Brain Trauma Dr. Raid Jastania, FRCPC Assistant Professor, Faculty of Medicine, Umm Alqura University Vice Dean, Faculty of Dentistry

Reference and Contact Robbins Basic Pathology http://www.pathoma.com/ Jastania@hotmail.com http://uqu.edu.sa/staff/ar/4180114

Brain Trauma Important Factors: Site of injury Severity Energy: velocity, mass Blunt force Sharp force Static head, moving head, rotational force Associated injury

Intracranial Hemorrhage Types: Epidural (Extra dural) Subdural Subarachnoid Space occupying lesion Increased intracranial pressue Decreased blood flow Brain ischemia Herniation

Epidural Hemorrhage Fracture of skull plates Meningeal arteries run in grooves in the inner side of bone plates Common injury of middle meningeal arteries at the temporal bone Bleeding in extradural space Displacement of brain Rarely due to venous injury

Subdural Hemorrhage Rotational or shearing force Injury of venous sinuses Common in the very young and the very old May be present without skull fracture May organize

Subarachnoid Hemorrhage Very common Usually small and not fatal Associated with brain contusion and laceration May be fatal if large Most common non-traumatic is due to rupture berry aneurysm in the circle of Willis

Brain Injury Contusions and lacerations Fracture Penetrating injury Hemorrhage Rotational injury Acceleration/Deceleration injury Shearing between different layers of brain Laceration deep in the brain Common at region of corpus callosum Diffuse axonal injury

Brain Injury Sometimes in the absence of hemorrhage Results in cerebral edema Swelling of brain Increased intracranial pressure Herniation: tentorium cerebelli and foramen magnum Findings: heavy brain, flat surface, hemorrhage and necrosis, compression of ventricles

Parenchymal Injury Changes: Wedge shape injury Edema Hemorrhage Subarachnoid hemorrhage Neuronal injury Inflammation Gliosis Cavity Diffuse axonal injury

Brain Injury Coup and contrecoup injury: Coup injury occurs when a static head is stuck Injury of scalp will overly injury to brain Contrecoup injury: Skull and brain are moving and suddenly arrested Injury of brain is opposite to scalp or skull injury

Herniation Subfalcine herniation Transtentorial herniation Tonsillar herniation

Subfalcine herniation Unilateral expansion of brain Displaces cingulate gyrus Compress anterior cerebral artery

Transtentorial herniation Medial aspect of the temporal lobe Compression of 3rd cranial nerve, pupillary dilatation Posterior cerebral artery, occipital lobe infarct Compression of contralateral cerebral peduncle, ipsilateral hemiparesis Duret hemorrhage in pons and midbrain

Tonsillar herniation Cerebellar tonsils through foramen magnum Compression of respiratory centers in the medulla