Post-Concussion Syndrome (PCS) can affect as many as 2 in every 5 people who don’t make a full recovery within 3 months of their injury. Common symptoms include headache, fatigue, difficulty concentrating, and depression. Little is known about the causes of PCS and there are no evidence-based treatments. To help close this knowledge gap, a new study surveyed 285 patients of a Canadian hospital.

The study, conducted by Carmen Hiploylee and colleagues from the Division of Neurosurgery, Neurology, University of Toronto and Toronto Western Hospital, Toronto, Canada, recruited 285 patients diagnosed with PCS based on the 4th International Conference on Concussion in Sport 2012 Zurich Consensus Statement, which defines concussion to include at least one symptom (e.g., headache, irritability, difficulty concentrating) for more than 3 months in combination with a negative brain computed tomography (CT) or magnetic resonance imaging (MRI) scan.

The participants completed a questionnaire to assess: (1) persisting symptoms; (2) time to recovery; (3) duration of PCS treatments tried and their effectiveness; (3) other conditions accompanying PCS, such as migraines, Attention Deficit Disorder (ADD), Attention Hyperactivity Deficit Disorder (ADHD), learning disability, or depression; (4) whether participants complied with a do-not-return-to-play recommendation from C.H.T. (a neurosurgeon with a special interest in concussion and PCS); (5) impact of the concussion on their life; and (6) limitations on previous or current type or, amount of schooling or work participants could do.

Results
(1) Persisting symptoms: For people with concussion who did not fully recover, common symptoms reported were headaches (68.8%), difficulty concentrating (67.5%), and fatigue (52.5%), while the three least common in this group were vomiting (1.3%), seizures (2.5%), and slurred speech (3.8%).

(2) Time to recovery: Hiploylee and colleagues found that only 27% of the study population eventually recovered, and 67% of those who recovered did so within the first year. The more symptoms reported, the longer the time to recovery, with each additional symptom reducing the recovery rate by approximately 20%.

Importantly, no study participant recovered from PCS lasting 3 years or longer.

(3) Duration of PCS treatments tried and their effectiveness: There was no significant difference between the people with concussion who recovered and those who did not for chiropractic manipulation, occupational therapy, physiotherapy, and psychotherapy. The people who recovered showed a trend toward finding balance exercises effective, whereas those people who did not fully recover showed a trend toward finding medication effective.

(4) Other conditions accompanying PCS: The presence of anxiety, ADD/ADHD, migraines, a learning disability, and thoughts/attempts of suicide before and after the concussion were not significantly different between people with concussion who recovered and those who did not.

(5) Compliance with a do-not-return-to-play recommendation from C.H.T.: Those who did not recover (n=80) were more likely to be non-compliant with a do-not-return-to-play recommendation, but these people did not differ from people who did recover from concussion (n=30) in terms of age and sex.

(6) Impact of the concussion on their life: People with concussion felt that concussion had impacted on their lives “a little”’ or “a moderate amount,” whereas those who did not fully recover felt the impact was “‘an extreme amount.”

(7) Limitations on previous or current type or amount of schooling or work tolerated: People with concussion who did recover did not feel limited in school/work, whereas people who did not fully recover felt limited.

Conclusions
This study shows that PCS could be permanent if full recovery has not occurred by 3 years. Each additional PCS symptom that appears slows full recovery. More long-term follow-up studies are needed to investigate recovery from PCS in the long-term.