Case 4 – An 18-year-old woman after a motor vehicle accident

An 18-year-old woman is brought to the emergency department by ambulance after suffering a motor vehicle accident. The patient had been alert when the paramedics arrived at the scene of the accident, but her level of consciousness declined en route to the hospital. The patient told the paramedics she had been unrestrained and had hit her windshield during the collision. On presentation the patient appears drowsy but is responsive to verbal commands. She complains of back and neck pain and a headache. The patient has a contusion and abrasion over her right temporal region; the remainder of her head, ear, eye, nose, and throat examination is normal. Neurological examination reveals no focal deficits, and cranial nerves II-XII are intact. Vital signs, a complete blood count, and blood chemistry test results are within normal limits. A lateral x-ray of the cervical spine reveals no abnormalities. Noncontrast CT scan of the head shows a small fracture of the skull in the temporal region and an underlying extra-axial lenticular hyperdensity.

What is the most likely diagnosis?

Epidural hematoma (EDH). EDH is an accumulation of blood between the inner table of the skull and the dural membrane. In a patient with a history of blunt head trauma, radiographic evidence of a temporal bone fracture, and an underlying lens-shaped collection of blood, EDH is the most likely diagnosis. Because the underlying brain has usually been spared from injury, prognosis is excellent if treated quickly and aggressively.

What are the typical clinical findings associated with this condition?

EDH is sometimes (approximately 20% of cases) characterized by a patient experiencing a lucid interval prior to experiencing a decline in consciousness. Many patients are comatose by the time they receive medical attention. Other common presenting signs and symptoms include headache, seizure, and vomiting.

What other symptoms can occur with this condition?

As in all expanding space-occupying lesions, increasing intracranial pressure can lead to brain herniation and possible death. Signs of increasing intracranial pressure that may signal imminent herniation include:

1. A triad of bradycardia, respiratory depression, and hypertension (Cushing’s triad)
2. Cranial nerve VI palsy
3. Dilated, sluggish, or fixed pupils
4. Papilledema secondary to impaired axonal transport and congestion of the optic nerve
5. Spontaneous periorbital bruising

What risk factors are associated with a worse prognosis?

The mortality rate for EDH is 5%-40% depending on the presence of the following risk factors:

1. Advanced age
2. Increased hematoma volume
3. Increased intracranial pressure
4. Intradural lesions
5. Lower Glasgow Coma Scale rating
6. Papillary abnormalities
7. Rapid clinical progression
8. Temporal location

What is the most appropriate management for this patient?

Treatment for EDH is the same as for all head trauma. Initial management focuses on hemodynamic stabilization and management of life-threatening issues. Burr holes are indicated if brain herniation appears imminent and definitive surgery cannot take place in the emergent setting. Definitive surgical treatment involves craniotomy and excavation of the underlying hematoma.

By Daniel Osei, MD, Resident in Orthopedic Surgery, Hospital for Special Surgery; in association with Le TT, Schabelman E, Shivaram A, and Klein J, eds: First Aid Cases for the USMLE Step 2 CK. New York: McGraw-Hill, 2007.