Are onconeural antibodies a clinical phenomenology in paraneoplastic limbic encephalitis?

Autoimmune Encephalitis Associated with Anti-N-methyl-D-aspartate Receptor and Anti-Hu Antibodies Successfully Treated with Carboplatin and Etoposide for Small-cell Lung Cancer

The coexistence of multiple autoantibodies associated with autoimmune encephalitis (AE) is rare. A 63-year-old woman developed psychosis and consciousness disorder. Her cerebrospinal fluid was positive for anti-N-methyl-D-aspartate receptor antibodies, and her serum was positive for anti-Hu antibodies. Enhanced computed tomography revealed a mass in the right pulmonary hilum. AE complicated with small-cell lung cancer was diagnosed. Immunotherapy (steroid therapy and intravenous immunoglobulin) and four courses of carboplatin-etoposide chemotherapy were required to improve her neurological symptoms. When the coexistence of multiple antibodies is detected, despite its rarity, aggressive detection and treatment of any underlying malignancy may be recommended.

Inflammation From Peripheral Organs to the Brain: How Does Systemic Inflammation Cause Neuroinflammation?

As inflammation in the brain contributes to several neurological and psychiatric diseases, the cause of neuroinflammation is being widely studied. The causes of neuroinflammation can be roughly divided into the following domains: viral infection, autoimmune disease, inflammation from peripheral organs, mental stress, metabolic disorders, and lifestyle. In particular, the effects of neuroinflammation caused by inflammation of peripheral organs have yet unclear mechanisms. Many diseases, such as gastrointestinal inflammation, chronic obstructive pulmonary disease, rheumatoid arthritis, dermatitis, chronic fatigue syndrome, or myalgic encephalomyelitis (CFS/ME), trigger neuroinflammation through several pathways. The mechanisms of action for peripheral inflammation-induced neuroinflammation include disruption of the blood-brain barrier, activation of glial cells associated with systemic immune activation, and effects on autonomic nerves via the organ-brain axis. In this review, we consider previous studies on the relationship between systemic inflammation and neuroinflammation, focusing on the brain regions susceptible to inflammation.

A Case Report of Neurosyphilis Limbic Encephalitis With Reversible Geschwind Syndrome and Mood Disorder

Limbic encephalitis is an inflammatory process of the limbic structures, with polymorphic clinical features, caused by paraneoplastic and nonparaneoplastic conditions and infections. We describe a case of neurosyphilis limbic encephalitis, presenting with reversible Geschwind syndrome (hyperreligiosity and hypergraphia) and mood disorder due to the predominant involvement of left mesial temporal structures in a previously healthy 34-year-old, left-handed woman. Because neurosyphilis can mimic common neuropsychiatric syndromes, it should be included in the differential diagnosis of psychiatric disorders with suspected general medical causes. This case of nondominant limbic encephalopathy caused by syphilis infection highlights the relevance of a careful investigation for secondary psychotic, mood, and personality disorders when assessing new-onset psychiatric illness and the importance of a multidisciplinary approach to provide a better outcome in patients with neurosyphilis.

Hypotension as a symptom of autonomic neuropathy in patients with advanced malignancies

AIMS

Hypotension can be a symptom of paraneoplastic autonomic neuropathy (PAN). Onconeural antibodies (OA) provide strong evidence for the paraneoplastic origin of neurological syndromes. Our goal was to assess the frequency of PAN among patients with advanced malignancies and hypotension using OA.

METHODS

Patients with advanced malignancies and hypotension were screened and enrolled as per protocol. Plasma levels of six classical OAs were assessed in these patients. We prospectively evaluated other symptoms of PAN in these patients.

RESULTS

31 patients out of 740 screened met the criteria of this cross-sectional study. OAs were present in 4 patients (12.9%). Anti-amphiphysin was found in 1 patient (3.23%), anti- CV2 (anti-CRPM5, anti- collapsin- response mediator protein) was present in 1 patient (3.23%), 1 patient (3.23%) was positive for anti-Hu and anti-Ma2 was present in 1 patient (3.23%). No patient was positive for 2 or more OAs. Normalization of blood pressure in concordance with partial remission occurred in 5 patients. The most used criteria for PAN were fulfilled in 9 patients.

