Paraneoplastic Morvan's syndrome following surgical treatment of recurrent thymoma: A case report

Occult bowel cancer presenting as Morvan syndrome

A man in his mid-60s presented with a 3-month history of progressive muscle twitching, agitation, cognitive impairment, insomnia, hyperhidrosis and lower limb pain. He had fasciculations, myokymia, myoclonus, exaggerated startle response and significant postural hypotension. Electrophysiological studies showed evidence of peripheral nerve hyperexcitability with neuromyotonia. Contactin-associated protein-like 2 antibodies (CASPR2) were strongly positive. A diagnosis of Morvan syndrome was made. CT of the chest, abdomen and pelvis was undertaken to identify any occult malignancy, and a large bowel carcinoma in situ was identified and resected. His central nervous system and autonomic symptoms significantly improved following surgery, but neuromyotonia persisted, and this was treated with intravenous immunoglobulins and steroids. Early detection of bowel cancer in this patient enabled curative treatment.

OUP accepted manuscript

A 50-year-old male with history of HIV, syphilis, paraneoplastic Morvan syndrome secondary to thymoma resected in 2013 presented recently with tachycardia, tremors, diarrhea, hyperhidrosis and bilateral lower extremity pain leading to the discovery of thymoma recurrence. He initially developed Morvan Syndrome after thymectomy in 2013 and gradually improved with negative anti-contactin-associated protein-like 2 antibody testing in 2017 and symptom resolution in 2018. Upon return of dysautonomia symptoms, subsequent imaging revealed widespread disease recurrence diffusely in the right lung parenchyma and pleura for which he underwent right extrapleural pneumonectomy. He was managed with low-dose prednisone perioperatively, but when his symptoms worsened, he was started on rituximab and methylprednisolone. Nearly 3 months from surgery, he died from urinary sepsis. This represents a unique case of recurrent paraneoplastic Morvan syndrome leading to the diagnosis of metastatic thymoma as well as the challenges of symptom control during the surgical management of the underlying disease.

Anesthetic Management of Robotic Thymectomy in a Patient With Morvan Syndrome: A Case Report

Morvan syndrome (MvS) is a rare acquired paraneoplastic autoimmune neuromyotonia with central and autonomic nervous system involvement that has been incompletely described in the literature. We describe the successful administration of general anesthesia for robotic thymectomy to an MvS patient with severe encephalopathy, cardiac dysautonomia, and peripheral nerve hyperexcitation. Importantly, thymus removal provided effective source control with eventual resolution of MvS symptoms. MvS is briefly reviewed and novel observations are described of related interactions between nondepolarizing neuromuscular blockade (NDNMB) and bispectral index (BIS).

Clinical characteristics of patients double positive for CASPR2 and LGI1-antibodies

OBJECTIVES

This study described the clinical characteristics of autoimmune neurological diseases with dual seropositive antibodies of CASPR2 and LGI1.

PATIENTS AND METHODS

Three patients, with antibodies targeting both CASPR2 and LGI1 (EUROIMMUN, FA 112d-1, Germany), hospitalized in Department of Neurology, Xuanwu Hospital, Capital Medical University from June 2016 to June 2019 were collected in this study. We summarized the clinical characteristics of patients with CASPR2 and LGI1 antibodies from a targeted literature review.

RESULTS

Three patients reported were all middle-aged and elderly male with diverse neurological symptoms, including seizures, psychological abnormalities, limb weakness and hyperhidrosis. Interestingly, three patients displayed three different clinical syndromes (isolated epilepsy, Morvan syndrome and limbic encephalitis, respectively). White blood cell and glucose in Cerebrospinal fluid (CSF) were normal and CSF for protein was slightly elevated. Electromyography (EMG) showed abnormal spontaneous firing in case 2. Brain magnetic resonance imaging (MRI) revealed bilateral hyper-intensity of the temporal lobe on T2 and FLAIR sequence in case 3. Cancer screening program of patient 2 showed thymoma. Cell based assay was positive in serum for both LGI1 and CASPR2 antibodies, while these antibodies were negative in CSF. They were treated with glucocorticoid or intravenous immunoglobulin (IVIG). Followed up for 6 months to 1 year, all patients got remission to different extent.

