What condition describes the gradual and permanent decline of cognitive abilities?

The condition that describes the gradual and permanent decline of cognitive abilities is dementia. Dementia is characterized by a progressive deterioration in memory, thinking, and social abilities, which impacts daily functioning. This decline may manifest in various forms, such as Alzheimer's disease, vascular dementia, or frontotemporal dementia, all of which lead to a decrease in cognitive function over time.

Dementia differs significantly from delirium, which is an acute and often reversible change in cognition typically due to medical illness, substance use, or metabolic imbalances. Myasthenia gravis is an autoimmune neuromuscular disorder that primarily affects muscle strength but does not directly cause cognitive decline. Multiple sclerosis, while it can lead to cognitive changes over time, primarily affects the central nervous system through demyelination and is not exclusively characterized by a decline in cognitive abilities. Therefore, dementia is the condition that specifically describes the gradual and permanent decline in cognitive function.