RESUMEN
Background and Objectives: Occlusion of the artery of Percheron (AOP) produces bilateral thalamic infarction classically leading to deficits of arousal. This nonspecific presentation complicates the diagnosis of acute ischemic stroke. We sought to describe the spectrum of clinical presentation, diagnostic neuroimaging findings, and outcomes in AOP infarction (AOPi). Methods: We conducted a keyword search of our health system's neuroimaging database from 2014 to 2022 to identify patients with AOPi. We abstracted patient demographics, clinical presentation, neuroimaging findings, acute treatment, and modified Rankin Scale (mRS) scores (at baseline, 3 months, and 12 months). We used descriptive statistics to report our findings. Results: Our initial keyword search identified 192 potential AOPi cases. Fifteen cases of AOPi were confirmed and included in our study (8 female [53%], median age 65 years [interquartile range (IQR): 59.5-79.5], median presenting NIHSS 6 [IQR: 2-22]). Common clinical findings on presentation were systolic blood pressure (SBP) > 140: 12 patients (80%); decreased level of consciousness (LOC): 11 patients (73%); diplopia: 8 patients (57%); disorientation: 6 patients (42%); dysarthria: 4 patients (28%); and acute memory/cognitive disturbance: 3 patients (21%). Twelve cases (80%) presented to the emergency department (ED). Median time from symptom onset to ED arrival was 774.5 minutes (IQR: 202.25-3789.0), 4 cases (27%) arrived within 4.5 hours, and one patient (7%) received intravenous thrombolysis. The median time from ED arrival to stroke diagnosis was 519.0 minutes (IQR: 227.5-1307). Head CT was only diagnostic when obtained >570 minutes from time last known well; MRI was diagnostic at all time points. Rates of functional independence (mRS ≤2) at baseline, 3 months, and 12 months were 64%, 21%, and 18%, respectively. Discussion: The diagnosis of stroke was considerably delayed in patients with AOPi, and only one patient received IV thrombolysis. SBP >140, impaired consciousness, and diplopia were the most common findings at presentation. CT was often nondiagnostic, but MRI demonstrated bilateral thalamic infarct in all cases. AOPi caused considerable long-term morbidity. Clinicians should maintain a high degree of suspicion for AOP stroke and consider thrombolysis in appropriately selected patients.
RESUMEN
Objective: To characterize how the proximity of deep brain stimulation (DBS) active contact locations relative to the cerebellothalamic tract (CTT) affect clinical outcomes in patients with essential tremor (ET). Background: DBS is an effective treatment for refractory ET. However, the role of the CTT in mediating the effect of DBS for ET is not well characterized. 7-Tesla (T) MRI-derived tractography provides a means to measure the distance between the active contact and the CTT more precisely. Methods: A retrospective review was conducted of 12 brain hemispheres in 7 patients at a single center who underwent 7T MRI prior to ventral intermediate nucleus (VIM) DBS lead placement for ET following failed medical management. 7T-derived diffusion tractography imaging was used to identify the CTT and was merged with the post-operative CT to calculate the Euclidean distance from the active contact to the CTT. We collected optimized stimulation parameters at initial programing, 1- and 2-year follow up, as well as a baseline and postoperative Fahn-Tolosa-Marin (FTM) scores. Results: The therapeutic DBS current mean (SD) across implants was 1.8 mA (1.8) at initial programming, 2.5 mA (0.6) at 1 year, and 2.9 mA (1.1) at 2-year follow up. Proximity of the clinically-optimized active contact to the CTT was 3.1 mm (1.2), which correlated with lower current requirements at the time of initial programming (R2 = 0.458, p = 0.009), but not at the 1- and 2-year follow up visits. Subjects achieved mean (SD) improvement in tremor control of 77.9% (14.5) at mean follow-up time of 22.2 (18.9) months. Active contact distance to the CTT did not predict post-operative tremor control at the time of the longer term clinical follow up (R2 = -0.073, p = 0.58). Conclusion: Active DBS contact proximity to the CTT was associated with lower therapeutic current requirement following DBS surgery for ET, but therapeutic current was increased over time. Distance to CTT did not predict the need for increased current over time, or longer term post-operative tremor control in this cohort. Further study is needed to characterize the role of the CTT in long-term DBS outcomes.