Pathogenesis, diagnosis and treatment of paraneoplastic neurologic syndromes

Immune-Related Toxicity in NSCLC: Current State-of-the-Art and Emerging Clinical Challenges

Immune checkpoint inhibitors have become standard-of-care for the treatment of NSCLC; however, their use brings with it the risk of a unique set of inflammatory side effects, termed immune-related adverse events (irAEs). The recognition, diagnosis, and management of irAEs have become essential to clinical practice, with the potential for high-grade toxicities affecting treatment decision-making. This manuscript provides a state-of-the-art review of irAEs as they pertain to patients with NSCLC, by summarizing the common and severe toxicities of the standard immune checkpoint inhibitor regimens and clinical treatment settings relevant to this disease and future directions.

Single-Center Retrospective Analysis of Paraneoplastic Syndromes with Peripheral Nerve Damage

There are few clinical and electrophysiological studies on paraneoplastic neurological syndrome (PNS) with peripheral nerve damage, which brings great challenges to clinical identification and diagnosis. We analyzed the clinical and electrophysiological data of twenty-five confirmed PNS cases using peripheral nerve damage patients. The results showed the most common chief complaint was weakness (20/25, 80%), followed by numbness (13/25, 52%). Nineteen patients (76%) exhibited peripheral nervous system lesions prior to occult tumors, and the median time from symptom onset to the diagnosis of a tumor was 4 months. The electrophysiological results revealed a higher rate of abnormal amplitudes than latency or conduction velocity, especially in sensory nerves. Meanwhile, we found that, compared with patients >65 y, patients aged ≤65 y exhibited more chronic onset (p = 0.01) and longer disease duration (p = 0.01), more motor nerve involvements (p = 0.02), more amplitude involvement (p = 0.01), and higher rates of the inability to walk independently at presentation (p = 0.02). The present study construed that weakness and paresthesia are common symptoms in PNS with peripheral nerve damage in some areas, and the electrophysiological results mainly changed in amplitude. Tumor screening in young and middle-aged patients with peripheral neuropathy cannot be ignored.

[Clinical analysis of 11 cases of lymphoma complicated with paraneoplastic neurological syndrome]

Objective: To evaluate the clinical characteristics, treatment, and prognosis of patients with paraneoplastic neurological syndrome (PNS) associated with lymphoma. Methods: Between January 2012 and May 2021, the clinical data of 11 patients with lymphoma complicated with PNS treated at Peking Union Medical College Hospital were retrospectively reviewed. Results: Among the 11 patients (8 male and 3 female) , the median onset age was 61 (range, 33-78) years. The symptoms of PNS preceded lymphoma in 10 patients. The median time from the onset of PNS to the diagnosis of lymphoma was 4 months. Of the 11 patients, one had Hodgkin's lymphoma, 8 had B-cell non-Hodgkin's lymphoma, and 2 had peripheral T-cell lymphoma. Seven patients were evaluated for onconeural antibody, of whom 2 were positive (1 for anti-Ma2 antibody and 1 for anti-Yo antibody) . Of the 11 patients, the PNS symptoms of 3 patients were located in the central nervous system, 4 were located in the peripheral nervous system, and 3 were located in the muscle. Eight of the 11 patients were treated with glucocorticoid-based immunosuppressive therapy before the diagnosis of lymphoma. Patients with central nervous system involvement and dermatomyositis responded well to glucocorticoid, whereas patients with peripheral neuropathy did not significantly benefit. All 11 patients were treated with chemotherapy after the diagnosis of lymphoma. The efficacy of chemotherapy was assessed in 9 patients, 7 cases achieved complete remission, 1 case was evaluated as stable disease, and 1 case was evaluated as disease progression. The PNS symptoms of the patients who achieved complete response were almost completely recovered. The median follow-up time was 42 (range, 4-95) months. At the end of the follow-up period, 6 of the 11 patients survived, 3 were lost to follow-up, and 2 died. The median overall survival of the whole group was not reached. Conclusions: PNS can involve various parts of the nervous system and can be associated with different types of lymphoma. Through early diagnosis and treatment, the PNS symptoms could improve in most patients who achieve complete remission of lymphoma.

Evaluation of the Updated Diagnostic Criteria for Paraneoplastic Neurologic Syndromes in China

Background

Recently, the paraneoplastic neurologic syndrome (PNS) diagnostic criteria have received a major update with a new score system over the past 16 years. We aimed to evaluate the diagnostic performance and clinical utility in China.

Methods

An eligible cohort of 113 Chinese patients diagnosed with PNSs from the Second Affiliated Hospital School of Medicine Zhejiang University and published data were enrolled retrospectively. Data including clinical phenotype, antibody type, the presence of cancer, and duration of follow-up were reviewed and re-evaluated to classify the diagnostic levels for the 2004 and 2021 PNS criteria. The performances of these 2 criteria were compared. The critical parameters of antibody and cancer for the updated criteria were further explored.

Results

The cohort consisted of 69 males and 44 females with a median age of 60 years. Limbic encephalitis (23, 20.4%), anti-Hu antibody (32, 28.3%), and small-cell lung cancer (32, 28.3%) were the most common clinical phenotype, detected antibody, and concomitant cancer, respectively. A total of 97 (85.8%) patients were diagnosed with definite PNS according to the 2004 criteria: only 42.3% (41/97) fulfilled the 2021 criteria, while the remaining 40, 14, and 2 re-diagnosed with probable PNS, possible PNS, and non-PNS. The requirement of cancers consistent with antibody and phenotype increased the specificity and thus greatly enhanced the accuracy of the 2021 criteria.

Conclusion

The updated criteria for PNS emphasized the consistency between cancer phenotype and antibody and showed a better diagnostic value. A better diagnostic yield could benefit disease management.

The Immunopathogenesis of Neuroinvasive Lesions of SARS-CoV-2 Infection in COVID-19 Patients

The new coronavirus disease COVID-19 was identified in December 2019. It subsequently spread across the world with over 125 M reported cases and 2.75 M deaths in 190 countries. COVID-19 causes severe respiratory distress; however, recent studies have reported neurological consequences of infection by the COVID-19 virus SARS-CoV-2 even in subjects with mild infection and no initial neurological effects. It is likely that the virus uses the olfactory nerve to reach the CNS and that this transport mechanism enables virus access to areas of the brain stem that regulates respiratory rhythm and may even trigger cell death by alteration of these neuronal nuclei. In addition, the long-term neuronal effects of COVID-19 suggest a role for SARS-CoV-2 in the development or progression of neurodegerative disease as a result of inflammation and/or hypercoagulation. In this review recent findings on the mechanism(s) by which SARS-CoV-2 accesses the CNS and induces neurological dysregulation are summarized.