Alzheimer's Disease Parkinson's Disease ALS Motor Neurone Disease Multiple Sclerosis Dementia Prion Diseases Motor Neurone Disease (MND) Stiff Person Syndrome Stiff-Person Syndrome Global Impact Specific Conditions Risk Factors Research and Studies Havana Syndrome Autoimmune Diseases Vascular Dementia Peripheral Nervous System Diseases Motor Neuron Disease Dementia Research Multiple Sclerosis (MS) Creutzfeldt-Jakob Disease Stiff-Person Syndrome (SPS) Progressive Supranuclear Palsy Neurodegenerative Diseases Aphasia