- General Approach to Head Injury
The presence of significant intracranial injury should be obvious from the mini-neurological exam of the initial survey. The secondary survey may reveal a decreasing level of responsiveness or localized neurological deficits. When you find evidence of neurological injury, detailed testing such as Dolls eyes and caloric testing can be left to the neurosurgical consultant.
The hallmark of cerebral injury is decreased level of consciousness. The differential diagnosis of decreased consciousness is TIPPS on the VOWELS:
T = Trauma
I = Infection
P = Psychological
P = Poisons
S = Shock
A = Alcohol
E = Epilepsy
I = Insulin
O = Opiates
U = Urea (metabolic)
Careful examination of the skull and facial bones may reveal evidence of an impact that makes intracranial injury more likely. Any patient who has some degree of minor head injury, who you do not x-ray or CT scan, should be reexamined before leaving the emergency department. Mastoid swelling and discoloration, widespread scalp hematoma, periorbital ecchymosis, and other classic signs of skull fracture often do not develop for hours.
Vital signs may reflect intracranial pathology. Increased intracranial pressure (ICP) often causes a slowing of respiration, then an increase with further elevation of ICP. The combination of systolic hypertension (widened pulse pressure), with slowed pulse is called the Cushing response to increased ICP. It often indicates a surgical lesion. Elevated temperature is common with cerebral injury. Tachycardia in the presence of head injury, unless due to some other injury, is a bad prognostic sign.
Fancy reflexes such as eyelid reflex, corneal reflex, Dolls eyes, and calorics are of little value acutely, and are best left to the neurosurgical consultant. The patient is best followed using pupil signs and a general scale of responsiveness such as the Glascow Coma Scale.
Glascow Coma Scale
To Voice 3
To Pain 2
Inappropriate Words 3
Incomprehensible Sounds 2
Obeys Commands 6
Localizes Pain 5
Withdraws to Pain 4
Flexion to Pain 3
Extension to Pain 2
Any patient with a decreased level of consciousness, a local neurological deficit, skull fractures in the vicinity of the middle meningeal artery, or a history of loss of consciousness of greater than two minutes should have a CT scan. Even if the CT scan is normal, any patient who is not neurologically normal, or who has been unconscious for greater than 5 minutes, should be admitted.
Patients with evidence of neurosurgical emergency (such as acute epidural hematoma) should have consultation immediately. Let the neurosurgeon decide if theres time for a CT scan. Back to Top
General Stabilization of Head Injury
The ABCs of trauma stabilization take priority over head injury. About 5% of patients with severe head injury will have a cervical spine fracture.
On recognition of significant head injury, place a call to the neurosurgeon at the first opportunity. If there is a delay, elevate the head of the stretcher and hyperventilate the patient. Other measures are best discussed with the consultant first.
Head injury victims often require intubation. Use lidocaine 1 mg/kg IV as pretreatment to prevent a rise in intracranial pressure with intubation.
Restrict fluids only if the patient is NOT in shock. The use of D5W TKO out of concern for cerebral swelling is inappropriate in the patient with low blood pressure.
Mannitol, as one gram per kilogram of body weight (about 50 grams in the average adult), may decrease brain volume and decrease intracranial pressure by drying out the brain temporarily. Give it only when surgery is imminent, or when uncal herniation is diagnosed. Lasix, 40 to 80 mg, may be given to decrease ICP further.
Aggressive hyperventilation with mechanical ventilation results in narrowing of cerebral vessels and may delay swelling. Aim for a PaCO2 of 25-30 mm Hg. However hyperventilation is not harmless, as the vessel narrowing may decrease cerebral blood flow to the point of causing ischemia. Neurosurgical consultation should be sought, if possible, before beginning aggressive hyperventilation.
The use of steroids in intracranial injury is controversial, and is probably of little benefit. Let the neurosurgeon decide.
Agitation may be treated with chlorpromazine, 25 mg IV. Diazepam or lorazepam may help. To immobilize for CT scanning, paralysis with succinyl choline (1-2 mg/kg) or pancuronium bromide (0.1 mg/kg) may be required.
About one out of twenty head-injury patients will have seizures in the first days following the injury. If blood pressure is stable, dilantin at 18 mg/kg can be given as prophylaxis. Back to Top
Simple skull fractures are not serious. Rule out brain injury or intracranial hemorrhage. Depressed skull fractures, where a portion of the skull is pushed downward, require neurosurgical consultation, as do open skull fractures. Fractures over the course of the middle meningeal artery or a major dural sinus can result in rapid intracranial bleeding.
Clinical Findings: Suspect skull fracture when significant injury is evident. The history of high-velocity localized trauma, or low-velocity diffuse trauma with widespread swelling or tenderness, suggests a higher likelihood of fracture. Skull fracture may be evident on exploration of scalp lacerations. A basilar skull fracture may result in blood behind the ear drum (or oozing from a ruptured eardrum), or CSF flow from ear or nose. Facial paralysis or unilateral deafness may be seen due to cranial nerve injury.
Diagnosis: Obtain x-rays of the skull if CT scanning is either not indicated, or cannot be done. If a CT scan is planned, skull x-rays are unnecessary. The fracture will be seen on CT.
Treatment: A simple skull fracture requires only observation for neurological injury. Any neurological abnormality, or abnormal finding on CT scan, requires neurosurgical consultation. Depressed skull fractures, if more than about 1/2 the skull thickness, are usually elevated in the operating room. Open skull fractures require consultation to rule out intracranial contamination. Back to Top
This hemorrhage is usually due to arterial bleeding from a meningeal artery. About 3/4 of the time, the epidural hematoma is due to a fracture over the middle meningeal artery. The blood dissects the dura mater away from the skull, with a resulting expanding mass.
