[Blood-brain barrier breakdown and autoimmune cerebellar ataxia]

Autoimmune cerebellar ataxia is a disease entity that affects the cerebellum and is induced by autoimmune mechanisms. The disease is classified into several etiologies, including gluten ataxia, anti-glutamate decarboxylase (GAD) ataxia, paraneoplastic cerebellar degeneration, primary autoimmune cerebellar ataxia and postinfectious cerebellar ataxia. The autoimmune response in the periphery cross-reacts with similar antigens in the cerebellum due to molecular mimicry. Breakdown of the blood‒brain barrier (BBB) could potentially explain the vulnerability of the cerebellum during the development of autoimmune cerebellar ataxia, as it gives rise to the entry of pathogenic autoantibodies or lymphocytes into the cerebellum. In this review, the maintenance of the BBB under normal conditions and the molecular basis of BBB disruption under pathological conditions are highlighted. Next, the pathomechanism of BBB breakdown in each subtype of autoimmune cerebellar ataxia is discussed. We recently identified glucose-regulated protein (GRP) 78 antibodies in paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome, and GRP78 antibodies induced by cross-reactivity with tumors can disrupt the BBB and penetrate anti-P/Q type voltage-gated calcium channel (VGCC) antibodies into the cerebellum, thus leading to cerebellar ataxia in this disease.

Paraneoplastic Cerebellar Degeneration Accompanied by Seropositivity for Anti-GAD65, Anti-SOX-1 and Anti-VGCC Antibodies Due to Small-cell Lung Cancer

Paraneoplastic cerebellar degeneration (PCD) is a paraneoplastic neurological syndrome that is rarely accompanied by seropositivity with a combination of multiple antibodies. We herein report a 50-year-old man with PCD accompanied by small-cell lung cancer (SCLC). This patient was seropositive for anti-glutamic acid decarboxylase 65, anti-SRY-related HMG-box gene 1 and anti-voltage-gated calcium channel antibodies. After chemoradiation therapy without immunotherapy, cerebellar ataxia of the trunk and limbs markedly improved, along with a notable amelioration of SCLC. This case suggests that tumor therapy should be started immediately and that a panel of anti-neuronal antibodies should be evaluated when PCD with SCLC is suspected.

Paraneoplastic Cerebellar Degeneration Leading to an Early Diagnosis of Peritoneal Serous Papillary Carcinoma

A 77-year-old female with a subacute progression of ataxia and serum anti-Yo antibodies was suspected to have paraneoplastic cerebellar degeneration (PCD). An examination of an underlying cancer showed no abnormality in the gynecological organs, but the findings did show a mass in the Douglas fossa. The mass was resected and diagnosed as stage IIB peritoneal serous papillary carcinoma (PSPC), a rare gynecologic cancer that is difficult to diagnose in the early stages. PCD was treated with intravenous immunoglobulin (IVIG). For an early diagnosis and treatment, PSPC should be included in the list of malignancies that cause PCD with anti-Yo antibodies.

Anti-Yo-Associated Paraneoplastic Cerebellar Degeneration: Case Series and Review of Literature

Anti-Yo-associated paraneoplastic cerebellar degeneration (PCD) syndrome is a very rare condition that is most commonly associated with breast and gynecologic cancers. Those cases associated with breast cancer tend to be human epidermal growth factor receptor 2 (HER2)-positive, though the reason for this correlation is unknown. Most commonly, the neurologic symptoms of the PCD syndrome predate the patient’s cancer diagnosis. Thus, prompt diagnosis of PCD is essential to allow for early treatment of the neurologic symptoms and the underlying malignancy. However, the prognosis is very poor for the anti-Yo-associated paraneoplastic syndrome, since neurologic damage is usually rapid and irreversible. Further progression may be stopped with appropriate treatment of cancer, but existing neurologic deficits at the time of diagnosis are usually permanent. Steroids, plasma exchange, and rituximab are commonly used treatments, though these have had mixed to poor results.

