The effect of thalamic hemorrhage on the fornix.

OBJECTIVES: The fornix is indirectly connected to the anterior thalamus via the mamilothalamic tract. There has been no diffusion tensor tractography (DTT) study on the effect of thalamic hemorrhage on the fornix. Using DTT, we attempted to investigate the effect of thalamic hemorrhage on the fornix in patients with thalamic hemorrhage.

SUBJECTS AND METHODS: Twenty-one consecutive patients with thalamic hemorrhage and 21 age-matched normal healthy control subjects were recruited. DTT data were acquired at an average of 21 days after onset. We measured fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the three parts of the fornix (column, body, and crus) respectively.

RESULTS: FA values of the affected and unaffected hemispheres in the patient group were lower than those of the control group in all three parts of the fornix (p < .05). By contrast, compared with the control group, the ADC value was found to be increased only in the body (p < .05).

CONCLUSIONS: According to our results, the FA value decrement with increased or normal ADC value in the patient group seems to indicate neuronal loss in the fornix, which appeared to be ascribed to secondary degeneration following thalamic hemorrhage.