The Short Answer Educational content only. Any suspected concussion warrants medical evaluation. Red flag symptoms warrant emergency evaluation. Consult treating providers including concussion specialists for individualized guidance. Your CT scan looks normal with PCS because CT identifies structural brain injuries, not the microscopic changes that drive PCS symptoms (Silverberg et al., 2020). CT scan identifies intracranial bleeding (subdural hematoma, epidural hematoma, subarachnoid hemorrhage), skull fractures, brain swelling, large tissue damage, and other emergencies requiring intervention. CT does not show microscopic axonal injury, diffuse axonal injury, neuroinflammatory changes, mitochondrial dysfunction, metabolic dysfunction, neurotransmitter imbalance, autonomic dysregulation, cerebral blood flow disruption, or other physiological changes driving PCS symptoms. Most concussion patients have normal CT scans; CT primarily rules out emergencies rather than diagnosing concussion. Concussion diagnosis based on symptoms and clinical evaluation including neurological examination, vestibular assessment, vision assessment, cervical spine evaluation, and cognitive evaluation. Normal CT does not rule out concussion or PCS. Advanced imaging including MRI, DTI, fMRI, and SPECT may show abnormalities in PCS but are not required for diagnosis. Specialized concussion centers may use advanced imaging for select patients. CT shows structural injuries, not concussion. CT shows structural injuries. Most concussion patients have normal CT. Most CTs normal. Concussion diagnosis based on symptoms, not imaging. Diagnosis based on symptoms. What CT Scan Shows Intracranial bleeding. Intracranial bleeding. Subdural hematoma. Subdural hematoma. Epidural hematoma. Epidural hematoma. Subarachnoid hemorrhage. Subarachnoid hemorrhage. Intracerebral hemorrhage. Intracerebral hemorrhage. Skull fractures. Skull fractures. Brain swelling. Brain swelling. Large tissue damage. Large tissue damage. Cerebral contusion. Cerebral contusion. Penetrating injury. Penetrating injury. Hydrocephalus. Hydrocephalus. Ventricular changes. Ventricular changes. Midline shift. Midline shift. Mass effect. Mass effect. What CT Scan Does Not Show Microscopic axonal injury. Microscopic axonal injury. Diffuse axonal injury. Diffuse axonal injury. Neuroinflammatory changes. Neuroinflammatory changes. Mitochondrial dysfunction. Mitochondrial dysfunction. Metabolic dysfunction. Metabolic dysfunction. Neurotransmitter imbalance. Neurotransmitter imbalance. Autonomic dysregulation. Autonomic dysregulation. Cerebral blood flow disruption. Cerebral blood flow disruption. White matter changes. White matter changes. Functional abnormalities. Functional abnormalities. Connectivity changes. Connectivity changes. Microbleeds. Microbleeds. Why CT Is Used Initially Rules out emergencies. Rules out emergencies. Fast acquisition. Fast acquisition. Widely available in ER. Widely available in ER. Identifies surgical emergencies. Identifies surgical emergencies. Lower cost than MRI. Lower cost than MRI. Useful for skull fractures. Useful for skull fractures. Useful for acute bleeding. Useful for acute bleeding. Standard of care for acute head injury. Standard for acute head injury. Identifies need for neurosurgery. Identifies need for neurosurgery. Concussion Diagnosis Without Imaging Diagnosis based on symptoms. Diagnosis based on symptoms. Clinical evaluation. Clinical evaluation. Neurological examination. Neurological examination. Vestibular assessment. Vestibular assessment. Vision assessment. Vision assessment. Cervical spine evaluation. Cervical spine evaluation. Cognitive evaluation. Cognitive evaluation. SCAT5 sideline assessment. SCAT5 sideline assessment. Concussion specialist evaluation. Concussion specialist evaluation. Symptom tracking supports diagnosis. Symptom tracking supports. Advanced Imaging in PCS MRI may show abnormalities. MRI may show abnormalities. Diffusion tensor imaging (DTI). DTI for white matter. Functional MRI (fMRI). fMRI for functional changes. SPECT imaging. SPECT for cerebral blood flow. PET imaging. PET for metabolic function. Magnetic resonance spectroscopy (MRS). MRS for metabolic function. Susceptibility weighted imaging (SWI). SWI for microbleeds. Available at specialized centers. Available at specialized centers. Not required for diagnosis. Not required for diagnosis. May support diagnosis in select cases. May support diagnosis. Normal CT Does Not Rule Out Concussion Most concussion patients have normal CT. Most CTs normal. Normal CT does not rule out concussion. Normal CT does not rule out concussion. Normal CT does not rule out PCS. Normal CT does not rule out PCS. Concussion symptoms diagnose concussion. Symptoms diagnose concussion. CT primarily rules out emergencies. CT rules out emergencies. CT does not assess concussion symptoms. CT does not assess symptoms. Specialist evaluation diagnoses concussion. Specialist evaluation diagnoses. Functional impact diagnoses concussion. Functional impact diagnoses. What CT Can Show in PCS Patients Usually normal in PCS. Usually normal. Occasionally shows microbleeds. Occasionally shows microbleeds. Occasionally shows white matter changes. Occasionally shows white matter changes. Rare ventricular changes. Rare ventricular changes. Generally not diagnostic of PCS. Generally not diagnostic of PCS. Normal CT despite severe PCS symptoms common. Normal CT despite severe symptoms common. CT