Frontotemporal dementia is an umbrella term for disorders affecting the areas of the brain that deal with personality, behaviour and language.

Bruce Willis has been diagnosed with frontotemporal dementia (FTD), his family says, nearly a year after the Die Hard franchise star retired from acting because aphasia had hampered his cognitive abilities.

“Since we announced Bruce’s diagnosis of aphasia in spring 2022, Bruce’s condition has progressed and we now have a more specific diagnosis: frontotemporal dementia,” his family said in a statement posted on The Association for Frontotemporal Degeneration website on Thursday.

“Unfortunately, challenges with communication are just one symptom of the disease Bruce faces. While this is painful, it is a relief to finally have a clear diagnosis.”

Here is what we know about FTD and its symptoms:

What is FTD?

FTD is an umbrella term for disorders affecting the areas of the brain that deal with personality, behaviour, language, and/or movement.

Frontotemporal degeneration is caused by progressive nerve cell loss in the brain’s frontal lobes or its temporal lobes.

Doctors say the frontal and temporal lobes of the brain shrink in a patient with FTD while certain substances accumulate in the brain.

FTD “can be misdiagnosed as a psychiatric problem or as Alzheimer’s disease”, according to the US-based National Institute on Aging.

The causes of FTD are not known, but according to the institute, “60 percent of people with FTD are 45 to 64 years old”.

Mayo Clinic said the risk of developing FTD is higher in patients who have a family history of dementia; it also says that FTD is the cause of up to a fifth of all dementia cases.

What are the symptoms?

Signs and symptoms vary depending on the area of the brain that is affected.

The disease can result in personality changes or modifications in behaviour that might make someone socially inappropriate, impulsive or apparently uncaring towards those around them.

Other sufferers lose their ability to use language.

According to the Johns Hopkins School of Medicine, some people also develop physical symptoms such “as tremors, muscle spasms or weakness, rigidity, poor coordination and/or balance, or difficulty swallowing”.

The Association for Frontotemporal Degeneration describes FTD as “an inevitable decline in functioning”, with an average life expectancy of seven to 13 years after the onset of symptoms.

What is the treatment?

According to the Association for Frontotemporal Degeneration, there is currently no treatment available to slow or cure the disease.

However, steps can be taken to manage symptoms, and some of those include proper nutrition, exercise, and stress management.

Experts also recommend that patients stay engaged in stimulating activities.