ALS is known as a disease that affects muscle movement. In some cases, though, it can also cause changes in a person’s thinking and behavior. Around 50% of people with ALS will eventually experience some change in cognitive ability or behavior, with those changes ranging from minor symptoms to full-blown dementia. 

Symptoms 

What do these changes in thinking and behavior look like? 

Similar to how the physical symptoms of ALS can vary widely from one patient to the next, thinking and behavioral changes can take on many different forms. Potential symptoms include: 

• Embarrassing, childish, inappropriate, or uncharacteristic behavior. 

• A focus on eating only one type of food, especially sweets, instead of a typical balanced diet. 

• A loss of table manners, including stuffing their mouth with food. 

• A lack of attention to basic hygiene, such as bathing, grooming, or wearing clean clothes. 

• Decision-making that shows a lack of judgment, and is a strong departure from the norm for that person. 

• A lack of concern for others, or for themselves. 

• An inability to concentrate, or an inability to shift focus from one activity to another. 

• Becoming fixated on a single idea or activity, and repeating it over and over. 

• Increased aggression. 

• Saying “no” when they mean “yes,” or vice versa. 

• Writing or speaking words in the wrong order, or saying something that doesn’t make sense. 

• Losing the ability to spell. 

• Forgetting the meanings of words. 

• Being able to think of the word they want to say, but being unable to say it. 

• An inability to follow simple instructions. 

• Difficulty remembering what they intend to do. 

About half of all people with ALS will never experience any of these symptoms. Some people may experience just one or two symptoms, while others might have most or even all of the symptoms listed above. 

Changes in thinking and behavior can be caused by ALS, but they can also be the result of other factors that may or may not be related to the disease. For example, a lack of oxygen caused by ALS-induced breathing difficulties can impair thinking abilities. Symptoms can also sometimes be related to medication side effects, anxiety of depression issues, a lack of sleep, or a separate pre-existing neurological disease. 

Risk Factors 

Some factors make it more likely that a person with ALS will experience changes to thinking or behavior. Risk factors include: 

• Older age. 

• Bulbar onset ALS, which means cases of ALS where the symptoms first appear in the muscles of the face and throat. 

• A family history of dementia. 

• Past neurological injury. 

• Abnormalities in gene C9orf72 in some families. 

However, some people living with ALS develop changes in thinking or behavior without having any of these risk factors. 

Diagnosis 

To diagnose cognitive and behavioral impairment symptoms, and determine whether they are related to ALS or caused by something else, you will need to see a neuropsychologist. The neuropsychologist will perform a cognitive evaluation, consisting of both written and verbal tests. The results of the tests will be compared to what is considered normal for people of a similar age and educational background, or to the patient’s own history, to diagnose whether the patient is impaired and determine what type of impairment it might be. 

Living With Changes in Thinking or Behavior 

Like the physical effects of ALS, cognitive and behavioral symptoms worsen over time. It is important, therefore, to be aware of the problem and get it diagnosed as early as possible. 

Because it can affect thinking processes and decision-making abilities, people living with ALS should consider setting up advance directives or end-of-life documents as soon as possible, while they are still able to think clearly. 

For family members and caregivers, it is important to manage expectations. If your expectations of what someone can do exceeds their ability, it can be frustrating for both the person living with ALS and the caregiver. 

When dealing with a loved one who has cognitive or behavioral impairment, family members and caregivers need to also take the time to care for themselves. Support groups or counseling services can help give you the emotional energy needed to better care for the needs of the person with ALS. 

It can be helpful to simplify communication with the person living with ALS. Speak slowly, break sentences up into short phrases, and ask questions that can be answered with a simple “yes” or “no.” Also, accompany them to all appointments so you can make sure all information is accurately relayed and remembered. 

Emotional Lability 

Besides cognitive and behavioral changes, some people with ALS experience changes in how they process and display emotions. They may laugh or cry at inappropriate times, even when they don’t necessarily feel happy or sad. They may also feel emotions more intensely than normal, or find it difficult to “shut off” an emotion once they begin feeling it. These symptoms are referred to as “emotional lability” or “pseudobulbar affect.” 

Emotional lability does not appear to be related to cognitive or behavioral impairment. Some patients experience emotional lability without having any other changes to their thinking or behavior, and some experience cognitive impairment without having emotional lability. Some patients experience both symptoms, while others have neither symptom. As with most aspects of ALS, every person’s journey is unique.