- The most common form of chronic dementia characterized by an anterograde amnesia defined by progressive and insidious impairment in learning and retaining new information and impairment in at least one other domain of cognitive function such as: impairment in language function, visuospatial skills and geographic ability, complex tasks and reasoning.
- The prevalence of the disease increases with age, affects both genders equally, and typically begins in the 6th and 7th decades.
- Mortality rate related to the disease is 10% per year.
- Risk factors include advancing age and familial history.
- Most cases are sporadic however, a small number of cases occur as autosomal dominant disease. Familial cases have been mapped to chromosomes 1, 2, 14, 19, and 21.
- Histopathologic diagnosis is based on the presence of substantial cerebral neuritic plaques and neurofibrillary tangles. The location of neurofibrillary tangles corresponds to the clinical evolution of specific symptoms and the severity of the disease.
- Neuritic plaques consist of aggregated β-amyloid peptide surrounded by degenerated neurons. The progression of changes of β-amyloidosis follows a predictable pattern with increasing numbers of β-amyloid containing deposits in the neocortex associated with increasing severity of dementia.
PERTINENT HISTORICAL FINDINGS/ CLINICAL SYMPTOMS
- Early: Progressive difficulties with anterograde amnesia: forgetting recent events and conversations, getting lost and forgetting to complete tasks, misplacing items.
- Mild: Mild progressions of symptoms continue with medication errors, difficulty managing money and changes in personality accompanying cognitive losses. Apathy, loss of interest in hobbies and activities is common. However, patients may be able to continue simple routines such as cooking meals, and taking walks.
- Moderate to Severe: As the disease progresses patient s require assistance in daily tasks such as preparing meals, paying bills and transportation and in later stages patients may require assistance with bathing, dressing, and toileting.
PERTINENT PHYSICAL EXAM FINDINGS
- The physical exam findings rest on the historical findings/ clinical symptoms and stage of the disease.
- It is important to perform a complete mental status evaluation to aid in detecting mild changes in short-term memory, language, visuospatial and cognitive function.
- Dementia with Lewy bodies.
- Huntington’s disease
- Progressive supra-nuclear palsy
- Corticobasal degeneration
- Wilson’s disease
- Amyotrophic lateral sclerosis
- Cerbrovascular disease
- The diagnosis is largely clinical and based on the history and examination findings.
- No laboratory tests can confirm the diagnosis.
- MRI finding of decreased hippocampal volume is useful when atrophy is present.
- Cholinesterase inhibitors have been shown to delay the progression of symptoms at 6-12 months in patients with mild-moderate disease, but not at 3-years. ( Donepezil, 5 or 10 mg/day, Galantamine. 16 or 24 mg/day, Rivastigmine, 6-12 mg/day0
- Glutamate-receptor antagonist as delays the progression of functional decline (Memantine, 10mg twice a day).
SURGICAL MANAGEMENT (when applicable)
- Not applicable
EMERGENCY MANAGEMENT (when applicable)
- Not applicable
PATIENT EDUCATION/ MAINTENANCE – PREVENTION
- There are no established preventive therapies
- Support for family caregivers is important.
- Important safety issues center around supervision of medications, finances, and motor vehicle, dangerous tools and firearm usage is critical.
- Patients with this disease often wander and become lost. Patient identification devices are helpful.
Dr. Zachary Lahlou