Primary Sjögren's syndrome (pSS)-related cerebellar ataxia: a systematic review and meta-analysis

Autoimmune Neurobeachin Cerebellar Ataxia

BACKGROUND

There are more than 30 immunoglobulin G (IgG) autoantibody biomarkers of autoimmune cerebellar ataxia reported.

OBJECTIVE

To describe a novel IgG biomarker targeting neurobeachin, a scaffolding protein integral to synapse formation and function.

METHODS

Clinical and laboratory-based assessment was used for a novel diagnostic biomarker of autoimmune ataxia.

RESULTS

A 46-year-old woman had ataxia onset followed by bilateral knee pain, attributable to rheumatoid arthritis. She was negative for standard neural antibodies. Her ataxia stabilized and tremor initially improved after corticosteroid treatment, but she progressed to wheelchair-dependence (on methotrexate and then rituximab) over 4 years, in keeping with the trajectory encountered by many with autoimmune ataxia. In contrast, her inflammatory arthritis remitted with immunotherapy. Neurobeachin-IgG was unmasked in serum and cerebrospinal fluid using protein arrays and confirmed using neurobeachin-specific confocal immunofluorescence and Western blot.

CONCLUSIONS

Neurobeachin-IgG is a new neural antibody biomarker of cerebellar ataxia among a growing antibody repertoire, collectively common but often individually rare. © 2024 International Parkinson and Movement Disorder Society.

Neurologic Manifestations of Rheumatologic Disorders

OBJECTIVE

This article provides an overview of the neurologic manifestations of sarcoidosis and select rheumatologic disorders. An approach to the assessment and differential diagnosis of characteristic clinical presentations, including meningitis and vasculitis, is also reviewed. A review of treatment options is included as well as discussion of distinct areas of overlap, including rheumatologic disease in the setting of neuromyelitis spectrum disorder and demyelinating disease in the setting of tumor necrosis factor-α inhibitors.

LATEST DEVELOPMENTS

An increased understanding of the immune mechanisms involved in sarcoidosis and rheumatologic diseases has resulted in a greater diversity of therapeutic options for their treatment. Evidence directing the treatment of the central nervous system (CNS) manifestations of these same diseases is lacking, with a paucity of controlled trials.

ESSENTIAL POINTS

It is important to have a basic knowledge of the common CNS manifestations of rheumatologic diseases and sarcoidosis so that they can be recognized when encountered. In the context of many systemic inflammatory diseases, including systemic lupus erythematosus, IgG4-related disease, and sarcoidosis, CNS disease may be a presenting feature or occur without systemic manifestations of the disease, making familiarity with these diseases even more important.

Paraneoplastic Neurological Syndromes of the Central Nervous System: Pathophysiology, Diagnosis, and Treatment

Paraneoplastic neurological syndromes (PNS) include any symptomatic and non-metastatic neurological manifestations associated with a neoplasm. PNS associated with antibodies against intracellular antigens, known as "high-risk" antibodies, show frequent association with underlying cancer. PNS associated with antibodies against neural surface antigens, known as "intermediate- or low-risk" antibodies, are less frequently associated with cancer. In this narrative review, we will focus on PNS of the central nervous system (CNS). Clinicians should have a high index of suspicion with acute/subacute encephalopathies to achieve a prompt diagnosis and treatment. PNS of the CNS exhibit a range of overlapping "high-risk" clinical syndromes, including but not limited to latent and overt rapidly progressive cerebellar syndrome, opsoclonus-myoclonus-ataxia syndrome, paraneoplastic (and limbic) encephalitis/encephalomyelitis, and stiff-person spectrum disorders. Some of these phenotypes may also arise from recent anti-cancer treatments, namely immune-checkpoint inhibitors and CAR T-cell therapies, as a consequence of boosting of the immune system against cancer cells. Here, we highlight the clinical features of PNS of the CNS, their associated tumors and antibodies, and the diagnostic and therapeutic strategies. The potential and the advance of this review consists on a broad description on how the field of PNS of the CNS is constantly expanding with newly discovered antibodies and syndromes. Standardized diagnostic criteria and disease biomarkers are fundamental to quickly recognize PNS to allow prompt treatment initiation, thus improving the long-term outcome of these conditions.

Primary Sjögren syndrome-related peripheral neuropathy: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Primary Sjögren syndrome (pSS) is a chronic, systemic, autoimmune disorder characterized by lymphocytic infiltrates of the exocrine organs, leading to sicca symptoms and parotid enlargement. pSS has been linked to various neurological manifestations, including peripheral neuropathy (PN). We aimed to provide a comprehensive analysis of the currently available evidence regarding pSS-related PN.

METHODS

A literature search in the PubMed database was performed, and 49 papers were eligible to be included in this systematic review and meta-analysis.

RESULTS

The pooled prevalence of PN in pSS is estimated to be 15.0% (95% confidence interval = 10.7%-20.7%). The mean age of pSS patients at PN diagnosis is 59 years. Among the patients with pSS and PN, 83% are females. Neuropathic symptoms usually precede or lead to the pSS diagnosis at a 2:1 ratio in patients with pSS-related PN. The commonest type of pSS-related PN is distal axonal polyneuropathy (80% of patients with pSS-related PN), followed by sensory ganglionopathy. Peripheral and cranial mononeuropathies-particularly trigeminal-are also frequent. Risk factors for developing PN include increasing age and presence of vasculitis. Immune-mediated pathogenetic mechanisms are discussed. Glucocorticoids are the most commonly used treatment option for managing pSS-related PN, when associated with vasculitis, followed by the use of intravenous immunoglobulin.

CONCLUSIONS

PN is very common in pSS patients. Evidence on long-term prognosis of PN in pSS is limited, and further research is needed. Research into the use of immunosuppressive medication in nonvasculitic neuropathies in the context of pSS merits further consideration.