Brain tumors can sometimes affect behavior and personality. The location, size, and type of tumor all play a role in determining if and how behavior is impacted. Understanding the connection between brain tumors and behavior changes can help patients and doctors identify tumors early as well as manage symptoms.
How do brain tumors form?
Brain tumors form when cells in the brain start to grow out of control. There are two main types of brain tumors:
- Primary brain tumors start in the brain. They can be benign (non-cancerous) or malignant (cancerous).
- Metastatic brain tumors spread to the brain from somewhere else in the body, usually from a primary cancer like lung, breast, or colon cancer.
Brain tumors cause problems in a few different ways:
- They take up space inside the skull, pressing on and damaging normal brain tissue.
- They disrupt the proper functioning of surrounding cells.
- They sometimes spread across critical parts of the brain.
Both benign and malignant tumors can cause serious problems depending on their size and location.
What are the most common brain tumor symptoms?
Brain tumors can cause a wide range of general and specific symptoms. Some of the most common symptoms include:
- Headaches – Often worse in the morning or when coughing/sneezing
- Nausea and vomiting
- Blurry or double vision
- Dizziness
- Clumsiness and balance problems
- Difficulty speaking, writing, and understanding language
- Numbness or tingling
- Changes in personality and behavior
- Seizures
- Memory problems
The symptoms someone experiences depends on the tumor type, size, location, and rate of growth. Symptoms often develop slowly over time and may seem minor at first.
How do brain tumors affect behavior and personality?
Behavior and personality changes are common symptoms of brain tumors. This happens because tumors can damage areas of the brain responsible for judgment, cognition, inhibition, mood, and impulse control.
Specific behavioral and personality changes may include:
- Inappropriate actions or responses
- Loss of social tact and manners
- Lethargy and slower thinking
- Depression or anxiety
- Mood swings and emotional outbursts
- Withdrawal from social situations
- Increased irritability or aggression
- Restlessness and agitation
- Acting impulsively
Behavior changes tend to be more common with tumors located in certain parts of the brain such as the frontal and temporal lobes. Damage to this area of the brain can impact executive functioning, reasoning, language, memory, and judgment.
Why do brain tumors cause behavior changes?
There are a few reasons why brain tumors can lead to behavioral and personality changes:
- Damage to surrounding tissue – Tumors take up space and put pressure on surrounding areas of the brain. This added pressure can impair function in those areas and networks.
- Swelling – Brain tumors are often surrounded by swollen tissue which can also compress and disturb function in adjacent parts of the brain.
- Shift in brain structures – Some tumors cause the brain to shift or herniate. This displacement can disrupt connections between key brain regions.
- Leakage of chemicals – Leakage of chemicals from tumors into surrounding brain tissue can cause inflammation and damage that changes behavior.
- Headaches – Chronic headaches from brain tumors can impact mood and irritability.
- Medications – Some medications used to treat brain tumors have side effects that influence behavior and personality.
- Stress – The difficulty of coping with symptoms can contribute to behavior changes like withdrawal and depression.
Frontal lobe tumors
The frontal lobes control important cognitive skills like problem solving, memory, language, judgment, and impulse control. Frontal lobe tumors often cause:
- Cognitive and memory problems
- Changes in personality
- Mood disorders like depression
- Lack of inhibitions
Temporal lobe tumors
The temporal lobes help regulate mood, behavior, and language skills. Tumors in this part of the brain can lead to:
- Aggressive outbursts
- Trouble understanding speech
- Memory loss
- Hallucinations
Parietal lobe tumors
The parietal lobes control sensation, spatial processing, and navigation. Tumors here may cause:
- Severe headaches
- Issues with coordination
- Inability to locate familiar places
- Difficulty writing
Occipital lobe tumors
The occipital lobes process visual information. Occipital lobe tumors can lead to:
- Vision loss or blindness
- Hallucinations
- Illusions
- Color agnosia – inability to recognize colors
How are behavior changes diagnosed?
Since behavior and personality changes have many causes, doctors use several methods to link them to a brain tumor:
- Imaging tests – CT, MRI, PET scans help locate tumors and determine if they are in areas that control behavior and personality.
- Neuropsychological evaluation – Assesses thinking skills, memory, problem solving to identify affected brain regions.
- Blood tests – Help rule out other causes like thyroid disorders, infections, and vitamin deficiencies.
- Clinical history – Looks at when symptoms started, what mediations the patient is taking, and how quickly changes occurred.
If imaging reveals a brain tumor located in an area related to the behavioral symptoms, that tumor is likely causing the changes.
Do benign brain tumors affect behavior?
Yes, benign (non-cancerous) brain tumors can affect behavior and personality. Even though benign tumors do not contain cancer cells, they continue to grow larger in the brain over time. Examples of benign tumors that frequently impact behavior include:
- Meningiomas – Grow along the membranes covering the brain. They put pressure on brain tissue.
- Acoustic neuromas – Develop along cranial nerves. They impede nerve cell function.
- Pituitary adenomas – Grow in the pituitary gland. They affect hormone levels.
- Craniopharyngiomas – Located near the pituitary gland. They damage nearby hypothalamus cells.
Even benign tumors can be life-threatening in some cases depending on their location and rate of growth.
Can radiation therapy affect behavior?
Yes, radiation therapy used to treat brain tumors can sometimes affect behavior. Potential side effects include:
- Memory loss
- Cognitive problems
- Fatigue
- Confusion
- Personality changes
These side effects may be short-term and resolve after treatment ends. But radiation can also damage healthy brain tissue and have longer lasting effects on mood, cognition, and behavior.
Can chemotherapy affect behavior?
Yes, chemotherapy drugs used to treat cancer can impact behavior due to their effects on the brain. Some potential side effects include:
- Memory and concentration problems
- Mood disorders like anxiety or depression
- Fatigue and lethargy
- Insomnia
- Mental fog or confusion
Chemotherapy drugs and combinations affect each person differently. Some people have mild side effects for a short time, while others develop more severe long-term cognitive and behavior changes.
How are behavior changes managed?
While the underlying tumor ultimately needs to be treated to resolve behavior and personality changes, some approaches help manage symptoms:
- Treating headaches and pain helps relieve irritation and frustration.
- Counseling provides support for coping with emotional and psychological effects.
- Cognitive rehabilitation can retrain thinking skills like memory and problem solving.
- Occupational therapy helps adapt to cognitive impairments in everyday routines.
- Medications for depression, anxiety, and other psychiatric symptoms.
- Identifying and avoiding triggers that worsen outbursts or mood swings.
With treatment of the tumor, some types of behavior changes and cognitive deficits do improve over time. But in many cases, some residual effects remain even after successful tumor treatment.
Conclusion
Brain tumors, both cancerous and benign, can lead to a variety of behavioral and personality changes. This happens through several mechanisms, especially damage to areas of the brain that control cognition, language, mood, judgment, and impulse control. While concerning, behavior changes are important clues that can lead to early diagnosis of a brain tumor. With treatment of the tumor and management of symptoms, some behavioral issues do typically improve. Increased understanding of this link helps doctors and patients monitor behavior changes and address any underlying brain tumors as quickly as possible.