Dementia: Reversible and Irreversible

There are more than 60 medical, psychiatric and neurologic conditions associated with dementia. Not long ago, it was believed that 20-40 percent of dementias were potentially reversible. Now recent studies suggest that most dementias, while manageable, remain irreversible, while less than 5 percent are reversible.

The following summary should help to differentiate between these two groups.

Reversible Dementias

Characteristics of reversible dementias:

• Can be reversed or cured
• Temporary condition
• Brain regains lost functions when treated

Common causes of reversible dementias:

• Brain disease
  • Tumors
  • Subdural hematoma
  • Hydrocephalus
• Depression
  • Response to life's stresses
  • Chemical imbalances in the brain
• Medication
  • Negative drug interactions
  • Drug overdose
  • Alcohol abuse
• Malnutrition
  • Vitamin (A, C, B-12 and folate) deficiencies
  • Mineral (iron) deficiencies
• Heart disease -- Lack of oxygen to the brain causes confusion
  • Arrhythmias
  • Congestive heart failure
  • Myocardial infarction
• Traumas
  • Usually due to falls
  • Concussions (skull fractures) or contusions (bruises) to the head
• Metabolic or endocrine disorders
  • Thyroid disease
  • Hypo/hyperglycemia and other electrolyte imbalances
  • Dehydration
  • Accidental hypothermia
  • Renal failure
  • COPD (Chronic Obstructive Pulmonary Disease)

• Infection
  
  • Produces fever, affecting brain's cognitive abilities
• Environmental changes
  • Visual and hearing loss
  • Loss of daylight and decrease in activities can result in "sundowning"
  • Heavy metal poisoning from gas leaks, exhaust fumes or other toxins

Irreversible Dementias

Characteristics of irreversible dementias:

• Result in permanent brain damage
• Cannot be reversed or cured

Common causes of irreversible dementias:

• Alzheimer's disease or Senile Dementia of the Alzheimer's type (SDAT)
  • Progressive mental deterioration spanning a long period of time (3-20 years)
  • Affects 60 percent of those diagnosed with irreversible dementia
  • Fourth leading cause of death in the United States

• Vascular dementia or Multi-infarct Dementia
  • Series of pockets of deteriorated tissue in the brain that cause a very erratic or unpredictable pattern.
  • Caused by multiple, small "mini-strokes" in the brain brought on by bleeding or lack of blood flow to the brain's blood vessels.
    • Hypertension (high blood pressure) and arteriosclerosis (hardening of the arteries) are precursors to these mini-strokes
  • Has an abrupt onset with a step-wise deterioration in function

• Other neurological diseases causing irreversible dementia
  • Parkinson's disease
  • Huntington's Chorea
  • Pick's disease
  • Creutzfeldt-Jakob disease
  • Down's Syndrome
  • AIDS

Source: "Understanding the Alzheimer's Disease and Related Dementias: Lesson 1 - Overview of Dementia." (no longer available on web)

Mace, N., MA and P. Rabins, MD, MPH. (1991) The 36-Hour Day, revised edition. Baltimore: Johns Hopkins University Press.

Compiled by the Lincoln/Greater Nebraska Chapter of the Alzheimer's Association, 1999.

For further information about Alzheimer's Disease or related disorders, contact the Alzheimer's Association at:

• Alzheimer's Association of the Great Area Plains, 402-420-2540 or 1-800-487-2585 (Helpline)
• Midlands Chapter, 402-572-3010 or 1-800-309-2112 (Helpline)