Basics
- Most common cause of dementia
- Progress, neurodegenerative disorder of unknown cause that commonly first manifests as impairment in memory
- As the disease progress the patient becomes more disoriented, has increased difficulty communicating and performing activities of daily living
- Treatment options are limited though Memantine (Namenda) and a class of drugs known as acetylcholinesterase inhibitors [like Tacrine (Cognex)] have demonstrated some cognitive benefits
Symptoms and Signs
- Initially: Loss of recent memory, often noticed only by close family members
- As the disease progresses the patient becomes increasingly disoriented to both when and where they are.
- Depression and other psychiatric symptoms are common
- Late: Patients often develop difficulty effectively communicating, naming objects, and making simple calculation often causing them to leave work and give up family financial responsibilities.
- A total cessation of speach, incontinence, and a bedridden state point to terminal manifestations of the disease
Demographics
- Sporadic with about 5% of cases associated with a familial cause (Familial Alzheimer disease- secondary to a mutated amyloid precursor protein on Chr 21)
- Increased risk in people with Down’s syndrome (aka trisomy 21)
Diagnosis
- A clinical diagnosis in that test often just exclude other, possibly treatable, causes of dementia
- MRI demonstrates ex vacuo enlargement of the ventricles and atrophy of the cerebral cortex
Treatment
- Memantine
- Tacrine
- Donepezil
- Rivastigmine
- Galantamine
- Medications are also used to treat the psychiatric manifestations of the disease
Prognosis
- Death is normally seen within 5-10 years of the first symptoms often secondary to infections or inanition
Differential Diagnosis
- Alcohol induced amnestic syndrome
- Lewy body dementia
- Vascular dementia
- Creutzfeldt-Jakob disease