1001 - Refractory Agitation with high-dose steroids in Susac Syndrome: a rare and challenging inpatient rehabilitation case

This 37 year old patient with a history of post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) not on home medications was placed on high dose oral prednisone, intravenous immunoglobulin, Cellcept, and Rituximab for acute management of autoimmune encephalopathy secondary to Susac syndrome and was transferred to inpatient rehabilitation. While on the inpatient rehabilitation unit, the patient developed severe motor restlessness, verbal aggression, and frequently made attempts to elope - symptoms which were not present during his acute hospitalization. The complexity was further heightened in the setting of a previous diagnosis of PTSD as the patient had recurrent nightmares, verbal outbursts, and episodes of paranoia. Multiple antipsychotics, antiepileptics, antidepressants, and benzodiazepines were trialed to manage agitation without improvement. However, tapering the high-dose oral steroids finally resulted in significantly fewer outbursts and other agitation symptoms.

Discussions:

Although high dose steroids are recommended for first-line treatment of Susac syndrome, worsening agitation as an unintended consequence has not been extensively explored. Low disease rates and variable presentations limit development of empirical evidence related to treatment complications when side-effects occur. The complexity of pre-existing conditions, in this case PTSD/AUD, contributes to the difficulty of treatment management in this patient population. This case also illustrates the importance of utilizing objectively validated tools for measuring agitation to better determine which medications and dosages contribute to improved symptoms when treatment plans are not yet effective.

Conclusions: Susac syndrome is an autoimmune condition presenting as a central nervous system symptom triad. We present a challenging case of a patient with pre-existing PTSD/AUD admitted for Susac syndrome whose rehabilitation course was complicated by agitation while on high dose steroids.