PSP-like syndrome after aortic surgery in adults (Mokri syndrome)

A rare progressive supranuclear palsy-like syndrome seemingly triggered by aortic surgery was first described in 2004. This largest case series to date describes the features of this syndrome.

We searched the Mayo Clinic electronic medical records using the advanced cohort explorer search engine for patients evaluated for neurologic symptoms after cardiac-aortic surgery in the past 30 years. Data were extracted to Microsoft Excel from the identified patients and included clinical and neuroimaging features and outcomes.

Twenty-five patients met the inclusion criteria. All surgeries were performed under thoracic aortic bypass and deep hypothermia. Surgery included aortic aneurysm, aortic valve repair, and/or aortic dissection repair. Surgical records were unavailable, although surgery was documented in the Mayo record as uncomplicated in 60% of cases. In the remaining cases, no particular intraoperative or postoperative complications were documented at a high frequency. A typical triad was documented: supranuclear gaze palsy (SNGP; 100%), gait imbalance (80%), and dysarthria (96%). Part or all of the triad was observed before hospital discharge and stabilized over the course of days-weeks. A second phase of symptom worsening plus new symptoms developed up to a year later; this decline continued for up to several years before stabilization. Delayed epileptic seizures occurred in 32% of patients. Brain MRI revealed only nonspecific findings.

This syndrome following adult thoracic aortic bypass surgery with deep hypothermia remains unexplained. It follows a biphasic course and is characterized by the triad of SNGP, unsteady gait, and a predominantly ataxic dysarthria.