Seizures, generalized or partial, are a common complication of head trauma, especially with moderated to severe TBIs. Seizures are more common in head injuries that have brain contusions, hematomas, or penetrating head injuries. Seizures can occur shortly after the injury or can occur for an extended period of time after the injury in a condition call post-injury epilepsy. Those who have early seizures are at higher risk to develop post-traumatic epilepsy.
Phenytoin is often used the first week after TBI. If seizures do not develop, the medication can be discontinued as there is little evidence that it prevents late-onset seizures.10 If seizures do occur, epilepsy can last for years after a TBI, even for a mild TBI. The relative risk of epilepsy ten years after a TBI is 1.51 or a mild TBI and 4.29 for a severe TBI.11
Brain injuries have the potential to lead to a coagulopathy (a disorder of blood coagulation) as they lead to a systemic release of tissue factors and brain phospholipids into the circulation leading to abnormal intravascular coagulation and a consumptive coagulopathy.12 Those with a coagulopathy after a TBI have a worse prognosis.
The ventricles can dilate when CSF builds up in the brain leading to hydrocephalus and an increased ICP. It often occurs soon after an injury but can occur after an extended period of time. Increased ICP may lead to cerebral edema, cerebral ischemia, cerebral hypoxia and brain herniation.
Skull fractures are another complication. When the matter between the dura and the arachnoid membrane tears, CSF can leak out in a condition called subdural hygroma. Fluid can leak out of the nose, ears and the mouth. Any tear in the brain’s protective matter increases the risk that bacteria can enter these spaces leading to meningitis.
Hemorrhagic stroke can result from an arterial bleed in the brain. Ischemic stroke can occur when a clot forms in the brain’s vessels. Blood clots can occur in the sinuses next to the brain. These clots usually occur within a few days of the injury. They present with seizures, headache, emesis, hemiparesis, and a creased level of consciousness.
The cranial nerves can also be injured when there is a TBI. It is estimated that only 0.3 percent of mild TBIs result in cranial nerve injuries.13 However, it is more common when there is a fracture, and it is near the base of the skull. The most commonly injured cranial nerve is the facial nerve (CN VII), which can result in paralysis of the face. Cranial nerve injury may lead to an impaired sense of smell or taste. If the patients lose their sense of smell, it will likely be permanent if it last one year after the injury.14 Double vision may occur and if it is to occur it is likely that cranial nerve IV has been affected. Damage to the trigeminal nerve (CN V) leads to facial pain.
Post-concussion syndrome can occur days or even months after a TBI and can occur with any degree of head injury from the mild to severe. Post-concussion syndrome is characterized by dizziness, vertigo, headache, reduced concentration, apathy, depression, sleep disturbance, confusion, irritability, and anxiety.
Amnesia can also occur after a head injury. Anterograde amnesia is impaired memory of events after the injury where retrograde amnesia is memory deficits of events prior to the injury.
Brain dysfunction can take many forms after a TBI. The following are problems that may present after a TBI:
- Impaired concentration and attention
- Impaired executive function
- Reduced hand-eye coordination
- Sensory deficits: vision, smelling, touching, hearing
- Aphasia (inability or reduced ability to communicate which can include impairments in expression or understanding written or verbal language)
- Dysartria (cannot speak the proper words due to dysfunction of the muscles used to speak)
- Reduced ability to carry out complex tasks
- Behavior changes or onset of mental illness (depression/anxiety)
- Social inappropriateness or aggression
Most of the recovery from a TBI occurs in the first six months and can be more gradual after the first six months.
Some problems may occur years after the head injury.1 Alzheimer’s disease is the most common type of dementia and is linked to a prior history of head injury. Parkinson’s disease can occur when there is a remote history of damage to the basal ganglia. As mentioned above, dementia pugilistica occurs in patients who have a history of head trauma. Posttraumatic dementia is dementia that occurs after a single TBI that results in a coma.
Agitation is commonly seen after a head injury. Other causes of agitation seen after a head injury may include: pain, depression, infection, side effects of medications, sleep deprivation, or electrolyte imbalance.
A myriad of other problems may occur after a TBI including:
- Deep vein thrombosis
- Gastrointestinal and genitourinary problems
- Organ failure