Update on Paraneoplastic Cerebellar Degeneration

Purpose of review: To provide an update on paraneoplastic cerebellar degeneration (PCD), the involved antibodies and tumors, as well as management strategies. Recent findings: PCD represents the second most common presentation of the recently established class of immune mediated cerebellar ataxias (IMCAs). Although rare in general, PCD is one of the most frequent paraneoplastic presentations and characterized clinically by a rapidly progressive cerebellar syndrome. In recent years, several antibodies have been described in association with the clinical syndrome related to PCD; their clinical significance, however, has yet to be determined. The 2021 updated diagnostic criteria for paraneoplastic neurologic symptoms help to establish the diagnosis of PCD, direct cancer screening, and to evaluate the presence of these newly identified antibodies. Recognition of the clinical syndrome and prompt identification of a specific antibody are essential for early detection of an underlying malignancy and initiation of an appropriate treatment, which represents the best opportunity to modulate the course of the disease. As clinical symptoms can precede tumor diagnosis by years, co-occurrence of specific symptoms and antibodies should prompt continuous surveillance of the patient. Summary: We provide an in-depth overview on PCD, summarize recent findings related to PCD, and highlight the transformed diagnostic approach.

CD8 T-cell-mediated cerebellitis directed against Purkinje cell antigen after ipilimumab for small cell lung cancer

We report a rapidly progressive and fatal CD8 T-cell-mediated cerebellitis after ipilimumab (cytotoxic T-lymphocyte-associated protein 4 inhibitor) for small cell lung cancer. Clinical features and histopathology were consistent with an accelerated form of paraneoplastic cerebellar degeneration. A patchy CD8 T-cell infiltrate spatially corresponded to areas of Purkinje cell loss, with occasional CD8 polarisation towards Purkinje cells. CD20-positive B cells were sparse. CD8 T-cell-mediated cerebellitis after immune checkpoint inhibitor treatment may recapitulate the early stages of paraneoplastic cerebellar degeneration.

Paraneoplastic Cerebellar Degeneration and Lambert-Eaton Myasthenic Syndrome with SOX-1 Antibodies

A 69-year-old man was admitted to our hospital for progressive muscle weakness in both lower limbs and limb ataxia (day 0). Nerve conduction studies showed low compound muscle action potential amplitudes at rest and increased amplitudes after maximum voluntary contraction. Blood testing revealed SOX-1 antibodies. He was diagnosed with paraneoplastic cerebellar degeneration and Lambert-Eaton myasthenic syndrome (PCD-LEMS). He died from aspiration pneumonia on day 9. Small-cell lung carcinoma (SCLC), which had not been obvious on computed tomography, was found during the autopsy. Patients with PCD-LEMS who test positive for SOX-1 antibodies should be carefully evaluated for SCLC.

Acute-onset paraneoplastic cerebellar degeneration secondary to neuroendocrine carcinoma with atypical prognosis: a case report

Paraneoplastic cerebellar degeneration (PCD) is a neurological syndrome that is likely caused by tumor-induced autoimmunity against the cerebellum. Neuroendocrine carcinoma (NEC) is a type of neoplasm with high-grade malignant histology and biological behavior. The prognosis for both PCD and NEC is typically poor. We report a case of PCD secondary to metastatic NEC in the lymph nodes, with an unknown primary origin. The case presented acute cerebellar manifestations with typical neuroimaging findings, but with atypical prognosis after lymph node dissection. Neurological symptoms can provide clues to potential tumors, and early antitumor treatment may have contributed to the positive prognosis of PCD secondary to NEC in the present case.

A Rare Coexistence of Paraneoplastic Cerebellar Degeneration: Papillary Thyroid Carcinoma

Paraneoplastic cerebellar degeneration (PCD) is a rare neuroimmunological disease that may accompany tumors. In this article, we present a patient with progressive gait difficulty who was diagnosed with PCD and, in a rare comorbidity, with papillary thyroid carcinoma (PTC) following malignancy screening. A 46-year-old male patient reported having experienced poor balance for 2 years. A neurological examination revealed nystagmus, intention tremor, and ataxia, and anti-thyroid peroxidase and anti-thyroglobulin levels were found to be elevated. A brain MRI showed significant cerebellar atrophy in the superior vermis. Malignancy screening for PCD was performed, and thyroid ultrasonography revealed a nodule in the left lobe, while PET/CT detected elevated focal F-18 fluorodeoxyglucose uptake in the thyroid. Onconeuronal antibodies (anti-Hu, anti-Yo, anti-Ri, anti-amphiphysin, anti-Tr, anti-PPCA-2, anti-Ma, anti-CV-1, and anti-ANNA-3) were negative. Pathologic examination of the thyroid revealed PTC, for which the patient was treated with 0.4 g/kg intravenous immunoglobulin and referred to the medical oncology department. This case demonstrates that clinicians must be alert to the rare comorbidity of PCD and PTC.

