Hashimoto Encephalopathy Presenting With Stroke-Like Episodes in an Adolescent Female: A Case Report and Literature Review

Diagnostic and Therapeutic Challenges of Steroid-Responsive Encephalopathy Associated With Thyroiditis: A Case Report

Steroid-responsive encephalopathy associated with thyroiditis (SREAT) is a rare autoimmune disorder characterized by cognitive dysfunction. SREAT is frequently overlooked despite its profound impact on patients and the healthcare system. This case report details a male patient who experienced a series of neuropsychiatric symptoms over several months, ultimately attributed to SREAT, emphasizing the critical impact of delayed recognition. The case underscores the diverse and often complicated presentations of SREAT, advocating for the timely consideration of autoimmune encephalopathy in patients with unexplained neuropsychiatric symptoms and abnormal thyroid function. Furthermore, it illustrates the effectiveness of steroids in managing SREAT and the challenges posed by long-term steroid use. Comprehensive diagnostic criteria and tailored treatment strategies are crucial for improving patient outcomes in this rare but impactful disorder.

Clinical presentations and treatment outcomes of Hashimoto encephalopathy at Siriraj Hospital - Thailand's largest national tertiary referral center

BACKGROUND

Hashimoto encephalopathy has multiple clinical presentations, and other than the presence of thyroid antibody, laboratory and imaging investigations are all non-specific. Data specific to the clinical presentations and treatment outcomes of patients with Hashimoto encephalopathy in Thailand remain scarce.

OBJECTIVES

To retrospectively investigate the clinical presentations and treatment outcomes of patients with Hashimoto encephalopathy at Siriraj Hospital.

METHODS

Patients who presented with acute encephalopathy at our center during July 2012-March 2017 were evaluated for eligibility. The inclusion criteria were positive anti-thyroperoxidase (anti-TPO) or anti-thyroglobulin (anti-Tg) in serum with negative neuronal antibody in serum or cerebral spinal fluid (CSF). Clinical presentations, symptom duration, laboratory results of thyroid status and thyroid autoantibody, CSF study, and clinical outcomes were collected.

RESULTS

Of the 204 patients who presented with encephalopathy, 31 (15.2%) were positive for the anti-TPO or anti-Tg antibody. Of those, 13 patients met the diagnostic criteria for Hashimoto encephalopathy. Clinical presentations included cognitive impairment (76.9%), clouding of consciousness (46.2%), and behavior change (30.8%). The neuropsychiatric presentations were visual hallucination (30.8%), auditory hallucination (15.4%), delusion (7.7%), and mood disturbance (23.1%). Other clinical presentations included seizure (38.5%), abnormal movement (23.1%), sleep disturbance (38.5%), ataxia (46.2%), stroke-like episode (15.4%), and fever (15.4%). Most patients (76.9%) had onset within < 3 months. Regarding outcomes, 1 patient who did not receive corticosteroid died from status epilepticus and septic shock. Among the 12 patients who received corticosteroid, 9 (75%) had marked improvement, 1 (8.3%) had slight improvement, and 2 (16.6%) had no clinical improvement. Seven patients (53.9%) had normal thyroid function, 4 patients (30.8%) had subclinical hypothyroidism, and 2 patients (15.4%) had subclinical hyperthyroidism.

CONCLUSIONS

The results of this study revealed cognitive impairment, neuropsychiatric symptoms, seizure, ataxia, and sleep disturbance to be common manifestations of Hashimoto encephalopathy. This condition should always be considered in individuals with subacute onset of unexplained cognitive impairment or cerebellar ataxia. Laboratory and neuroimaging investigations were all found to be nonspecific in Hashimoto encephalopathy. Most patients responded well to treatment, so clinical suspicion and early diagnosis and treatment will lead to improved patient outcomes.

Autoimmune Encephalitis

Autoimmune encephalitis is a common and treatable cause of encephalitis in children and adults. Individuals present with a variety of symptoms, including altered mental status, behavioral changes, irritability, insomnia, developmental regression, seizures, dyskinetic movements, and autonomic instability. Evaluation includes electroencephalography, magnetic resonance imaging, and lumbar puncture. Once infectious and other causes are reasonably ruled out, treatment should be started empirically without waiting for antibody confirmation. Early clinical suspicion is key, as the outcome depends on early initiation of immunotherapy, including corticosteroids, intravenous immunoglobulin, and/or plasmapheresis. Severe or refractory cases require other treatments, such as rituximab, cyclophosphamide, or other immunotherapies using novel monoclonal antibodies. Psychiatry should be involved early for the management of behavioral issues. Additional considerations include management of seizures and dyskinesias. ICU admission may be required for management of hypoventilation necessitating mechanical ventilation (either intrinsic or iatrogenic, eg, from sedatives), refractory seizures, and dysautonomia. Anti-N-methyl-d-aspartate receptor and other forms of autoimmune encephalitis are less often associated with neoplasia (such as ovarian teratoma) in children compared with adults, but screening and removal of tumor if present should be performed.

