Concussion

Concussion

Concussion: Acute pathophysiology and findings
Authors: Calvin Howard Cormac Southam Yvette Ysabel Yao Reviewers: Emily Ryznar Mao Ding, Gary Klein* * MD at time of publication
Activation of inhibitory
cholinergic system of dorsal pontine tegmentum (structure with role in sleep- wake regulation)
Disruption of reticular activating system (brain area that regulates arousal)
Altered level of consciousness
Direct blow to the head or the body that causes an impulsive force to the head (i.e., falls, motor vehicle accidents, sports, assaults)
Skull acceleration / deceleration
Coup (brain strikes skull on side of impact)
Brain tissue swelling
Cerebral edema (fluid build up around brain)
↑ Intracranial pressure
Cerebral herniation
(shifting of brain tissue into adjacent space)
Contrecoup (brain strikes skull on opposite side of impact)
Anatomical damage
Skull fracture
Broken bone fragments ruptures blood vessels
Intracranial hemorrhage
(bleeding into brain tissue)
Papilledema (swelling around optic disk, where optic nerve enters eyeball)
Disruption of messages from eye to brain
Vision problems (i.e., blurred or double vision)
Cellular damage
Indiscriminate, rapid neurotransmitter release
↑Extracellular K+ and glutamate, accumulation of intracellular calcium
Ionic disequilibrium across neuronal membrane
Energy consumed by Na+/K+ ATPase pumps to re-establish ionic homeostasis
↑ Cerebral glucose metabolism
↑ Energy demand
Brain injury
Axonal stretch due to
biomechanical forces
Microtubule disruption
Structural (cytoskeletal) disturbance
Axonal degeneration
Impaired neural communication
Broken bone fragments
Ruptures blood vessels
Compresses blood vessels
↓ Cerebral blood flow
↓ Cerebral glucose supply
↓ Energy supply
↓ Oxygenated blood to brain
Brain cell death
Chronic brain atrophy
Persistent impaired cognition
Cellular energy crisis (mismatch between energy supply and demand due to effort in restoring homeostasis)
Nausea, vomiting
↓ Participation in daily Confusion, disorientation, unsteadiness, headache activities and work
Death Anxiety, depression
Legend:
Pathophysiology
Mechanism
Sign/Symptom/Lab Finding
Complications
Published February 12, 2019, updated March 27, 2023 on www.thecalgaryguide.com