The Anatomy of Head Trauma

Many structures can be injured during head trauma

Head trauma affects important structures of the face, neck and skull. The brain is one of the most sensitive organs that can be damaged by head trauma. In addition, the eyes, ears, sinuses, nose, facial tissues and breathing structures may also be injured.

For moderate to severe head trauma, numerous specialists often become involved in the plan of care. These include neurosurgeons, eye doctors, ear nose and throat specialists, and plastic surgeons.

Nurse practitioners, nurses, therapists and counselors also provide specialized care.

Brain Injury from Head Trauma

The brain controls all unconscious and conscious activities. It is the core processor of all body functions, and manages everything from body temperature and digestion, to the ability to read these words.

The brain is protected and surrounded by the skull. There are three important layers of tissue around the brain. These are called the:

  1. Dura mater
  2. Arachnoid membrane
  3. Pia Mater

The brain is bathed in fluid called cerebrospinal fluid. This fluid also flows around the entire length of the spinal cord. Cerebrospinal fluid cushions the brain and absorbs some of the normal day-to-day shocks from movement and exercise.

Blood Flow to the Brain After Head Trauma

The brain is surrounded by a network of critical arteries. These run between two of the tissue layers that surround the brain: the pia mater and arachnoid membrane.

In order for the brain to get the blood, nutrients and oxygen it needs, these blood vessels have to be intact and under normal pressure.

One concern after head trauma is damage to these blood vessels. If they rupture and bleed, it can lead to a large blood clot that presses down on brain tissues. When that happens, blood flow to the brain slows down and brain cells begin to die.

Anatomy of the Brain

Located at the lower back of the brain is the cerebellum and brainstem. The cerebellum controls motor movements such as balance and posture, and enables learning new skills such as riding a bicycle. The brainstem carries motor and sensory connections from the main part of the brain to the rest of the body as well as controls all basic life functions, including blood pressure, heart rate, breathing, level of consciousness and sleep cycle.

The rest of the brain, the larger portion, is called the cerebral cortex. The cerebral cortex is split into 4 distinct lobes.

  • Frontal Lobe
  • Temporal Lobe
  • Parietal Lobe
  • Occipital Lobe

Each of these lobes controls specific functions such as behavior, motor, sensory, language, and vision. Head trauma can damage one or several of these areas of the brain, resulting in specific changes in senses, learning, movement and behavior.

Eye Damage from Head Trauma

The eyes can be damaged by puncture, bruising, rupture and scraping. Bleeding into the globe of the eye is dangerous, because as pressure goes up, blood flow to the nerves that make vision possible goes down.

Any changes in vision after head trauma should always be immediately evaluated at the Emergency Department or by an ophthalmologist.

Eye injury might take time to make itself evident. Glaucoma after an injury may happen all of a sudden, or little by little. Traumatic glaucoma is a condition in which the eye’s natural fluid drainage system becomes clogged. This may be from old blood cells, or tissues that were dislodged during the head trauma.

Closed angle glaucoma is a medical emergency and happens suddenly. Symptoms include eye pain, nausea, vomiting, loss of vision, seeing rainbow halos around lights, and eye redness.

Open angle glaucoma happens over time, and symptoms may not be noticed until nerve damage at the back of the eye causes loss of vision.

Facial Damage from Head Trauma

The skull, facial bones and sinuses may be fractured or crushed from head trauma. The tissues covering the face may be burned, scraped or torn from the face. The bones surrounding the eye socket may also fracture and damage the eye.

Any time a head trauma is experienced, it’s recommeded to be evaluated in the Emergency Department or see a primary care provider for a complete, in-person evaluation.

Sources:

James D. Kretlow, Ph.D.,1 Aisha J. McKnight, M.D.,1 and Shayan A. Izaddoost, M.D Facial Soft Tissue Trauma; Facial Trauma; Semin Plast Surg. 2010 Nov; 24(4): 348–356.

Sihota R1, Kumar S, Gupta V, Dada T, Kashyap S, Insan R, Srinivasan G. The The

 (2008) Early predictors of traumatic glaucoma after closed globe injury: trabecular pigmentation, widened angle recess, and higher baseline intraocular pressure. ) Arch Ophthalmol. 2008 Jul;126(7):921-6

U.S. National Library of Medicine (2014) Head Injuries; https://www.nlm.nih.gov/medlineplus/headinjuries.html

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