Mild head injury complication

Post-concussion symptoms may result from brain injury or from trauma involving head and neck structures. These include headache (commonest), dizziness (including vertigo and nonspecific dizziness), neuropsychiatric symptoms, and cognitive impairment. These typically develop in the first days after mild traumatic brain injury (TBI) and generally resolve within a few weeks to a few months. Post-traumatic vertigo may be due to direct injury to cochlear/vestibular structures, labyrinthine concussion, BPPV, perilymphatic fistulae, vertebral artery dissection amongst others.

Diffuse cerebral swelling occurs after a second concussion, while an athlete is still symptomatic from an earlier concussion. Some have suggested a similarity with this phenomenon and the shaken baby syndrome. The cause is hypothesized to be disordered cerebral autoregulation causing cerebrovascular congestion and malignant cerebral edema with increased intracranial pressure. The second impact syndrome is a rare and somewhat controversial complication. It is unclear why this is not a more frequently reported occurrence in boxers who seem at very high risk for repeated concussions within a short time span.

Defined as a slowly progressive disease (tauopathy) that takes years to decades to develop, often providing a significant latent period between when the neurotrauma occurs and when symptoms develop. It was first described in Boxers, and is thought to be due to repetitive head injury. Clinical features include behavioral disturbances such as impulsivity, depression, and lack of oversight, followed later by cognitive impairment. Pathological criteria include neurofibrillary tangles (NFTs) in a perivascular distribution and within superficial cortical areas with occasional amyloid and TDP-43 protein aggregations. Neurotrauma may have many lasting deleterious consequences, including the potential for increased risk and accelerated development of Alzheimer’s disease and motor neuron disease.

Mild TBI is associated with a twofold increase in the risk of epilepsy for the first 5 years after injury. Seizures occurring within the first week of injury are acute symptomatic events and are not considered epilepsy. Half of the seizures consistent with post-traumatic epilepsy will occur in the first year; 80% will occur within 2 years. Prophylactic treatment with anticonvulsants does not prevent post-traumatic epilepsy and is not recommended.