Detection of the hippocampal formation asymmetry in patients with posttraumatic stress disorder

Th e goal of this work was to analyze asymmetry of hippocampal formation in PTSD patients. Th e objects of the analysis were  MRI scans of patients with PTSD with established cognitive function damage. MRI scans were obtained using MAGNET IMPACT SIEMENS , TESLA in T and T relaxation. Th e measurement of hippocampal formation dimensions, and comparisons between the right and the left side were done using evaluate distance program on the MRI instrument of the Institute of Radiology at Sarajevo Clinics Center. We tested  patients with PTSD , years of average age with standard deviation of , years. Based on the analysis of our results regarding the size of hippocampal formation in all the three projections (axial, coronal and sagital ), in the group of patients with PTSD, we can the make the following observations: . In axial slice the length of hippocampal formation measured on the left and right side is signifi cantly asymmetric in all patients . In the sagital slice, the hippocampal formation measured on the left side is in many cases longer than in the right –  . In coronal slice no signifi cant diff erences were found in the proportion of patients according to symmetry/asymmetry of hippocampal formation width on the left and right. . Th e diff erence in average size of hippocampal formation between the left and right side measured in axial and coronal slices is not statistically signifi cant, but it is signifi cant in sagitall slice. So, the results of this new research, showed smaller hippocampal dimensions in PTSD as measured using MRI. We have to be careful about what projection we are refusing to as being watched hippocampal formation because the results will depend on that. We suggest that future studies be done in more projections because of the importance of statistically signifi cant conclusions. MRI – volumetric measurements have their value.


Introduction
Hypersensibility, avoiding / emotional weakening and repeatedly occurring situations with hard remembrance of trauma are defined signs of PTSD.Many PTSD symptoms are results of limbic structure hyperactivity, which can contribute to dysfunction of this system through their many projections into prefrontal cortex, and thus cause the loss of performance in frontal functions.Th is hyperactivity might be a physiological correlate of fear recognition structure, which is readily activated and may be an initiator of emotional abnormality, such as sudden incidents of hypersensibility and sense of horror.Th e goal of this work was to analyze asymmetry of hippocampal formation in PTSD patients.

Material and Methods
The analyzed material included  MRI scans of patients with PTSD with ascertained cognitive function damage.MRI scans were obtained using MAGNET IMPACT SIEMENS , TESLA in T and T relaxation.Th e measurement of hippocampal formation, and comparison between the right and the left side were done using software for distance evaluation on the MRI from the Institute of Radiology of Clinics Center in Sarajevo.We tested  patients with PTSD, , years of average age with standard deviation of , years.We performed the following calculations: .The number of patients with PTSD according to symmetry/asymmetry of hippocampal formation between the right and the left side .Analysis of patients with PTSD by the average size of hippocampal formation on left and right side Signifi cance of diff erences is tested using t -test

Results
Th e lengths of hippocampal formation on the left and right side in axial slice are signifi cantly asymmetric in all patients.Value of Chi -square test is: ChiSq = , level of confi dence is p < ,.Th e diff erence in length of hippocampal formation on the left and right side in sagitall slice is not statistically significant at the level of confi dence p < ,.Value of ChiSq = ,.( Sign. for level p <, ).In coronal slice there are no signifi cant diff erences in patient proportion regarding symm/asymm of hippocampal formation width on the right and left side.Based on the analysis of our results related to the size of hippocampal formation in all the three projection ( axial, coronal and sagital ), in a group of patients with PTSD (Table  and  ), we can make the following observations: .In axial slice the length of hippocampal formation measured on left and right side is significantly asymmetric in all patients.In the sagital slice the hippocampal formation measured on the left side is in many cases longer, than in the right - .
On coronal slice no significant differences were found in the proportion of patients according to symmetry/asymmetry of hippocampal formation width on the left and right..The difference in average size of hippocampal formation between the left and right side measured in axial and coronal slices is not statistically significant, but it is significant in sagital slice.So, the results of this new research, showed smaller hippocampal dimensions in PTSD as measured using MRI.We have to be careful about what projection we are refusing to as being watched hippocampal formation because the results will depend on that.We suggest that future studies be done in more projections because of the importance of statistically significant conclusions.MRI -volumetric measurements have their value.

Conclusion
. Asymmetry of hippocampal formation in PTSD is evident .Th e results of new research, showed smaller hippocampal dimensions in PTSD as measured using MRI..Th e projection of hippocampal formation analysis needs to be carefully decided on as it will infl uence the results and conclusions..We suggest that future studies be done in more projections because of the importance of statistically signifi cant conclusions AIDA SARAČHADŽIHALILOVIĆ, FARUK DILBEROVIĆ: DETECTION OF THE HIPPOCAMPAL FORMATION ASYMMETRY IN PATIENTS WITH POSTTRAUMATIC STRESS DISORDER Th e diff erences in average size of hippocampal formation between the right and the left side are not statistically signifi cant for axial and coronal slices, but it is significant for sagital slice.The values of t-test are: a) axial slice: t = , not signifi cant b) coronal slice: t = , not signifi cant c) sagitall slice: t = , signifi cant p < ,DiscussionPeterson et al.()clearly proved that MRI -hippocampal formation exactly displays structural and functional relations between memory defi cit and hippocampal damage in broad spectrum of normal aging all the way to demency.Koenen et al. ()evaluated cognitive evidence that exposure to chronic stress may damage hippocampal formation, region well known for its role in declarative memory.Th is study pointed out neurotoxic role of corticosteroids, where their high levels may cause atrophy and / or disappearance of hippocampal cells.

TABLE 1 .
Patients with PTSD according to simmetry/asimmetry of hippocampal formation between the right and the left side in the axial, coronal and sagital slice

TABLE 2 .
Average size of the hippocampal formation on the right and left side in axial, coronal and sagital slices in patients with PTSD AIDA SARAČHADŽIHALILOVIĆ, FARUK DILBEROVIĆ: DETECTION OF THE HIPPOCAMPAL FORMATION ASYMMETRY IN PATIENTS WITH POSTTRAUMATIC STRESS DISORDER BOSNIAN JOURNAL OF BASIC MEDICALSCIENCES 2007; 7 (2): 164-167