An event-related brain potential investigation of PTSD and PTSD symptoms in abused children

Abstract

We tested 186 children ranging in age from 6 years, 10 months to 13 years, 7 months; 174 suffered either physical and/or sexual abuse, and 12 were nonabused children. Abused subjects were grouped in four different ways. The primary grouping was based on whether subjects satisfied the DSM III-R criteria for posttraumatic stress disorder (PTSD). Secondary groupings were based upon the three symptom clusters used to make the PTSD diagnosis (arousal, avoidance, and reexperiencing). In each of these groupings three separate subgroups were formed with approximately 25 percent in the high and low symptom count subgroups and the remaining 50 percent in the middle symptom count subgroup. Subjects listened to four different intensity levels (65, 80, 95, and 102 dB) of a 1 KHz tone, pseudo-randomly ordered, while event-related brain potentials (ERPs) were recorded. Two separate blocks were used, one with short intervals (4 +/- 1 sec) between tones and the other with longer intervals (17 +/- 2 sec). PTSD subjects presented a greater P2-N2 ERP intensity gradient (i.e., a larger increase in the P2-N2 ERP component as tone intensity increased) than did abused subjects without PTSD. Abused subjects with the highest number of reexperiencing symptoms showed a similar P2-N2 augmenting effect when compared to those with the lowest number of reexperiencing symptoms. Subjects with the highest number of arousal symptoms showed a shallower intensity gradient for the N1-P2 ERP component than did those with fewer arousal symptoms. The results are discussed in relation to previous results reported on adults with PTSD and in terms of CNS processing of stimulus intensity information.

Intensity dependence of auditory P2 in monozygotic twins discordant for Vietnam combat: Associations with posttraumatic stress disorder

“…Rather, male veterans with PTSD had significantly steeper P2 amplitude intensity slopes, much like those reported in our previous study of female Vietnam nurse veterans [11] and in the study of abused children with PTSD [10]. These findings suggest that the observed heightened intensity dependence in PTSD is not sex, age, or trauma specific.…”

“…Contrary to findings of decreased P2 amplitude intensity slopes reported in previous studies of male combat veterans with PTSD [1,9], we found increased P2 amplitude intensity slopes, similar to those reported for female veterans [11] and abused children [10] with PTSD. Additionally, mixed-model, random-effects analysis including the combat-unexposed twins revealed a significant diagnosis × combat exposure interaction.…”

“…In a study of sexually and/or physically abused children, McPherson and colleagues found that children with PTSD (77% female) had significantly steeper P2-N2 intensity dependence slopes than abused children without PTSD (50% female) [10]. Metzger and colleagues also found increased P2 intensity dependence slopes in a study of female Vietnam nurse veterans with PTSD versus those without [11].…”

“…Although Metzger et al [11] employed a paradigm that closely paralleled the original study of Vietnam veterans [1], the paradigm and slope measurement used by McPherson and colleagues [10] differed considerably from those used in the studies of male combat veterans [1,9]. For example, the study by McPherson and colleagues used longer interstimulus intervals and employed a monetary incentive button-press task, whereas the remaining studies used a passive listening paradigm [10]. The McPherson et al study also calculated slope from the change in the peak-to-peak amplitude between the P2 and N2 component across tone intensities [10].…”

“…For example, the study by McPherson and colleagues used longer interstimulus intervals and employed a monetary incentive button-press task, whereas the remaining studies used a passive listening paradigm [10]. The McPherson et al study also calculated slope from the change in the peak-to-peak amplitude between the P2 and N2 component across tone intensities [10].…”