A 23-year-old, previously healthy man was involved in a motor vehicle collision. He lost consciousness at the scene but recovered by the time emergency medical services arrived. The patient was alert and awake in the ambulance but lost consciousness again soon after arriving at the emergency department. His breath smells of alcohol. Blood pressure is 130/90 mm Hg, pulse is 68/min, and respirations are 12/min. A bruise is noted over the left temple area. The left pupil is mildly dilated. Brain imaging would most likely reveal blood accumulating between which of the following tissues?

Question

A 23-year-old, previously healthy man was involved in a motor vehicle collision.  He lost consciousness at the scene but recovered by the time emergency medical services arrived.  The patient was alert and awake in the ambulance but lost consciousness again soon after arriving at the emergency department.  His breath smells of alcohol.  Blood pressure is 130/90 mm Hg, pulse is 68/min, and respirations are 12/min.  A bruise is noted over the left temple area.  The left pupil is mildly dilated.  Brain imaging would most likely reveal blood accumulating between which of the following tissues?

Quizplus · Accepted Answer

11ec160b_39bc_8516_9249_19a8207868e9_MD0001_00 Epidural hematoma is an accumulation of blood between the skull bone and dura mater. Most cases are due to fracture of the pterion region of the skull (often involving the temporal bone with associated scalp contusion) and a subsequent rupture or tear of the middle meningeal artery. Epidural hematoma characteristically results in transient loss of consciousness at the time of impact followed by a lucid period in which the patient regains consciousness. However, the eventual expansion of the hematoma results in elevated intracranial pressure (ICP) and can lead to brain herniation, coma, and death. Signs of elevated ICP include altered mental status, nausea/vomiting, and Cushing reflex (ie, bradycardia, irregular breathing, hypertension). An ipsilateral dilated pupil can also occur due to uncal herniation and oculomotor nerve compression. The diagnosis is confirmed with a noncontrast CT scan demonstrating a hyperdense, biconvex (lens-shaped) mass between the brain and skull. Epidural hematomas do not cross suture lines due to the tight adherence of the dura to the calvarium at these points. (Choice A) The epicranial aponeurosis (galea aponeurotica) and outer periosteum cover the exterior surface of cranial bones. Intracranial hemorrhages are located inside the cranial vault. (Choice B) Subarachnoid hemorrhage results in blood accumulation between the arachnoid mater and pia mater. It most often occurs due to rupture of berry aneurysms or arteriovenous malformations of the anterior communicating, posterior communicating, or middle cerebral arteries. Patients typically have severe headache and nuchal rigidity. (Choice D) Subdural hematoma (SDH) is located between the dura mater and arachnoid mater and results from tearing of the bridging cortical veins. It typically presents in older patients with profoundly depressed mental status at onset (acute SDH) or an insidious onset of headache and confusion (chronic SDH) (Choice E) The pia mater is closely adherent to the brain surface and does not form a space for accumulation of blood. Educational objective: Epidural hematoma is an accumulation of blood between the bone and dura mater. It typically occurs due to a tear of the middle meningeal artery associated with fracture of the pterion region of the skull (often involving the temporal bone). Patients characteristically have transient loss of consciousness followed by a lucid interval before increasing intracranial pressure leads to neurologic deterioration.

A 23-Year-Old, Previously Healthy Man Was Involved in a Motor