Hashimoto's encephalopathy in children and adolescents

Fifteen-minute consultation: The efficient investigation of infantile and childhood epileptic encephalopathies in the era of modern genomics

The investigation of children presenting with infantile and childhood epileptic encephalopathies (ICEE) is challenging due to diverse aetiologies, overlapping phenotypes and the relatively low diagnostic yield of MRI, electroencephalography (EEG) and biochemical investigations. Careful history and thorough examination remain essential as these may identify an acquired cause or indicate more targeted investigation for a genetic disorder. Whole exome sequencing (WES) with analysis of a panel of candidate epilepsy genes has increased the diagnostic yield. Whole genome sequencing (WGS), particularly as a trio with both parents' DNA, is likely to supersede WES. Modern genomic investigation impacts on the timing and necessity of other testing. We propose a structured approach for children presenting with ICEE where there is diagnostic uncertainty, emphasising the importance of WGS or, if unavailable, WES early in the investigative process. We note the importance of expert review of all investigations, including radiology, neurophysiology and biochemistry, to confirm the technique used was appropriate as well as the results. It is essential to counsel families on the risks associated with the procedures, the yield of the procedures, findings that are difficult to interpret and implication of 'negative' results. Where children remain without a diagnosis despite comprehensive investigation, we note the importance of ongoing multidisciplinary care.

A Rare Cause of Autistic Regression in a Boy with Down Syndrome: Hashimoto Encephalopathy

Background:

Hashimoto encephalopathy (HE) is a rare condition associated with autoimmune thyroid disease. We aimed to report the youngest patient with Down syndrome and HE with an unusual presentation.

Case Report:

Six years and six months old boy with Down syndrome admitted due to loss of speech. His physical development was appropriate for his age and had no goiter. Neurological examination revealed the absence of eye contact and stereotypic movements. Autism spectrum disorder was considered based on his result on Gilliam autism evaluation scale. He had subclinical hypothyroidism with markedly elevated anti-thyroid peroxidase antibody level, rare spikes in the frontocentral area were found in electroencephalography, and cranial magnetic resonance imaging was normal. Neurologic improvement was observed to a treatment with glucocorticoid and thyroid hormone.

Conclusion:

HE might be considered in patients with Down syndrome along with progressive cognitive decline and autistic regression.

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.

Use of therapeutic plasma exchange for pediatric neurological diseases

Therapeutic plasma exchange is used to treat neurological diseases in the pediatric population. Since its first use in pediatric patients with hepatic coma in the form of manual whole blood exchange, therapeutic plasma exchange has been increasingly used to treat these disorders of the nervous system. This expansion is a result of improved techniques and apheresis instruments suitable for small children, as well as the recognition of its applicability to many diseases in the pediatric population. This review provides a historical overview of the use of therapeutic apheresis in children and highlights the most common applications for therapeutic plasma exchange to treat neurological disorders in children.

Attempted Suicide in a Woman With Steroid-responsive Encephalopathy Associated With Autoimmune Thyroiditis: A Case Report

Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT) is a rare phenomenon that manifests with nonspecific psychiatric and neurological signs and symptoms, an elevated serum thyroid peroxidase antibody level, and a positive treatment response to corticosteroids. Current literature describes highly varied presentations of the disease, which makes its diagnosis a challenging endeavor. The psychiatric symptoms of SREAT, in particular, are very difficult to ascribe to the correct diagnosis, as there are few laboratory or imaging modalities available to workup these manifestations. As a result, authors have attempted to compose rough guidelines that would help clinicians more easily recognize SREAT, which is important given the wide accessibility and efficacy of the main treatment for this condition. We present the case of a young woman diagnosed with SREAT who presented after a suicide attempt. Although signs and symptoms of depression, psychosis, and mania have been well described as potential manifestations of the disorder, attempted suicide as a primary presentation of SREAT has not been well captured in the current literature. In fact, it appears that suicidal thoughts and attempts are not nearly as prevalent as would be expected given the high prevalence of psychiatric signs and symptoms in the disorder, but rather, they appear to be quite rare phenomena. In this case report, we identify other articles in the literature that address suicidal thoughts or attempts in association with SREAT. The patient described in our report is one of the only cases of a suicide attempt in the context of a primarily depressed state as a result of SREAT.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice - Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Eighth Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating and categorizing indications for the evidence-based use of therapeutic apheresis (TA) in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Eighth Edition of the JCA Special Issue continues to maintain this methodology and rigor in order to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Eighth Edition, like its predecessor, continues to apply the category and grading system definitions in fact sheets. The general layout and concept of a fact sheet that was introduced in the Fourth Edition, has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of TA in a specific disease entity or medical condition. The Eighth Edition comprises 84 fact sheets for relevant diseases and medical conditions, with 157 graded and categorized indications and/or TA modalities. The Eighth Edition of the JCA Special Issue seeks to continue to serve as a key resource that guides the utilization of TA in the treatment of human disease.

