A Study Of Line Bisection And Number Bisection In Patients With Schizophrenia

Objective Neglect is a clinical syndrome that patients can't notice, report and characterize the stimulation which from the contralateral space of injury-brain. The studies have shown that the injuries of both brain hemispheres can lead to neglect symptoms, but more serious symptoms, higher frequences and longer period of neglect were found on the right hemisphere danage than the lef one. Cognitive dysfunction including attention deficit is the core feature of schizophrenia, it may relate to the structural and functional abnormalities of the hemispheres. The line and number bisection test, for evaluating the neglect phenomenon have been used in the study of spatial-attention disorder of pateints with schizophrenia, but the results is not consistent. This study will use the Line Bisection Test (LBT) and the Number Bisection Test (NBT) to explore spacial attentional deficits and its relationship to hemisphere in patients with schizophrenia.Methods 51 schizophrenia patients and 55 age, sex and education-matched healthy controls were meatured with LBT and NBT. .In the line bisection test, all subjects were asked to mark the mid-point of 2-20cm length of the ten line segments and each line deviation rates and the mean deviation rate were caculated. In the number bisection test, participants heard two numbers with fixed number intervals,for wich the size of the interval could be 3 (for example, 1-3), 5 (for example, 1-5), 7 (for example, 1-7) and 9 (for example, 1-9). All participants wre asked to answer the midpoint number and each number deviation rates and the mean deviation rate were caculated.Results In the line bisection test, shcizophrenic patients showed a negative deviation, in which the 2cm line(-0.03±0.74)% and mean (-0.02±0.03)% deviation rates were more significantly leftward than that of the normals[(0.00±0.02, -0.00±-0.01)%, P<0.05] respectively, the mean deviation rates of the patient (P<0.01) and control goups (P<0.05) were also significantly leftward compared with zero value. In the number bisection test, schizophrenic patients showed a negative deviations and a significant leftward bias on the interval 5(-0.07±0.18)%, 7(-0.08±0.22)% and 9(-0.09±0.28)% than that of the normals [(-0.01±0.05), (0.01±0.08) and (0.00±0.14)%, P<0.05] respectively.Conclusion In the line bisection test, schizophrenic patients showed a negative deviation in the offset rates of all ten lines. The mean deviation rate and most deviation rates were significantly leftward compared with zero value, and the mean deviation rate was more significantly leftward than the normals, showing that patients easily ignore the line on the right side. In the number bisection test, schizophrenic patients showed a negative deviations and a significant leftward bias on the interval 5,7 and 9 than the normals respectively, also confirmed the existence of right side neglect. Schizophrenic patients had a right-neglect, suggesting that spacial attentional deficits was existed, and it may be related to the left cerebral hemisphere dysfunction.