An autoimmune cause means a potentially reversible course

If autoimmune dementia is misdiagnosed as an irreversible progressive neurodegenerative disorder, it may delay a correct diagnosis beyond the window of reversibility (6–12 months) and result in devastating consequences for the patient and family. An accurate diagnosis and early-initiated immunotherapy give patients the best possible outcome.

35%

Among Mayo Clinic patients diagnosed with and treated for an autoimmune dementia, 35% were initially misdiagnosed as having a neurodegenerative disorder.

When to consider testing

Consider autoimmune testing for patients presenting with new-onset dementia or cognitive impairment and one or more of the following:

• Rapid onset and progression
• Fluctuating course
• Psychiatric accompaniments (psychosis, hallucinations)
• Movement disorder (myoclonus, tremor, dyskinesia)
• Headache
• Autoimmune stigmata (e.g., physical signs or personal/family history of diabetes, thyroid disorder, vitiligo, prematurely gray hair, myasthenia gravis, rheumatoid arthritis, systemic lupus erythematosus)

• History of cancer
• Smoking history (20+ pack years) or other cancer risk factors
• Inflammatory cerebrospinal fluid
• Neuroimaging atypical for degenerative etiology
• Prior treatment with immune checkpoint inhibitors
• Antibody prevalence in epilepsy and encephalopathy APE2) score is ≥4¹

Key testing

DMC2 | Dementia, Autoimmune/Paraneoplastic Evaluation, Spinal Fluid

DMS2 | Dementia, Autoimmune/Paraneoplastic Evaluation, Serum