Clinical characteristics of paediatric Hashimoto's encephalopathy

BACKGROUND

Hashimoto's encephalopathy, also known as steroid responsive encephalopathy, is associated with thyroid antibodies (SREAT) and is a rare but serious form of encephalopathy. In this paper, we describe the signs, symptoms, outcome, and treatments as noted in the case reports reviewed.

METHODS

We searched PubMed, Embase, and the Cochrane library for articles in which cases of Hashimoto's encephalopathy were described. The case description had to include the diagnosis, age, sex, presenting symptoms, and diagnostic tests.

RESULTS

We retrieved 360 articles and 65 fulfilled the inclusion criteria. These articles gave reports of 100 cases, with a mean age of 10.9 (range 2.8-19), 78 of whom were female. Epilepsy (79) - including epileptic state [24] - behavioural problems [36], hallucinations [21], headache [21], and decline in school performance [19] were most often reported. Antithyroid peroxidase (aTPO) was reported elevated in all patients. Most children [70] recovered fully, however 16 had late sequelae, mostly epilepsy. Therapies used include steroids, intravenous gammaglobulines, and cytostatics.

CONCLUSIONS

Epilepsy, behavioural problems, decline in school performance, and hallucinations are frequent symptoms of Hashimoto's encephalopathy. Steroids are the basis of treatment, although other immunomodulatory drugs seem to be successful. About one in ten children will experience late sequelae. In any child with unexplained neurological, psychiatric, or psychological dysfunction, serum anti-thyroidperoxidase (aTPO) should be determined.

Hashimoto Encephalopathy

Hashimoto encephalopathy (HE) is a steroid-responsive, acute or subacute encephalopathy, characterised by autoimmune thyroiditis associated with elevated antithyroid antibody titres. An 11-year-old girl was admitted to the Department of Paediatrics with generalised tonic-clonic seizures, left facial paralysis and right hemiparesis. Ceftriaxone and acyclovir were applied, and methyl prednisolone 2 mg kg^-1 day^-1 was administered orally. The hemiparesis improved on the 3^rd day of treatment, but the facial paralysis persisted into the 15^th day. When she developed somnolence, she was transferred to the paediatric intensive care unit and provided with respiratory support after intubation. Antithyroid peroxidase (Anti-TPO) and Antithyroglobulin antibody (Anti-Tg) levels were measured at 112.3 IU mL^-1 and 74.6 IU mL^-1, respectively. HE was considered as the provisional diagnosis, for which intravenous methyl prednisolone 30 mg kg^-1 for 5 days followed by prednisolone 1.5 mg kg^-1 day^-1 were administered. The patient's clinical status did not improve; therefore, she underwent therapeutic plasma exchange (1/1 ratio) for 8 days, followed by intravenous immunoglobulin 1 gr kg^-1 for 2 days. As her clinical condition did not improve, rituximab and endoxane treatments were planned. Unfortunately, these treatments were postponed as she developed ventilator-associated pneumonia at the follow-up. She developed septic shock on the 14th day of follow-up, and noradrenaline and dopamine infusions were commenced. Despite all the efforts, she remained unresponsive and died from cardiac arrest. By reporting this case, we aimed to stress that HE should be considered as an aetiology of encephalopathy when infectious, neoplastic, autoimmune, toxic and metabolic causes are excluded.

Hashimoto encephalopathy in pediatric patients: Homogeneity in clinical presentation and heterogeneity in antibody titers

OBJECTIVE

Hashimoto encephalopathy is an autoimmune encephalopathy characterized by elevated antithyroid antibodies and a favorable response to corticosteroid. This study delineated the clinical characteristics of pediatric Hashimoto encephalopathy and the significance of low antithyroid antibody titers in diagnosis and treatment.

SUBJECTS AND METHODS

Clinical manifestations, antibody titers, and treatment responses were retrospectively reviewed in six consecutive children diagnosed with Hashimoto encephalopathy between August 2008 and July 2016.

RESULTS

Age at diagnosis was 10-17years. Presenting symptoms were seizures, altered consciousness, behavioral changes, psychosis, tremor, and dystonia. Thyroid function was normal in five patients, and one had hypothyroidism prior to the encephalopathy. Antithyroid antibody titer was increased at presentation in five patients and one week later in the other. Antibody levels were extremely varied (anti-thyroglobulin, 20.5-2318.0U/ml; anti-thyroid peroxidase, 12.5-2231.0U/ml; reference range, <60U/ml) and <180U/ml in two patients. Electroencephalogram was abnormal in five patients. Brain magnetic resonance imaging was unremarkable. Four patients responded to high-dose corticosteroid and one improved with additional intravenous immunoglobulin. The remaining patient did not respond to both treatments and normalized after plasmapheresis. Autoantibody titers decreased with treatment response in the acute stage. Two patients with low antibody titers showed similar clinical presentations and responses.

