As the name indicates, the frontal lobe is located toward the front of the brain. Brain damage to the frontal lobe is caused by injuries and trauma that occur at the front of the head, resulting in brain lesions. While it is involved in various brain functions, such as planning, self-awareness, altering strategies, and spontaneous behavior, the primary function of the frontal lobe is motor control. Frontal lobe brain damage is defined by specific deficiencies in behavior, including motor impairment, a loss of spontaneity, and difficulties changing strategies. Damage can also result in a lack of self-awareness, problems with planning, and Broca's aphasia, a condition resulting in speech difficulties.
Located toward the back of the frontal lobe is the primary motor cortex, which is made up of many different neurons that are connected to different muscles throughout the body. As such, this region of the brain is directly involved in motor function and muscle control. Connection between the primary motor cortex and the different muscles is contralateral, meaning that the right primary motor cortex controls the left side of the body and the left primary motor cortex controls the right side of the body. Due to this contralateral connection, damage to the primary motor cortex produces paralysis, or a loss of movement, to the side of the body opposite to where the frontal lobe brain damage has occurred.
Frontal lobe brain damage can also cause deficiencies in other behavioral responses, such as a slowing down of thought processes and a lack of spontaneity. A patient with this kind of deficiency may still have a reaction toward events in his or her environment, but will demonstrate difficulty in initiating behavior. This type of brain damage may also cause patients to have problems altering strategies and applying new strategies to different problems.
On the left region of the frontal lobe is Broca's area. Broca's area controls muscles that are involved in speech and many neurons found in this area contain memory sequences for the muscle movements needed to pronounce words. When this area is damaged, a patient will suffer from a condition called Broca's aphasia, a condition causing language impairment. The patient will have difficulty repeating words and naming objects, but word comprehension will remain undamaged.
In addition, there are a variety of issues that may develop as a result of frontal lobe brain damage. A loss of self-awareness may become further apparent, and patients with damaged frontal lobes are considered to have bland personalities. These people become indifferent toward events that should otherwise have an emotional effect. Frontal lobe brain damage causes many deficits, but one of the most inflicting is a difficulty in planning. This type of deficit makes day-to-day living a struggle, where simple tasks, such as holding down a job, become a challenge.