Head injury

Primary Brain Injury

Concussion: Mild traumatic brain injury (TBI) with transient neurological dysfunction; symptoms include headache, dizziness, and confusion.
Contusion: Bruising of brain tissue, often associated with more severe TBI; may present with focal neurological deficits.
Diffuse Axonal Injury (DAI): Shearing injury to the brain’s white matter, typically from high-speed accidents; leads to prolonged unconsciousness and poor prognosis.
Intracerebral Hemorrhage: Bleeding within the brain parenchyma, often seen in severe head trauma; presents with focal deficits and increased intracranial pressure.
Epidural Hematoma: Arterial bleeding, typically from the middle meningeal artery; associated with a “lucid interval” followed by rapid deterioration.
Subdural Hematoma: Venous bleeding, often in elderly or alcohol-dependent patients; presents with fluctuating consciousness and focal neurological signs.
Subarachnoid Hemorrhage: Bleeding into the subarachnoid space, often traumatic; presents with “thunderclap” headache, neck stiffness, and photophobia.
Skull Fracture: May be associated with underlying brain injury; can be open or closed, with or without involvement of the cranial base (e.g., basal skull fracture).

Secondary Brain Injury

Hypoxia: Reduced oxygen delivery to the brain, often due to airway compromise or systemic hypotension following the injury.
Hypotension: Systemic hypotension can exacerbate brain injury by reducing cerebral perfusion.
Increased Intracranial Pressure (ICP): Resulting from edema, hemorrhage, or mass effect; can lead to herniation syndromes and further brain injury.
Herniation Syndromes: Displacement of brain tissue due to increased ICP; examples include uncal herniation, which can compress the oculomotor nerve, and tonsillar herniation, which can compress the brainstem.
Seizures: Post-traumatic seizures can contribute to secondary brain injury and are more common in severe TBIs.
Infection: Secondary to open fractures or skull base fractures with CSF leaks; risk of meningitis or brain abscess.
Electrolyte Imbalance: Hypo- or hypernatremia can occur due to syndrome of inappropriate antidiuretic hormone secretion (SIADH) or diabetes insipidus.
Coagulopathy: Can worsen bleeding; may be related to pre-existing conditions, medications, or disseminated intravascular coagulation (DIC) following severe trauma.

Mechanism of Injury

Details of the Event: High-impact events (e.g., road traffic accidents, falls from height) are more likely to cause significant brain injury compared to low-impact events.
Speed of Impact: Higher speed correlates with a higher risk of severe injury, particularly diffuse axonal injury or intracranial hemorrhage.
Object Involved: Blunt trauma is more likely to cause contusions and hematomas, while penetrating trauma can cause focal brain injuries and an increased risk of infection.
Loss of Consciousness: Duration and occurrence of loss of consciousness (LOC) help gauge the severity of the injury; prolonged LOC suggests more severe injury.
Amnesia: Retrograde (before the event) and anterograde (after the event) amnesia are important indicators of brain injury severity.
Seizure Activity: Post-traumatic seizures suggest more severe brain injury and may require prophylactic anticonvulsant treatment.
Bleeding or CSF Leak: Rhinorrhea or otorrhea (clear fluid from the nose or ears) may indicate a basal skull fracture.
Associated Injuries: Look for signs of trauma elsewhere, which can affect management priorities.
Alcohol or Drug Use: Intoxication can mask symptoms of brain injury or contribute to the injury itself.

Background

Past Medical History: Pre-existing conditions such as coagulopathy, previous head injury, or neurological disorders may influence the injury’s severity and management.
Drug History: Particularly anticoagulants or antiplatelet drugs, which can increase the risk of significant hemorrhage.
Family History: Consider any family history of bleeding disorders or hereditary conditions that might impact recovery or risk of complications.
Social History: Assess for social factors that might affect recovery, such as living situation, support systems, and occupation.
Previous Head Injuries: History of previous head injuries may predispose to chronic traumatic encephalopathy (CTE) or increase the risk of more severe injury.
Allergies: Important to note any allergies, especially if imaging contrast or certain medications might be needed.
Psychiatric History: Pre-existing psychiatric conditions, such as depression or anxiety, may be exacerbated by the trauma and affect recovery.
Occupation and Recreational Activities: High-risk occupations or sports may increase the risk of recurrent head injuries.
Advanced Directives: For patients with significant trauma, it’s essential to understand their wishes regarding life-sustaining treatment.

Initial Imaging

CT Head: The first-line imaging for head injury to assess for fractures, hemorrhage, and brain edema; usually performed without contrast.
Skull X-Ray: May be used in specific cases to identify fractures, particularly in resource-limited settings, but has largely been replaced by CT.
Cervical Spine Imaging: Often performed in conjunction with head CT to rule out spinal injuries in patients with significant trauma.

Blood Tests

Full Blood Count (FBC): To assess for anemia, infection, or thrombocytopenia, which may affect management.
Coagulation Profile: Particularly important in patients on anticoagulants or with a history of bleeding disorders.
Urea and Electrolytes: To assess for electrolyte imbalances, especially if the patient has altered consciousness.
Glucose: Hypoglycemia or hyperglycemia can affect neurological function and needs to be corrected promptly.
Toxicology Screen: If substance abuse is suspected, which may affect management and prognosis.
Blood Alcohol Level: Important in trauma patients to assess for alcohol intoxication, which may mask symptoms of brain injury.
Crossmatch: In severe trauma, crossmatching blood is important if transfusion is anticipated.

Advanced Imaging and Other Tests

MRI Brain: Used in cases where CT is inconclusive or to assess for diffuse axonal injury, ischemic injury, or small contusions not visible on CT.
Electroencephalogram (EEG): May be indicated if seizures are suspected or to assess brain activity in prolonged unconsciousness.
Intracranial Pressure (ICP) Monitoring: In severe TBI, monitoring ICP can guide management to prevent secondary brain injury.
Cerebral Perfusion Scan: Sometimes used to assess cerebral blood flow in cases of severe brain injury.
Neuropsychological Testing: In mild to moderate TBI, testing can assess cognitive deficits and help plan rehabilitation.
Lumbar Puncture: Rarely performed in head injury but may be indicated if there is suspicion of meningitis or subarachnoid hemorrhage without evidence on imaging.
Echocardiogram: To assess for cardiac function in trauma patients with suspected cardiovascular compromise.
Carotid Doppler Ultrasound: May be indicated if there is a suspicion of carotid artery dissection or stroke following neck trauma.

Neurosciences