Paraneoplastic rhombencephalitis and brachial plexopathy in two cases of amphiphysin auto-immunity

Case report: Reversible brain atrophy with low titer anti-amphiphysin antibodies related to gastric adenocarcinoma

Amphiphysin (AMPH) autoimmunity is associated with a variety of neurological complications, including encephalitis, peripheral neuropathy, myelopathy, and cerebellar syndrome. Its diagnosis is based on clinical neurological deficits and the presence of serum anti-AMPH antibodies. Active immunotherapy, such as intravenous immunoglobulins, steroids, and other immunosuppressive therapies, has been reported to be effective in most patients. However, the extent of recovery varies depending on the case. Herein, we report the case of a 75-year-old woman with semi-rapidly progressive systemic tremors, visual hallucinations, and irritability. Upon hospitalization, she developed a mild fever and cognitive impairment. Brain magnetic resonance imaging (MRI) showed semi-rapidly progressive diffuse cerebral atrophy (DCA) over 3 months, while no clear abnormal intensities were observed. The nerve conduction study revealed sensory and motor neuropathy in the limbs. The fixed tissue-based assay (TBA) failed to detect antineuronal antibodies; however, based on commercial immunoblots, the presence of anti-AMPH antibodies was suspected. Therefore, serum immunoprecipitation was performed, which confirmed the presence of anti-AMPH antibodies. The patient also had gastric adenocarcinoma. High-dose methylprednisolone, and intravenous immunoglobulin were administered and tumor resection was performed, resulting in resolution of the cognitive impairment and improvement in the DCA on the post-treatment MRI. After immunotherapy and tumor resection, the patient's serum was analyzed using immunoprecipitation, which showed a decrease in the level of anti-AMPH antibodies. This case is noteworthy because the DCA showed improvement after immunotherapy and tumor resection. Additionally, this case demonstrates that negative TBA with positive commercial immunoblots do not necessarily indicate false positive results.

Limbic Encephalitis With Dual Positivity

Limbic encephalitis is a well-defined clinical disorder among paraneoplastic neurological syndromes. Although it is not always possible to identify specific autoantibodies in limbic encephalitis, the presence of anti-neuronal nuclear antibody type 1 (ANNA1 or anti-Hu), anti-Ma2, collapsin response mediator protein 5 (CRMP-5-IgG or anti-CV2), anti-GABA_B receptors and anti-amphiphysin antibodies are often detected. A 66-year-old male patient with complaints of forgetfulness was evaluated in our clinic after having seizures. In the neurological examination, the patient was found to be confused. In cranial MR fluid-attenuated inversion recovery (FLAIR) and T2-weighted images, the right hippocampal and parahippocampal structures showed hyperintense areas complying with limbic encephalitis. He had improvement with a course of 2 g/kg intravenous immunoglobulin (IVIG) followed by high-dose methylprednisolone therapy. Following the high-dose methylprednisolone therapy, anti-PCA1 (Yo) and anti-amphiphysin antibodies were positive and the tissue pathology report confirmed combined small-cell carcinoma and large-cell neuroendocrine carcinoma of the lung. In recent years, paraneoplastic neurological syndromes are better recognized with the identification of specific antibodies and the ubiquitous information on pathogenesis. This is the first known report in the literature that a case with both positive anti-PCA1 (Yo) and anti-amphiphysin antibodies together and underlying small-cell and large-cell neuroendocrine carcinomas.

Anti-amphiphysin encephalitis: Expanding the clinical spectrum

Objective

An analysis of the clinical features of autoimmune encephalitis accompanied by anti-amphiphysin antibodies.

Methods

The data of encephalitis patients with anti-amphiphysin antibodies were retrospectively evaluated, including demographics, neurological and laboratory findings, imaging, treatment, and prognostic predictions.

Results

Ten patients aged between 29 and 78 years (median age 52 years) were included. The male: female ratio was 4:6. Limbic encephalitis was found in nine patients while epileptic seizures were present in seven patients. All patients showed anti-amphiphysin antibody positivity in sera while one ninth was positive for CSF antibody. The EEG findings were abnormal, including reductions in background activity, and the presence of diffuse slow waves, sharp waves, and spikes and waves. Five patients showed signs of increased T2 signals in the medial temporal lobe on MRI while PET showed either hyper- or hypo-metabolic changes in several brain regions, including the temporal lobe, hippocampus, basal ganglia, frontal and parietal cortices. Nine of ten patients were treated with immunotherapy, with improvements of varying degrees. There was a significant reduction in seizure frequency, and all patients were seizure-free at last follow-up.

