Dementia in ALS

  • Medical Author: Joe Verghese, MD, MRCPI
  • Medical Editor: Nestor Galvez-Jimenez, MD
  • Medical Editor: Francisco Talavera, PharmD, PhD
  • Medical Editor: Helmi L Lutsep, MD
Reviewed on 11/15/2021

What Facts Should I Know about Dementia in ALS?

ALS (Lou Gehrig's disease)
A person with ALS may live for about two to five years from the time of diagnosis.

What Is the Medical Definition of Amyotrophic Lateral Sclerosis (ALS)?

  • Amyotrophic lateral sclerosis (ALS) is a devastating disorder. It affects the part of the nervous system that controls voluntary movements. ALS is sometimes called Lou Gehrig's disease, after the famous baseball player who died of the disease. The muscles become progressively weaker, and the disease eventually leads 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 5 years of the onset of symptoms.

Do ALS Patients Get Dementia?

  • Most experts believe that ALS does not affect a person’s mental processes. In most people, neither cognitive processes (such as thinking, learning, memory, and speech) nor behavior is affected. Occasionally, however, a person with ALS does experience profound mental changes, which are called dementia. Dementia is a severe brain disorder that interferes with a person’s ability to carry out everyday activities.

Can ALS Affect the Brain?

  • Dementia in ALS is thought to be due to the destruction of cells in the frontal lobe of the brain. The frontal lobe is the part of the brain from the forehead back to the ears. This type of dementia is often called frontal lobe dementia. Frontal lobe dementia has other causes besides ALS. We are still learning about why ALS causes frontal lobe dementia in some people.
  • Dementia is rare in ALS. It occurs in all ethnic groups and in both men and women. People aged 55-65 years are most likely to be affected.

Dementia in ALS Causes

We do not know what causes frontal lobe dementia in people with ALS. A few people have a family history of this type of dementia, but we do not understand the connection between this dementia and ALS. More than one cause may be involved.

Dementia in ALS Symptoms

Frontal lobe dementia in ALS usually appears 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, 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.

The cognitive changes often precede symptoms of ALS. Throughout the dementia, the following typical signs and symptoms of ALS also progress:

  • Limb weakness
  • Swallowing problems
  • Muscle wasting (atrophy)
  • Muscle twitches (fasciculations)
  • Shortness of breath

When to Seek Medical Care for Dementia in ALS

You are the best person to judge whether you are experiencing changes that suggest ALS and dementia. Any changes in personality, behavior, speech, or memory warrant a visit to your health care provider.

Exams and Tests for Dementia in ALS

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 examinations, 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, your medications, your habits and lifestyle, and your work, military, and travel history. The physical examination will focus on signs of ALS and other disorders that can cause similar symptoms. It will also include tests of mental statuses, such as answering questions and following simple directions. Since depression is common in ALS, the medical interview will include an evaluation for depression.

Lab Tests

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

Imaging Studies

Brain scans are the best way to find brain abnormalities that can cause dementia.

  • CT scan is like an x-ray but shows greater detail. It may show frontal lobe shrinkage (atrophy) in ALS with dementia.
  • MRI shows even greater detail.
  • Single-photon emission computed tomography (SPECT) images can show problems in brain functioning. SPECT is available at only a few large medical centers.

Other Tests

  • Electroencephalography (EEG) measures electrical activity in the brain. It is sometimes helpful in distinguishing various causes of dementia symptoms.
  • Electromyography (EMG) measures electrical activity in muscles. It can be used to distinguish ALS from other conditions that cause similar symptoms but are not motor neuron diseases.

Dementia in ALS Treatment

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

Medications for Dementia in ALS

No specific treatment is available for frontal lobe dementia in motor neuron disease.

  • The few available treatments for motor neuron diseases have had little effect on dementia. Riluzole (Rilutek) is currently the only approved medication for motor neuron diseases. No strong evidence shows that this drug improves dementia due to motor neuron disease.
  • Another drug widely used to treat motor neuron disease, gabapentin (Neurontin), has shown no positive effects on dementia.
  • 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 medication.

Dementia in ALS Follow-up

The person with frontal lobe dementia in motor neuron disease requires 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.

Prevention of Dementia in ALS

There is no known way to prevent motor neuron disease or dementia that goes along with it. This is an area of intense research in motor neuron diseases.

Outlook for Dementia in ALS

Right now, no cure is available for frontal lobe dementia or the underlying motor neuron disease. These are terminal illnesses, meaning that they cause death. Most people with motor neuron disease die within 5 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 3 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 or even communicate your wishes.

Support Groups and Counseling

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 death.
  • Your loved ones also feel anxious about your death and how much they will miss you. 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.

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 don't want to "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 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 thresholds 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 motor neuron disease and dementia:

  • The group allows the person to express his or her true feelings in an accepting, nonjudgmental 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:


  • Dementia is a decline and/or loss of memory, reasoning, judgment, behavior, language and other mental abilities that are not a part of normal aging; it usually progressively worsens over time.
  • Dementia, senility, and Alzheimer's disease are not the same things.
  • In general, there are many causes of dementia, but all dementia diseases result from dysfunction of a person's cerebral cortex, directly or indirectly.
  • There are irreversible, and potentially reversible causes of dementia.
  • Early signs and symptoms of dementia may go unrecognized, but the first sign is usually loss of short-term memory.
  • Some of the other early dementia symptoms and signs include:
    • Personality changes
    • Mood swings
    • Poor judgment
    • Paranoia or suspiciousness
Reviewed on 11/15/2021
Medically reviewed by Jon Glass, MD; American Board of Psychiatry and Neurology


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