findings do not correlate with symptom severity. CT findings don't correlate. Other imaging more sensitive for PCS. Other imaging more sensitive. When MRI Adds Diagnostic Value Persistent severe symptoms. Persistent severe symptoms. Atypical presentation. Atypical presentation. Persistent focal neurological deficits. Persistent focal deficits. Late deterioration. Late deterioration. Suspected diffuse axonal injury. Suspected diffuse axonal injury. Disability documentation. Disability documentation. Legal documentation. Legal documentation. Research participation. Research participation. Specialist evaluation recommendation. Specialist evaluation recommendation. Imaging Validity for PCS Recognition PCS is real condition regardless of imaging. PCS is real regardless of imaging. Microscopic injury not visible on standard imaging. Microscopic injury not visible. Symptoms drive diagnosis. Symptoms drive diagnosis. Specialist clinical evaluation drives diagnosis. Specialist clinical evaluation drives. Neuropsychological testing supports diagnosis. Neuropsychological testing supports. Functional impact documents diagnosis. Functional impact documents. Normal imaging does not invalidate symptoms. Normal imaging does not invalidate. Multiple specialists agree on diagnosis. Multiple specialists agree. Communicating With Disbelievers Education about CT limitations. Education about CT limitations. Most concussions normal on CT. Most concussions normal on CT. Specialist diagnosis supports validity. Specialist diagnosis supports. Neuropsychological testing objective. Neuropsychological testing objective. Multiple specialist agreement strongest. Multiple specialist agreement strongest. Symptom log documents pattern. Symptom log documents pattern. Functional impact documentation. Functional impact documentation. Advanced imaging may show abnormalities. Advanced imaging. Educational materials from CDC and Brainline. Educational materials. Supporting Mobility Routine These exercises support recovery through nervous system regulation. JME 155 Diaphragmatic breathing supports vagal tone and parasympathetic regulation during early concussion recovery. 10 breaths every 60-90 minutes. JME 14 Chin tucks reduce upper cervical tension common in concussion injury. 10 repetitions with 5-second holds. JME 1 Cervical rotation supports cerebral blood flow and nervous system regulation. 10 repetitions each direction. JME 150 Thoracic rotation restores breathing depth shallow during concussion recovery. 8 repetitions per direction. Start your 3-day free trial for joint-specific mobility programs that support nervous system regulation through concussion recovery. Common Mistakes About CT and Concussion Assuming normal CT rules out concussion. Normal CT does not rule out. Assuming CT diagnoses concussion. CT does not diagnose concussion. Requesting CT for concussion diagnosis. CT not needed for concussion diagnosis. Repeated CT for monitoring. Repeated CT not needed for monitoring. Not following up with concussion specialist. Specialist follow-up important. Does normal CT mean I do not have a concussion? No. Normal CT does not rule out concussion. Most concussion patients have normal CT. CT identifies structural injuries including bleeding, fractures, and large tissue damage but does not show microscopic axonal injury, neuroinflammatory changes, or other physiological changes driving concussion symptoms. Concussion diagnosis based on symptoms and clinical evaluation. Why did they do a CT if it cannot show concussion? CT primarily rules out emergencies including intracranial bleeding, skull fractures, and brain swelling requiring immediate intervention. CT does not diagnose concussion but identifies emergencies. CT is standard of care for acute head injury to rule out emergencies. Fast acquisition, wide availability, and lower cost make CT useful for emergency evaluation. Should I get an MRI if my CT is normal? Most concussion patients do not need MRI. MRI considered for persistent severe symptoms, atypical presentation, persistent focal neurological deficits, late deterioration, suspected diffuse axonal injury, disability documentation, or legal documentation. Specialist evaluation recommends MRI when appropriate. MRI not required for concussion diagnosis. How is concussion diagnosed if not by CT? Concussion diagnosed by symptoms and clinical evaluation including neurological examination, vestibular assessment, vision assessment, cervical spine evaluation, cognitive evaluation, SCAT5 sideline assessment, and concussion specialist evaluation. Neuropsychological testing supports diagnosis. Symptom tracking documents pattern. Functional impact documents diagnosis. What imaging best shows concussion? No standard imaging routinely shows concussion. Advanced imaging at specialized centers may show abnormalities including diffusion tensor imaging (DTI), functional MRI (fMRI), SPECT, PET, magnetic resonance spectroscopy (MRS), and susceptibility weighted imaging (SWI). Advanced imaging not required for diagnosis. Most diagnosed through clinical evaluation. References Patricios, J. S., et al. (2023). Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport, Amsterdam, October 2022. British Journal of Sports Medicine, 57(11), 695-711. PubMed Silverberg, N. D., et al. (2020). Management of concussion and mild traumatic brain injury: a synthesis of practice guidelines. Archives of Physical Medicine and Rehabilitation, 101(2), 382-393. PubMed