Managing Personality & Behavior Shifts From Brain Tumors

The changes that alarm families are rarely dramatic. Someone stops starting conversations. Someone laughs at the wrong moment, or says something blunt at a funeral. A patient person snaps. A meticulous person stops noticing mess. A warm person seems flat and hard to reach.

Two things are worth saying plainly. First, this is a physical symptom. It belongs in the same category as a headache or weakness. It is not a character change, and it is not a choice. Second, the person may be unable to see it. Loss of insight is itself a symptom. That is why arguing about whether they have changed almost never works.

• Frontal lobe. Personality, restraint and planning sit here. Tumors in this area are linked with disinhibition, irritability, aggression, apathy and poor judgement. They also make it hard to start tasks or put them in order. Apathy is very often mistaken for laziness or depression.
• Temporal lobe. This handles memory, language and emotion. Changes include word-finding difficulty, forgetting recent conversations, and emotional volatility. Some people get odd sensations or déjà vu. Those are in fact seizure activity.
• Swelling around the tumor. Edema, or swelling, can change behavior markedly. Changes caused by swelling after surgery or radiotherapy may improve as recovery goes on.
• Hormonal effects. These can alter mood and sexual interest, particularly with tumors affecting the pituitary gland.

Do not conclude that the tumor has progressed before you go through the drug chart with the team.

• Steroids such as dexamethasone reduce swelling. But they often cause anxiety, irritability, mood swings, sleeplessness and appetite change. At higher doses they can cause confusion and, rarely, steroid-induced psychosis. The effects usually track dose changes. That is why dates matter.
• Anti-seizure medicines can cause irritability, agitation or low mood in some people. Alternatives exist. Ask, rather than assuming this is the tumor.
• Opioids, sleeping tablets and antidepressants, alone or combined, can produce confusion or flatness.

A sudden change over hours or days is not a personality issue. It can indicate delirium from infection, raised pressure, seizures or a metabolic problem. The signs to act on, and how fast, are set out under When to get help sooner below.

• Keep a behavior diary. Note the date, the time, what happened, what came immediately before, and the current medication doses. It identifies triggers such as fatigue, hunger, noise or late afternoon. And it gives the team something concrete to work from.
• Reduce the load. One instruction at a time. Short sentences. Less background noise. Tasks broken into steps, and a predictable order to the day.
• Do not quiz. Testing memory (“who came yesterday?”) causes distress without benefit. Supply the information instead.
• Address the behavior, not the character. “That is not okay to say here” works better than “why would you say that?”
• Safety. Ask about the rules on driving after a brain tumor diagnosis or a seizure. Consider supervising finances and major decisions. Plan in advance what you will do if there is aggression, including who to call.
• Tell friends what is happening, so behavior is not misread and people do not quietly drift away.

Neuropsychological assessment. It maps memory, attention, language and executive function. It turns “he is different” into specifics, with strategies attached. Occupational therapy, for daily function and home adaptations. Speech and language therapy, for word-finding and swallowing. Neuro-rehabilitation. And palliative care, which is about symptom control and support. It can be involved early, alongside treatment.

Caring for someone whose personality has changed is exhausting. It is hard to convey that to anyone who has not done it. Grieving a person who is still here has a name: ambiguous loss. It is a normal response, not disloyalty. So is anger at the person, followed straight away by guilt about the anger.

Ask for your own support, not only theirs. That means a carer's assessment where one exists, respite, and your own counseling. In the UK, The Brain Tumor Charity runs a free helpline (0808 800 0004) and support groups. In the US, ask the oncology social worker about brain-tumor-specific caregiver groups. Distress screening applies to caregivers too. You are entitled to be asked how you are doing.

Behavior changes have two speeds. Slow drift is something to manage. A change that arrives over hours or a day or two is a medical event, and the strategies on this page are the wrong tool for it.

• Call 911 or go to an emergency department if a seizure lasts longer than five minutes, or one seizure follows another without the person fully coming round in between. NINDS notes that five minutes is enough to damage neurons, and that a seizure that long is unlikely to stop by itself. Treat a first-ever seizure the same way. Do the same for a sudden collapse in alertness, a new weakness down one side, or a sudden change in speech.
• Call 911 or go to an emergency department if confusion comes on over hours, they no longer know where they are or what time it is, or they are much harder to rouse than yesterday. Falling alertness with a brain tumor can mean rising pressure inside the skull, and that is assessed in an emergency department, not by phone. Do the same for a sudden severe headache, or a headache with repeated vomiting.
• Call the team the same day if they start seeing or hearing things that are not there, if a headache is worse in the morning or on lying flat without the features above, or if aggression has become unsafe for them or for you.
• Call the team within a day or two if irritability, low mood, sleeplessness or agitation started or worsened after a steroid dose change or a new medicine. Bring the behavior diary and the dates. These effects usually track the dose, and the dose can often be adjusted.

• NINDS — Epilepsy and Seizures
• The Brain Tumour Charity — Coping with personality changes
• NCI — Memory or Concentration Problems and Cancer Treatment
• NCI — Support for Caregivers of Cancer Patients
• NCI — Cognitive Impairment in Adults with Cancer (PDQ)