Advances in Therapies of Cerebellar Disorders: Immune-mediated Ataxias

The identification of an increasing number of immune mediated ataxias suggests that the cerebellum is often a target organ for autoimmune insults. The diagnosis of immune mediated ataxias is challenging as there is significant clinical overlap between immune mediated and other forms of ataxia. Furthermore the classification of immune mediated ataxias requires further clarification particularly for those ataxias where no specific antigenic trigger and associated antibodies have been identified. Recognition of immune mediated ataxias remains imperative as therapeutic interventions can be effective, although given the relative rarity of this entity, large-scale treatment trials may not be feasible. This review will discuss advances in therapies for immune mediated ataxias based on what is currently available in the literature.

Plasma exchange for treating anti-Yo-associated paraneoplastic cerebellar degeneration: Case report and literature review

RATIONALE

Paraneoplastic cerebellar degeneration (PCD) is a rare neurodegenerative syndrome associated with antibodies targeting the Purkinje cells of the cerebellum. Most cases of anti-Yo-associated PCD occur in females, with <20 cases reported in males. Herein, we report a male patient with anti-Yo-associated PCD who was treated with plasma exchange and achieved a favorable outcome.

PATIENT CONCERNS

A 64-year-old man presented with progressive ataxia, gait instability, and dysuria. Electroencephalography, electromyography, brain and spinal neuroimaging, and routine laboratory examinations were all normal. The anti-neuronal antibody Anti-Yo was detected in the serum but not in the cerebrospinal fluid (CSF).

DIAGNOSIS

The patient was diagnosed with definite anti-Yo-associated PCD based on the clinical manifestations, anti-Yo was detected in the serum and response to treatment.

INTERVENTIONS

At beginning, the patient was treated with dexamethasone (10 mg/day for 10 days). Then, plasma exchange was performed.

OUTCOMES

After treated with dexamethasone, no clinical improvement was noted in this patient. In the following month, his condition deteriorated. However, after two courses of plasma exchange, neurological examination showed marked improvement in gait. After four courses of plasma exchange, the patient could walk independently, the Romberg test was negative, and anti-Yo antibodies were undetectable. At the 6-month follow-up, the patients' symptoms were relieved, and tests for anti-Yo antibodies remained negative.

LESSONS SUBSECTIONS

Treatment with plasma exchange for anti-Yo-associated male PCD patients without a concomitant tumor are recommend and need more studies.

Immunological Bases of Paraneoplastic Cerebellar Degeneration and Therapeutic Implications

Paraneoplastic cerebellar degeneration (PCD) is a rare immune-mediated disease that develops mostly in the setting of neoplasia and offers a unique prospect to explore the interplay between tumor immunity and autoimmunity. In PCD, the deleterious adaptive immune response targets self-antigens aberrantly expressed by tumor cells, mostly gynecological cancers, and physiologically expressed by the Purkinje neurons of the cerebellum. Highly specific anti-neuronal antibodies in the serum and cerebrospinal fluid represent key diagnostic biomarkers of PCD. Some anti-neuronal antibodies such as anti-Yo autoantibodies (recognizing the CDR2/CDR2L proteins) are only associated with PCD. Other anti-neuronal antibodies, such as anti-Hu, anti-Ri, and anti-Ma2, are detected in patients with PCD or other types of paraneoplastic neurological manifestations. Importantly, these autoantibodies cannot transfer disease and evidence for a pathogenic role of autoreactive T cells is accumulating. However, the precise mechanisms responsible for disruption of self-tolerance to neuronal self-antigens in the cancer setting and the pathways involved in pathogenesis within the cerebellum remain to be fully deciphered. Although the occurrence of PCD is rare, the risk for such severe complication may increase with wider use of cancer immunotherapy, notably immune checkpoint blockade. Here, we review recent literature pertaining to the pathophysiology of PCD and propose an immune scheme underlying this disabling disease. Additionally, based on observations from patients' samples and on the pre-clinical model we recently developed, we discuss potential therapeutic strategies that could blunt this cerebellum-specific autoimmune disease.