CONCLUSION

The frequency of PAN may be underestimated in a busy oncology clinic. Assessing OAs may aid in the differential diagnosis of hypotension of unknown origin.

Anti-Ma2-antibody-associated encephalitis: An atypical paraneoplastic neurologic syndrome

Paraneoplastic syndromes are a heterogeneous group of conditions affecting cancer patients, where the signs and symptoms are not owing to the local effects of the tumour but instead owing to humoral or immunologic effects. We describe an unusual presentation of a paraneoplastic neurologic syndrome presenting with predominant involvement of the hypothalamus and deep grey nuclei secondary to an anterior mediastinal germinoma and associated with anti-Ma2 antibody.

What is the significance of onconeural antibodies for psychiatric symptomatology? A systematic review

BACKGROUND

Patients with intracellular onconeural antibodies may present with neuro-psychiatric syndromes. We aimed to evaluate the evidence for an association between well-characterized onconeural antibodies and psychiatric symptoms in patients with and without paraneoplastic central nervous system syndromes.

METHODS

Eligible studies were selected from 1980 until February 2017 according to standardized review criteria and evaluated using Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). We included studies describing the psychiatric symptomatology of onconeural antibody positive patients and the prevalence of onconeural antibodies in patients with psychiatric disorders.

RESULTS

Twenty-seven studies met the inclusion criteria. Six studies reported on the prevalence of well-characterized onconeural antibodies in patients with different psychiatric disorders, ranging from 0% to 4.9%. Antibody prevalence in controls was available from three studies, ranging from 0% to 2.8%. Data heterogeneity precluded a meta-analysis. Two cerebrospinal fluid studies found well-characterized onconeural antibodies in 3.5% and 0% of patients with psychotic and depressive syndromes, respectively.

CONCLUSIONS

The available evidence suggests that the prevalence of well-characterized onconeural antibodies in patients with psychiatric disorders is generally low. However, the question whether onconeural antibodies are important in select patients with a purely psychiatric phenotype needs to be addressed by appropriately designed studies in the future.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature: Part 3: Neurological paraneoplastic syndromes, involving the central nervous system

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes that can complicate lung cancer appears useful. This article is the third of a series of five and deals mainly with neurological paraneoplastic syndromes involving the central nervous system.

Paraneoplastic syndromes revealing ovarian teratoma in young and menopausal women: report of two cases

Paraneoplastic syndromes are a heterogeneous group of clinical and biological manifestations caused by underling neoplasms. They can reveal ovarian teratoma which express neuroendocrine proteins, or contain mature or immature neural tissue inducing an autoimmune response. The etiological investigation is then crucial to early identification of the tumor in order to optimize the prognosis and to limit neurological sequelae. In case of ovarian teratoma, management is essentially based on surgical resection sometimes associated with immunotherapie. We report two new cases of ovarian teratoma revealed by paraneoplastic syndromes in young and menopausal woman.

Limbic encephalitis following immunotherapy against metastatic malignant melanoma

Novel immunotherapies are increasingly being used to treat malignant melanoma. The use of such agents has been associated with triggering autoimmunity. However, there has been a paucity in reports of limbic encephalitis associated with these immunotherapies. Pembrolizumab, a monoclonal antibody against programmed cell death antigen (PD-1), is currently being trialled in the UK to treat malignant melanoma. We report a unique case of antibody-negative limbic encephalitis presenting 1 year after starting pembrolizumab, in the context of malignant melanoma. The patient presented with progressive cognitive decline. MRI of the brain revealed signal change within the limbic structures. Cerebrospinal fluid studies confirmed evidence of inflammation with raised white cell count and protein. We were able to prevent further progression of symptoms by stopping pembrolizumab and treating the patient instead with steroids. We advocate considering autoimmune neuroinflammation as a differential for neurological disorders presenting in patients receiving PD-1 antagonist treatment and immunotherapy in general.

Limbic encephalitis

We present a case of paraneoplastic limbic encephalitis, describing the presenting features, diagnosis and management plan. Limbic encephalitis is one differential of rapidly progressive dementia. We describe a rational approach to the diagnosis of the patient with rapid cognitive decline.