Background Hashimoto encephalopathy has been described as a syndrome of encephalopathy and high serum antithyroid antibody concentrations that is responsive to glucocorticoid therapy, but these could be chance associations. Objective To study a patient with Hashimoto encephalopathy and to review the literature to determine whether Hashimoto encephalopathy is an identifiable syndrome. Data Sources and Extraction We searched the MEDLINE database to June 2002 for "Hashimoto" or "autoimmune thyroiditis" and "encephalopathy" and examined all identified articles and articles referenced therein, including all languages. We included all patients with noninfectious encephalopathy (clouding of consciousness and impaired cognitive function) and high serum antithyroid antibody concentrations. We excluded patients if they did not meet these inclusion criteria or if their symptoms could be explained by another neurologic disorder. We recorded clinical features and the results of imaging, electroencephalographic, thyroid function, and cerebrospinal fluid studies. Data Synthesis We identified 85 patients (69 women and 16 men; mean age, 44 years) with encephalopathy and high serum antithyroid antibody concentrations. Among these patients, 23 (27%) had strokelike signs, 56 (66%) had seizures, 32 (38%) had psychosis, 66 (78%) had a high cerebrospinal fluid protein concentration, and 80 (98%) of 82 had abnormal electroencephalographic findings. Thyroid function varied from overt hypothyroidism to overt hyperthyroidism; the most common abnormality was subclinical hypothyroidism (30 patients [35%]). Among patients treated with glucocorticoids, 66 (96%) improved. Conclusions The combination of encephalopathy, high serum antithyroid antibody concentrations, and responsiveness to glucocorticoid therapy seems unlikely to be due to chance. However, there is no evidence of a pathogenic role for the antibodies, which are probably markers of some other autoimmune disorder affecting the brain.

https://jamanetwork.com/journals/jamaneurology/articlepdf/783630/NNR20012.pdf

Hashimoto encephalopathy: syndrome or myth?

OBJECTIVE: The authors assess the present position of catatonia in diagnostic classification systems and consider the merits of designating catatonia as a separate diagnostic category with defined criteria. METHOD: Following the logical steps to establish diagnostic validity when the etiology of a syndrome is unknown, the authors review the literature on the features that delineate catatonia as a syndrome, the prevalence and response to treatment of catatonia, and the conditions that are associated with catatonia. RESULTS: Catatonia is a well-defined syndrome that can be reliably ascertained. Although more than 40 motor signs of catatonia are known, the presence of two prominent features for 24 hours or longer is sufficient to identify the syndrome. Catatonia is found in about 10% of acutely ill psychiatric inpatients and is more commonly observed in persons with mood disorder than in those with schizophrenia. It is found in many conditions and presents mainly as retarded-stuporous or excited-delirious fo...

Catatonia in Psychiatric Classification: A Home of Its Own

Background Steroid-responsive encephalopathy associated with autoimmune thyroiditis (SREAT), often termed Hashimoto encephalopathy , is a poorly understood and often misdiagnosed entity. Objective To characterize the clinical, laboratory, and radiologic findings in patients with SREAT to potentially improve recognition of this treatable entity. Design Retrospective analysis of clinical features and diagnostic test data. Setting Two affiliated tertiary care referral institutions. Patients Twenty consecutive (6 male) patients diagnosed as having SREAT from 1995 to 2003. Main Outcome Measures Clinical features and ancillary test findings associated with SREAT. Results The median age at disease onset was 56 years (range, 27-84 years). The most frequent clinical features were tremor in 16 (80%), transient aphasia in 16 (80%), myoclonus in 13 (65%), gait ataxia in 13 (65%), seizures in 12 (60%), and sleep abnormalities in 11 (55%). All patients were assigned an alternative misdiagnosis at presentation, most commonly viral encephalitis (n = 5), Creutzfeldt-Jakob disease (n = 3), or a degenerative dementia (n = 4). The most frequent laboratory abnormalities were increased liver enzyme levels in 11, increased serum sensitive thyroid-stimulating hormone levels in 11, and increased erythrocyte sedimentation rate in 5. In only 5 patients (25%) did cerebrospinal fluid abnormalities suggest an inflammatory process. Magnetic resonance imaging abnormalities believed to be related to the encephalopathy were present in 5 patients (26%). Conclusions The clinical, laboratory, and radiologic findings associated with SREAT are more varied than previously reported. Misdiagnosis at presentation is common. This treatable syndrome should be considered even if the serum sensitive thyroid-stimulating hormone level and erythrocyte sedimentation rate are normal, the cerebrospinal fluid profile does not suggest an inflammatory process, and neuroimaging results are normal. Until the pathophysiologic mechanism of this and other autoimmune encephalopathies is better characterized, we believe that descriptive terms that reflect an association rather than causation are most appropriate for this syndrome.

