Subject: Auditory fMRI as a reliable diagnostic of schizophrenia? From: Tony Miller <ajmiller(at)MIT.EDU> Date: Fri, 23 Apr 2004 21:54:03 -0400[I thought some AUDITORY listmembers might be interested... -AJM] -----------------Press Release-------------------- http://www.yale.edu/opa/newsr/04-04-21-01.all.html Imaging test could be used to diagnose schizophrenia New Haven, Conn. -- An abnormal pattern in an area of the brain that governs hearing may be an accurate method of diagnosing schizophrenia, according to a study by Yale researchers and collaborators. "These results seem to point to a cardinal abnormality in schizophrenia," said Godfrey Pearlson, M.D., professor of psychiatry at Yale School of Medicine, director of the Olin Neurospychiatry Research Center at the Institute of Living in Hartford, and senior author of the study published in Biological Psychiatry. "Using this imaging test, we were able to identify patients with schizophrenia with 97 percent accuracy." Pearlson, Vince Calhoun and Kent Kiehl later replicated their initial finding with an independent sample and achieved a 94 percent rate of accuracy. Calhoun and Kiehl have appointments at the Olin Center and Yale. Currently, the clinical diagnosis of schizophrenia is based on a constellation of psychiatric symptoms. The mental illness also has been associated with both structural and functional abnormalities in neocortical networks including frontal, parietal, and temporal regions of the brain, but there has been no diagnostic test for the disorder. Abnormalities in auditory cortex structure and function are prominent features of the brains in persons with schizophrenia, particularly in the superior temporal gyrus (SRG). Reduction in size of the SRG may correlate with the severity of auditory hallucinations and of formal thought disorder. However, all of these previously documented anatomic differences overlap significantly with those of healthy controls and are thus not useful for diagnosis. "Therefore, this newly reported functional brain change results in almost total separation of patients and healthy controls in two independent samples, and thus has possible diagnostic utility," Pearlson said. Data were collected from two locations. One group consisted of 17 outpatients with chronic schizophrenia matched with 17 healthy persons in Vancouver, B.C. Another group consisted of eight patients and eight healthy persons in Hartford, Conn. "These results have the potential to provide a powerful, quantitative clinical tool for the assessment of schizophrenia," Pearlson said. -----------------Pubmed Abstract-------------------- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15050866 Aberrant localization of synchronous hemodynamic activity in auditory cortex reliably characterizes schizophrenia. Calhoun VD, Kiehl KA, Liddle PF, Pearlson GD. Biol Psychiatry. 2004 Apr 15;55(8):842-9. Institute of Living, Olin Neuropsychiatry Research Center, 200 Retreat Avenue, Hartford, CT 06106, USA. BACKGROUND: Among the most prominent features of schizophrenic brains are abnormalities in auditory cortex structure and function, particularly in the superior temporal gyrus (STG). In this study, we attempted to examine auditory cortex function using an intrinsic, task-uncorrelated measure. METHODS: Using functional magnetic resonance imaging data, we calculated synchronous hemodynamic independent maps (SHIMs) of auditory cortex in patients with schizophrenia and matched healthy control subjects while they performed an auditory oddball task. RESULTS: Patient SHIMs revealed greater synchrony in ventral and medial STG regions (including auditory association Brodmann area [BA] 42); control SHIMs had greater synchrony in dorsal and lateral STG regions (which did not include BA 42). A within-participant subtractive comparison of these two sets of regions differentiated schizophrenic from healthy control subjects with 97% accuracy initially (further validated by a retest of the healthy control subjects) and performed with 94% accuracy in a confirmatory study of new subjects scanned at a different site. CONCLUSIONS: These results shed new light on STG functional differences in schizophrenia, suggest that aberrant patterns of coherence in temporal lobe cortical regions are a cardinal abnormality in schizophrenia, and have the potential to provide a powerful, quantitative clinical tool for the assessment of schizophrenia. -- Tony Miller Eaton-Peabody Laboratory, Massachusetts Eye and Ear Infirmary 243 Charles St, Boston, MA 02114 ajmiller(at)mit.edu | (617) 510-3629 | http://tonymiller.info