Various clinical features of patients with anti-Hu associated paraneoplastic neurological syndromes: An observational study

Update in autoimmune and paraneoplastic myelopathies: Newly described antigen targets and antibody testing

Myelopathy is an increasingly recognized presentation of many antibody-mediated neuroinflammatory disorders. While specific features of certain autoimmune myelopathies such as aquaporin-4 antibody associated neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein associated disorder (MOGAD) are well-characterized, other less commonly seen antibody-associated myelopathies are not as well-defined. These include but are not limited to, Hu/ANNA1, anti-glial fibrillary acidic protein (GFAP), anti-CV2/collapsin response mediator protein (CRMP5), and amphiphysin. Here, we review the mentioned more common antibody mediated myelopathies as well those that as less common, followed by a review of differentials that may mimic these disorders.

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.

[Paraneoplastic sensorimotor neuropathy with anti-Hu antibody associated with gallbladder carcinoma]

A 78-year-old woman experienced gait disturbance. She became unable to walk within a month. On admission, her cranial nerves were normal. She had motor weakness in the arms and legs, dysesthesia of the peripheral extremities, impaired deep sensation in the legs, and hyporeflexia in the arms and legs. She was initially diagnosed with Guillain-Barré syndrome; therefore, she was treated with intravenous immunoglobulin therapy and steroid mini-pulse therapy, however improvements of her neurological deficits were minimal. Anti-Hu antibody was positive in serum and gallbladder carcinoma was detected. She was treated with chemotherapy but neurological symptoms worsened progressively. Gallbladder carcinoma can rarely cause anti-Hu associated paraneoplastic sensorimotor neuropathy.

A Rare Case of Sensory Neuropathy Associated with Transitional Cell Carcinoma of the Bladder

Malignancies can trigger an autoimmune response against the nervous system and manifest as paraneoplastic neurological syndromes (PNS). Initial symptoms of PNS may develop up to 5 years prior to the diagnosis of the underlying malignancy. We report a rare case of PNS associated with transitional cell carcinoma of the bladder in a 70-year-old male with a 6-month history of rapidly progressive symmetric sensory neuropathy. Peripheral neuropathy serological workup was unremarkable. A paraneoplastic neuropathy panel revealed anti-Hu autoantibodies. Further evaluation with a whole-body PET scan could not identify the primary malignancy, but it showed hypermetabolic hilar lymph nodes. An endobronchial ultrasound biopsy of the hilar lymph nodes was negative for cancer. The patient developed painless hematuria 2.5 years after the onset of the sensory neuropathy. Cystoscopy with biopsy revealed non-muscle-invasive transitional cell carcinoma of the bladder. Progression of the sensory neuropathy stopped after tumor resection. This case highlights the importance of a diligent and systematic approach to diagnose PNS. A relentless search is often required to detect PNS-associated occult malignancies.

Paraneoplastic Neurological Syndromes: Study of Prevalence in a Province of the Lombardy Region, Italy

Paraneoplastic neurological syndromes (PNSs) are a heterogeneous group of rare immune-mediated diseases associated with cancer. The aim of this study was to investigate the prevalence of PNSs in the province of Brescia. PNS prevalence was calculated using the Lombardy regional hospital admission records from 1998 to 2003. We used the website "Epidemiologic and Economic Atlas of Hospital Activities in Lombardy" and the "International Statistical Classification of Diseases and Related Health Problems". In the province of Brescia, we found 54 cases of PNSs, 29 with subacute neuropathies, five with paraneoplastic cerebellar degeneration and 20 with encephalomyelitis. Peripheral nervous system diseases were the most frequent neurological disorders. In Lombardy, the number of PNS patients admitted was 322 (133 with encephalomyelitis, 21 with paraneoplastic cerebellar degeneration, 166 with polyneuropathies and two with optic degeneration). In Lombardy, the prevalence of PNSs was 25 in 100,000 hospital admissions and 5.92 in 100,000 for the Lombardy population. Our results show a discrete presence of PNS patients in the province of Brescia and in the Lombardy region as a whole.