TY - JOUR
T1 - Reduced language lateralization in first episode schizophrenia
T2 - A near infrared spectroscopy study
AU - Chou, Po Han
AU - Lin, Wei Hao
AU - Li, Wang Rung
AU - Huang, Chih-Mao
AU - Sun, Chia-Wei
N1 - Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/8/1
Y1 - 2017/8/1
N2 - Background Diminished functional lateralization in language-related areas is found in chronic schizophrenia (SZ). However, whether this reduced lateralization exists at the early stage of SZ remains unclear. The present study aimed to investigate language lateralization in first episode schizophrenia (FES) using near infrared spectroscopy (NIRS) during a letter version of verbal fluency test (VFT). Methods A total of 28 FES patients and 33 healthy controls (HCs) underwent NIRS while performing a VFT. Six regions of interests (ROIs) were defined: the bilateral frontal-, inferior frontal gyrus (IFG), and temporal regions. Laterality index (LI) was calculated and compared between the two groups in ROIs. In addition, we investigated whether language lateralization was correlated with severity of clinical symptoms. Results Across all ROIs, LI was significantly reduced in FES patients (p = 0.037) compared to controls in the IFG region. In addition, LI was not found to be correlated with VFT performance, the PANSS positive, negative or general psychopathology subscales. Conclusions Our study demonstrated a diminution of leftward functional lateralization in the IFG during a VFT in FES patients. This is the first NIRS study to report reduced functional lateralization in patients at the early stage of schizophrenia.
AB - Background Diminished functional lateralization in language-related areas is found in chronic schizophrenia (SZ). However, whether this reduced lateralization exists at the early stage of SZ remains unclear. The present study aimed to investigate language lateralization in first episode schizophrenia (FES) using near infrared spectroscopy (NIRS) during a letter version of verbal fluency test (VFT). Methods A total of 28 FES patients and 33 healthy controls (HCs) underwent NIRS while performing a VFT. Six regions of interests (ROIs) were defined: the bilateral frontal-, inferior frontal gyrus (IFG), and temporal regions. Laterality index (LI) was calculated and compared between the two groups in ROIs. In addition, we investigated whether language lateralization was correlated with severity of clinical symptoms. Results Across all ROIs, LI was significantly reduced in FES patients (p = 0.037) compared to controls in the IFG region. In addition, LI was not found to be correlated with VFT performance, the PANSS positive, negative or general psychopathology subscales. Conclusions Our study demonstrated a diminution of leftward functional lateralization in the IFG during a VFT in FES patients. This is the first NIRS study to report reduced functional lateralization in patients at the early stage of schizophrenia.
KW - First episode schizophrenia
KW - Functional hemispheric lateralization
KW - Near infrared spectroscopy
KW - Verbal fluency test
UR - http://www.scopus.com/inward/record.url?scp=85019892620&partnerID=8YFLogxK
U2 - 10.1016/j.pnpbp.2017.05.001
DO - 10.1016/j.pnpbp.2017.05.001
M3 - Article
C2 - 28499897
AN - SCOPUS:85019892620
SN - 0278-5846
VL - 78
SP - 96
EP - 104
JO - Progress in Neuro-Psychopharmacology and Biological Psychiatry
JF - Progress in Neuro-Psychopharmacology and Biological Psychiatry
ER -