Fronto-temporal connections have long been thought to be involved in schizophrenia. Two fronto-temporal connections of interest are uncinate fasciculus (UF) and cingulum bundle (CB), which recently have been investigating using Diffusion Tensor Imaging (DTI), a new technique that affords an opportunity to evaluate white matter fiber integrity in vivo. Using this technique, we previously reported abnormalities in UF and CB in chronic patients. Additionally, we noted that schizotypal personality disordered subjects showed UF but not CB abnormalities.

Here, we sought to determine whether or not UF and CB white matter integrity are altered at initial onset of illness, and are specific to schizophrenia. We evaluated twelve first-episode schizophrenia, 12 first-episode affective psychosis and 12 controls using DTI on a 1.5T magnet. Fractional anisotropy (FA) and mean diffusivity (Dm) were used to quantify water diffusion, and cross-sectional area was defined with a directional threshold method.

Findings showed bilateral reduction of UF FA, but not Dm, in first-episode schizophrenia compared with controls and first-episode affective psychotic patients. For CB, there were no statistically significant group differences for either FA or Dm.

These findings suggested that UF white matter integrity, but not CB white matter integrity, is altered at initial onset of schizophrenia and may be specific to schizophrenia. In contrast, CB abnormalities are not present at first episode of schizophrenia and may reflect progressive changes that occur over the course of the illness. The latter will need to be investigated using a longitudinal design.