Impulse Control Due to Frontal Lobe Injury

The frontal lobe of the brain is considered to be the center of personality and emotional functioning. Disruption to frontal lobe functioning due to injury can potentially affect a spectrum of behaviors including impulse control.

Functions

• The frontal lobe controls a wide variety of high-level functions including motor behavior, problem solving, memory, language, judgment, decision making, social behavior, sexual behavior, motivation, and impulse control.

Localization of Function

• The frontal lobe has several regions that control different specific functions. The primary motor cortex governs planning, initiation, and execution of physical movement. The dorsolateral area controls executive functions such as planning, strategizing, and decision making. The prefrontal cortex participates in verbal, visual, and spatial memory. The orbitofrontal cortex regulates impulse control, behavioral inhibition, and social behavior.

Disturbance in Function

• The location, nature, and extent of frontal lobe tissue injury will determine the nature of emotional, motivational, and behavioral disruptions. Impulse control issues will result if trauma occurs to the orbitofrontal cortex, or if trauma is extensive or systemic, such as can occur with closed-head injuries, tumors, degenerative diseases, or severe strokes.

Phineas Gage's Injury

• A well-known case report written in 1848 by Dr. John Harlow, M.D., describes the plight of one Phineas Gage, a railway worker who had a long metal rod blasted through his left cheek, through his eye, and out of the top of his head, causing damage to his frontal lobe. Mr. Gage survived the accident but had well-documented changes to his personality. Before the accident he was organized, well mannered, temperate, and respectful to others. Following the accident, he was, according to Dr. Harlow, "fitful, irreverent, indulging at times in the grossest profanity (which was not previously his custom), manifesting but little deference for his fellows". He had difficulty following through with tasks and showed other planning and executive dysfunctions that typify impulse control problems because of frontal lobe injury.

Recovery

• Depending on the extent of damage, the development of new connections between cells of the brain can cause functional reorganization of the brain. Different areas of the brain can take over lost functions. Intensive therapy following injury is critical to successful rehabilitation.