Anti-SOX1 Antibodies in Paraneoplastic Neurological Syndrome

Anti-Sry-like high mobility group box (SOX) 1 antibodies (abs) are partly characterized onconeural autoantibodies (autoabs) due to their correlation with neoplastic diseases. Anti-SOX1 abs are associated with various clinical manifestations, including Lambert-Eaton myasthenic syndrome (LEMS) and paraneoplastic cerebellar degeneration (PCD). However, the clinical characteristics of patients with anti-SOX1 abs have not been described in detail. This review systematically explores the reported patients with anti-SOX1 abs and analyzes these cases for demographic characteristics, clinical features, coexisting neuronal autoabs, neuroimaging findings, treatment, and clinical outcomes. In addition, considering that PCD is the most common paraneoplastic neurological syndrome and that the association between PCD and anti-SOX1 abs remains unclear, we focus on the presence of autoabs in relation to PCD and associated tumors. PCD-associated autoabs include various intracellular autoabs (e.g., anti-Hu, anti-Yo, anti-Ri, and anti-SOX1) and cell-surface autoabs (anti-P/Q-type voltage-gated calcium channel). Commonly involved tumors in PCD are small-cell lung cancer (SCLC), gynecological, and breast tumors. LEMS is the most common clinical symptom in patients with anti-SOX1 abs, followed by PCD, and multiple neuronal autoabs coexist in 47.1% of these patients. SCLC is still the predominant tumor in patients with anti-SOX1 abs, while non-SCLC is uncommon. No consistent imaging feature is found in patients with anti-SOX1 abs, and there is no consensus on either the therapy choice or therapeutic efficacy. In conclusion, the presence of anti-SOX1 abs alone is a potential predictor of an uncommon paraneoplastic neurological disorder, usually occurring in the setting of LEMS, PCD, and SCLC. The detection of anti-SOX1 abs contributes to an early diagnosis of underlying tumors, given the diversity of clinical symptoms and the absence of characteristic neuroimaging features.

Immune-mediated Cerebellar Ataxias: Practical Guidelines and Therapeutic Challenges

Immune-mediated cerebellar ataxias (IMCAs), a clinical entity reported for the first time in the 1980s, include gluten ataxia (GA), paraneoplastic cerebellar degenerations (PCDs), antiglutamate decarboxylase 65 (GAD) antibody-associated cerebellar ataxia, post-infectious cerebellitis, and opsoclonus myoclonus syndrome (OMS). These IMCAs share common features with regard to therapeutic approaches. When certain factors trigger immune processes, elimination of the antigen( s) becomes a priority: e.g., gluten-free diet in GA and surgical excision of the primary tumor in PCDs. Furthermore, various immunotherapeutic modalities (e.g., steroids, immunoglobulins, plasmapheresis, immunosuppressants, rituximab) should be considered alone or in combination to prevent the progression of the IMCAs. There is no evidence of significant differences in terms of response and prognosis among the various types of immunotherapies. Treatment introduced at an early stage, when CAs or cerebellar atrophy is mild, is associated with better prognosis. Preservation of the "cerebellar reserve" is necessary for the improvement of CAs and resilience of the cerebellar networks. In this regard, we emphasize the therapeutic principle of "Time is Cerebellum" in IMCAs.

Cerebellar Ataxia With Extreme Photophobia Associated With Anti-SOX1 Antibodies

Anti-SOX1 antibodies are associated with diverse neurological syndromes, targeting both the central (paraneoplastic cerebellar degeneration) and peripheral nervous systems (Lambert Eaton myasthenic syndrome, paraneoplastic neuropathy). Although the pathogenic role of these antibodies remains unclear, their strong association with underlying neoplastic disease (mainly small-cell lung cancer) has designated them as onconeural antibodies. Here, we present a case of cerebellar ataxia with marked photophobia, with severe atrophy of the cerebellum and brain stem, associated with anti-SOX1 antibodies without evidence of an underlying malignancy. Although anti-SOX1-associated cerebellar syndrome is infrequent, investigation of these antibodies should be considered as a part of the diagnostic algorithm if more common causes have been ruled out. Extensive brain stem lesions causing disruption of the trigeminal pathway and its connections with the pretectal area might explain the underlying mechanism of the associated photophobia. Early recognition of anti-SOX1 antibodies, exclusion of underlying neoplasm, and prompt initiation of immunotherapy are essential to achieve a better outcome.

Paraneoplastic cerebellar degeneration associated with cerebellar hypermetabolism: Case report

RATIONALE

Paraneoplastic cerebellar degeneration (PCD) is an immune-mediated neurological deficit affecting the cerebellum. Anti-Yo antibody positive PCD is a rare occurrence most likely associated with gynecologic or breast malignancies. The identification of the underlying tumor is a diagnostic challenge in many of these patients.

PATIENT CONCERNS

We present a 68-year-old woman with acute symptoms of PCD as a first sign of underlying occult malignancy. Further investigation revealed a positive anti-Yo antibody. Although brain magnetic resonance imaging (MRI) was unremarkable, positron emission tomography (PET)/computed tomography (CT) revealed intense hypermetabolism of cerebellum and diffused hypometabolism in the rest of brain. On 1-year follow-up, despite the primary malignancy is still unknown, her symptoms improved significantly after immunotherapy.

