Concomitant cervical spine fractures are the primary driver of disability after traumatic vertebral artery dissection: A Case series of 123 patients.

Background: Traumatic vertebral artery dissections (tVADs) occur in up to 20% of patients with head trauma, yet data on their presentation and associated sequelae are limited. Aims and Objectives: To characterize the tVAD population and identify factors associated with clinical outcomes. Materials and Methods: We retrospectively analyzed all cases of tVAD at our institution from January 2004 to December 2018 with respect to mechanism of injury, clinical presentation, anatomic factors, associated pathologies, and relevant outcomes. Results: Of the 123 patients with tVAD, the most common presenting symptoms were neck pain (n=76, 67.3%), headache (57.5%), and visual changes (29.6%). 101 cases (82.1%) were unilateral, and 22 cases (17.9%) were bilateral. V2 was the most involved anatomic segment (83 cases, 70.3). 30 cases (25.4%) led to stroke, and 39 cases (31.7%) had a concomitant cervical fracture. The anatomic segment and number of segments involved, and baseline clinical and demographic characteristics were not associated with risk of stroke. Patients with associated fractures were older (50.3 years v. 36.4 years, p=0.0233), had a higher comorbid disease burden (CCI 1 vs. CCI 1, p<0.0007), were more likely to smoke (OR 3.0 [1.2178, 7.4028], p=0.0202), be male (OR 7.125 [3.0181, 16.8236], p<0.0001), and have mRS≥3 at discharge (OR 3.0545 [1.0937, 8.5752], p=0.0449). On multivariable regression, only fracture independently predicted mRS≥3 at discharge (OR 5.6898 [1.5067, 21.4876], p=0.010). Conclusion: tVADs may be associated with stroke and/or cervical fracture. Presenting symptoms predict stroke, but baseline demographic and clinical characteristics do not. Comorbid cervical fractures, not stroke, drive negative outcomes.

Traumatic and Spontaneous Vertebral Artery Dissections: An Analysis of Tertiary-Center 310 Patient Cohort.

BACKGROUND: Vertebral artery dissections (VADs) are rare yet potentially devastating events. While the etiology of these events is either traumatic or spontaneous, there is a paucity of quantitative literature comparing the two. OBJECTIVE: To identify differences in predisposing factors, event characteristics, and clinical outcomes between traumatic VADs (tVADs) and spontaneous VADs (sVADs). METHODS: We retrospectively identified patients with VADs presenting to our institution at VAD onset with at least a 3-mo follow-up. Demographics, event characteristics, treatment details, and neurological outcomes as modified Rankin scale (mRS) scores were collected. RESULTS: Of the 310 patients sustaining 366 VADs total, 187 (60.3%) patients experienced a total of 221 (60.4%) sVADs and 123 (39.7%) patients experienced a total of 145 (39.6%) tVADs. sVADs were more likely to occur in the intracranial course of the artery (P = .042) and have a lower mRS at discharge, 3-month, and last clinical follow-up (P = 003, .002, and .001, respectively). tVADs were more likely associated with concomitant fractures (P < .001). CONCLUSION: Despite similar patient populations, tVADs are associated with higher mRS scores at all time points. Although further study is needed, this may suggest other concomitant trauma rather than the VAD itself is contributing to worse neurological status in patients with tVADs.

Clinical Characteristics, Course, and Outcomes of Vertebral Artery Dissections in the Postpartum Period.

BACKGROUND: Postpartum vertebral artery dissections (ppVADs) are rare but potentially morbid conditions that occur in otherwise healthy patients. OBJECTIVE: To evaluate clinical characteristics of ppVADs. METHODS: Demographic, clinical, treatment, and outcome data were collected on ppVADs and are presented in a case series of 12 patients and compared to the general cohort. RESULTS: In total, 12 patients had ppVADs in our cohort of 310 patients with vertebral artery dissections (VADs). They occurred 11.27 days (95% CI, -0.85 to 23.39) postdelivery. Of these, there were 5 (42%) with a hypertensive disorder of pregnancy, and 4 (33%) who had migraines. A total of 3 (25%) had ischemic strokes and 1 (8%) had a subarachnoid hemorrhage. In total, 2 patients (17%) had unfavorable modified Rankin Scale (mRS, 2-6) at discharge from hospital. Patients with ppVADs more often had bilateral VADs (42% vs 17%, P = .03), had pseudoaneurysms (50% vs 18%, P = .0068), were younger (33.83 years vs 44.32 years, P = .018), and had lower Charlson Comorbidity Index (CCI = 0 vs 0.99, P = .0038). Anticoagulant treatment was used in a similar percentage of patients. Multivariate analysis revealed 3 factors were predictive of change in mRS: CCI (OR = 1.09, 95% CI, 1.02-1.15), stroke (OR = 0.78, 95% CI, 0.65-0.95), and mRS at hospital discharge (OR = 0.80, 95% CI, 0.74-0.87). CONCLUSION: There are only 15 isolated ppVADs reported in the literature; this study adds 12 patients with 17 ppVADs. Postpartum VADs occur in younger, healthier patients than in the general cohort, raising questions about mechanism of injury. The majority of ppVADs have good neurological outcomes.

