Dementia in Amyotrophic Lateral Sclerosis (ALS)

Medically Reviewed by Christopher Melinosky, MD on March 06, 2024
Written by WebMD Editorial Contributors
10 min read

Amyotrophic lateral sclerosis (ALS) is a devastating disease that affects the part of the nervous system that controls voluntary movements. ALS is also called Lou Gehrig's disease, after the famous baseball player who died of the disease. The muscles become progressively weaker, eventually leading to paralysis and death.

ALS is one of a group of diseases known as motor neuron diseases. Neurons are nerve cells, and motor neurons control movement. Persons with motor neuron disease gradually lose muscle control and become paralyzed. No cure is available for ALS or any other motor neuron disease. The effects of these diseases are not reversible. Most people with ALS die within five years of the onset of symptoms.

Most experts believe that ALS usually does not affect a person’s mental processes. In most people, neither cognitive processes (such as thinking, learning, memory, and comprehension) nor behavior is affected. However, researchers have increasingly begun to recognize that in some cases, people with ALS can experience cognitive changes that are severe enough to be called dementias. Dementias are a type of severe brain disorder that interferes with a person’s ability to carry out everyday activities that involve attention, memory, planning, and organized thinking. Research on the relationship between ALS and dementias is ongoing.

The relationship between dementia and ALS is not well understood, but is thought to reflect damage to cells in the frontal and temporal lobe of the brain. The frontal lobe is the part of the brain from the forehead back to the ears, while the temporal lobe is found on the sides of the brain that correspond to the temples.

While dementia can occur in some ALS patients, it is uncertain whether ALS is its cause, or a concurring problem. Some researchers believe that there may be a common origin to explain why a subset of people with ALS have cognitive symptoms that are similar to that seen in fronto-temporal dementia. However, the cause or causes of dementia in people with ALS is yet to be pinpointed.

Dementia is rare in ALS, but when it occurs, it crosses ethnic and gender boundaries. People ages 55 to 65 are most likely to be affected.

Fronto-temporal dementia-like symptoms in ALS usually appear as a change in personality and behavior. The exact nature of this change varies from person to person. The following symptoms are common:

  • Apathy (lack of interest, withdrawal)
  • Lack of emotion
  • Reduced spontaneity
  • Loss of inhibition
  • Restlessness or overactivity
  • Social inappropriateness
  • Mood swings

Cognitive symptoms include the following:

  • Memory loss
  • Loss of speech and/or language comprehension, partial or complete
  • Loss of reasoning or problem-solving ability

Some individuals develop repetitive rituals involving hoarding, dressing, wandering, or using the bathroom. Others may overeat or develop strange eating rituals.

Cognitive changes can precede, follow, or coincide with the movement symptoms of ALS. Throughout the course of the dementia, the following typical signs and symptoms of ALS also progress:

In ALS, most people are aware of problems with physical strength and weakness in their hands, arms or legs. People with dementia do not always realize that they are having problems with their thinking. Because dementia is not a common feature associated with ALS, and can have many causes, it is important to see your health care provider if you develop any changes in personality, behavior, language comprehension, or memory.

 

Changes in personality, behavior, or cognitive functions have many different causes. The causes vary by age, sex, and various other factors. Your health care provider will have the difficult job of sorting out all the possible different causes of your symptoms. He or she will ask many questions, perform exams, and conduct tests to try to pinpoint the cause.

The medical interview will include questions about your symptoms and how they started, your medical problems now and in the past, your family members' medical problems, exposure to alcohol, cigarettes, street drugs or environmental toxins, your medications, your habits and lifestyle, and your work, military, and travel history. The physical exam will focus on neurological signs of ALS and other disorders that can cause similar symptoms. It will also include tests of mental status, such as answering questions and following simple directions. Because depression is also common in ALS, the medical interview will include an evaluation for depression.

Lab tests for dementia

There is no lab test that will diagnose dementia. Blood may be tested for other conditions that can cause dementia symptoms.

Imaging studies for dementia

Brain scans are the best way to see changes in brain structure that can be associated with some forms of dementia. Here are the types used to look at the brain:

  • A CT scan uses finely focused X-rays to show greater detail than a simple X-ray. It may show frontal lobe shrinkage (atrophy) in ALS with dementia.
  • MRI scans use magnets to show even greater detail of brain structures.
  • Single-photon emission computed tomography (SPECT) images are also sometimes used to show problems in brain functioning. SPECT is available at only a few large medical centers.

Other tests for dementia

  • Electroencephalography (EEG) measures electrical activity in the brain. It is sometimes helpful in distinguishing various causes of dementia symptoms.
  • Neuropsychological testing is a series of tests that helps pinpoint the areas of concern and can help distinguish between the types of dementia or diseases that mimic dementia.

Treatment of dementia in ALS and other motor neuron diseases focuses on relieving symptoms.

No specific drug treatment is available for frontal lobe dementia in motor neuron diseases like ALS.

  • The few available treatments for motor neuron diseases may have applications in treating dementia. Edaravone (Radicava), tofersen (Qalsody), and Riluzole (Rilutek) are the only approved medications for motor neuron diseases. Research shows they may help slow damage to motor neurons which affect memory in much the same way they slow the degenerative motor skills aspects of ALS.
  • Gabapentin (Neurontin) is a drug sometimes used to treat muscle spasms, cramps or twitches in people with motor neuron diseases such as ALS, and has shown possible value for treating agitation in some forms of dementia (such as vascular dementia, or Alzheimer's disease), but has not been shown to affect dementia symptoms in patients related to motor neuron disease.
  • Drugs called cholinesterase inhibitors used in Alzheimer's disease (another type of dementia) may worsen irritability in people with frontal lobe dementia. These include donepezil (Aricept), rivastigmine (Exelon), and galantamine/galanthamine (Reminyl).