CONCLUSION

Through the detailed analysis of three patients, the combination of both antibodies contributes to a broad spectrum of neurological symptoms in the central, peripheral, and autonomic nervous systems. The patients with same antibodies can have different clinical syndromes. Early tumor screening and immunotherapy will improve the prognosis of the disease.

A systematic review of paraneoplastic syndromes associated with thymoma: Treatment modalities, recurrence, and outcomes in resected cases

OBJECTIVE

Paraneoplastic syndromes associated with thymomas remain incompletely understood. The objective was to examine the association between surgically resected thymomas and paraneoplastic syndromes over the past half century.

METHODS

A primary PubMed/MEDLINE search was used to identify published articles describing paraneoplastic syndromes associated with thymomas from 1960 to 2019. A secondary search identified additional articles referenced in the articles found in the primary search. Kaplan-Meier and log-rank test were used for time-to-event data analyses.

RESULTS

From 407 articles describing 507 patients, 123 different paraneoplastic syndromes were associated with thymoma. The 5 most common paraneoplastic syndromes were myasthenia gravis, pure red cell aplasia, lichen planus, Good syndrome, and limbic encephalitis. Complete or partial resolution of paraneoplastic syndrome symptoms after surgery was noted in 76% of patients, of whom 21% had a relapse or new paraneoplastic syndrome onset after surgery. The most common adjunctive therapy associated with resolution of paraneoplastic syndrome was corticosteroids (30%). For all patients after surgery, thymoma recurrence was observed in 17% of cases, whereas recurrence of paraneoplastic syndrome was observed in 34% of cases, and both were observed in approximately 11% of cases. The 5- and 10-year overall survivals were 78% and 66%, respectively. Improved overall survival was associated with patients who had total resolution from paraneoplastic syndrome.

CONCLUSIONS

A comprehensive assessment of publications over the past half century suggests that a multimodal treatment approach that includes surgical resection of thymomas is able to achieve paraneoplastic syndrome resolution in a majority of patients. Onset of new paraneoplastic syndromes after surgery is associated with the recurrence of the first paraneoplastic syndrome, and resolution of paraneoplastic syndrome is associated with improved overall survival.

Non-Myasthenia Gravis Immune Syndromes and the Thymus: Is There a Role for Thymectomy?

Thymectomy has long been considered, performed, and discussed for many different nonmyasthenic immune syndromes. Thymectomy is now an established treatment for MG, and has been performed for other immune syndromes with varying degrees of improvement. Although numerous reports document immune syndromes' association with thymoma, few address the role of thymectomy in symptom resolution. This review assesses thymectomy in the various nonmyasthenic immune syndromes for which it has been tried. Based on this review, it seems appropriate to revisit a more active role for thymectomy in pure red cell aplasia, pemphigus, rheumatoid arthritis, autoimmune hemolytic anemia, and ulcerative colitis.

Current Treatment Options for Peripheral Nerve Hyperexcitability Syndromes

PURPOSE OF REVIEW

Peripheral nerve hyperexcitability (PNH) syndromes are divided into primary and secondary groups based on the presence or absence of demonstrable peripheral nerve disease. In this review, we systematically evaluate the evidence for current therapies and supportive managements based on autoimmune, paraneoplastic, and genetic components in pathophysiology reported in the literature.

RECENT FINDINGS

Current therapy options are based on symptomatic management as well as focusing the underlying immune/genetic/paraneoplastic pathology by immunosuppressants, chemotherapy, and surgery. Further research is desired to provide treatment options geared specifically towards addressing PNH. Supportive care can also be an area for future research.

Functional Impairments in a Patient with Morvan Syndrome: A Case Presentation

A 48-year-old man with lung squamous cell carcinoma was admitted to acute care with cognitive impairment after recent chemotherapy. He developed myoclonus, ataxia, agitation, and visual hallucinations. Morvan syndrome, a rare voltage-gated potassium channel antibody disorder characterized by neuromyotonia with central nervous system dysfunction, was eventually diagnosed. He received plasmapheresis and was admitted to inpatient rehabilitation, where he safely participated in therapies. By focusing on neuromuscular rehabilitation, balance training, fine motor skills, and cognitive retraining emphasizing skills relevant to the patient's premorbid cognitive activities, the patient demonstrated significant functional improvement, decreasing the burden of care of his caregivers.

LEVEL OF EVIDENCE

V.