Chiropractic associated vertebral artery dissection: An analysis of 34 patients amongst a cohort of 310.

BACKGROUND: Vertebral artery dissections (VAD) are a rare but important cause of ischemic stroke, especially in younger patients. Many etiologies have been identified, including MVAs, cervical fractures, falls, physical exercise, and cervical chiropractic manipulation. The goal of this study was to investigate the subgroup of patients who suffered a chiropractor-associated injury and determine how their prognosis compared to other-cause VAD. METHODS: We conducted a retrospective chart review of 310 patients with vertebral artery dissections who presented at our institution between January 2004 and December 2018. Variables included demographic data, event characteristics, treatment, radiographic outcomes, and clinical outcomes measured using the modified Rankin Scale. FINDINGS: Overall, 34 out of our 310 patients suffered a chiropractor-associated injury. These patients tended to be younger (p = 0.01), female (p = 0.003), and have fewer comorbidities (p = 0.005) compared to patients with other-cause VADs. The characteristics of the injuries were similar, but chiropractor-associated injuries appeared to be milder at discharge and at follow-up. A higher proportion of the chiropractor-associated group had injuries in the 0-2 mRS range at discharge and at 3 months (p = 0.05, p = 0.04) and no patients suffered severe long-term neurologic consequences or death (0% vs. 9.8%, p = 0.05). However, when a multivariate binomial regression was performed, these effects dissipated and the only independent predictor of a worse injury at discharge was the presence of a cervical spine fracture (p < 0.001). INTERPRETATION: Chiropractor-associated injuries are similar to VADs of other causes, and apparent differences in the severity of the injury are likely due to demographic differences between the two populations.

Vertebral Artery Dissections With Concurrent Intracranial Hemorrhage: A Case Series of 13 Patients Among a Cohort of 301.

BACKGROUND: Vertebral artery dissections (VADs) are a rare cause of ischemic stroke that can occasionally lead to intracranial hemorrhage (ICH). This study aims to identify differences in predisposing factors, event characteristics, and outcomes between patients with only a VAD and patients with VAD and concomitant ICH. METHODS: We conducted a retrospective chart review of 301 patients who presented with VADs at our institution from 2004-2018. A total of 13 patients were identified with VAD and concomitant ICH. Data were collected on demographics, event characteristics, treatments, and neurologic outcomes, measured using the modified Rankin Scale (mRS). RESULTS: VAD+ICH and VAD-only groups were similar in terms of age, sex, and recorded comorbidities. Additionally, etiology of the dissections did not seem to vary between groups (P = 0.6), even when selecting for traumatic causes such as motor vehicle accidents (P = 0.22) and violence (P = 0.25). Concomitant strokes and aneurysms/pseudoaneurysms occurred in similar proportions as well, but cervical fractures were more common in the VAD+ICH group (P = 0.003). Using the mRS as a measure of neurological outcome, we found that the VAD+ICH group had worse neurologic function at discharge, 3-month follow-up, and last follow-up (P < 0.001). CONCLUSIONS: Patients who experienced an ICH in addition to a VAD did not have any identifiable risk factors. Cervical spine fractures were more common in patients with VAD and ICH. VAD patients with a concomitant ICH have worse neurologic outcomes than patients with only a VAD.

Characteristics and Predictors of Outcome of Pseudoaneurysms Associated With Vertebral Artery Dissections: A 310-Patient Case Series.

BACKGROUND: Vertebral artery dissections (VADs) are a common cause of stroke in young patients and can result in various secondary effects, including pseudoaneurysm formation. OBJECTIVE: To identify differences in predisposing factors and outcomes for VADs with and without concomitant pseudoaneurysms. METHODS: We retrospective chart reviewed patients who presented to our institution at the time of VAD with at least a 3-mo clinical follow-up. Demographics, VAD characteristics, treatment, and outcomes represented as modified Rankin scale (mRS) scores were collected. RESULTS: Of 310 patients with a VAD included in this study, 301 patients had an identified pseudoaneurysm status, with 54 pseudoaneurysm-associated VADs and 247 VADs not associated with pseudoaneurysm. VAD patients with associated pseudoaneurysms were more likely to be female (P < .004), have bilateral VADs (P < .001), and have fewer vertebral artery segments affected (P = .018), and less likely to have stroke (P < .008) or occlusion of the vertebral artery (P < .001). There was no difference in the proportion of patients treated with antiplatelet agents (P = .12) or anticoagulants (P = .27) between the groups. VAD patients with associated pseudoaneurysms were more likely to have a higher mRS at 3-mo follow-up (P = .044) but not discharge (P = .18) or last follow-up (P = .05). VAD patients with pseudoaneurysms were equally likely to have resolution of occlusion (P = .40) and stenosis (P = .19). CONCLUSION: Demographics and clinical and radiological characteristics of VADs associated with pseudoaneurysms are different from those without associated pseudoaneurysms. Vertebral artery dissections with concomitant pseudoaneurysms are neither associated with worse functional nor radiographic outcomes.