https://jamanetwork.com/journals/jamaneurology/articlepdf/790539/NOC50033.pdf

Steroid-Responsive Encephalopathy Associated With Autoimmune Thyroiditis

Objectives: To describe the clinical features and coexisting serum autoantibodies in seven patients with encephalitis associated with autoantibodies to α-dendrotoxin-sensitive voltage-gated potassium channels (VGKCs), and to compare this disorder with other autoimmune encephalopathies. Methods: Clinical information was obtained from a retrospective review of medical records and telephone interviews. All autoantibody testing was performed in a single laboratory. Results: The seven patients were examined for subacute cognitive and behavioral changes. Seizures, usually temporal-onset complex partial type, were documented in six patients, and all seven patients had EEG abnormalities. None had symptoms or signs of neuromuscular hyperexcitability. One described hypersalivation. Four patients had additional autoantibody markers of neurologic autoimmunity (muscle acetylcholine receptor, striational, P/Q-type calcium channel, or GAD65), and two had thyroperoxidase antibodies. Two patients had a history of cancer: one had active prostate adenocarcinoma, and the second had a remote history of tongue carcinoma. Cranial MRI demonstrated mesial temporal lobe abnormalities in all patients. One patient improved spontaneously, and six were treated with IV methylprednisolone. Three improved remarkably with treatment. At follow-up evaluation, one had no cognitive deficits, four had mild persistent short-term memory dysfunction, and two had persistent disabling behavioral deficits. Conclusions: Voltage-gated potassium channel antibodies are a valuable serologic marker of a potentially reversible autoimmune encephalopathy. The neurologic manifestations of this disorder are indistinguishable from paraneoplastic limbic encephalitis but are distinct from Morvan syndrome and Hashimoto encephalopathy.

Potentially reversible autoimmune limbic encephalitis with neuronal potassium channel antibody

Case material and retrospective studies support the use of both lorazepam and ECT in treating catatonia, but few prospective investigations exist and none employ quantitative monitoring of response. In this study we test their efficacy in an open, prospective protocol, and define a "lorazepam test' with predictive value for treatment. Twenty-eight patients with catatonia were treated systematically with parenteral and/or oral lorazepam for up to 5 days, and with ECT if lorazepam failed. Outcome was monitored quantitatively during the treatment phase with the Bush-Francis Catatonia Rating Scale (BFCRS). In 16 of 21 patients (76%) who received a complete trial of lorazepam (11 with initial intravenous challenge), catatonic signs resolved. A positive response to an initial parenteral challenge predicted final lorazepam response, as did length of catatonic symptoms prior to treatment. Neither demographic variables nor severity of catatonia predicted response to lorazepam. Four patients failing lorazepam responded promptly to ECT. It is concluded that lorazepam and ECT are effective treatments for catatonia. The rating scale has predictive value and displays sensitivity to change in clinical status.

Catatonia. II. Treatment with lorazepam and electroconvulsive therapy.

We describe 5 patients with a relapsing encephalopathy in association with Hashimoto's disease and high titers of anti-thyroid antibodies. The presentation is usually with a subacute onset of confusion, alteration in conscious level, and focal or generalized seizures. The relapsing course, association with myoclonus or tremulousness, and episodes of stroke-like deterioration are characteristic features. The long-term prognosis is favorable with steroid therapy, though additional immunosuppressive therapy may be required. Neurologic investigation typically shows a diffusely abnormal EEG, high CSF protein level without pleocytosis, and normal brain CT and cerebral angiogram. Isotope brain scan may show patchy abnormal uptake. Hashimoto's encephalopathy should be recognized as a definite neurologic entity and added to the list of CNS complications of thyroid disease.

Hashimoto's encephalopathy: a steroid-responsive disorder associated with high anti-thyroid antibody titers--report of 5 cases.

Karl Ludwig Kahlbaum was the first to describe catatonia in 1868. There has been a tendency to consider catatonia as a psychiatric disease despite many case reports demonstrating a wide range of medical and neurological as well as psychiatric causes. We present our accumulated experience of the catatonic syndrome. Most cases (36%) were associated with affective illness but five cases (20%) had a defined organic disorder. A significant minority had no identifiable cause and there was only one case of schizophrenia. The idiopathic and affective groups had a high incidence of recurrent catatonic episodes and many had a family history of a similar problem. The prognosis was excellent, except for the few patients who presented with the acute and rapidly progressive form of the syndrome which led to acute renal failure.

https://jnnp.bmj.com/content/jnnp/49/9/991.full.pdf

The syndrome of Karl Ludwig Kahlbaum.

A randomised comparison is made between methylprednisolone, 1 g intravenously daily for 7 days, and a standard ACTH regime for the treatment of multiple sclerosis in acute relapse. It is found that methylprednisolone produces a more rapid clinical improvement than ACTH but confers no longer term benefit when the two treatments are compared at 3 months. It is proposed that intravenous methylprednisolone does have a role to play in the management of a patient with an acute relapse of multiple sclerosis.

https://jnnp.bmj.com/content/jnnp/48/2/157.full.pdf

T J Walls

Papers

Hashimoto's encephalopathy: a steroid-responsive disorder associated with high anti-thyroid antibody titers--report of 5 cases.

The syndrome of Karl Ludwig Kahlbaum.

Intravenous methylprednisolone for multiple sclerosis in relapse.