Frontal lobe dementia or frontotemporal dementia make up approximately 10 percent of dementia cases. According to the National Institute of Neurological Disorders and Stroke, dementia is characterized by a loss of two or more complex brain functions such as speech, memory and problem solving that is not reversible. Dementias affecting the frontal lobe of the brain cause changes in behavior such as mood swings, inattention or impulsivity and changes in verbal expression such as difficulty finding words to express emotions or difficulty understanding words.
Behavioral Changes
Behavioral changes are the most prominent symptom of frontal dementia that can differentiate it from more common forms of dementia such as Alzheimer's and Parkinsonism. The frontal lobe of the brain is responsible for integrating information obtained through the senses. Dementias that damage the connections between areas of the frontal lobe can cause unusual behaviors such as easy distractibility, social isolation and difficulty with emotional expression as the ability to interpret sensory information and act appropriately is lost.
Difficulty with Expression
The all-inclusive term for difficulty with language is aphasia. Different types of aphasia can occur depending on what area of the brain is affected by dementia. Language areas located in the frontal lobe of the brain cause patients to have difficulty finding the words to express themselves and these patients can occasionally appear mute. Patients with damage to the frontal lobe can still understand what is being said to them, however, they lose the ability to string words together sensibly. Sentences are generally shortened and may lack conjunctions or prepositions that make speech fluent.
Difficulty with Sensory Information
Damaged brain tissue in the frontal lobe can also affect the way in which sensory information is processed in the brain. Patients have difficulty recognizing objects and naming them. At the same time, patients with any type of dementia lose the ability to recall long-term memories. The combination of these two symptoms often causes patients who suffer from frontal lobe dementia to appear mute. Diagnosis of frontal lobe dementia involves ruling out other reversible causes of unusual behaviors and difficulty with language such as acute substance intoxication or meningitis. Imaging, such as CT and MRI, can rule out other causes such as a brain tumor or bleeding in the brain. In cases of frontal lobe dementia, these scans generally show a loss of brain tissue volume in the frontal lobe.
