Association between limbic system lesions and anxiety in persons with multiple sclerosis

Persons with Multiple Sclerosis (PwMS) have a higher rate of anxiety and depression than the general population. Depression has been associated with clinical relapses; temporal lesions were shown to predict depression severity. Anxiety is considerably understudied. The role of MS lesions in the limbic system is also understudied, partly due to difficulties identifying limbic lesions on standard 1.5 and 3 Tesla MRI.

This is a retrospective study of 23 PwMS who underwent 7T MRI on the same day as completing the Hospital Anxiety and Depression Scale (HADS). MRI was performed on a Siemens 7T MRI Plus and an 8-channel transmit coil with 32 receiver channels operating in pTx mode. MP2RAGE and DIR-SPACE sequences were analyzed to determine the number of lesions within the limbic system.

The median number of lesions in the limbic system was 2.0 (range 0-7). When comparing the presence or absence of lesions in the limbic system, there was a significant relationship with anxiety (X² (1, N = 23)=4.44, p = 0.035), but not for depression.

Although only a small sample size, this study provides preliminary evidence that lesions in the limbic system are associated with the presence of anxiety in PwMS. This relationship warrants further investigation.