Differential diagnosis of schizophrenic symptoms complicated with brain anomalies including bilateral temporal arachnoid cysts by eye mark recorder and PET: a case study
Shiraishi, H.; Ishii, K.; Takahashi, S.; Shoda, K.; Higashimoto, T.; Uki, J.; Ishihara, I.; Kojima, T.
Seishin Shinkeigaku Zasshi 101(4): 350-367
1999
ISSN/ISBN: 0033-2658 PMID: 10375980 Document Number: 510043
Bilateral temporal arachnoid cysts and other intracranial congenital lesions including a moderately large left temporal arachnoid cyst accompanied by remarkable dysplasia of the temporal lobe in particular were discovered by chance during computerized axial tomography of a 26-year-old Japanese male who had been diagnosed as schizophrenia approximately 10 years earlier. A detailed re-assessment revealed no other organic symptoms or signs. His symptoms and clinical course met the DSM-IV criteria for schizophrenia, disorganized type. Based on his symptoms, positron emission tomography (PET) and the eye-movement recording test developed by Kojima et al. were performed. In addition, psychological tests including WAIS, Rorschach Test, and Wechsler's Memory Test were administered for further differential diagnosis. PET using continuous inhalation of oxygen 15-gas revealed a regional decrease in CBF and CMRO2 in the superior medial frontal lobe including the anterior cingulate gylus, findings sometimes associated with schizophrenia. However, no abnormal findings were noted around the arachnoid cysts. In the eye-movement recording test, several parameters including the responsive search score (RSS) were about the same level as that commonly observed in schizophrenics and are classified as schizophrenia by discrimination analysis. The psychological tests offered no reason to doubt the diagnosis of schizophrenia. Thus, the patient was diagnosed as schizophrenia with arachnoid cysts and other intracranial lesions. The way of diagnosis we used here might bring forth a breakthrough in schizophrenia research by differentiating schizophrenia from the other organic brain diseases.