Proton magnetic resonance spectroscopy of the frontal, cingulate and perirolandic cortices and its relationship to skin conductance in patients with schizophrenia

Abstract

The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 ± 0.03; control = 1.12 ± 0.04) and in the right (schizophrenia = 0.88 ± 0.02; control = 0.94 ± 0.03) and left (schizophrenia = 0.84 ± 0.03; control = 0.94 ± 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 ± 0.05) than the controls (0.95 ± 0.02, P < 0.05) and the subgroup with normal SCL (0.88 ± 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.

N-acetyl aspartate concentration in the anterior cingulate cortex in patients with schizophrenia: A study of clinical and neuropsychological correlates and preliminary exploration of cognitive behaviour therapy effects

“…Right dorsal Glx was inversely correlated with illness duration.Ohrmann et al (2008)Schizophrenia patients ( n  = 43, all on atypical) Healthy participants ( n  = 37)NAA, Cho, Cr, Glx, WCST learning potentialNo difference in metabolite concentration between patients and healthy participants. NAA and Glx concentrations were positively associated with WCST learning potentialSanches et al (2008)Schizophrenia patients ( n  = 37) Healthy participants ( n  = 37)NAA/(Cho + Cr) ratio in left and right anterior middle frontal gyrus, ACC and perirolandic area (reference), basal skin conductance and skin conductance response to auditory stimuli of 1 s tones of 80 dB. Patients and healthy participants classified into skin conductance responders (2 S.D.…”

Metabolic alterations associated with schizophrenia: a critical evaluation of proton magnetic resonance spectroscopy studies

“…2011), in medicated CSP (Sanches et al . ; Ongur et al . ), in childhood onset schizophrenia (O'Neill et al .…”

1H-magnetic resonance spectroscopy in first episode and chronic schizophrenia patients

“…Jessen et al reported that NAA/Cho ratio was decreased in the frontal lobe in FEPs, and low NAA/Cho ratio and high Cho/Cre ratio in the ACC were related to switching to chronic schizophrenia (43). It was also reported that CSPs had lower NAA/Cho levels than healthy individuals, and it was proposed that the decrease in NAA/Cho ratio reflected the presence of neuronal loss (9,44).…”

“…Although it was reported that NAA decreases in the prefrontal lobe and medial temporal region including the hippocampus were a consistent finding in schizophrenia patients (4), no change in NAA levels could be found in the dorsolateral prefrontal cortex (DLPFC) of subjects with high genetic risk of schizophrenia (5), medicated patients with chronic deficit-syndrome schizophrenia (6), and medicated chronic patients (7) as compared to controls. However, several studies reported decreased PFC NAA levels in medicated chronic schizophrenia patients (CSPs) (8,9), first episode patients (FEPs) (7,10,11), and medicated schizophreniform spectrum patients (12). Similarly, several studies reported decreased hippocampal NAA levels (4), and a few studies reported unaltered NAA levels in chronic patients (13,14) and in medicated and unmedicated FEPs (15)(16)(17).…”

“…They also reported that there was an increasing tendency in Cho levels in the temporal lobe in CSPs, a decreasing tendency in NAA levels in FEPs, and a statistically significant increase in Cho levels in the frontal lobe in both patient groups when compared with the controls (29). Along with differences between brain imaging techniques, there are limitations as some studies investigating FEPs and CSPs were focused on single brain areas such as the DLPFC, thalamus, or medial temporal cortex (8,9,29), and some of first episode studies included patients with psychotic disorders other than schizophrenia. Therefore, it is still unclear whether there are differences in neuronal integrity between FEPs and CSPs and which areas are related with the differences (15,18).…”