The Relationship between Cerebral Vasoreactivity and Post-Concussive Symptom Severity.

Area of Science:

• Neurology
• Vascular Physiology

Background:

• The underlying pathophysiology of post-concussion symptom burden remains unclear.
• Cerebrovascular dysfunction is a potential contributing factor to persistent concussion symptoms.

Purpose of the Study:

• To investigate the association between cerebrovascular vasoreactivity and concussion symptom severity.
• To determine if impaired ability of cerebral vasculature to buffer arterial gas changes relates to post-concussion symptoms.

Main Methods:

• Assessed vasoreactivity using middle cerebral artery blood flow velocity (transcranial Doppler ultrasound) and end-tidal CO2 during air rebreathing in 15 concussion participants.
• Quantified symptom burden using the Post-Concussion Symptom Scale.
• Employed linear models to explore relationships between vasoreactivity, headache severity, and cognitive difficulties.

Main Results:

• A strong linear relationship was observed between increases in CO2 and cerebrovascular conductance (R² = 0.81, p < 0.05).
• Average cerebral vasoreactivity was 0.018 ± 0.003 cm⁻¹s⁻¹mmHgCO2⁻¹.
• Higher vasoreactivity showed a strong association with more severe headaches (R² = 0.57, p < 0.01) and worse cognitive symptoms (R² = 0.71, p < 0.01).

Conclusions:

• Cerebral vasoreactivity is significantly related to the severity of post-concussive headaches and cognitive symptoms.
• Findings suggest that cerebrovascular dysfunction plays a role in the pathophysiology of post-concussion symptom burden.
• This association has implications for developing targeted treatment strategies for concussion recovery.