DIAGNOSES

Paraneoplastic cerebellar degeneration.

INTERVENTIONS

The patient was given IV methylprednisolone 500 mg once a day for 5 consecutive days, followed by oral prednisone 60 mg once a day for 3 months.

OUTCOMES

The patient's symptoms were gradually improved during the hospitalization period. On one year follow up, she was able to walk independently and perform some simple tasks.

LESSONS

Cerebellar hypermetabolism in PCD suspected patients may help confirming the diagnosis in an earlier stage and may predict a better outcome after immunotherapy.

Paraneoplastic cerebellar degeneration associated with breast cancer: A case report and review of the literature

Paraneoplastic cerebellar degeneration (PCD) is a rare neurological complication of cancer characterized by rapid development of cerebellar ataxia. We herein present a case of a 67-year-old female patient with PCD caused by breast cancer. The patient presented with progressively worsening cerebellar deficits that had been misdiagnosed for several months prior to the identification of the anti-Yo autoantibodies in the serum. A whole-body positron emission tomography/computed tomography scan revealed a lesion in the lower outer quadrant of the left breast with slightly increased metabolism. On mammography, a lobulated high-density mass was identified in the left breast. The patient underwent left breast lumpectomy and the histological examination confirmed the presence of an invasive ductal carcinoma. After breast surgery, the patient exhibited marked neurological improvement at the 12-month follow-up. Therefore, it is crucial that clinicians include paraneoplastic neurological syndromes in the differential diagnosis of neurological disorders. The detection of characterized onconeural antibodies in the serum or cerebrospinal fluid may provide guidance in the search for an underlying tumor.

Paraneoplastic cerebellar degeneration: Yo antibody alters mitochondrial calcium buffering capacity

Aim

Neurodegeneration is associated with dysfunction of calcium buffering capacity and thereby sustained cellular and mitochondrial calcium overload. Paraneoplastic cerebellar degeneration (PCD), characterized by progressive Purkinje neurone degeneration following paraneoplastic Yo antibody internalization and binding to cerebellar degeneration‐related protein CDR2 and CDR2L, has been linked to intracellular calcium homeostasis imbalance due to calbindin D_28k malfunction. Therefore, we hypothesized that Yo antibody internalization affects not only calbindin calcium binding capacity, but also calcium‐sensitive mitochondrial‐associated signalling, causing mitochondrial calcium overload and thereby Purkinje neurone death.

Methods

Immunohistochemically, we evaluated cerebellar organotypic slice cultures of rat brains after inducing PCD through the application of Yo antibody‐positive PCD patient sera or purified antibodies against CDR2 and CDR2L how pharmacologically biased mitochondrial signalling affected PCD pathology.

Results

We found that Yo antibody internalization into Purkinje neurons caused depletion of Purkinje neurone calbindin‐immunoreactivity, cannabinoid 1 receptor over‐activation and alterations in the actions of the mitochondria permeability transition pore (MPTP), voltage‐dependent anion channels, reactive oxygen species (ROS) and Na⁺/Ca²⁺ exchangers (NCX). The pathological mechanisms caused by Yo antibody binding to CDR2 or CDR2L differed between the two targets. Yo‐CDR2 binding did not alter the mitochondrial calcium retention capacity, cyclophilin D‐independent opening of MPTP or activity of NCX.

Conclusion

These findings suggest that minimizing intracellular calcium overload toxicity either directly with cyclosporin‐A or indirectly with cannabidiol or the ROS scavenger butylated hydroxytoluene promotes mitochondrial calcium homeostasis and may therefore be used as future neuroprotective therapy for PCD patients.

