Serotonergic correlation with anger and aggressive behavior in acute stroke patients: an intensity dependence of auditory evoked potentials (IDAP) study

Anger and aggressive behavior (AB) are two of the main post-stroke behavioral manifestations, which could imply both an anger trait (TA) or a state condition of anger (SA). Serotonergic system is thought to play an inhibitory control on aggressive impulse. Nevertheless, whether 5HT has the same role in TA and in SA, is still debated. Intensity dependence of auditory evoked potentials (IDAP) is thought to be inversely related to the central 5HT tone. The aim of this study was to evaluate, in acute stroke patients, the 5HT system involvement in AB by IDAP. Consecutive stroke patients were evaluated and compared with healthy controls. The Spielberger Trait Anger Scale (STAS) was used to assess AB, SA and TA. Patients with AB and TA showed a significantly increased IDAP value, whereas patients with SA had a significantly lower IDAP; this indicates an increased 5HT tone. In acute stroke patients with AB, there is a decreased central 5HT tone. Surprisingly, we found an opposite 5HT feature between patients with TA and those showing SA, suggesting that the hypothesis of aggression based on 5HT deficiency requires further investigations. This might open new strategies in the treatment of post-stroke AB.