratory and diagnostic workup, which was done over the course of a 15-day hospitalization. The patient recovered after initial treatment with intravenous methylprednisolone and was then switched to prednisone p.o.

CONCLUSION

This case report illustrates the importance of awareness for Hashimoto encephalopathy, as it remains one of the few easily treatable and reversible causes of rapid cognitive decline.

Hashimoto's encephalopathy

We report a case of Hashimoto’s encephalopathy with atypical and partially reversible MRI findings. T2-weighted MRI images revealed bilaterally symmetric areas of increased signal in the mesial temporal lobes and basal ganglia. Despite clinical and imaging improvement after steroid therapy, some memory deficits and MRI abnormalities persisted.

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT): case report of reversible coma and status epilepticus in an adolescent patient and review of the literature

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), also termed Hashimoto's encephalopathy (HE), is a rare immune-mediated disorder and is also affecting children and adolescents. It is characterized by altered mental status, seizures, and cognitive dysfunction. Therapeutic options include steroid treatment and prognosis range from complete recovery, a relapsing course to long-term cognitive sequelae. We describe a previously healthy 13-year-old girl presenting to the emergency room with coma and refractory status epilepticus. Generalized tonic-clonic seizures persisted after pre-hospital infusion of antiepileptic medication. She was found to have highly elevated levels of thyroid-stimulating hormone and anti-thyroid peroxidase antibodies not only in blood but also in cerebrospinal fluid while showing negative results for traumatic, infectious, metabolic, toxic, neoplastic, or other known specific autoimmune diseases. Cranial neuroimaging revealed no abnormality. A diagnosis of SREAT was established, and the patient improved rapidly on corticosteroids and levothyroxine therapy. However, 3 months after the discontinuation of steroid treatment, the girl relapsed. The current literature regarding SREAT is reviewed and summarized.

CONCLUSION

In children with SREAT, early diagnosis and treatment with corticosteroids is crucial and can lead to rapid clinical improvement. Clinicians should be aware of this uncommon but treatable condition, especially in female adolescents with unexplained seizures or an encephalopathic state.

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.

Differential diagnosis of white matter lesions: Nonvascular causes-Part II

The knowledge of characteristic lesion patterns is important in daily practice imaging, as the radiologist increasingly is required to provide precise differential diagnosis despite unspecific clinical symptoms like cognitive impairment and missed elaborated neurological workup. This part II dealing with nonvascular white matter changes of proven cause and diagnostic significance aimed to assist the evaluation of diseases exhibiting lesions exclusively or predominantly located in the white matter. The etiologies commented on are classified as follows: (a) toxic-metabolic, (b) leukodystrophies and mitochondriopathies, (c) infectious, (d) neoplastic, and (e) immune mediated. The respective mode of lesion formation is characterized, and typical radiological findings are displayed. More or less symmetrical lesion patterns on the one hand as well as focal and multifocal ones on the other are to be analyzed with reference to clinical data and knowledge of predilection sites characterizing major disease categories. Complementing spinal cord imaging may be useful not only in acute and relapsing demyelinating diseases but in certain leukodystrophies as well. In neuromyelitis optica (NMO), the detection of a specific antibody and some recently published observations may lead to a new understanding of certain deep white matter lesions occasionally complicating systemic autoimmune disease.

Steroid-responsive thalamic lesions accompanying microbleeds in a case of Hashimoto's encephalopathy with autoantibodies against α-enolase

A 67-year-old man receiving antithrombotic therapy developed rapidly progressive amnesia. T2-weighted images of brain MRI revealed hyperintense lesions in the bilateral thalami accompanied by microbleeds. Antithyroglobulin antibodies and autoantibodies against the N-terminal of α-enolase (NAE) were identified in the patient's serum; therefore, Hashimoto's encephalopathy (HE) was suspected. Although the patient's radiological findings improved following steroid therapy, his symptoms did not improve, possibly due to increased thalamic microbleeds. Because anti-NAE antibodies are possibly associated with vasculitis, HE accompanied by anti-NAE antibodies may be exacerbated by microbleeds in patients receiving antithrombotic therapy.

Autoimmune encephalopathies and epilepsies in children and teenagers

Recognition of autoimmune encephalopathies and epilepsies in children and teenagers with acute or subacute onset of central nervous system dysfunction, through detection of the pertinent antibody on serum or cerebral spinal fluid, or through a response to immunotherapy may lead to an early diagnosis, and thus expedited implementation of immunotherapy and improved neurological outcome. The epidemiology of pediatric autoimmune encephalopathy and epilepsy is not well established, but advances in disease-specific biomarker discovery have lead to identification of disorders with either a cytotoxic T cell mediated pathogenesis or (more recently) possible autoantibody mediated disorders. This review summarizes the clinical presentations and recommended evaluations and treatment of pediatric epileptic encephalopathy suspected to be of autoimmune etiology.

Steroid-responsive encephalopathy associated with Hashimoto thyroiditis

An 11-year-old girl presented with sudden sensory disturbance and left-sided muscle weakness. MRI revealed ischaemic change in the right lateral thalamus and the right internal capsule. During sonographic work-up of the cervical arteries, inflammation of the thyroid gland was noted. The results of the thyroid function tests and antibody titers confirmed Hashimoto thyroidits. Under high-dose corticosteroids, the girl had a full neurological recovery.

Isolated adrenocorticotropic hormone deficiency associated with Hashimoto's disease and thyroid crisis triggered by head trauma. Case report

A 47-year-old man presented to our hospital after suffering transient loss of consciousness and falling to the floor. On admission, his Glasgow Coma Scale score was 11 (E3V3M5), and he exhibited restlessness. Blood examination revealed hyperthyroidism. Computed tomography showed slight traumatic subarachnoid hemorrhage. He developed fever and tachycardia, and was diagnosed with thyroid crisis. Magnetic resonance imaging showed a brain contusion in the right frontal lobe, and encephalopathy signs in the right frontal and insular cortex. Immunocytochemical examinations suggested Hashimoto's disease, and hormone examinations revealed plasma levels were undetectably low of adrenocorticotropic hormone (ACTH) and low of cortisol. Pituitary stimulation tests showed inadequate plasma ACTH and cortisol response, consistent with isolated ACTH deficiency (IAD). The final diagnosis was IAD associated with Hashimoto's disease. Hydrocortisone replacement therapy was continued, and the patient was nearly free from neurological deficits after 18 months. The neuroimaging abnormalities gradually improved with time.