Context: Dizziness, postural instability, and poor sleep quality are all commonly reported post-concussion and individually relate to poor outcomes.
Objective: To examine sleep quality and postural stability among adolescents who did and did not report dizziness within two weeks of concussion.
Design: Cross-sectional study.
Setting: Research laboratory.
Patients or other participants: Participants ages 12–18 years within 14 days of concussion (n=58, 15.2±1.8 years; 50% female; 7.1±3.1 days post-injury) and uninjured controls (n=73; 15.8±1.3 years; 42% female).
Main outcome measures: Participants completed pre-injury and current dizziness ratings on the Post-Concussion Symptom Inventory (PCSI) and current sleep quality on the Pittsburgh Sleep Quality Index (PSQI). Participants also completed postural stability assessments (single/dual-task tandem gait and modified Balance Error Scoring System [mBESS]).
Results: We grouped concussion patients into dizzy (n=21) or not dizzy (n=37) groups based on PCSI dizziness ratings: difference between current and pre-injury dizziness rating >3=dizzy; difference <3=not dizzy. The dizzy and not dizzy groups both reported significantly worse sleep quality than the control group (PSQI score: mean=9.6±3.7 vs 7.2±3.5 vs 4.3±2.6; p<0.001) upon univariable comparison. Similarly, the dizzy group performed slowest on single and dual-task tandem gait, followed by the not dizzy group, then the control group (single-task TG: mean= 27.2±11.7 sec vs 21.2±6.3 vs 14.7±3.6; p<0.001); (dual-task TG: mean=38.4±16.2 sec vs 29.9±7.2 vs 21.6±7.5; p<0.001). Both concussion groups demonstrated significantly more errors than the control group on the mBESS (mean=9.8±5.1 vs 6.9±5.8 vs 3.8±3.5; p<0.001). After controlling for total symptom severity in the multivariable model, tandem gait, but not mBESS or sleep quality, was associated with dizziness.
Conclusion: Individuals with post-concussion dizziness also demonstrated impaired tandem gait performance, while poor sleep quality was associated with total symptom severity. Identifying and treating the underlying dysfunction contributing to dizziness and postural instability may guide individualized rehabilitation strategies and facilitate recovery.