Head Injury and Anatomy

Head Injuries

• Falls can lead to fractures, wounds, muscle injury, and psychological distress.

Anatomy of the Scalp and Skull

• The scalp consists of three layers: skin, subcutaneous tissue, and epicranial aponeurosis.
• The skull is composed of many bones, including cranial bones connected by sutures.
• The skull has three cranial fossae: anterior (frontal lobe), middle (parietal, temporal, and occipital lobes), and posterior (cerebellum and brainstem).

Meninges and Brain Structure

• Three layers of meninges provide extra protection: dura mater, arachnoid mater, and pia mater.
• Dura mater lies above the epidural space, where the middle meningeal artery is located.
• Arachnoid mater has a subarachnoid space containing blood vessels and CSF.
• Pia mater adheres to the surface of the brain.
• White matter is made up of a large network of nerve fibers (axons) for information exchange.
• Grey matter has a large number of neurons for processing and releasing information.

Cerebral Blood Flow (CBF) and Perfusion Pressure (CPP)

• CBF is essential for cerebral functioning and is tightly regulated by metabolic demands.
• CBF is determined by blood viscosity, blood vessel dilation, and CPP.
• CPP is determined by blood pressure (BP) and intracranial pressure (ICP).
• Autoregulation aims to maintain adequate and stable CBF, crucial for maintaining cerebral homeostasis.
• The brain is sensitive to over/under perfusion, and inadequate CBF can lead to LOC, cellular ischemia, or death.

Traumatic Brain Injury (TBI)

• TBI can occur due to primary brain injury or secondary brain injury.
• Primary brain injury occurs at the time of injury, while secondary brain injury is a cascade of events exacerbating the initial damage.

Signs and Symptoms of TBI

• Headache/head discomfort
• Dizziness
• Nausea and vomiting
• Altered conscious state/unconscious
• Trismus
• Drowsiness/fatigue
• Confusion
• Abnormal pupils
• Abnormal motor response and posturing (decorticate and decerebrate)
• Seizures
• Ataxia
• Amnesia
• Neck pain
• Blurred vision
• Balance disturbance
• Noise/light sensitivity
• Anxiety
• Increased emotions/agitation
• Fogginess
• Poor concentration

Assessments for Falls and Minor Head Injuries

• Full physical examination to rule out other injuries
• Postural vital signs and mobility assessment
• FRAT or EAR (elderly at risk assessment)
• Consider sociological aspects
• Assessments for minor head injuries include considering C-spine, managing A, B, C, examining the skull for deformities, and checking for CSF leaks.