The neuropathology of the adult cerebellum

This chapter summarizes the neuropathologic features of nonneoplastic disorders of the adult cerebellum. Gait ataxia and extremity dysmetria are clinical manifestations of diseases that interrupt the complex cerebellar circuitry between the neurons of the cerebellar cortex, the cerebellar nuclei (especially the dentate nuclei), and the inferior olivary nuclei. The cerebellum is a prominent target of several sporadic and hereditary neurodegenerative diseases, including multiple system atrophy, spinocerebellar ataxia, and Friedreich ataxia. Purkinje cells display selective vulnerability to hypoxia but a surprising resistance to hypoglycemia. A classic toxin that damages the cerebellar cortex is methylmercury, but the most common injurious agent to Purkinje cells is ethanol. Many drugs cause ataxia, but doubts continue about phenytoin. Ischemic lesions of the cerebellum due to arterial thrombosis or embolism cause a spectrum of symptoms and signs, depending on the territory involved. Large hemorrhages have an unfavorable prognosis because they displace critical brainstem structures or penetrate into the fourth ventricle. Fungal infections and toxoplasmosis of the cerebellum, and cerebellar progressive multifocal leukoencephalopathy, have become rarer because of improved control of the acquired immunodeficiency syndrome. Ataxia is a prominent feature of prion disease. Adult-onset Niemann-Pick type C1 disease and Kufs disease may have a predominantly ataxic clinical phenotype. The adult cerebellum is also vulnerable to several leukodystrophies. A rare but widely recognized complication of cancer is paraneoplastic cerebellar degeneration.

Immune-mediated ataxias

Immune-mediated cerebellar ataxia (CA) comprises a group of rare diseases that are still incompletely described, and are probably underdiagnosed. Both acute and progressive progressions are possible. Different syndromes have been identified, including CA associated with anti-GAD antibodies, the cerebellar type of Hashimoto encephalopathy, primary autoimmune CA, gluten ataxia, opsoclonus-myoclonus syndrome, and paraneoplastic cerebellar degenerations. Most of these syndromes are associated with autoantibodies targeting neuronal antigens. Additionally, autoimmune CA can be triggered by infections, especially in children, and in rare cases occur in the context of an autoimmune multisystem disease, such as systemic lupus erythematosus, sarcoidosis, or Behçet disease. A careful workup is needed to distinguish autoimmune CA from other causes. In adults, a paraneoplastic origin must be ruled out, especially in cases with subacute onset. Neurologic outcome in adults is frequently poor, and optimal therapeutic strategies remain ill defined. The outcome in children is in general good, but children with a poor recovery are on record. The precise pathophysiologic mechanisms even in the presence of detectable autoantibodies are still largely unknown. Further research is needed on both the clinical and mechanistic aspects of immune-mediated CA, and to determine optimal therapeutic strategies.

Rehabilitation for a patient with anti-Yo antibody-positive paraneoplastic cerebellar degeneration caused by breast cancer: A case report and literature review

RATIONALE

Rehabilitation for paraneoplastic cerebellar degeneration (PCD) has been indicated as necessary. However, there are only a few reports on rehabilitation in PCD. We describe the course of physical and cognitive functions and activities of daily living (ADL) in a patient with PCD and examine the effect of rehabilitation, along with a review of relevant literature.

PATIENT CONCERNS

A 42-year-old woman experienced rapid deterioration in cerebellar symptoms and was unable to walk. The cerebellar symptoms improved after mastectomy, which was performed 3 months after the onset of symptoms. However, the cerebellar symptoms exacerbated 11 months after the onset of symptoms. She underwent immunotherapy because the level of anti-Yo antibodies was high, and anti-glutamic acid decarboxylase antibodies were detected.

DIAGNOSES

She was diagnosed with anti-Yo antibody-positive PCD caused by breast cancer.

INTERVENTIONS

Rehabilitation was performed preoperatively, postoperatively, and at 1 year after the onset of symptoms.

OUTCOMES

Her physical function and ADL improved after the surgery and at 1 year after the onset of symptoms. Finally, she regained the ability to walk between parallel bars supported with one hand and a walking frame.

LESSONS

Given the results of this case and the relevant literature, it appears that rehabilitation improves physical function and ADL after oncotherapy. Particularly, initiating treatment within three months of onset of symptoms may enable patients to walk without assistance.

Anti-Yo positive and late-onset paraneoplastic cerebellar degeneration associated with ovarian carcinoma: A case report

RATIONALE

Paraneoplastic cerebellar degeneration (PCD) is a rare nonmetastatic neurological complication often associated with ovarian, breast, and other gynecologic cancers. Anti-Yo is one of the antionconeural antibodies found in patients with PCD. It primarily emerges before a malignancy is detected.

PATIENT CONCERNS

In this report, we describe an unusual case involving a patient who exhibited anti-Yo-positive PCD 1 year after being diagnosed with ovarian cancer.

DIAGNOSES

Histopathology of the resected tissues and Antineuronal antibody testing.

INTERVENTIONS

The patient was treated with intravenous immunoglobulin (IVIG, 1 g/d) for 1 week and a large-dose of methylprednisolone (0.4 g/kg/d) for 5 days. At the same time, underlying complications were prevented actively, and the peripheral nerves were protected.

