Psychiatric disturbances in radiologically isolated syndrome

Radiologically isolated syndrome (RIS) is characterized by incidental lesions suggestive of multiple sclerosis (MS) on MRI without typical symptoms of MS. Clinically isolated syndrome (CIS) is characterized by a first episode of neurologic symptoms caused by demyelination in the central nervous system. To date, psychiatric disorders have not been systematically addressed in RIS subjects. We assessed emotional disturbances, personality features and health-related quality of life (HRQoL) in a cohort of RIS patients as compared with clinically isolated syndrome (CIS).

Twenty-eight RIS patients, 25 clinically isolated syndrome (CIS) patients, and 22 healthy subjects were enrolled in the study. Participants were administered a mood scale (Hamilton Depression Rating Scale), behavioural measures (Personality Assessment Inventory), and fatigue measures (Fatigue Impact Scale for Daily Use). HRQoL was quantified using the EuroQol-5.

14 (50%) of RIS patients had clinically significant depression, with over one-third of these having moderate depression, scores virtually identical to those observed in CIS patients. 11 of 28 (39.3%) subjects with RIS had anxious depression, a figure three times higher than that found in CIS patients. RIS patients' HAMD-17 total score showed a very strong correlation with severity of fatigue. In addition, RIS patients reported lower HRQoL (p = 0.036) and a significantly higher symptoms load for somatisation compared to both CIS and control groups (p < 0.002).

RIS patients had high rates of depression, particularly anxious depression and somatization. Future studies are warranted to clarify whether these psychiatric disturbances are causally associated with a distinct white matter psychopathologic process.