Bruce Willis, the 'Die Hard' star, is battling frontotemporal dementia (FTD). The beloved actor was diagnosed with the progressive brain disease about two years ago. Prior to this, he was diagnosed with aphasia in 2022, which makes it difficult to communicate. His wife Emma Heming recently shared an update on Willis' health. “Bruce is still very mobile. Bruce is in really great health overall. It’s just his brain that is failing him,” she said in a conversation with ABC special. Here’s everything you need to know about the rare condition that Bruce Willis has. What is Frontotemporal Dementia? Frontotemporal dementia (FTD) is a neurological disorder that occurs when nerve cells in the frontal and temporal lobes of the brain are lost. This causes the lobes to shrink. These areas of the brain control personality, emotions, behavior, and speech.FTD isn't one condition but a group of disorders that can affect behavior, personality, language, and movement. This is one of the most common dementias occurring in younger people. The symptoms appear between the ages of 40 and 65. However, it can also occur in older people. It can affect both women and men equally.Types of FTD Frontotemporal disorders are grouped into three types, defined by the earliest symptoms.Behavioral-variant FTD: This is the most common type of FTD, and the person may experience. They act strangely around others and may cause embarrassing social situations. Primary progressive aphasia: This affects the ability to communicate. This includes challenges in using language to speak, read, write, and understand what others are saying. In the case of aphasia, the person may experience difficulty in using or understanding words and may also have slurred speech. Movement-related FTD: This occurs when the parts of the brain that control movement are damaged. Other types include:Frontotemporal dementia with ParkinsonismFTD-ALSWhat are the symptoms? The symptoms of FTD depend on which part of the brain it is affected. In the early stages, it can be hard to identify the type, as the symptoms and the order in which they appear can vary from one person to another. Also, the same symptoms may occur for different disorders and vary from one stage of the disease to the next as different parts of the brain are affected.Here are some of the symptoms of behavioral variant frontotemporal dementia (bvFTD), the most common type.Challenges in planning and sequencingDifficulty prioritizing tasks or activitiesRepeating the same activity or saying the same word over and overApathyLack of empathyDecreased self-awarenessActing impulsively or saying or doing inappropriate things without considering how others perceive the behaviourBecoming uninterested in family or activities they used to care aboutDisplaying flat, exaggerated, or improper emotions that seem disconnected from the situationDifficulty reading social signals, seeming to lack empathyCompulsive eating or taking food from others’ plates In some people, these symptoms may be accompanied by physical symptoms, such as: TremorsMuscle spasms or weaknessStiffnessPoor coordination or balanceTrouble swallowingHow can the condition be diagnosed?The condition is often hard to diagnose, as it resembles the symptoms of other diseases, such as Alzheimer's, or mood disorders like depression. However, a doctor may identify the condition based on the following: Performing an exam and looking at the symptoms Personal and family medical history Laboratory testsGenetic testing By evaluating behavior, memory, thinking, language skills, and physical functionBrain imagingUnfortunately there is no treatment to cure, or slow down FTD, only the symptoms are treated.