[Proton magnetic resonance spectroscopy of prefrontal lobe and thalamus in schizophrenics: correlation with clinical characteristics].

Objective To explore the characteristics of different subtypes of schizophrenics on prefrontal lobe and thalamus by proton magnetic resonance spectroscopy (1H-MRS) and its relationship.Methods From August 2007 to April 2010 at our center,a total of 159 schizophrenics fulfilling the third edition criteria of Chinese Classification of Mental Disorders (CCMD-Ⅲ) were recruited.And prefrontal lobe and thalamus were evaluated by muhi-voxel 1H-MRS.There were 88 males and 71 females.There were first-episode (n =54) and not-first-episode (n =105 ),negative subtype ( n =125 )and positive subtype ( n =34 ),medicated ( n =96) and non-medicated ( n =63 ) by different criteria.The levels of N-acetylaspartate ( NAA),choline-containing compounds (Cho) and creatine compounds (Cr) were measured and the ratios of NAA/Cr and Cho/Cr determined.Positive and negative syndrome soale (PANSS) and Wisconsin card sorting test (WCST) were also assessed.Only 45 normal controls received 1H-MRS.Results On left prefrontal lobe and left thalamus,the NAA/Cr ratios in different subtypes of patients were lower than those in normal controls ( P ＜ 0.05 or 0.01 ).The NAA/Cr ratios in patients of non-first-episode ( 1.48 ± 0.34),negative subtype ( 1.40 ± 0.35 ) and medicated ( 1.47 ± 0.36 ) on right thalamus were also lower than those in normal controls ( 1.62 ± 0.37,t =2.25,3.56,2.28,P ＜ 0.05 or P ＜ 0.01 ).Compared with positive subtype schizophrenics,the NAA/Cr ratios in those of negative subtype on right thalamus were lower ( 1.40 ± 0.35 vs 1.60 ± 0.37,t =2.92,P ＜ 0.01 ).On right thalamus of nonmedicated schizophrenics,there was a negative correlation between the duration of illness and the ratio of NAA/Cr (r =- 0.38,P ＜ 0.05 ) and a positive correlation between the duration of illness and the ratio of Cho/Cr (r =0.43,P ＜0.01 ).On right thalamus of negative subtype schizophrenics,the ratios of NAA/Cr were negatively correlated with the total score of PANSS and the score of negative factor respectively ( r =-0.36,-0.40,P＜0.05).On left prefrontal lobe of different subtypes,the ratios of NAA/Cr were negatively correlated with the total score of PANSS,the score of negative factor,responses errors and persistent errors (P ＜ 0.01 ) and positively correlated with completed categories and conceptual level responses ( P ＜ 0.05 or P ＜ 0.01 ).Conclusion Abnormalities in neuronal function and/or integrity are present on left prefrontal lobe and left thalamus in schizophrenics.And right thalamus is probably involved in non-first-episode subtype,negative subtype and non-medicated subtype.Different subtypes of schizophrenics may have different characteristics of 1 H-MRS due to the duration of illness and their clinical symptoms. Key words: Schizophrenia ;  Magnetic resonance spectroscopy ;  Prefrontal lobe ;  Thalamus ; Case-controlled study