There are several theories behind the formation of senile plaques and neurofibrillary tangles. The amyloid hypothesis is currently the most commonly accepted explanation.
A second theory is that Alzheimer disease (AD) is caused by an abnormal aggregation of the tau protein, a microtubule-associated protein that stabilizes microtubules in the cell. Dementia is caused by a neurodegenerative disease .These produce overlapping clinical syndromes. Less common neurodegenerative disorders such as progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), multisystem atrophy, and Huntington disease can also be associated with dementia
Common causes include:
- Alzheimer's Disease
- Binswanger's Disease
- Multi-infarct disease
- Parkinson's Disease
- Midlife obesity
There several other causes of dementia mentioned in table below :
Causes in Alphabetical Order
Mnemonics to remember causes
Dementia: treatable causes
- Drug toxicity
- Emotional (depression, anxiety, OCD, etc.)
- Metabolic (electrolytes, liver dz, kidney dz, COPD)
- Eyes/ Ears (peripheral sensory restrictions)
- Nutrition (vitamin, iron deficiencies/ NPH [Normal Pressure Hydrocephalus]
- Tumors/ Trauma (including chronic subdural hematoma)
- Infection (meningitis, encephalitis, pneumonia, syphilis)
- Arteriosclerosis and other vascular disease
Dementia: some common causes
- Environmental (eg CO poisoning)
Dementia: reversible dementia causes
- Drugs / Depression
- Multi-infarct/ Medication
- Clarfield AM (September 1988). "The reversible dementias: do they reverse?". Ann Intern Med. 109 (6): 476–86. doi:10.7326/0003-4819-109-6-476. PMID 3046450.
- Morris JC (2003). "Dementia update 2003". Alzheimer Dis Assoc Disord. 17 (4): 245–58. doi:10.1097/00002093-200310000-00010. PMID 14657790.
- Caselli RJ (September 2003). "Current issues in the diagnosis and management of dementia". Semin Neurol. 23 (3): 231–40. doi:10.1055/s-2003-814743. PMID 14722819.
- Knopman DS, Boeve BF, Petersen RC (October 2003). "Essentials of the proper diagnoses of mild cognitive impairment, dementia, and major subtypes of dementia". Mayo Clin. Proc. 78 (10): 1290–308. doi:10.4065/78.10.1290. PMID 14531488.