Memory Loss & Dementias

Dementia is not a disease itself, but a group of symptoms that are caused by various conditions. Dementia is marked by cognitive decline — the loss of memory and thinking ability that interferes with everyday life. Dementia can also fundamentally change a person’s personality, mood and behavior.

If dementia is suspected, it is important to see a physician who specializes in dementia, memory-related illnesses or geriatrics when you notice that you or your loved one is showing signs of forgetfulness that interfere with daily life. Most dementias cannot be cured or reversed at this time, and there is a great need for research to find a cure. There are medications, however, that may be able slow the progression of the dementia and help manage many dementia-related symptoms. Just as important, there are services that can greatly help the caregiver.

There are several manifestations of dementia, the most common being Alzheimer’s disease:


Vascular dementia (also known as multi-infarct dementia [MID]) is related to Alzheimer’s disease but impairment is often more sudden. It impairs a person’s thinking, reasoning, planning and memory due to reduced blood flow to the brain. Strokes or other damage to blood vessels feeding the brain can cause brain damage, which can result in vascular dementia. Risk factors for vascular dementia are the same as those for cardiovascular diseases: high blood pressure, heart disease, diabetes, smoking and high cholesterol. Controlling these risk factors can help prevent vascular dementia, as well.

Lewy body dementia (LBD) impairs a person’s ability to think, causes visual hallucinations and produces symptoms that are similar to Parkinson’s disease, including tremors and rigid muscles. It is characterized by proteins that develop near the brain stem (the back of the brain involved in controlling involuntary bodily functions) and spread to the cerebral cortex (the front of the brain involved in voluntary control of the body and thinking) and other parts of the brain. Certain brain chemicals are altered, damaging the patient’s perception, thinking and behavior. There is no cure for Lewy body dementia, but specialists can help mitigate the symptoms of LBD with medications.

Frontotemporal dementia is caused by a deterioration of the frontal and anterior temporal lobes of the brain, the parts of the brain that control personality, behavior, language, movement and sometimes memory. This is the part of the brain behind the bones of forehead and in front of the ears. It is characterized by a relatively abrupt change in personality and behavior, usually strikes earlier than Alzheimer’s disease (AD), between the ages of 40 and 65. Treatment focuses primarily on medications that can help manage symptoms. 

Normal pressure hydrocephalus (NPH)
dementia is a rare condition caused when excess cerebrospinal fluid (CSF) is trapped in the ventricles (spaces or cavities between brain structures) of the brain. Hydrocephalus refers to water in the head or on the brain, which is usually associated with increased pressure in the CSF (similar to blood pressure). In NPH the pressure of the CSF is at the high end of the normal range and there is excess CSF present. The excess fluid at high-normal pressure causes physically distorts the brain and typically results in impairment of memory, gait and bladder control. NPH can be treated, to some extent, by implanting a shunt that drains the excess CSF into the abdominal cavity, where it is safely absorbed. Response to treatment varies in each individual.

Parkinson’s disease dementia is a progressive disorder of the nervous system. Changes in motor skills — hand tremors, stiff or rigid muscles, short gait and slowed movements — are the most familiar signs of the disease. However, non-motor symptoms are becoming more evident. These symptoms include dementia, depression, anxiety (excessive nervousness, but specifically the unpleasant sensation due to unreal or imagined danger) and sleep difficulties. Medications can alleviate some PD-related symptoms. Surgery called deep brain stimulation (DBS) can help with tremors in patients who don’t respond well to medications. 

Huntington’s disease (HD) is a genetic, progressive neurodegenerative disease that causes dementia, significantly impaired movement and psychiatric disorders. Both voluntary and involuntary movement is affected. The patient can lose the ability to plan, make new memories, think and have conversations with others. Clinical depression, lack of impulse control and obsessive-compulsive disorder (OCD) are common in patients with Huntington’s disease. Medications, psychotherapy, speech therapy and physical therapy can help alleviate some of the symptoms. 

Dementia can also be caused by certain forms of substance abuse, medication interactions, hormone imbalances, infections and deficiencies in vitamin B12 (cobalamin) or folic acid (B vitamin). Depending on the severity of the condition, dementia caused by these factors can be treated, improved or cured.

Additional information is available to help you learn more about forms of dementia:

TREATMENT LOCATIONS

Our physicians at Houston Methodist specialize in dementia at the following convenient locations.