Dementia due to metabolic causes
Dementia is loss of brain function that occurs with certain diseases.
Dementia due to metabolic causes is a loss of brain function that can occur with abnormal chemical processes in the body. If these processes can be treated soon enough, brain function can return to normal. Left untreated, these chemical abnormalities cause permanent brain damage and dementia.
Metabolic causes of dementia include:
- Endocrine disorders, such as Addison disease, Cushing disease
- Heavy metal exposure, such as to lead, arsenic, mercury, or manganese
- Repeat episodes of low blood sugar (hypoglycemia), most often seen in people with diabetes who use insulin
- Hyperparathyroidism, which is a very high level of calcium in the blood
- Hypothyroidism (low levels of thyroid hormone) or thyrotoxicosis (very high levels of thyroid hormone in the body)
- Liver cirrhosis
- Kidney failure
- Nutritional disorders, such as vitamin B1 deficiency, vitamin B12 deficiency, pellagra, or protein-calorie malnutrition
- Poisons, such as methanol
- Severe alcohol use
- Wilson disease
- Disorders of the mitochondria (energy-producing parts of cells)
- Rapid changes in sodium level
Metabolic disorders may cause confusion and changes in thinking or reasoning. These changes may be short-term or lasting. Dementia occurs when the symptoms are not reversible. Symptoms can be different for everyone. They depend on the health condition causing the dementia.
The early symptoms of dementia can include:
- Difficulty with tasks that take some thought but used to come easily, such as balancing a checkbook, playing games (such as bridge), and learning new information or routines
- Getting lost on familiar routes
- Language problems, such as trouble with names of familiar objects
- Losing interest in things previously enjoyed, flat mood
- Misplacing items
- Personality changes and loss of social skills, which can lead to inappropriate behaviors
As the dementia gets worse, symptoms are more obvious and interfere with the ability to take care of yourself:
- Changing sleep patterns, often waking up at night
- Forgetting details about current events, forgetting events in one's life history
- Having difficulty doing basic tasks, such as preparing meals, choosing proper clothing, or driving
- Having hallucinations, arguments, striking out, and behaving violently
- More difficulty reading or writing
- Poor judgment and losing the ability to recognize danger
- Using the wrong word, not pronouncing words correctly, speaking in confusing sentences
- Withdrawing from social contact
The person may also have symptoms from the disorder that caused dementia.
Exams and Tests
An examination of the nervous system (neurologic examination) can show different problems, depending on the cause.
Tests to diagnose a medical condition causing the dementia may include:
- Ammonia level in the blood
- Blood chemistry, electrolytes
- Blood glucose level
- BUN, creatinine to check kidney function
- Liver function tests
- Lumbar puncture (spinal tap)
- Nutritional assessment
- Thyroid function tests
- Vitamin B12 level
Treatment focuses on managing the disorder and controlling symptoms. With some metabolic disorders, treatment may stop or even reverse the dementia symptoms.
Medications used to treat Alzheimer disease have not been shown to work for this type of dementia. Sometimes these drugs are used anyway, when other treatments are unable to control the underlying problems.
Plans should also be made for home care for a loved one with dementia.
Outcome varies, depending on the cause of the dementia and the amount of damage to the brain.
Complications may include the following:
When to Contact a Medical Professional
Call for an appointment if symptoms get worse or continue. 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.
Treating the metabolic disorder may reduce the risk of developing this type of dementia.
Apostolova LG, DeKosky ST, Cummings JL. The dementias. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, Pa: Elsevier Saunders; 2012:chap 66.
Reviewed By: Joseph V. Campellone, M.D., Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.