Rapid-onset dystonia-parkinsonism is associated with reduced cerebral blood flow without gray matter changes.

Purpose: Previous research showed discrete neuropathological changes associated with rapid-onset dystonia-parkinsonism (RDP) in brains from patients with an ATP1A3 variant, specifically in areas that mediate motor function. The purpose of this study was to determine if magnetic resonance imaging methodologies could identify differences between RDP patients and variant-negative controls in areas of the brain that mediate motor function in order to provide biomarkers for future treatment or prevention trials. Methods: Magnetic resonance imaging voxel-based morphometry and arterial spin labeling were used to measure gray matter volume and cerebral blood flow, respectively, in cortical motor areas, basal ganglia, thalamus, and cerebellum, in RDP patients with ATP1A3 variants (n = 19; mean age = 37 ± 14 years; 47% female) and variant-negative healthy controls (n = 11; mean age = 34 ± 19 years; 36% female). Results: We report age and sex-adjusted between group differences, with decreased cerebral blood flow among patients with ATP1A3 variants compared to variant-negative controls in the thalamus (p = 0.005, Bonferroni alpha level < 0.007 adjusted for regions). There were no statistically significant between-group differences for measures of gray matter volume. Conclusions: There is reduced cerebral blood flow within brain regions in patients with ATP1A3 variants within the thalamus. Additionally, the lack of corresponding gray matter volume differences may suggest an underlying functional etiology rather than structural abnormality.

The benefit of radiosurgery for ARUBA-eligible arteriovenous malformations: a practical analysis over an appropriate follow-up period.

OBJECTIVE The authors of this study found that, given the latency period required for arteriovenous malformation (AVM) obliteration after stereotactic radiosurgery (SRS), a study with limited follow-up cannot assess the benefit of SRS for unruptured AVMs. METHODS The authors reviewed their institutional experience with "ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations)-eligible" AVMs treated with SRS between 1987 and 2016, with the primary outcome defined as stroke (ischemic or hemorrhagic) or death (AVM related or AVM unrelated). Patients with at least 3 years of follow-up in addition to those who experienced stroke or died during the latency period were included. Secondary outcome measures included obliteration rates, patients with new seizure disorders, and those with new focal deficits without stroke. RESULTS Of 233 patients included in this study, 32 had a stroke or died after SRS over the mean 8.4-year follow-up (14%). Utilizing the 10% stroke or death rate at a mean 2.8-year follow-up for untreated AVMs in ARUBA, the rate in the authors' study is significantly lower than that anticipated at the 8.4-year follow-up for an untreated cohort (14% vs 30%, p = 0.0003). Notwithstanding obliteration, in this study, annualized rates of hemorrhage and stroke or death after 3 years following SRS were 0.4% and 0.8%, respectively. The overall obliteration rate was 72%; new seizure disorders, temporary new focal deficits without stroke, and permanent new focal deficits without stroke occurred in 2% of patients each. CONCLUSIONS After a sensible follow-up period exceeding the latency period, there is a lower rate of stroke/death for patients with treated, unruptured AVMs with SRS than for patients with untreated AVMs.

Stereotactic Radiosurgery for Dural Arteriovenous Fistulas without Cortical Venous Reflux.

BACKGROUND: The rationale for treatment of dural arteriovenous fistulas (dAVFs) without cortical venous reflux is symptomatic resolution. Most studies of dAVF treatment, including those for stereotactic radiosurgery, have focused on angiographic obliteration instead of clinical symptomatic outcome. METHODS: The authors evaluated their institutional experience with stereotactic radiosurgery for cerebral dAVFs without cortical venous reflux from 1991 to 2016, evaluating angiographic and clinical outcomes, focusing on the course of pulsatile tinnitus and/or ocular symptoms after treatment. They subsequently pooled their results with those from a systematic literature review. RESULTS: Pooled outcomes data from 349 low-risk dAVF (120 patients with pulsatile tinnitus and 229 patients with ocular symptoms) were analyzed. Over a mean follow-up of 2.6 years, 77% of patients presenting with pulsatile tinnitus experienced resolution and an additional 21% had improvement, with an angiographic obliteration rate of 70.9%. Among 229 patients with ocular symptoms from carotid-cavernous dAVFs, improvement or resolution of symptoms occurred in 95% of those with chemosis, 90% of those with ophthalmoparesis, and 96% of those with proptosis. The angiographic obliteration rate was 76.2%. There were six permanent complications in 349 total treated low-risk dAVF (1.7%). CONCLUSIONS: Rates of clinically significant symptomatic improvement/resolution of symptoms referable to "low-risk" dAVFs are even greater than their angiographic obliteration rate, an important factor in patient counseling and when considering the optimal treatment approach for these dAVFs.