CONCLUSIONS

The clinical presentations and treatment responses in Hashimoto encephalopathy were similar, irrespective of antithyroid antibody titer. Because the initial antithyroid antibody titers can be normal or mildly-elevated, follow-up testing of antithyroid antibodies is required in patients who are clinically suspect for Hashimoto encephalopathy.

Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis Presenting with Fever and Confusion

Steroid-Responsive Encephalopathy Associated with Autoimmune Thyroiditis (SREAT) is a diagnostic conundrum as it may present with a myriad of nonspecific clinical features and laboratory and neuroimaging investigations are not diagnostic. We report a case of a 65-year-old female who presented with an acute febrile illness associated with headache and confusion, tangential thoughts, and loose association. Based on neutrophil leukocytosis in the full blood count and elevated inflammatory markers, she was commenced on empirical intravenous antibiotics suspecting meningoencephalitis. Further evaluation found a very high titer of both anti-thyroid peroxidase (anti-TPO) antibodies and anti-thyroid globulin antibodies. She was clinically and biochemically euthyroid. EEG showed right sided frontal intermittent rhythmic delta activity (FIRDA). Cranial MRI revealed age related cerebral atrophy and nonspecific periventricular white matter changes. A diagnosis of SREAT was made and she was treated with intravenous methylprednisolone followed by oral prednisolone. Her condition improved dramatically within 48 hours of starting steroids. SREAT is a diagnosis of exclusion in patients with a central nervous system disorder. There are no specific clinical features or investigative findings. Elevated anti-TPO antibodies are considered a hallmark of SREAT and steroid responsiveness supports the diagnosis. Prompt diagnosis and treatment reverses the neurological dysfunction in most cases.

Hashimoto's encephalopathy and anti-MOG antibody encephalitis: 50 years after Lord Brain's description

PURPOSE

To consider the role of anti-MOG Abs associated encephalitis in Hashimoto's Encephalitis (HE).

RESULTS

A 10 year old girl with pre-existing Hashimoto's thyroiditis presented with dysarthria, ataxia and lethargy whilst euthyroid. Brain MRI showed multifocal T2 and FLAIR hyperintense lesions. She responded promptly to treatment with corticosteroids. Her clinical scenario was comparable to a sizeable minority of patients diagnosed with HE in the literature, who have similar brain MRIs. Serum was positive for anti-myelin oligodendrocyte glycoprotein (MOG) Ab, implicating this antibody-mediated process in this patient's illness.

CONCLUSION

We hypothesize that anti-MOG Ab associated demyelination may underlie a subset of patients with HE.

Autoantibody-Associated Movement Disorders in Children: Proven and Proposed

Movement disorders secondary to autoantibodies in children represent a rapidly expanding group of conditions. Once considered to be limited to poststreptococcal Sydenham's chorea or rare cases of childhood systemic lupus erythematosus, a variety of antibody-related movement abnormalities are now seen as part of noninfectious autoimmune encephalitis or within an expanding list of postinfectious disorders. In this article, several proposed autoantibody-mediated movement disorders in children are reviewed. In each one, there is a hypothesized antibody biomarker that is believed to be pathogenic and cause the clinical symptoms. As will be discussed, in some, such as anti-NMDA receptor encephalitis, the strength of supporting evidence is strong. In others, antibodies have been identified, but their role as the pathophysiological mechanism remains undetermined. Lastly, there are proposed disorders, such as PANDAS, that are controversial on both a clinical and autoimmune basis.

Focal neurological presentation in Hashimoto's encephalopathy mimicking a vascular occlusion of the middle cerebral artery

Hashimoto's encephalopathy is a rare form of autoimmune encephalopathy. It is likely an underdiagnosed entity especially in the setting of focal neurological defects. We report a case of a 49-year-old man who presented with "strange behavior"of a day's duration. Examination was significant only for lethargy, poor attention span and agitation. Routine labs revealed leucocytosis. Head CT scan was unremarkable. Lumbar puncture showed high white blood cells with lymphocytosis and elevated protein level. The patient was empirically treated for meningitis without improvement. His symptoms progressed to sudden right-sided weakness, ataxia and right facial droop. The MRI and magnetic resonance angiogram (MRA)were normal. The patient’s focal neurological signs improved spontaneously. Encephalopathy work-up was negative except for positive anti-Thyroid Peroxidaseand antithyroglobulin. The patient was treated as Hashimoto encephalopathy with steroids and azathioprine with marked improvement. Our case highlights how focal neurological findings can potentially mislead the provider to consider vascular aetiologies in Hashimoto's encephalopathy.