COEXISTENCE OF MULTIPLE SCLEROSIS AND ALZHEIMER DISEASE: WHAT WE KNOW SO FAR?

Background: Multiple sclerosis (MS) and Alzheimer disease (AD) are neurodegenerative diseases with distinct pathophysiology but similar burdens. Early cognitive impairment in MS is unusual but, due to disease modifying therapies (DMT) advancements and bigger life expectancy, its coexistence with AD has become more common. Objective: To report a coexistence case of MS and AD. Methods: Retrospective case report and literature review. Results: 58-year-old patient presented with work issues, behavioral changes, gait disturbance and unbalance. It was disclosed an impairment of attention span, multitasking, executive dysfunction, and loss of memory for recent events. A PET/CT showed hypometabolism in frontal lobes and CSF analysis disclosed oligoclonal bands and increased TAU protein levels. The patient was initially treated with donepezil, with poor response. A later brain MRI showed typical demyelinating MS lesions. The patient was treated with Natalizumab due to high lesion load and functional impairment. Conclusion: As MS patients live longer, it’s important to recognize age-related comorbidities such as AD. In our patient a poor relapse perception contributed for a late MS diagnosis. The evaluation with PET/CT and increased TAU levels in CSF highly suggests a coexistence with AD. There are no peer-reviewed studies regarding coexisting MS and AD. Further research is necessary to better understand the clinical, demographic, and neuropathological features of the coexistence of both diseases.