Conclusion

Autoimmune encephalitis with anti-amphiphysin antibodies has a variety of clinical manifestations. The most common symptom is limbic encephalitis. Although relief from seizures can be achieved relatively easily, many patients suffer psychiatric, cognitive, and sleep sequelae. The disease was found to be associated with a lower incidence of cancer than has been previously reported for paraneoplastic neurologic syndromes.

Pain as a First Manifestation of Paraneoplastic Neuropathies: A Systematic Review and Meta-Analysis

INTRODUCTION

Paraneoplastic neurological syndromes (PNS) consist of a heterogeneous group of neurological disorders triggered by cancer. The aim of this systematic review is to estimate the reported prevalence of pain in patients with paraneoplastic peripheral neuropathy (PPN).

METHODS

A systematic computer-based literature search was conducted on PubMed database.

RESULTS

Our search strategy resulted in the identification of 126 articles. After the eligibility assessment, 45 papers met the inclusion criteria. Full clinical and neurophysiological data were further extracted and involved 92 patients with PPN (54.5% males, mean age 60.0 ± 12.2 years). The commonest first manifestation of PPN is sensory loss (67.4%), followed by pain (41.3%), weakness (22.8%), and sensory ataxia (20.7%). In 13.0% of the cases, pain was the sole first manifestation of the PPN. During the course of the PPN, 57.6% of the patients may experience pain secondary to the neuropathy.

CONCLUSIONS

Pain is very prevalent within PPN. Pain specialists should be aware of this. Detailed history-taking, full clinical examination, and requesting nerve conduction studies might lead to an earlier diagnosis of an underlying malignancy.

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.

[Anti-amphiphysin antibody-positive paraneoplastic neurological syndrome with a longitudinally extensive spinal cord lesion of the dorsal column]

A 53-year-old woman was admitted to our hospital because of gait disturbance and paresthesia of the lower extremities. She also had marked deep sense impairment in her lower limbs. Cervical MRI showed a longitudinally extensive spinal cord lesion of the dorsal column at levels C1-T11. The findings of cerebrospinal fluid examination, including the IgG index (0.65), were normal. Serum anti-AQP4 antibody was negative, but anti-amphiphysin antibody was positive. Electrophysiological examinations suggested the presence of lesions in the dorsal column of the spinal cord and dorsal root ganglion (DRG). Enlargement of and fluorodeoxyglucose accumulation in her left parasternal lymph node was observed on contrast-enhanced CT and PET-CT, respectively. The lymph node biopsy was underwent by using thoracoscopy. The metastasis of carcinoma was pathologically confirmed. Although the primary tumor was not detected on PET-CT re-examination, immunostaining of the biopsied lymph node specimen was positive for both the progesterone receptor and estrogen receptor. On the basis of these findings, the patient was diagnosed with paraneoplastic neurological syndrome due to potential breast cancer. The disorder is an immunological subacute sensory neuropathy with a longitudinally extensive spinal cord lesion of the dorsal column and a DRG lesion.

