Treatment of Movement Disorder Emergencies in Autoimmune Encephalitis in the Neurosciences ICU.

Immune response against neuronal and glial cell surface and cytosolic antigens is an important cause of encephalitis. It may be triggered by activation of the immune system in response to an infection (para-infectious), cancer (paraneoplastic), or due to a patient's tendency toward autoimmunity. Antibodies directed toward neuronal cell surface antigens are directly pathogenic, whereas antibodies with intracellular targets may become pathogenic if the antigen is transiently exposed to the cell surface or via activation of cytotoxic T cells. Immune-mediated encephalitis is well recognized and may require intensive care due to status epilepticus, need for invasive ventilation, or dysautonomia. Patients with immune-mediated encephalitis may become critically ill and display clinically complex and challenging to treat movement disorders in over 80% of the cases (Zhang et al. in Neurocrit Care 29(2):264-272, 2018). Treatment options include immunotherapy and symptomatic agents affecting dopamine or acetylcholine neurotransmission. There has been no prior published guidance for management of these movement disorders for the intensivist. Herein, we discuss the immune-mediated encephalitis most likely to cause critical illness, clinical features and mechanisms of movement disorders and propose a management algorithm.

The psychopharmacology of primary and metastatic brain tumors and paraneoplastic syndromes.

Brain tumors and paraneoplastic syndromes can cause various neuropsychiatric symptoms. Rarely, psychiatric symptoms may be the initial presentation of the underlying neurologic lesion. Brain imaging studies are crucial in the diagnosis of brain tumors. Paraneoplastic syndromes are mostly immune-mediated, and antineuronal antibodies may be detected in the blood or cerebrospinal fluid. Clinical suspicion is very important in assisting the diagnostic workup. Treatment of the psychiatric symptoms depends on the nature of the symptoms. Selection of the psychotropic agent has to be done carefully to minimize complications such as seizures and delirium secondary to anticholinergic toxicity. With advances in targeted therapies, immunology, and genetics, the future appears more promising.

Neurological autoimmune disorders with prominent gastrointestinal manifestations: A review of presentation, evaluation, and treatment.

BACKGROUND: The identification of autoantibodies directed against neuronal antigens has led to the recognition of a wide spectrum of neurological autoimmune disorders (NAD). With timely recognition and treatment, many patients with NAD see rapid improvement. Symptoms associated with NAD can be diverse and are determined by the regions of the nervous system affected. In addition to neurological symptoms, a number of these disorders present with prominent gastrointestinal (GI) manifestations such as nausea, diarrhea, weight loss, and gastroparesis prompting an initial evaluation by gastroenterologists. PURPOSE: This review provides a general overview of autoantibodies within the nervous system, focusing on three scenarios in which nervous system autoimmunity may initially present with gut symptoms. A general approach to evaluation and treatment, including antibody testing, will be reviewed.

Clinical characteristics of patients with paraneoplastic myelopathy.

Paraneoplastic myelopathy is rare paraneoplastic neurological syndromes. We reviewed patients through medical records system and screened patients who presented with myelopathy, and/or coexisting cancer, and/or onconeural antibodies. Nine patients were identified as paraneoplastic myelopathy presenting with progressive subacute (2/9) or insidious (7/9) myelopathy. CSF abnormalities included elevated protein, 5; pleocytosis, 4; excess oligoclonal bands, 6. Seven patients had onconeural antibody. Cancer was confirmed histopathologically in 6 and diagnosed by PET-CT in 1. Four patients had symmetric, longitudinally extensive grey matter or tract-specific changes on spinal cord MRI. It was associated with significant morbidity and had poor response to treatment.

Immune-mediated disorders.

Paraneoplastic and autoimmune encephalitis comprise a group of immune-mediated disorders that are associated with different immune effector mechanisms. Classic paraneoplastic neurologic syndromes are triggered by an antitumor immune response. The disease is considered to result from a T-cell response; in addition, patients harbour high titers of autoantibodies against intracellular antigens that are considered as epiphenomenon but are useful diagnostic markers. Neuropathology consists of T-cell-dominated inflammation, marked neuronal loss, and microglial activation with upregulation of HLA-DR. In the last decade, an increasing number of diseases associated with autoantibodies against neuronal surface antigens have been described. There is strong evidence that these autoantibodies are pathogenic and the associated syndromes are generally termed as antineuronal autoimmune encephalitis. Patients typically present with limbic, multifocal, or diffuse encephalitis and respond to immunotherapy. Neuropathologic descriptions are restricted to few biopsy and autopsy specimens and show mild inflammatory infiltrates and microglial activation, together with reduced expression of the respective target antigens, immunoglobulin deposits, and a variable degree of complement activation. Other putative autoimmune disorders of the central nervous system include, among others, Rasmussen encephalitis, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS), acute cerebellitis, Susac syndrome, and Hashimoto encephalitis. While pathologic studies suggest an immune-mediated disease for Rasmussen encephalitis, CLIPPERS, acute cerebellitis, and Susac syndrome, neuropathologic descriptions of Hashimoto encephalitis are rare and the pathogenesis deserves further study.