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.

A 15-Year-Old Boy With Refractory Status Epilepticus

In this case report, we discuss a 15-year-old previously healthy boy who presented with acute onset encephalopathy with refractory status epilepticus requiring pentobarbital-induced burst suppression for seizure control. We review the differential diagnosis and important diagnostic considerations for pediatric patients presenting with acute encephalopathy. We then review Hashimoto encephalopathy (SREAT) and discuss presentation, diagnosis, and treatment.

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.

Cerebellopathy secondary to anti-peroxidase antibody-mediated toxicity. A special case of Hashimoto encephalopathy

OBJECTIVE

The aim of this case report is to highlight the importance of recognizing uncommon causes of cerebellar involvement.

CASE PRESENTATION

A 45-year-old woman with no medical history who presented gait instability that appears suddenly and evolves rapidly in two weeks, causing frequent falls. Neurological examination revealed an inability to walk due to severe ataxia, accompanied by global hypotonia, appendicular dysmetria, opsoclonus and dysarthria. We studied this patient with cerebellar syndrome, obtaining as relevant findings global cerebellar atrophy in MRI (magnetic resonance imaging) and especially, considerably elevated levels of antibodies against thyroid peroxidase (TPO). The patient was treated with high doses of intravenous methylprednisolone for 5days. Six months after diagnosis and in treatment with low doses of prednisone, the patient is asymptomatic.

CONCLUSION

We must considerer the cerebellar involvement secondary to steroid responsive encephalopathy associated with autoimmune thyroiditis (SREAT) in a patient in whom other more frequent causes of isolated cerebellar disease have been ruled out.

Guidelines on the Use of Therapeutic Apheresis in Clinical Practice-Evidence-Based Approach from the Writing Committee of the American Society for Apheresis: The Seventh Special Issue

The American Society for Apheresis (ASFA) Journal of Clinical Apheresis (JCA) Special Issue Writing Committee is charged with reviewing, updating, and categorizing indications for the evidence-based use of therapeutic apheresis in human disease. Since the 2007 JCA Special Issue (Fourth Edition), the Committee has incorporated systematic review and evidence-based approaches in the grading and categorization of apheresis indications. This Seventh Edition of the JCA Special Issue continues to maintain this methodology and rigor to make recommendations on the use of apheresis in a wide variety of diseases/conditions. The JCA Seventh Edition, like its predecessor, has consistently applied the category and grading system definitions in the fact sheets. The general layout and concept of a fact sheet that was used since the fourth edition has largely been maintained in this edition. Each fact sheet succinctly summarizes the evidence for the use of therapeutic apheresis in a specific disease entity. The Seventh Edition discusses 87 fact sheets (14 new fact sheets since the Sixth Edition) for therapeutic apheresis diseases and medical conditions, with 179 indications, which are separately graded and categorized within the listed fact sheets. Several diseases that are Category IV which have been described in detail in previous editions and do not have significant new evidence since the last publication are summarized in a separate table. The Seventh Edition of the JCA Special Issue serves as a key resource that guides the utilization of therapeutic apheresis in the treatment of human disease. J. Clin. Apheresis 31:149-162, 2016. © 2016 Wiley Periodicals, Inc.

Neuropsychiatric Manifestation of Hashimoto's Encephalopathy in an Adolescent and Treatment

Hashimoto's encephalopathy is usually underdiagnosed and untreated because of complex neuropsychiatric manifestation. We report a case of an adolescent female with Hashimoto's encephalopathy who responded well to a combination of aspirin and levothyroxine. A 16-year-old girl presented at psychiatric emergency services with a depressive episode, menstrual irregularities, and a 5-month past history of thyroid swelling. On clinical examination, she was in a euthyroid state with insignificant neurological history. However, her previous investigation revealed a hypothyroid state. Her magnetic resonance imaging findings demonstrated infarcts in the bilateral gangliocapsular region and left frontal periventricular deep white matter lesion. Ultrasonography of the thyroid and fine needle aspiration cytology confirmed lymphocytic thyroiditis. Anti-thyroid peroxidase (289 IU/ml) antibody titer was elevated (289 IU/mL). Her depressive symptoms responded well to antidepressants, mood stabilizers, nonsteroidal anti-inflammatory drugs, and levothyroxine. She remained in the euthyroid state and then in the euthymic state for 3 years. Hashimoto's encephalopathy is steroid-responsive encephalopathy. Most researchers have observed a dramatic response to steroids with or without levothyroxine. A clinician may consider aspirin as an alternative to a steroid in long-term management to avoid steroid-related side effects and contraindications.