OUTCOMES

Although most patients with anti-Yo-positive PCD do not improve after treatment, our patient significantly improved after receiving active and effective treatment.

Rapid Eye Movement Sleep Behavior Disorder in Paraneoplastic Cerebellar Degeneration: Improvement with Immunotherapy

STUDY OBJECTIVES

To report two female patients with paraneoplastic cerebellar degeneration (PCD) related to breast cancer that presented with rapid eye movement-sleep behavior disorder (RBD) and improved sleep symptoms with immunotherapy.

METHODS

The two patients were evaluated through clinical scale and polysomnography before and after therapy with intravenous immunoglobulin.

RESULTS

RBD was successfully treated with immunotherapy in both patients. Score on the RBD screening questionnaire dropped from 10 to 1 or 0, allied with the normalization of polysomnographic findings.

CONCLUSIONS

A marked improvement in RBD after immunotherapy in PCD raises the hypothesis that secondary RBD may be an immune-mediated sleep disorder.

'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 2: Anti-PKC-gamma, anti-GluR-delta2, anti-Ca/ARHGAP26 and anti-VGCC

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects, and provides a summary and outlook.

'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

'Medusa-head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 1: Anti-mGluR1, anti-Homer-3, anti-Sj/ITPR1 and anti-CARP VIII

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa-head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

Diagnosis of Dual Malignancy by 18F-FDG PET/CT in the Setting of Paraneoplastic Cerebellar Degeneration

We describe a rare case of paraneoplastic cerebellar degeneration (with detectable antineuronal antibody anti-Yo) in which (18)F-FDG PET/CT aided in the detection of 2 synchronous malignancies (one thyroid cancer and the other breast cancer). Interestingly, the primary breast malignancy was non-(18)F-FDG-avid and was detected through the presence of a metastatic (18)F-FDG-avid axillary lymph node. Surgery for both was undertaken in the same sitting, and there was improvement of the neurologic features soon after the surgical removal of the malignancies.

Paraneoplastic cerebellar degeneration in a patient with ovarian cancer

OBJECTIVE

Herein, we report a case of ovarian serous carcinoma with paraneoplastic cerebellar degeneration.

CASE REPORT

A 44-year-old female presented to our hospital with dizziness, slurred speech, and ataxic gait. Brain magnetic resonance imaging was normal. A lumbar puncture revealed a normal cell count in the cerebrospinal fluid, but slightly elevated protein. Her serum cancer antigen -125 level was high (2126.4 U/mL), and abdominal computed tomography disclosed a pelvic mass measuring 11 cm in diameter. Exploratory laparotomy was then performed, and a frozen section of the tumor revealed serous carcinoma.

CONCLUSION

According to the surgical findings and pathological report, The International Federation of Gynecology and Obstetrics (FIGO) Stage IIIC, Grade 3, serous-type ovarian cancer was diagnosed. Due to the abovementioned symptoms and signs, we performed a serial test to document the presence of anti-Yo antibody in this patient.

Response to abdominal hysterectomy with bilateral salpingo-oophorectomy in postmenopausal woman with anti-yo antibody mediated paraneoplastic cerebellar degeneration

Paraneoplastic cerebellar degeneration (PCD) is a rare neurological disorder characterized by a widespread loss of Purkinje cells associated with a progressive pancerebellar dysfunction. PCD often precedes the cancer diagnosis by months to years. Here, we report a case of 44-year old postmenopausal woman who presented with PCD symptoms and high levels of anti-Yo antibodies titer since 8 months. We failed to conclude any neoplastic focus after thorough laboratory and imaging study. She minimally responded to methylprednisolone and immunoglobulin therapies. Despite therapy she was severely disabled. Planned abdominal hysterectomy with bilateral salpingo-oophorectomy (AHBSO) was done, histology revealed grade IIA borderline serous papillary carcinoma of ovary. Her neurological deficit responded dramatically to AHBSO. It is first case report who emphasize the response of AHBSO with presentation of anti-Yo antibody-mediated PCD and hidden nidus in post menopausal women.

Paraneoplastic cerebellar degeneration as the first evidence of malignancy: a case report

Paraneoplastic cerebellar degeneration (PCD) is an immune-mediated paraneoplastic disorder affecting the cerebellum. PCD associated with ovarian malignancy is a rare occurrence with fewer than 100 cases reported in published work. PCD patients express anti-Yo antibody, one of the anti-onconeuronal antibodies which is most likely associated with gynecologic or breast malignancies. In this report, we present the case of a 65-year-old postmenopausal woman presenting with acute symptoms of PCD as a first sign of ovarian malignancy.