Rapidly-progressive catatonia responsive to zolpidem in a patient with ovarian teratoma-associated paraneoplastic encephalitis.

Psychiatric symptoms and catatonia are key components of the clinical presentation of paraneoplastic encephalitis; additionally symptoms can be long-lasting and often difficult to treat. We report a 73-year-old patient with rapidly progressive catatonia not responsive to immunotherapy, tumor resection, electroconvulsive therapy, or benzodiazepines who had significant improvement after zolpidem administration. This report suggests that zolpidem is an option in the treatment of patients with refractory catatonia and paraneoplastic encephalitis.

Anti-Hu Antibody-associated Paraneoplastic Neurological Syndrome Showing Peripheral Neuropathy and Atypical Multifocal Brain Lesions.

A 64-year-old Japanese woman presented with a three-month history of progressive numbness and weakness of the lower extremities. A neurological examination and nerve conduction study indicated sensorimotor polyneuropathy. Since the serum anti-Hu antibody titer was remarkably elevated, paraneoplastic neurological syndrome was highly suspected. A thoracoscopic biopsy of the hilar lymph nodes, in which (18)F-fluorodeoxyglucose uptake was obviously increased, revealed pathological findings for small-cell lung cancer (SCLC). Subsequently, the patient presented with generalized tonic-clonic seizures, and cerebral MRI showed reversible multifocal brain lesions, considered to reflect paraneoplastic encephalopathy. After two courses of chemotherapy for SCLC, the brain lesions totally disappeared.

Paraneoplastic subacute lower motor neuron syndrome associated with solid cancer.

We retrospectively analyzed three patients with pure motor neuronopathy followed for more than four years in our center. The patients presented a rapidly progressive lower motor neuron syndrome (LMNS) over the course of a few weeks leading to a severe functional impairment. The neurological symptoms preceded the diagnosis of a breast adenocarcinoma and a thymoma in the first two patients, one of them with anti-CV2/CRMP5 antibodies. Cancer was not detected in the third patient who had circulating anti-Hu antibodies. A final diagnosis of paraneoplastic syndrome was made after investigations for alternative causes of lower motor neuron syndrome. Early diagnosis, combined treatment of the underlying cancer, and immunomodulatory treatment led to neurological improvement of the disease in two out of the three cases in which the cancer was diagnosed. Cases of subacute LMNS with rapid progression may occur as an expression of a paraneoplastic neurological syndrome. Identification of these syndromes is important, as the treatment of underlying malignancy along with immunomodulatory treatment may result in a favorable long-term outcome of these potentially fatal diseases.

A destructive feedback loop mediated by CXCL10 in central nervous system inflammatory disease.

OBJECTIVE: Paraneoplastic neurologic disorders (PND) are autoimmune diseases associated with cancer and ectopic expression of a neuronal antigen in a peripheral tumor. Patients with PND harbor high-titer antibodies and T cells in their serum and cerebrospinal fluid (CSF) that are specific to the tumor antigen, and treatment with the immunosuppressant FK506 (tacrolimus) decreases CSF white blood cell counts. The objective of this study was to determine the effect of FK506 on CSF chemokine levels in PND patients. METHODS: CSF samples before and after FK506 treatment were tested by multiplex assay for the presence of 27 cytokines. Follow-up in vitro experiments aimed to determine whether T cells secrete CXCL10 in response to cognate antigen. RESULTS: Here we report that PND patients harbor high levels of the chemokine CXCL10 in their CSF. CXCL10 is a cytokine that recruits CXCR3(+) cells such as activated T cells, and we found that FK506 treatment specifically decreased CSF CXCL10 from among 27 cytokines tested. In vitro, CXCL10 was only produced during antigen-specific cognate interactions between T cells and antigen-presenting cells (APCs) when interferon-γ (IFNγ) receptors were present on the T cell. INTERPRETATION: These results support a model in which antigen-specific T cell stimulation by PND APCs triggers IFNγ, followed by CXCL10 production and further lymphocyte recruitment, suggesting that treatments targeting T cells or CXCL10 in the central nervous system (CNS) may interrupt a destructive positive feedback loop present in CNS inflammation.

