Concussion

Neurology

Description

A concussion is a transient disturbance of brain function caused by biomechanical forces that induce rapid acceleration–deceleration or rotational shear of cerebral tissue without macroscopic structural injury on conventional neuroimaging. It belongs to the spectrum of mild traumatic brain injury (mTBI) and is characterised clinically by an acute change in mental status, memory, or behaviour, frequently accompanied by somatic, cognitive, and emotional symptoms that evolve over minutes to hours and generally resolve within seven to fourteen days in adults and up to four weeks in children.

Symptoms

Common acute manifestations include headache, dizziness, nausea, vomiting, blurred or double vision, photophobia, phonophobia, balance disturbance, confusion, slowed processing, anterograde or retrograde amnesia, emotional lability, irritability, and sleep disruption. Loss of consciousness occurs in fewer than ten percent of cases and is not required for diagnosis. Symptoms typically peak within twenty-four hours, fluctuate over subsequent days, and gradually diminish; persistent post-concussion symptoms beyond one month are termed prolonged or post-concussion syndrome.

Risk Factors

Previous concussion, high-risk activities such as contact sport, military blast exposure, occupational falls, alcohol or substance intoxication, attention-deficit/hyperactivity disorder, migraine history, female sex, lower neck strength, improper sports technique, and inadequate protective equipment increase susceptibility or prolong recovery. Genetic polymorphisms in apolipoprotein E ε4 or ANKK1-DRD2 dopamine receptor pathways may further modulate cognitive outcome.

Diagnosis

Diagnosis is clinical, integrating mechanism of injury with acute and evolving symptoms. The standardized SCAT6 or Child SCAT6 tools evaluate cognition, neurologic function, and symptom severity on the sideline. Immediate red-flag signs—deteriorating consciousness, focal neurologic deficit, repeated emesis, seizure, suspected skull fracture—necessitate CT to identify intracranial haemorrhage. Routine imaging is otherwise normal and not indicated for isolated concussion. Neuropsychological testing establishes cognitive baseline and tracks recovery. Serum biomarkers GFAP and UCH-L1 aid triage in emergency departments but lack specificity for concussion.

Treatment

Management begins with physical and cognitive rest for twenty-four to forty-eight hours followed by graded return-to-activity under symptom monitoring. Early introduction of sub-symptom threshold aerobic exercise (stationary cycling 20 minutes/day at 70–80 % maximum heart rate) accelerates recovery. Headache responds to acetaminophen or limited NSAIDs, while amitriptyline or topiramate treat migrainous features. Sleep hygiene, melatonin, and brief cognitive-behavioural therapy address insomnia and anxiety. Vestibular or vision therapy corrects balance and oculomotor deficits. Athletes follow a six-step return-to-sport progression, advancing 24 hours per stage if asymptomatic. Strict abstention from contact risk is maintained until full symptom resolution and normal neurocognitive performance.

Outlook

Eighty-five percent of adults recover fully within two weeks and children within four weeks; predictors of prolonged recovery include prior concussion within one year, female sex, migraine, learning disorders, depression, and high initial symptom burden. Proper graduated exertion, early vestibulo-ocular therapy, and avoidance of premature return to play reduce persistent symptoms. Second-impact syndrome—rapid catastrophic cerebral oedema after repeat concussion—is rare but fatal and highlights the necessity of complete recovery before re-exposure.

Complications

Post-concussion syndrome, post-traumatic migraine, persistent vestibular dysfunction, anxiety or depression, sleep disorders, second-impact syndrome, cumulative cognitive impairment with repetitive injuries, and rare chronic traumatic encephalopathy constitute recognised sequelae of inadequately managed concussion.

Prevention

Properly fitted helmets in cycling and contact sports, mouthguards, enforcement of concussion protocols, rule changes to limit head-first impacts, neck-strengthening programmes, seat-belt use, fall-prevention measures in elderly, and avoidance of intoxicated driving reduce incidence. Player and coach education on recognising and reporting concussion ensures timely removal and recovery.

Support

Patients should maintain a regular sleep schedule, stay hydrated, avoid alcohol, screen time, and loud environments early in recovery, perform daily light aerobic exercise as tolerated, and keep a symptom diary. School or workplace accommodations—reduced workload, frequent breaks, no exams for forty-eight hours—facilitate cognitive rest. Family or teammates must monitor for symptom escalation and prevent risk of repeat injury.