Clinical Findings: There is usually a history of loss of consciousness, followed by a lucid interval. Level of consciousness decreases as the hematoma expands. The hematoma may take a few hours to strip the dura away from the skull. As it expands, confusion, somnolence, and vomiting may develop. Usually there are no localizing findings until significant midline shift has occurred. At that point, a fixed dilated pupil is seen (almost always on the side of the impact), with a contralateral hemiparesis. Both pupils may become fixed and dilated as uncal herniation progresses.
Diagnosis: Suspect epidural hematoma from history and physical exam findings. The clinical picture alone is often sufficient for intervention. When the diagnosis is not clear, a CT scan will show a lens-shaped collection of blood over a cerebral hemisphere. The blood forms a more rounded shape because the tough dural attachments to the skull tend to keep it more localized.
Treatment: The hematoma must be evacuated immediately by placement of a burr hole by a trained person. If neurosurgical care is not immediately available, a trained emergency physician can place the burr hole while awaiting flight to a neurosurgical center. Give mannitol if uncal herniation is diagnosed. Prognosis for recovery is good, as there is usually very little underlying brain injury. Back to Top
This hemorrhage occurs between the dura mater and the arachnoid membranes, usually due to rupture of the bridging veins as the brain shifts during a rapid deceleration. Patients with cerebral atrophy are more prone to subdural hematoma. There is often significant underlying brain injury due to the nature of the trauma.
Clinical Findings: The patient is often deeply comatose due to diffuse cerebral injury. Localizing neurological findings may be present on the side of the injury due to underlying cerebral contusion and parenchymal hemorrhage. With shift of mid-line structures, an ipsilateral fixed dilated pupil may be seen, with contralateral hemiparesis. Because of this combination of neurological effects, the physical findings may be complex and confusing until a CT scan reveals the source of the various neurological findings.
Diagnosis: Suspect subdural hematoma with deceleration injury of the head with neurological injury. CT scan confirms that the clinical findings are due to subdural hemorrhage and not to tissue swelling and intraparenchymal hemorrhages. The scan shows a wide-spread crescent-shaped collection of blood over one hemisphere. The sickle-shape differentiates subdural blood from epidural hemorrhage.
Treatment: Surgical evacuation is required for larger hemorrhages. The neurosurgeon will decide. Prognosis is usually poor due to underlying brain injury. Back to Top
Bruising of the brain may occur either at the site of impact, or at the opposite side as the brain rebounds (contrecoup injury). Contusion is most common over the bony prominences of the sphenoid ridge and nasal plates, affecting the anterior temporal lobes and subfrontal cortex. Direct frontal impact injures the frontal lobes. Damage is most severe at the tips of the gyri, with surface hemorrhage often leading to subarachnoid blood.
Clinical Findings: Cerebral contusion will usually result in localizing neurological deficits. For example, contusion of the motor cortex may result in localized weakness on the opposite side of the body. Temporal lobe contusion commonly results in an inability to fix memory the victim doesnt remember what hes told from one minute to the next.
Diagnosis: The CT scan may be normal in mild cases. More typically, swelling of the gyri is seen, with diffuse increased density suggesting widespread tiny hemorrhages. Subarachnoid blood may be seen.
Treatment: All patients with cerebral contusion should be admitted to the hospital for observation. Those with major swelling, or those in whom the neurological exam cannot be followed, may have an intracranial pressure monitor placed. Persistent neurological deficits and seizures may occur. Back to Top
Hemorrhage within the substance of the brain is called intracerebral hemorrhage. It often occurs at a focus of cerebral contusion. Hemorrhage can be delayed by hours or days the blood may not be seen on initial CT scan.
Clinical Findings: Early signs of intracerebral hemorrhage are those of localized neurological deficits, due to local injury and local pressure on nerve tissue by the expanding hemorrhage. Later, decreasing level of consciousness occurs if intracranial pressure elevates, and signs of uncal herniation may develop if the hemorrhage becomes large enough to displace intracranial structures. Uncal herniation can occur rapidly without signs of increasing intracranial pressure with focal hemorrhage in the tip of the temporal lobe.
Diagnosis: On CT scan, local well-defined areas of increased density are seen at sites of hemorrhage, usually with a bulge or stretch effect seen on surrounding brain tissue.
Treatment: Small intracerebral hemorrhages are observed in the hospital, often with intracranial pressure (ICP) monitoring. Hemorrhages with significant mass effect, or that elevate the ICP, are treated with surgical evacuation. Seizures and neurological deficits are common. Back to Top
Bullets and sharp objects may penetrate the brain. Secondary bleeding and edema may cause further damage due to disruptive effects of local hemorrhage and edema, or due to global increase in ICP.
Clinical Findings: Where the history of injury is not clear in the patient with decreased consciousness, a thorough examination of the scalp may reveal an unsuspected bullet or stab wound. Localizing neurological deficits are usually present.
Diagnosis: Skull x-rays or CT scan will show the location of the foreign material.
Treatment: Any impaled object should be stabilized in place. For all penetrating injuries, immediate neurosurgical consultation is necessary. Back to Top
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All material referenced through this menu is excerpted from copyrighted works by Bruce Argyle, MD. You are welcome to use selected portions, as long as appropriate credit is given. The credit for the text referenced through this menu is:
Argyle, B., Trauma One! Computer Program Manual.
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