[Autonomic neuropathy as the first presentation of T-cell malignant lymphoma--a case report].

A 61-year-old man noted flu-like symptoms. Not long afterwards, he felt constipation, nausea, and blackout when standing or sitting. His blood pressure was 110/70 mmHg in the supine position. On sitting blood pressure dropped to 73/34 mmHg. Heart rate increased from 65 to 78 beats per minutes. He did not have fever, edema, or skin rash. The remainder of the general medical examination was normal. A neurological examination revealed normal higher mental, and sensori-motor functions. The blood test revealed leukocytosis 7,320/µl, LD 1,426 IU/l, IL-2R 921 U/ml, and CRP 11.5 mg/dl. A whole body CT scan and cranial MR imaging showed no significant change. Thoracic spine MR imaging revealed multiple T1 low signal small foci in part of the vertebral body suggesting bone metastasis of the tumor. The heart/mediastinum ratio of (123)I-meta-iodobenzylguanidine scintigraphy early imaging was 2.42. The nerve conduction study and electrocardiogram coefficient of variation of R-R intervals showed no abnormalities. Two months after the onset of symptoms, he was found to have glove-and-stocking-form muscle weakness and sensory impairment. The nerve conduction study performed four months after the onset revealed a decreased conduction velocity and conduction block suggesting demyelinated nerve. His neurological manifestations progressed subacutely, despite high-dose intravenous immunoglobulin therapy. Five months after the onset, a histopathological diagnosis of T-cell malignant lymphoma was made on a skin biopsy specimen from the facial rash. To summarise, the present case was a rare example of paraneoplastic autonomic neuropathy as the initial clinical feature in association with T-cell malignant lymphoma.

A prospective open-label study of sirolimus for the treatment of anti-Hu associated paraneoplastic neurological syndromes.

BACKGROUND: Several lines of evidence suggest a T cell-mediated immune response in paraneoplastic neurological syndromes with anti-Hu antibodies (Hu-PNS). In order to investigate whether suppression of T cell-mediated immune responses in Hu-PNS patients improved their neurological outcome, we performed a prospective open-label, single-arm study on sirolimus. METHODS: Seventeen progressive Hu-PNS patients were treated with sirolimus with an intended treatment duration of 8 weeks. Primary outcome measures were (i) functional improvement, defined as a decrease of one or more points on the modified Rankin Scale (mRS), and (ii) improvement of neurological impairment, defined as an increase of one or more points on the Edinburgh Functional Impairment Tests (EFIT). RESULTS: One patient showed improvement on both clinical scales (mRS and EFIT). This patient presented with limbic encephalitis and improved dramatically from an mRS score of 3 to mRS 1. Another patient, with subacute sensory neuronopathy, remained stable at mRS 2 and improved one point on the EFIT scale. The other patients showed no improvement on the primary outcome measures. Median survival was 21 months. CONCLUSION: We conclude that treatment of Hu-PNS patients with sirolimus may improve or stabilize their functional disabilities and neurological impairments. However, the effects of this T cell-targeted therapy were not better than reported in trials on other immunotherapies for Hu-PNS. Trial Registration https://www.clinicaltrialsregister.eu/ctr-search/trial/2008-000793-20/NL.

Paraneoplastic brainstem encephalitis in a patient with exceptionally long course of a metastasized neuroendocrine rectum neoplasm.

BACKGROUND: Paraneoplastic neurological syndromes (PNS) have frequently been described in patients with lung or breast cancer. However, some reports also described a correlation to carcinoid tumors, probably triggered via the excessive release of hormones. CASE PRESENTATION: We report the case of a 40-year-old woman that was diagnosed with a neuroendocrine neoplasm (NEN) of the rectum and multiple synchronous liver metastases ten years ago. She initially responded well to transarterial chemoembolization (TACE), resulting in prolonged disease stabilization. However, ten years after initial diagnosis the patient developed unspecific neurological symptoms that could not be classified by standard neurological diagnostic work-up. Special laboratory analysis revealed a high titer of anti-Ri (ANNA-2), a well-characterized antibody that is associated with paraneoplastic neurologic syndromes. The patient's symptoms improved markedly after a 5-day-course of high-dose glucocorticoid therapy. To our knowledge, this is the first report of a Ri-positive PNS in a patient with hormone-negative rectal NEN. CONCLUSION: PNS can complicate the patient's clinical course, response to treatment, impact prognosis and even be interpreted as metastatic spread. However, owing to their rarity, the knowledge of these syndromes is very helpful in order to be able to provide evidence-based diagnostic and therapeutic approaches.