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

BACKGROUND

Hashimoto encephalopathy is a rare form of encephalopathy thought to be of autoimmune etiology. Cognitive changes and seizures are the most commonly reported presenting manifestation. Stroke-like episodes have also been documented in these individuals. We describe a rare adolescent with Hashimoto encephalopathy who presented with stroke-like symptoms.

PATIENT DESCRIPTION

A previously well 15-year-old girl experienced sudden-onset language disturbance and right hemiparesis. Her symptoms resolved, but weeks later, she began experiencing refractory seizures, episodes of status epilepticus, and cognitive decline. An extensive evaluation was unremarkable, but thyroid peroxidase antibodies were elevated, and a diagnosis of Hashimoto encephalitis was made. Steroid therapy was initiated, and her symptoms resolved with return to baseline cognitive function.

CONCLUSION

Hashimoto encephalopathy is a highly treatable condition that may be considered in the differential diagnosis of children and adolescents presenting with stroke-like symptoms.

Hashimoto's encephalopathy: A rare proteiform disorder

Hashimoto's encephalopathy (HE) is a rare not well understood, progressive and relapsing multiform disease, characterized by seizures, movement disorders, subacute cognitive dysfunction, psychiatric symptoms and responsiveness to steroid therapy. The disorder is generally associated with thyroid diseases and the most common feature is the presence of anti-thyroperoxidase antibodies (TPOAb). Patients are usually euthyroid or mildly hypothyroid at presentation. All age groups can be affected. The pathophysiology is still unclear, especially the link between elevated serum TPOAb and the encephalopathy. Most reported cases occurred in women and girls. Unspecific symptoms, non-pathognomonic laboratory neurophysiology and neuroimaging features make its diagnosis a real challenge for clinicians. The case of a 16 year old boy, with a clinical picture of HE associated with hypothyroidism, demonstrating an excellent response to high dose steroids is presented together with a systematic review of the literature.

A spectrum of inflammation and demyelination in acute disseminated encephalomyelitis (ADEM) of children

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that involves multifocal areas of the white matter, rarely the gray matter and spinal cord, mainly affecting children and mostly occurring 1-2weeks after infections or more rarely after vaccinations. Though a specific etiologic agent is not constantly identified, to evaluate carefully patient's clinical history and obtain adequate samples for the search of a potential ADEM causal agent is crucial. In the case of a prompt diagnosis and adequate treatment, most children with ADEM have a favorable outcome with full recovery, but in the case of diagnostic delays or inappropriate treatment some patients might display neurological sequelae and persistent deficits or even show an evolution to multiple sclerosis. The suspicion of ADEM rises on a clinical basis and derives from systemic and neurologic signs combined with magnetic resonance imaging of the central nervous system. Other advanced imaging techniques may help an appropriate differential diagnosis and definition of exact disease extension. Although there is no standardized protocol or management for ADEM, corticosteroids, intravenous immunoglobulin, and plasmapheresis have been successfully used. There is no marker that permits to identify the subset of children with worse prognosis and future studies should try to detect any biological clue for prevision of neurologic damage as well as should optimize treatment strategies using an approach based on the effective risk of negative evolution.

Thyroid-related neurological disorders and complications in children

BACKGROUND

Thyroid hormones exert critical roles throughout the body and play an important and permissive role in neuroendocrine, neurological, and neuromuscular function.

METHODS

We performed a PubMed search through June 2014 with search terms including "hypothyroidism," "hyperthyroidism," "neurological complications," "neuropathy," "myopathy," "congenital hypothyroidism," and "encephalopathy." Relevant publications reviewed included case series, individual case reports, systematic reviews, retrospective analyses, and randomized controlled trials. The neurological outcomes of congenital hypothyroidism were reviewed, along with the clinical features of associated neuromuscular syndromes of both hypothyroidism and hyperthyroidism, including other autoimmune conditions. Evidence for, and pathophysiological controversies surrounding, Hashimoto encephalopathy was also reviewed.

RESULTS

The establishment of widespread newborn screening programs has been highly successful in attenuating or preventing early and irreversible neurological harm resulting from congenital thyroid hormone deficiency, but some children continue to display neuromuscular, sensory, and cognitive defects in later life. Acquired disorders of thyroid function such as Hashimoto thyroiditis and Graves' disease are associated with a spectrum of central nervous system and/or neuromuscular dysfunction. However, considerable variation in clinical phenotype is described, and much of our knowledge of the role of thyroid disease in childhood neurological disorders is derived from adult case series.

