Subacute Cerebellar Syndrome Research Articles

Anti-mGluR1 encephalitis: Case illustration and systematic review.

The literature for immune-mediated neurological disorders is evolving like no other field of neurological illnesses. Many new antibodies or disorders have been described in the last decade. The cerebellum is a brain structure susceptible to these immune-mediated pathologies, and anti-metabotropic glutamate receptor 1 (mGluR1) antibody has a predilection to the cerebellar tissue. Anti-mGluR1 encephalitis is a rare autoimmune disease affecting the central and peripheral nervous systems, triggering an acute or subacute cerebellar syndrome with varying degrees of severity. Anti-mGluR1 encephalitis is a rare autoimmune disease affecting the central nervous system. We aimed to systematically review reported cases of anti-mGluR1 encephalitis and summarize their clinical presentation, management, outcomes, and case reports. A search of the PubMed and Google Scholar databases was conducted and included all cases of anti-mGluR1 encephalitis published in English before October 1, 2022. A comprehensive systematic review was conducted using "metabotropic glutamate receptor type 1," "mGluR1," autoantibodies," "autoantibodies," "autoimmunity," and "antibody" as keywords. The risk of bias assessment of the evidence was performed using appropriate tools. The qualitative variables were presented as frequency and percentage. Including our case, 36 cases of anti-mGluR1 encephalitis (19 males, median age 52.5 years, 11.1% pediatric cases) have been reported. The most common clinical manifestations are ataxia, dysarthria, and nystagmus. Initial imaging was normal in 44.4% of patients; however, 75% of patients showed abnormality later in the disease course. The first-line therapy options include glucocorticoids, intravenous immunoglobulin, and plasma exchange. Rituximab is the most commonly used second-line treatment. Complete remission was achieved in only 22.2% of patients, and 61.8% were disabled by the end of their course. Anti-mGluR1 encephalitis manifests as symptoms of cerebellar pathology. Although the natural history has not been completely elucidated, early diagnosis with prompt initiation of immunotherapy could be imperative. Any patient suspected to have autoimmune cerebellitis should be tested for the presence of anti-mGluR1 antibody in the serum and cerebrospinal fluid. Escalation to an aggressive therapy approach should be applied in cases that do not respond to first-line therapies, and extended follow-up durations are required in all cases.

Anti-Yo Paraneoplastic Cerebellar Degeneration and Breast Cancer: A Long Survival of Persistent Cerebellar Syndrome

Paraneoplastic neurological syndromes (PNS) occur in 1–3% of all cancer patients with several cancer-related neurologic diseases involving any part of the nervous system. Paraneoplastic cerebellar degeneration (PCD) is a specific type of PNS characterized by sub-acute cerebellar syndrome with trunk and limb ataxia, dysarthria, diplopia, and vertigo. We report herein the case of a 70-year-old female patient with cerebellar symptoms and transient anti-Yo antibody PCD positivity manifested three years after a breast cancer diagnosis who is currently neurologically stable after an extended follow-up.

Paraneoplastic Ataxia: Antibodies at the Forefront Have Become Routine Biomarkers.

Paraneoplastic cerebellopathies are immune-mediated disorders targeting primarily the cerebellar circuitry, often presenting in a subacute course. The syndrome often develops before the cancer. Therefore, its identification often leads secondarily to a diagnosis of cancer, a critical step to stabilize symptoms. Two categories of antibodies have been identified these last 30years: (a) onconeuronal antibodies which are directed against intracellular antigens, and (b) antibodies which are directed against synaptic and cell surface proteins. These latter impact on the location and function of the antigens, causing a genuine neuronal dysfunction. Appropriate and fast tumor screening has emerged as a recommendation facing a subacute cerebellar syndrome suspected to be paraneoplastic. Search for antibodies is now a milestone for the diagnosis.

Subacute cerebellar ataxia following respiratory symptoms of COVID-19: a case report