Paraneoplastic neuropathy

Recent progress in serological screening of paraneoplastic antibodies and in diagnostic imaging techniques to detect malignancies has enabled a broadening of the concept of paraneoplastic neurological syndromes by integrating nonclassic clinical features. The peripheral nervous system is frequently involved in patients with paraneoplastic syndrome and may be seen alone or in combination with involvement of other areas of the nervous system. Destruction of dorsal root ganglion cells due to lymphocytic infiltration, especially with CD8-positive cytotoxic T cells, has been postulated to mediate the classic syndrome of subacute sensory neuronopathy. However, the motor and autonomic nervous systems are frequently affected. Indeed, patients can develop clinical features compatible with Guillain-Barré syndrome, chronic inflammatory demyelinating polyneuropathy, or brachial plexopathy. Other forms of paraneoplastic neuropathy are vasculitic neuropathy, autoimmune autonomic ganglionopathy, and chronic intestinal pseudo-obstruction. Various onconeural antibodies, including anti-Hu, anti-CV2/CRMP-5, and anti-ganglionic acetylcholine receptor antibodies, are associated with neuropathy. Somatic neuropathy is the most common manifestation in patients with anti-Hu and anti-CV2/CRMP-5 antibodies, while anti-ganglionic acetylcholine receptor antibody is associated with autonomic neuropathies. A whole-body fluorodeoxyglucose positron emission tomography scan may be useful to detect malignancy in patients with unremarkable conventional radiological findings. Recognition and diagnosis of paraneoplastic neuropathy is important, as neuropathic symptoms usually precede the identification of the primary tumor, and treatment at an earlier stage provides better chances of good outcomes.

Malignant cell infiltration in the peripheral nervous system

The peripheral nervous system can be affected by malignancies involving different mechanisms. Neoplastic nerve lesion by compression, invasion, and infiltration is rare and occurs in particular in leukemia (neuroleukemiosis) and lymphoma (neurolymphomatosis). Its occurrence is much rarer in cancer, and even less so in sarcoma. The neoplastic infiltration of peripheral nerves by solid tumors is characterized by specific topographical sites such as the base of the skull, the ear, nose and throat region, and the cervico-brachial plexus as well as the lumbar and sacral plexus. Rarely malignant invasion affects the cranial nerves of the face where it can spread centripetally. Autonomic nerves and ganglia can also be affected. The retrograde spread of cancer in nerves is a bad prognostic sign. The clinical diagnosis is determined by tumor type, the pattern of involvement, and often pain.

Rhombencephalitis / brainstem encephalitis

Rhombencephalitis (RE) is a syndrome of multiple causes and multiple outcomes. Most authors now use the terms "rhombencephalitis" and "brainstem encephalitis" interchangeably even though anatomically they are slightly different. The etiologic categories of RE include infections, autoimmune diseases, and paraneoplastic syndromes (PNS). Listeria is the most common cause of infectious RE. Listeria RE primary occurs in healthy young adults. It usually occurs as a biphasic time course with a flu-like syndrome followed by brainstem dysfunction; 75% of patients have a cerebrospinal fluid (CSF) pleocytosis, and almost 100% have an abnormal brain MRI scan. Positive CSF and blood cultures are the most specific for diagnosis. Treatment primarily is with ampicillin. Enterovirus 71 is probably the second most common infectious cause of RE; however, 95% of cases have occurred in the Asian-Pacific region and there is no specific treatment. Herpes simplex virus (HSV) is the third most common infectious cause of RE, and about 80% of cases are caused by HSV1 and 20% by HSV2. About 50% only had involvement of the brainstem whereas the other 50% also had supratentorial involvement of the temporal and frontal lobes. Mortality with acyclovir treatment was 22% versus those not on acyclovir 75%. Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV6) have caused a few cases. The most common autoimmune etiology is Behçet disease. Over 90% of those with Behçet RE had abnormal MRI scans and 94% had a CSF pleocytosis. Treatment is with corticosteroids and immunosuppressive agents, but only 25% have complete recovery. Paraneoplastic causes are the third category of RE. Brain MRIs are usually normal; there is usually a CSF pleocytosis but the protein is usually normal. Often anti-neuronal antibodies can be found. Prognosis is poor and treatment is only partially beneficial. Because Listeria and HSV are the most common treatable acute causes of RE, we recommend empiric therapy with ampicillin and acyclovir for all cases after samples have been obtained from CSF and blood for cultures and the polymerase chain reaction (PCR). Antibiotics can be changed based upon MRI, culture results, PCR results, and antibody studies.

Neuromuscular complications

Although direct neoplastic involvement of muscle tis-sue is surprisingly rare, considering the large amount of body mass that is represented by muscle tissue, the most important and unresolved muscle effect is muscle cachexia.Other associations, such as inflammatory, paraneo-plastic, toxic, and several extremely rare associations,have been described. Drug-induced toxicity and radiation recall syndrome need to be taken into consideration when muscle symptoms appear in patients with cancer.