Background: Although elevated concentrations of both corticotropin-releasing hormone (CRH) and norepinephrine are present in the cerebrospinal fluid (CSF) of patients with post-traumatic stress disorder (PTSD), the effects of exposure to traumatic stimuli on these stress-related hormones in CSF are unknown.
Methods: A randomized, within-subject, controlled, cross-over design was used, in which patients with war-related PTSD underwent 6-h continuous lumbar CSF withdrawal on two occasions per patient (6-9 weeks apart). During one session the patients watched a 1-h film containing combat footage (traumatic film) and in the other a 1-h film on how to oil paint (neutral film). At 10-min intervals, we quantified CRH and norepinephrine in CSF, and ACTH and cortisol in plasma, before, during, and after symptom provocation. Subjective anxiety and mood were monitored using 100-mm visual analog scales. Blood pressure and heart rate were obtained every 10min from a left leg monitor.
Results: Eight of 10 patients completed two CSF withdrawal procedures each. A major drop in mood and increases in anxiety and blood pressure occurred during the traumatic relative to the neutral videotape. CSF norepinephrine rose during the traumatic film relative to the neutral videotape; this rise directly correlated with magnitude of mood drop. In contrast, CSF CRH concentrations declined during the trauma-related audiovisual stimulus, both absolutely and relative to the neutral stimulus; the magnitude of CRH decline correlated with degree of subjective worsening of anxiety level and mood. Plasma cortisol concentrations were lower and ACTH levels similar during the stress compared with the neutral videotape.
Conclusions: CSF concentrations of the stress hormones norepinephrine and CRH differentially change after exposure to 1h of trauma-related audiovisual stimulation in chronic, combat-related PTSD. While the CSF norepinephrine increase was postulated, the decline in CSF CRH levels is surprising and could be due to audiovisual stress-induced increased uptake of CSF CRH into brain tissue, increased CRH utilization, increased CRH degradation, or to an acute stress-related inhibition or suppression of CRH secretion.