Symptoms of autonomic dysfunction amongst those with acute post-traumatic headache due to mild traumatic brain injury

Autonomic dysfunction symptoms have previously been described amongst those with persistent post-traumatic headache (PTH) attributed to mild traumatic brain injury (mTBI). This novel study investigated symptoms of autonomic dysfunction amongst those with acute (< 3 months) PTH (APTH) due to mTBI and the association of these symptoms with the likelihood for PTH improvement.

It was hypothesized that participants with APTH would exhibit significantly higher symptoms of autonomic dysfunction compared to healthy controls (HC), and that, individuals with APTH whose headaches improve with time would have less severe symptoms of autonomic dysfunction at baseline compared to those who did not have PTH improvement.

Adults aged 18 to 70 years with APTH attributed to mTBI according to International Classification of Headache Disorders (ICHD-3) diagnostic criteria, with PTH onset between 7 and 56 days prior to enrollment, were enrolled. Participants maintained a daily headache diary and attended a baseline research visit, and 4-week and 16-week follow-up research visits. Presence and impact of autonomic symptoms were measured at each research visit using the Survey of Autonomic Symptoms (SAS). PTH improvement vs. non-improvement was determined using headache diary data.

Compared to HC (n = 36), individuals with APTH (n = 56) reported significantly greater symptoms of autonomic dysfunction (SAS symptom scores) and negative impact from such symptoms (total impact scores). At the baseline research visit, mean [SD] SAS symptom score among those with APTH was 2.9 [2.0] vs. 0.9 [0.8] (p < 0.001) in HC. At baseline, the impact of autonomic symptoms measured using the SAS total impact score was 8.3 [6.2] among those with APTH vs. 2.1 [1.9] (p < 0.001) among HC. The most common and severe symptoms in the APTH group were lightheadedness, dry mouth or eyes, nausea, and cold feet. Participants who went on to have PTH improvement had numerically lower baseline autonomic symptom scores (p = 0.068) and significantly lower total impact scores (p = 0.024) than those who did not have PTH improvement.

Participants with APTH due to mTBI have significantly more symptoms of autonomic dysfunction than HC. Higher baseline severity of autonomic symptoms corresponds to a lower likelihood of PTH improvement over time.