CONCLUSIONS

Early and aggressive normalization of thyroxine levels in newborn infants with congenital hypothyroidism is important in minimizing neurological sequelae, but maternal thyroid hormone sources are also critically important to the early developing brain. A spectrum of neurological disorders has been reported in older children with acquired thyroid disease, but the frequency with which these occur remains poorly defined in the literature, and much must be extrapolated from adult data. A high index of suspicion for acquired thyroid disease is paramount in the investigation of many neurological disorders of youth, as many reported sequelae of hypothyroidism and hyperthyroidism are reversible with appropriate endocrine management.

Tic disorder probably associated with steroid responsive encephalopathy with autoimmune thyroiditis (SREAT)

Steroid responsive encephalopathy with autoimmune thyroiditis (SREAT), a rare disorder in individuals of all age groups, including children, is characterized by high titers of anti-thyroid peroxidase antibodies. The present report concerns a previously healthy 12-y-old boy who presented with motor tics. The patient underwent an extensive work-up to identify the underlying etiologies and risk factors predisposing him to tic disorder. Based on the clinical and laboratory results, a diagnosis of SREAT was made. Although some studies have reported associated behavioral and cognitive changes, myoclonus, seizures, pyramidal tract dysfunction, psychosis, and coma. The authors describe a case of tic disorder, probably due to SREAT, as well as its course of treatment.

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.

Hashimoto encephalopathy

The authors present a case report and review the literature on Hashimoto encephalopathy. The onset of the disease may be marked by focal and then progressively generalized seizures or other neurological symptoms, but a cognitive decline or various psychiatric symptoms may also emerge. High levels of anti-thyroid peroxidase antibodies and/or anti-thyroglobulin antibodies are present in the serum. Corticosteroid treatment usually results in an improvement of symptoms. The syndrome is frequently overlooked and, therefore, the authors strongly recommend testing serum thyroid autoantibodies in cases with encephalopathy of unknown origin independently on the presence of thyroid disease in the patient or family history. The importance of long-term immunosuppressive treatment should also be stressed. Orv. Hetil., 2013, 154, 1312–1316.

Hashimoto's encephalopathy: identification and long-term outcome in children

OBJECTIVE

To identify the clinical findings of Hashimoto's encephalopathy (HE) in children and assess their neurological outcome.

METHODS

In this retrospective observational study of 42 children with encephalitis dominated by acute neuro-behavioral features, eight met the diagnostic criteria of HE. Their biological, EEG and brain MRI characteristics were compared to those of the other 34 children. Their clinical outcome was also compared to that of 14 children with Hashimoto's thyroiditis (HT).

RESULTS

All eight HE children were girls and had high levels of anti-thyroid peroxidase (TPO) antibodies at onset (4043.3 ± 2969.8 IU/mL, inclusion criteria: TPO > 60 IU/mL) despite normal T4 and TSH levels in six of them. All HE children had abnormal EEG and brain MRI was abnormal in four of them. Relapses were observed in five children with a second relapse, despite steroid therapy, occurring sooner after the previous episode (median 18 days (range 17-188) vs 213 days (range 14-518)). Immunosuppressive therapy was started in all five children and two developed sequelae by the last follow-up visit (after 4 ± 1.3 years). Mean anti-TPO antibody titers were significantly higher in HE children than in those with Hashimoto's thyroiditis (HT) (4043.3 ± 2969.8 IU/mL vs 1980.9 ± 3449.9 IU/mL, p = 0.03). Four HE children subsequently developed hypothyroidism whereas only one HT patient presented encephalitis.

CONCLUSION

HE is characterized by suggestive clinical symptoms with high levels of anti-TPO antibodies and, in most cases, normal T4 and TSH titers. Despite steroid treatment, relapses and sequelae are frequent. HE may evolve toward HT, but the reverse appears to be rare.

Hashimoto’s encephalopathy presenting as acute cognitive decline in an elderly male

Hashimoto’s encephalopathy (HE) is a rare form of reversible encephalopathy characterized by the presence of anti-thyroid antibodies in serum and/or cerebrospinal fluid. The syndrome is more common in women and the presentation varies considerably. Here, we report a case of an elderly male with a history of Hashimoto’s thyroiditis, presenting with acute cognitive decline. A diagnosis of HE was established based on the presence of anti-thyroid antibodies in the serum, diffuse electroencephalography changes and lack of an alternative explanation. The patient promptly responded to steroids and was discharged on the 8^th day of admission. We suggest that an assessment of thyroid antibodies should be included in anyone presenting with acute cognitive decline in the absence of alternative explanation.