Differential Diagnosis for Cerebellar Ataxia with Positive Autoantibodies
Single Most Likely Diagnosis
- Systemic Lupus Erythematosus (SLE): The presence of positive ANA, chromatin antibody, and RNP antibodies strongly suggests an autoimmune disorder, with SLE being a leading candidate due to its association with a wide range of autoantibodies and potential neurological manifestations, including cerebellar ataxia.
Other Likely Diagnoses
- Mixed Connective Tissue Disease (MCTD): Given the presence of RNP antibodies, which are characteristic of MCTD, and the overlap of symptoms with other autoimmune diseases, MCTD is a plausible diagnosis. It combines features of SLE, scleroderma, and polymyositis/dermatomyositis, and can present with neurological symptoms.
- Sjögren's Syndrome: Although primarily known for its exocrine gland involvement, Sjögren's Syndrome can also present with neurological manifestations, including ataxia, and is associated with positive ANA and other autoantibodies.
Do Not Miss Diagnoses
- Paraneoplastic Cerebellar Degeneration (PCD): This condition, often associated with specific autoantibodies (though not typically ANA or RNP), can present with subacute cerebellar ataxia and is linked to underlying malignancies. Missing this diagnosis could delay the detection of cancer.
- Multiple Sclerosis (MS): Although MS typically presents with optic neuritis, spinal cord lesions, or brainstem symptoms, ataxia can be a feature. The presence of autoantibodies might suggest an autoimmune etiology, but MS is an important consideration due to its potential for severe disability if not treated.
Rare Diagnoses
- Antiphospholipid Syndrome (APS): While APS can cause neurological symptoms, including ataxia, it is more commonly associated with thrombotic events and miscarriages. The presence of positive autoantibodies could suggest APS, but it would be less likely without a history of thrombosis or pregnancy complications.
- Hashimoto's Encephalopathy: A rare condition associated with Hashimoto's thyroiditis, characterized by encephalopathy and sometimes ataxia, with elevated anti-thyroid antibodies. It's a diagnosis to consider in patients with unexplained neurological symptoms and thyroid autoantibodies, though it's less directly linked to the specific autoantibodies mentioned.