Behavior disturbances may improve with medications that include:

People with fronto-temporal dementia-like symptoms require regularly scheduled follow-up visits with the medical professional coordinating his or her care. These visits will give the coordinator a chance to check progress and monitor behavioral changes. The coordinator can make recommendations for changes in treatment if any are necessary.

There is no known way to prevent ALS or the dementia that may be seen with it. This is an area of intense research in motor neuron diseases.

There is no cure for fronto-temporal lobe dementia or ALS, the underlying motor neuron disease. Motor neuron diseases are terminal illnesses, meaning that they cause death. Most people with motor neuron disease die within five years of the first symptoms. The actual cause of death is usually respiratory failure or infections related to respiratory disability.

Motor neuron disease linked to dementia seems to be even more aggressive. People with this form of the disease usually die within three years of the first symptoms.

If you have motor neuron disease, you should take the opportunity to express your wishes about medical care, estate planning, and personal issues while you are still able.

  • Preferences concerning medical care at the end of life should be clarified early and documented in your medical chart. Your spouse and other close family members should understand your wishes. Early clarification of these wishes prevents conflicts later when you are not able to speak for yourself.
  • You should consult a lawyer as early as possible. Personal affairs should be settled. Later in the disease, you may not be able to sign papers (such as designating a health care proxy and appointing someone to have power of attorney over your financial, legal and business affairs) or even communicate your wishes.

 

Living with motor neuron disease presents many new challenges, both for the affected person and for family and friends.

  • You will naturally have many worries about the disabilities that come with the disease. You worry about how your family will cope with the demands of your care. You wonder how they will manage when you are no longer able to contribute. You may feel anxious about loss of independence and death.
  • Your loved ones also feel anxious about future uncertainties, issues about your quality of life and need for physical care, and the prospect of death. They wonder how they will care for you through your illness. Money is almost always a concern.
  • Many people in this situation feel anxious and depressed, at least sometimes. Some people feel angry and resentful; others feel helpless and defeated.

If you are affected by motor neuron disease, talking about feelings and concerns may help.

  • Your friends and family members can be very supportive. They may be hesitant to offer support until they see how you are coping. Don't wait for them to bring it up. If you want to talk about your concerns, let them know.
  • Some people worry that they will "burden" their loved ones, or they prefer talking about their concerns with a more neutral professional. A social worker, counselor, or member of the clergy can be helpful if you want to discuss your feelings and concerns about having a motor neuron disease. Your primary care provider or neurologist should be able to recommend someone.

 

Family caregivers play a very important role in the care of persons with this condition. If you are a caregiver, you know that caring for a person with dementia can be very difficult.

  • It affects every aspect of your life, including family relationships, work, financial situation, social life, and physical and mental health.
  • You may feel unable to cope with the demands of caring for a dependent, difficult relative.
  • Besides the sadness of seeing your loved one's condition, you may feel frustrated, overwhelmed, resentful, and angry. These feelings may in turn leave you feeling guilty, ashamed, and anxious. Depression is not uncommon.

Different caregivers have different threshholds for tolerating these challenges. For many caregivers, just "venting" or talking about the frustrations of caregiving can be very helpful. Others need more help, but may feel uneasy about asking for it. One thing is certain, though: If the caregiver is given no relief, he or she can burn out, develop his or her own mental and physical problems, and become unable to continue as a caregiver.

This is why support groups were invented. Support groups are groups of people who have lived through the same difficult experiences and want to help themselves and others by sharing coping strategies. Mental health professionals strongly recommend taking part in support groups for families affected by serious disease. Support groups serve a number of different purposes for a person living with the extreme stress of being a caregiver for a person with a motor neuron disease and dementia:

  • The group allows the person to express his or her true feelings in an accepting, non-judgmental atmosphere.
  • The group's shared experiences allow the caregiver to feel less alone and isolated.
  • The group can offer fresh ideas for coping with specific problems.
  • The group can introduce the caregiver to resources that may be able to provide some relief.
  • The group can give the caregiver the strength he or she needs to ask for help.

Support groups meet in person, on the telephone, or on the Internet. To find a support group that works for you, contact the organizations listed below. You can also ask your health care provider or behavior therapist, or go on the Internet. If you do not have access to the Internet, go to the public library.

For more information about support groups, contact the following agencies:

 

ALS Association

1275 K Street NW, Suite 250
Washington, DC 20005
(202) 407-8580

www.alsa.org

Les Turner ALS Foundation

5550 W. Touhy Avenue, Ste. 302
Skokie, IL 60077
(847) 679-3311

www.lesturnerals.org

Project ALS
801 Riverside Drive, Ste. 6G
New York, NY 10032

(855) 900-2ALS (2257) or (212) 420-7382

https://www.projectals.org

National Institute of Neurological Disorders and Stroke

xmlns:o="urn:www.microsoft.com/office" xmlns:st1="urn:www.microsoft.com/smarttags" xmlns:w="urn:www.microsoft.com/word">NIH Neurological Institute
P.O. Box 5801
Bethesda, MD 20824
(800) 352-9424 or (301) 496-5751

www.ninds.nih.gov