Dementia due to metabolic causes

Definition

Dementia due to metabolic causes is a loss of mental function that can occur with diabetes, thyroid disease, and other metabolic disorders.

Causes, incidence, and risk factors

How often this condition affects different ages, genders, and races varies based on the disorder that is causing the dementia.

Metabolic causes of dementia include:

• Endocrine disorders
  • Addison's disease
  • Cushing's disease
  • Diabetic ketoacidosis
  • Diabetic nephropathy
  • Insulinoma or hypoglycemia
  • Hyperparathyroidism
  • Hypoparathyroidism
  • Hypothyroidism
  • Pheochromocytoma
  • Thyrotoxicosis
• Metabolic disorders
  • Acid/base disorders of any type
  • Fluid electrolyte disorders of any type
  • Hypercalcemia
  • Hyponatremia
  • Kidney failure with uremia
  • Liver disease
  • Porphyria
• Nutritional disorders
  • Vitamin B1 deficiency
  • Vitamin B12 deficiency
  • Pellagra
  • Protein-calorie malnutrition

Symptoms

Dementia that occurs with metabolic disorders may cause confusion and changes in intellect or reasoning. These changes may be temporary or permanent.

• Decrease in:
  • Feeling (sensation)
  • Hearing
  • Movement
  • Speech
  • Vision
• Difficulty making sense of person, place, or time
• Language difficulties
• Loss of bladder control
• Personality changes
• Slowly worsening loss of:
  • Intellectual function
  • Judgment
  • Memory

Signs and tests

An examination of the nervous system (neurologic examination) can show different problems, depending on the cause. Abnormal reflexes may be present.

Tests may include:

• Ammonia level in the blood
• Blood chemistry, electrolytes
• Blood glucose level, glucose tolerance tests
• BUN, creatinine
• Electroencephalograph (EEG)
• Head CT scan
• Head MRI scan
• Liver function tests
• Lumbar puncture (spinal tap)
• Mental status test
• Nutritional assessment
• Thyroid function tests
• Urinalysis
• Vitamin B12 level

Treatment

Treatment focuses on the cause of the disorder and on controlling symptoms. Treatment of the cause may include:

• Dietary supplements
• Medicines

As the symptoms get worse, the person may need 24-hour monitoring and care in the home or in a care facility.

Long-term care may include:

• Controlling aggression or agitation with behavior modification or medication
• Safety measures to protect the person from injury

Expectations (prognosis)

The outcome varies depending on the cause of the dementia and the amount of damage to the brain.

Complications

• Brain injury that is not reversible
• Complications from the condition that is causing the dementia
• Inability to function or care for self
• Inability to interact with others
• Increased infections anywhere in the body
• Side effects of medications used to treat the disorder

Calling your health care provider

Call your health care provider if you have symptoms of dementia.

Call for an appointment if your symptoms get worse or continue, even with treatment for the metabolic cause, or if you have new symptoms.

Go to the emergency room or call the local emergency number (such as 911) if there is a sudden change in mental status or a life-threatening emergency.

Prevention

Treating the metabolic disorder may reduce the risk of developing this type of dementia.

References

Farlow MR, Cummings JL. Effective pharmacologic management of Alzheimer's disease. Am J Med. 2007;120:388-397.

Goetz CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders;2007.