Middle and Inferior Temporal Gyrus Gray Matter Volume Abnormalities in Chronic Schizophrenia: An MRI Study

Abstract

Objective-The middle temporal gyrus and inferior temporal gyrus subserve language and semantic memory processing, visual perception, and multimodal sensory integration. Functional deficits in these cognitive processes have been well documented in patients with schizophrenia. However, there have been few in vivo structural magnetic resonance imaging (MRI) studies of the middle temporal gyrus and inferior temporal gyrus in schizophrenia.Method-Middle temporal gyrus and inferior temporal gyrus gray matter volumes were measured in 23 male patients diagnosed with chronic schizophrenia and 28 healthy male subjects by using high-spatial-resolution MRI. For comparison, superior temporal gyrus and fusiform gyrus gray matter volumes were also measured. Correlations between these four regions and clinical symptoms were also investigated.Results-Relative to healthy subjects, the patients with chronic schizophrenia showed gray matter volume reductions in the left middle temporal gyrus (13% difference) and bilateral inferior temporal gyrus (10% difference in both hemispheres). In addition, the patients showed gray matter volume reductions in the left superior temporal gyrus (13% difference) and bilateral fusiform gyrus (10% difference in both hemispheres). More severe hallucinations were significantly correlated with smaller left hemisphere volumes in the superior temporal gyrus and middle temporal gyrus.Conclusions-These results suggest that patients with schizophrenia evince reduced gray matter volume in the left middle temporal gyrus and bilateral reductions in the inferior temporal gyrus. In conjunction with findings of left superior temporal gyrus reduction and bilateral fusiform gyrus reductions, these data suggest that schizophrenia may be characterized by left hemisphere-selective dorsal pathophysiology and bilateral ventral pathophysiology in temporal lobe gray matter.The middle temporal gyrus is located on the lateral surface of the temporal lobe ventral to the superior temporal gyrus. The inferior temporal gyrus is located on the lateral and inferior surfaces of the temporal lobe, ventral to the middle temporal gyrus. Previous functional neuroimaging studies have suggested that the middle temporal gyrus and inferior temporal gyrus are involved in several cognitive processes (1), including language and semantic memory processing (middle temporal gyrus) (1-3), as well as visual perception (inferior temporal gyrus) (4,5) and multimodal sensory integration (6). Functional deficits in these cognitive domains, i.e., language (7), semantic memory (8), and complex visual perception (9), have been reported in schizophrenia. Thus, it may be reasonable to assume that the middle temporal gyrus and inferior temporal gyrus play important roles in the pathophysiology of schizophrenia. However, these regions have received little attention in structural magnetic resonance imaging (MRI) studies of schizophrenia.For temporal lobe cortical structures, left superior temporal gyrus gray matter abnormality is the most frequently ...

An auditory processing abnormality specific to liability for schizophrenia

“…Using data from intracranial electrode arrays recorded during dichotic auditory paradigms researchers have identified neural generators of the scalp-recorded N1 as potentially residing in the superior temporal gyrus (Neelon et al, 2006). Reduced volume of the left posterior superior temporal gyrus has been described in several studies of patients with schizophrenia (McCarley et al, 2002;Onitsuka et al, 2004;Shenton, Dickey, Frumin, & McCarley, 2001), in contrast to studies of patients with affective disorders (Hirayasu et al, 2000;Hirayasu et al, 1998). In light of N1 amplitude reduction being evident in relatives of schizophrenia, one investigation found gray matter reductions of the left lateral temporal regions specific to the genetic risk for schizophrenia while genetic risk for bipolar disorder was associated with gray matter reductions of the anterior cingulate and ventral striatum (McDonald et al, 2004).…”

Functional neuroimaging of word priming in males with chronic schizophrenia

“…Several papers have reported abnormalities in subsets of these regions using a variety of techniques (Gaser et al, 2004;Lennox et al, 1999;Shergill et al, 2003;Sibersweig et al, 1995;Stephane et al, 2001;Weiss & Heckers, 1999). This includes a report from our laboratory showing that volumes of the left middle temporal gyrus were correlated with levels of auditory hallucinations (Onitsuka et al, 2004). In another report, functional imaging was performed on a patient actively hallucinating (Lennox et al, 1999).…”

Dynamic causal modelling of effective connectivity during perspective taking in a communicative task

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