Vertebral artery dissections with and without cervical spine fractures: Analysis of 291 patients.

OBJECTIVES: Vertebral artery dissections occur when tears in the intimal layer of the vertebral artery and are associated with trauma, infection, and spontaneous etiologies. We aimed to identify differences in predisposing factors and outcomes in vertebral artery dissections associated with cervical spine fractures compared to those not associated with cervical spine fractures. PATIENTS AND METHODS: We conducted a retrospective chart review of patients with vertebral artery dissections who presented to our institution at the time of dissection and had a minimum of 3 month follow-up and collected data on demographics, event characteristics, treatments, and outcomes in the form of modified Rankin scale scores. RESULTS: In total, 291 patients with VAD were included in this study. Thirty-nine patients with VADs had associated fracture, while 252 patients had VADs without fracture. VAD patients with associated cervical fractures were more likely to be male (p < 0.001), have a greater number of comorbid conditions (p < 0.01), be smokers (p = 0.045), or have violence (p < 0.001) or motor vehicle accidents (p < 0.001) as the cause of their VADs. VAD patients with associated cervical fractures were less likely to have associated aneurysms or pseudoaneurysms (p = 0.002). VAD patients with associated cervical fractures were more likely to have higher mRS at discharge from the hospital (p < 0.001), 3 month follow-up (p < 0.001), and last follow-up (p < 0.001). CONCLUSION: Cervical spine fracture is likely the primary driver of poor neurological outcomes following vertebral artery dissection with associated cervical spine fracture.

Automated home cage training of mice in a hold-still center-out reach task.

An obstacle to understanding neural mechanisms of movement is the complex, distributed nature of the mammalian motor system. Here we present a novel behavioral paradigm for high-throughput dissection of neural circuits underlying mouse forelimb control. Custom touch-sensing joysticks were used to quantify mouse forelimb trajectories with micron-millisecond spatiotemporal resolution. Joysticks were integrated into computer-controlled, rack-mountable home cages, enabling batches of mice to be trained in parallel. Closed loop behavioral analysis enabled online control of reward delivery for automated training. We used this system to show that mice can learn, with no human handling, a direction-specific hold-still center-out reach task in which a mouse first held its right forepaw still before reaching out to learned spatial targets. Stabilogram diffusion analysis of submillimeter-scale micromovements produced during the hold demonstrate that an active control process, akin to upright balance, was implemented to maintain forepaw stability. Trajectory decomposition methods, previously used in primates, were used to segment hundreds of thousands of forelimb trajectories into millions of constituent kinematic primitives. This system enables rapid dissection of neural circuits for controlling motion primitives from which forelimb sequences are built. NEW & NOTEWORTHY A novel joystick design resolves mouse forelimb kinematics with micron-millisecond precision. Home cage training is used to train mice in a hold-still center-out reach task. Analytical methods, previously used in primates, are used to decompose mouse forelimb trajectories into kinematic primitives.

Vocal learning in songbirds requires cholinergic signaling in a motor cortex-like nucleus.

Cholinergic inputs to cortex modulate plasticity and sensory processing, yet little is known about their role in motor control. Here, we show that cholinergic signaling in a songbird vocal motor cortical area, the robust nucleus of the arcopallium (RA), is required for song learning. Reverse microdialysis of nicotinic and muscarinic receptor antagonists into RA in juvenile birds did not significantly affect syllable timing or acoustic structure during vocal babbling. However, chronic blockade over weeks reduced singing quantity and impaired learning, resulting in an impoverished song with excess variability, abnormal acoustic features, and reduced similarity to tutor song. The demonstration that cholinergic signaling in a motor cortical area is required for song learning motivates the songbird as a tractable model system to identify roles of the basal forebrain cholinergic system in motor control. NEW & NOTEWORTHY Cholinergic inputs to cortex are evolutionarily conserved and implicated in sensory processing and synaptic plasticity. However, functions of cholinergic signals in motor areas are understudied and poorly understood. Here, we show that cholinergic signaling in a songbird vocal motor cortical area is not required for normal vocal variability during babbling but is essential for developmental song learning. Cholinergic modulation of motor cortex is thus required for learning but not for the ability to sing.