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Symptoms and Signs of Dementia in Head Injury

Doctor's Notes on Dementia in Head Injury

Head injury occurs when an outside force hits the head hard enough to cause the brain to move violently within the skull. This force can cause shaking, twisting, bruising (contusion), or sudden change in the movement of the brain (concussion). Violent jarring of the brain can damage brain tissue and tear nerves, blood vessels, and membranes. Even a mild head injury can cause prolonged or permanent declines in cognition called dementia, which describes problems that affect thinking and concentration, memory, communication, personality, interactions with others, mood, and behavior.

Symptoms of dementia resulting from head injuries may include problems thinking clearly, memory loss, difficulty concentrating, slowed thought processes, irritability, easy frustration, impulsiveness, mood swings, inappropriate behavior in social situations, grooming and dressing becomes eccentric or neglected, restlessness, agitation, insomnia, aggression, combativeness, hostility, headache, fatigue, apathy, and other vague, nonspecific physical symptoms.

Medical Author: John P. Cunha, DO, FACOEP
Medically Reviewed on 3/11/2019


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.