Neurological Abnormalities in Chinese Schizophrenic Patients

Background: This study attempted to examine the prevalence and type of neurological signs in Chinese patients with schizophrenia. Methods: A cross-sectional design was adopted with the use of the Cambridge Neurological Inventory (CNI). The CNI is comprised of 7 subscales, including motor coordination, sensory integration, disinhibition, extrapyramidal signs, dyskinesia, catatonia, and pyramidal signs. The former 3 subscales were classified as soft signs, whereas the latter 4 subscales were classified as hard signs. A total of 250 Chinese schizophrenic patients and 90 normal controls were recruited. Results: Patients exhibited significantly more signs than normal controls in all subscales but pyramidal signs (p < 0.00005). Significant differences were also found in total soft signs, total hard signs as well as total neurological signs (p < 0.0005). The three subscales of soft signs showed a relatively better sensitivity and specificity as compared with the four subscales of hard signs. Improvement in sensitivity and specificity was demonstrated when the subscales were collapsed into total soft signs, total hard signs and total neurological signs. A cut-off of 4 in total soft signs yields a sensitivity of 0.63 and specificity of 0.71; whereas a cut-off of 1 in total hard signs yields a sensitivity of 0.78 and specificity of 0.89. A global cut-off of 5 in total neurological signs results in a sensitivity of 0.81 and specificity of 0.73 for detecting schizophrenia versus normal. Conclusions: High levels of neurological abnormality characterize schizophrenic patients. An extended assessment battery of CNI provides even better discrimination of patients from normal controls, and soft signs are more strongly associated with schizophrenia than are hard signs in the Chinese sample.