BackgroundSevere acute respiratory syndrome virus 2 (SARS-CoV-2) is spreading globally and causes most frequently fever and respiratory symptoms, i.e. Coronavirus disease 2019 (COVID-19), however, distinct neurological syndromes associated with SARS-CoV-2 infection have been described. Among SARS-CoV-2-infections-associated neurological symptoms fatigue, headache, dizziness, impaired consciousness and anosmia/ageusia are most frequent, but less frequent neurological deficits such as seizures, Guillain-Barré syndrome or ataxia may also occur.Case presentationHerein we present a case of a 62-year-old man who developed a subacute cerebellar syndrome with limb-, truncal- and gait ataxia and scanning speech 1 day after clinical resolution of symptomatic SARS-CoV-2 infection of the upper airways. Apart from ataxia, there were no signs indicative of opsoclonus myoclonus ataxia syndrome or Miller Fisher syndrome. Cerebral magnetic resonance imaging showed mild cerebellar atrophy. SARS-CoV-2 infection of the cerebellum was excluded by normal cerebrospinal fluid cell counts and, most importantly, absence of SARS-CoV-2 RNA or intrathecal SARS-CoV-2-specific antibody production. Other causes of ataxia such as other viral infections, other autoimmune and/or paraneoplastic diseases or intoxication were ruled out. The neurological deficits improved rapidly after high-dose methylprednisolone therapy.ConclusionsThe laboratory and clinical findings as well as the marked improvement after high-dose methylprednisolone therapy suggest a post-infectious, immune-mediated cause of ataxia. This report should make clinicians aware to consider SARS-CoV-2 infection as a potential cause of post-infectious neurological deficits with an atypical clinical presentation and to consider high-dose corticosteroid treatment in case that a post-infectious immune-mediated mechanism is assumed.

Clinical features, prognostic factors, and antibody effects in anti-mGluR1 encephalitis

To clinically characterize patients with anti-metabotropic glutamate receptor (mGluR) 1 encephalitis, to identify prognostic factors, and to study the immunoglobulin G (IgG) subclasses and effects of antibodies on neuronal mGluR1 clusters. Clinical information on new and previously reported patients was reviewed. Antibodies to mGluR1 and IgG subclasses were determined with brain immunohistochemistry and cell-based assays, and their effects on mGluR1 clusters were studied on rat hippocampal neurons. Eleven new patients were identified (10 adults, 1 child);4 were female. In these and 19 previously reported cases (n = 30, median age 55 years), the main clinical manifestation was a subacute cerebellar syndrome that in 25 (86%) patients was associated with behavioral/cognitive changes or other neurologic symptoms. A tumor was found in 3 of 26 (11%). Brain MRI was abnormal in 7 of 19 (37%) at onset and showed cerebellar atrophy in 10 of 12 (83%) at follow-up. Twenty-five of 30 (83%) patients received immunotherapy. Follow-up was available for 25: 13 (52%) had clinical stabilization; 10 (40%) showed significant improvement; and 2 died. At the peak of the disease, patients with bad outcome at 2 years (modified Rankin Scale score > 2, n = 7) were more likely to have higher degree of initial disability, as reflected by a worse Scale for Assessment and Rating of Ataxia score, and more frequent need of assistance to walk. Antibodies to mGluR1 were mainly IgG1 and caused a significant decrease of mGluR1 clusters in cultured neurons. Anti-mGluR1 encephalitis manifests as a severe cerebellar syndrome, often resulting in long-term disability and cerebellar atrophy. The antibodies are pathogenic and cause significant decrease of mGluR1 clusters in cultured neurons.

Langerhans cell histiocytosis with initial central nervous system presentation as a mimic of neurosarcoidosis

We report the case of a 58-year-old Caucasian woman who presented with a subacute cerebellar syndrome accompanied by disturbance of the hypothalamic–pituitary axis and was diagnosed with isolated neurosarcoidosis based on radiological findings including typically located cerebral lesions (infratentorial and pituitary stalk). Due to persistent clinical and radiological disease activity during several years despite escalation of immunosuppressive treatment, the diagnosis was reevaluated, and a transsphenoidal biopsy of a lesion at the pituitary stalk was performed revealing Langerhans cell histiocytosis. In this case, we discuss the different steps leading to the diagnostic error, as well as the presence of red flags, which should have led to an earlier diagnostic reevaluation.

Brain Imaging in Cerebellar Ataxia Associated with Autoimmune Polyglandular Syndrome Type 2

Autoimmune polyglandular syndrome (APS) type 2 (Schmidt syndrome) is a disorder characterized by a combination of autoimmune adrenal insufficiency, autoimmune thyroid disease, and type 1 autoimmune diabetes mellitus. We describe the first case of subacute cerebellar syndrome associated with APS type 2. Brain magnetic resonance imaging showed atrophy of the cerebellum and the vermis, as well as of the anterior pituitary gland. Magnetic resonance spectroscopy showed decreased N-acetylaspartate/creatine ratio in the cerebellum and in the pons. Our findings expand the spectrum of neurological deficits in APS type 2 and underlines that cerebellar pathways may be a main target of the disorder.