Isolated cerebellar hypermetabolism on FDG PET in a case of remitted primary breast lymphoma

We present here a case of primary non-Hodgkin's lymphoma of the breast that succumbed in a sub-acute course to death after three months of initial remission. The fluorodeoxyglucose positron emission tomography imaging during the declining clinical status showed isolated cerebellar hypermetabolism.

Seronegative paraneoplastic cerebellar degeneration: the PNS Euronetwork experience

BACKGROUND AND PURPOSE

To describe the characteristics of patients presenting a paraneoplastic cerebellar degeneration without classical onconeural antibodies (seronegative PCD).

METHODS

Thirty-nine seronegative PCD patients from the Paraneoplastic Neurological Syndrome Euronetwork were retrospectively analyzed and compared with 180 patients with PCD associated with classical onconeural antibodies (seropositive PCD).

RESULTS

No patient had anti-CASPR2 or anti-mGluR1 antibodies. No significant difference between the clinical characteristics of seronegative and seropositive PCD patients was observed. Yet the frequency of associated tumors was different. Lymphoma was more frequent in seronegative than in seropositive women (24% vs. 2%, P = 0.002) whilst gynecological cancer were less frequent (38% vs. 74%, P = 0.002). In comparison with seropositive men, seronegative men more frequently had a non-small-cell lung cancer (27% vs. 6%, P = 0.08) or a genitourinary cancer (22% vs. 0%, P = 0.04) but less frequently a small-cell lung cancer (23% vs. 74%, P = 0.002). Seronegative and seropositive PCD patients with similar tumors had a similar overall survival.

CONCLUSION

The clinical characteristics of seronegative and seropositive PCD are similar but the spectrum of associated tumors is different. The immunological scenario of seronegative PCD seems to be different from that of limbic encephalitis with only few patients harboring anti-neuropile antibodies.

Paraneoplastic cerebellar degeneration caused by ovarian clear-cell carcinoma

Paraneoplastic cerebellar degeneration is a paraneoplastic neurological syndrome caused by the remote effect of certain systemic cancers and is characterized by subacute cerebellar symptoms. A 62-year-old woman suffering from unidentified cerebellar symptoms was admitted to our hospital. Paraneoplastic cerebellar degeneration was suspected and ovarian cancer was detected after the systemic examination for malignancy. The symptoms of vertigo and dysarthria were improved a little after surgical operation and treatments of γ-globulin, steroid pulse and tacrolimus hydrate. The cerebellar symptoms of paraneoplastic cerebellar degeneration are often evident prior to detection of malignancy. It is important to perform systemic examination for malignancy in case of unidentified cerebellar symptoms.

Paraneoplastic cerebellar degeneration associated with ovarian cancer

Paraneoplastic cerebellar degeneration (PCD) is a rare neurological disorder characterized by a widespread loss of Purkinje cells associated with a progressive pancerebellar dysfunction. PCD often precedes the cancer diagnosis by months to years. Here, we report the case of a 64-year-old woman who developed PCD symptoms, associated with high levels of anti-Yo antibodies, one year after a previous diagnosis of ovarian cancer. Clinical features, pathogenesis and treatment of PCD associated with cancer are discussed according to previous studies.

Paraneoplastic cerebellar degeneration: new insights into imaging and immunology

Brain imaging is usually remarkably unremarkable in paraneoplastic cerebellar degeneration

Cerebellar hypermetabolism in paraneoplastic cerebellar degeneration

A 51 year old man with paraneoplastic cerebellar degeneration from gastric adenocarcinoma showed cerebellar hypermetabolism and increased perfusion on brain FDG-PET scan and SPECT during the acute stage of his illness. The patient underwent subtotal gastrectomy. The intensity of the hypermetabolism had decreased markedly on follow-up FDG-PET 3 months later following two cycles of chemotherapy. We suggest that the cerebellar hypermetabolism may have been due to an acute inflammatory process associated with an immunological reaction.

Clinical insights into paraneoplastic cerebellar degeneration

Neuroimaging is usually unremarkable in paraneoplastic cerebellar degeneration (PCD), at least in the early stages of the disease. A patient with proven PCD is reported in whom it could be shown that cerebellar atrophy evolved very rapidly and was present in early imaging studies. Even with the use of the whole spectrum of modern diagnostic tools, the underlying malignancy can be difficult to diagnose. In addition to mammography, MRI is recommended in these cases and repeat FDG-PET may be necessary.