Anti-CV2 associated cerebellar degeneration after complete response to chemoradiation of head and neck carcinoma

Paraneoplastic cerebellar degeneration is a rare neurological disorder that frequently precedes the detection of malignancy. Here, we report the case of a 60 year-old woman with locally advanced squamous cell carcinoma of the tongue who developed a subacute cerebellar syndrome associated with the presence of anti-CV2/CRMP5 antibodies in the cerebrospinal fluid, after achieving complete remission of the primary tumor and the involved cervical lymph nodes by chemoradiation. The patient's symptoms on presentation were dizziness and gait unsteadiness. On examination she showed dysarthria, nystagmus and limb and gait ataxia. The diagnosis of paraneoplastic cerebellar syndrome was made on the basis of the clinical findings and immunological testing that revealed the presence of anti-CV2/CRMP5 antibodies in the patient's cerebrospinal fluid. This syndrome, which is very rare in association with head and neck cancer, commonly precedes the detection of malignancy by a year or more and has been documented in only a few cases after completion of anticancer treatment.

What lies beneath the tent? JC-virus cerebellar granule cell neuronopathy complicating sarcoidosis

A 49-year-old, HIV-negative woman with sarcoidosis presented with a subacute unilateral cerebellar syndrome. A brain MRI revealed a hyperintense lesion without mass effect in the left cerebellar hemisphere, but no pathology above the tentorium. Steroid therapy for presumed neurosarcoidosis was ineffective and the patient deteriorated progressively. Cerebellar biopsy showed abnormal granule cells and demyelination. Immunocytochemistry confirmed the diagnosis of progressive multifocal leucoencephalopathy (PML) with JC (John Cunningham) virus granule cell neuronopathy. The patient succumbed to progressive brainstem dysfunction despite treatment with cidofovir. Although rare, PML should be considered in all patients with impaired cell-mediated immunity and unexplained neurological dysfunction, even in the absence of HIV infection.

Subacute cerebellar syndrome as the first manifestation of AIDS dementia complex

A patient presented with a subacute cerebellar syndrome in absence of cognitive impairment or other symptoms. He became demented several months after the onset of the disease. Necropsy demonstrated the typical features of the AIDS dementia complex and severe loss of Purkinje cells of the cerebellum. Patients with subacute cerebellar dysfunction should be evaluated for the presence of human immunodeficiency virus infection.

Effect of steroid treatment in cerebellar ataxia associated with anti-glutamic acid decarboxylase antibodies

Glutamic acid decarboxylase (GAD) catalyses the transformation of glutamate into γ-aminobutyric acid (GABA). Anti-GAD autoantibodies (GAD-Ab) have been associated with insulin-dependent diabetes mellitus (IDDM) and with other possibly immunomediated syndromes...

Sub‐acute cerebellar degeneration with anti‐Yo autoantibodies: immunohistochemical analysis of the immune reaction in the central nervous system

We report the pathological findings of a woman with a sub-acute cerebellar syndrome who had undergone surgery 3 years before for endometrial carcinoma. Both serum and cerebrospinal fluid contained high titres of autoantibodies against the cytoplasm of Purkinje cells that recognized a band of 62 kDa on immunoblotting of neuronal extracted proteins (pattern anti-Yo). No tumour was found despite a full range of gynaecological investigations; the neoplastic marker CA125 was slightly elevated and oligoclonal bands were detected in the cerebrospinal fluid. The patient died from acute myocardial infarction 4 months after developing this syndrome. At autopsy, no macroscopic evidence of tumour was obtained and the brain showed no abnormalities. On microscopic examination of the central nervous system diffuse degeneration of Purkinje cells could be seen throughout the cerebellum. Immunohistochemical analysis showed a CD8 lymphocyte infiltration in the cerebellum and cerebral cortex and diffuse microglial activation throughout the brain. These cells expressed high levels of MHC-II antigens on their cell membranes. The serum autoantibodies reacted with the cytoplasm of the remaining Purkinje cells. The short interval between the onset of symptoms and death of the patient could explain the difference between our findings and those reported in the literature in which no inflammatory infiltrates were detected. The immunohistochemical findings as well as the inflammatory cerebrospinal fluid profile seen in our case seem to support the concept that in paraneoplastic cerebellar degeneration with anti-Yo antibodies, an immune mediated mechanism is responsible for the damage to the cerebellum.

Reversal of subacute paraneoplastic cerebellar syndrome with intravenous immunoglobulin

Reversal of subacute paraneoplastic cerebellar syndrome with intravenous immunoglobulin

Remission of a paraneoplastic cerebellar syndrome

A case history is reported of spontaneous improvement of a sub-acute paraneoplastic cerebellar syndrome, that is before treatment of the primary (lung) tumour.