Reducing blood flow pulsation artifacts in 3D time-of-flight angiography by locally scrambling the order of the acquisition at 3 T and 7 T.

PURPOSE: Non-contrast-enhanced time of flight (TOF) is a standard method for magnetic resonance angiography used to depict vessel morphology. TOF is commonly performed with a 3D steady-state acquisition, employing a short repetition time to support high resolution imaging. At 7 T, TOF exhibits substantial increase in SNR and contrast, improving its clinical value. However, one of the remaining challenges, exacerbated at 7 T, is the presence of artifacts due to pulsatile blood flow, especially near major blood vessels. In this study we examine a method to significantly reduce these artifacts. METHODS: We recently introduced a new "local-scrambling" approach that semi-randomizes the acquisition order of the phase encodes, to achieve a controllable cutoff frequency above which the artifacts are drastically reduced. With this approach, artifacts resulting from fast local fluctuations such as cardiac pulsation are significantly reduced. In this study, we explore the ability of this local-scrambling approach to reduce pulsatile blood flow artifacts in a 3D TOF acquisition. Cartesian line-by-line and center-out ordering, with and without local-scrambling, were compared in simulations and in human brain imaging at 3 and 7 T scanners. RESULTS: In the simulations the artifact intensity showed a 10-fold reduction using local-scrambling compared to line-by-line and 4-fold compared to center-out ordering. In vivo results show that artifacts are much more pronounced at 7 T compared to 3 T, and in both cases they are effectively reduced by local-scrambling. CONCLUSION: Local-scrambling improves image quality for both line-by-line and center-out ordering. This approach can easily be implemented in the scanner without any changes to the reconstruction.

Minimally invasive discectomy versus open laminectomy and discectomy for the treatment of cauda equina syndrome: A preliminary study and case series.

Background: Cauda Equina syndrome (CES) is a potentially devastating condition and is treated usually with urgent open surgical decompression of the spinal canal. Currently, the role of minimally invasive discectomy (MID) as an alternative surgical technique for CES is unclear. Objective: The purpose of this study was to compare clinical outcomes following MID and open laminectomy and discectomy for the treatment of CES. Methods: The study cohort included patients that underwent surgery due to CES at our institute. Patients' outcomes included: surgical complications, length of hospitalization, postoperative lower extremity motor score (LEMS), Numerical Rating Scale (NRS) for leg and back pain, Oswestry disability index (ODI), and the EQ-5D health-related quality of life questionnaire. Results: Twelve patients underwent MID and 12 underwent open laminectomy and discectomy. Complications and revisions rates were comparable between the groups. Postoperative urine incontinence and saddle dysesthesia improved in 50% of patients in both groups. LEMS improved from 47.08 ± 5.4 to 49.27 ± 0.9 in the MID group and from 44.46 ± 5.9 to 49.0 ± 1.4 in the open group. Although, leg pain improved in both groups from 8.4 ± 2.4 to 3 ± 2.1 in the MID and from 8.44 ± 3.3 to 3.88 ± 3 in the open group, significant improvement in back pain was found only in the MID group. Final functional scores were similar between groups. Conclusions: Our preliminary results suggest that minimally invasive discectomy is an effective and safe procedure for the treatment of CES when compared to open laminectomy and discectomy. However, MID in these cases should only be considered by surgeons experienced in minimally invasive spine surgery. Further studies with bigger sample sizes and long-term follow-ups are needed.

Posttraumatic Stress Symptoms After Stroke: The Effects of Anatomy and Coping Style.

BACKGROUND: Posttraumatic stress disorder (PTSD) can be triggered by life-threatening medical emergencies, such as stroke. Data suggest that up to 25% of stroke survivors will develop PTSD symptomatology, but little is known about predisposing factors. We sought to examine whether neuroimaging measures and coping styles are related to PTSD symptoms after stroke. METHODS: Participants were survivors of first-ever, mild-moderate ischemic stroke, or transient ischemic attack from the TABASCO study (Tel Aviv Brain Acute Stroke Cohort). All participants underwent a 3T magnetic resonance imaging at baseline and were examined 6, 12, and 24 months thereafter, using neurological, neuropsychological, and functional evaluations. At baseline, coping styles were evaluated by a self-reported questionnaire. PTSD symptoms were assessed using the PTSD checklist. Data were available for 436 patients. RESULTS: Forty-eight participants (11%) developed probable PTSD (PTSD checklist ≥44) during the first year after the stroke/transient ischemic attack. Stroke was more likely to cause PTSD than transient ischemic attack. Stroke severity, larger white matter lesion volume, and worse hippocampal connectivity were associated with PTSD severity, while infarct volume or location was not. In a multivariate analysis, high-anxious and defensive coping styles were associated with a 6.66-fold higher risk of developing poststroke PTSD ([95% CI, 2.08-21.34]; P<0.01) compared with low-anxious and repressive coping styles, after adjusting for age, education, stroke severity, brain atrophy, and depression. CONCLUSIONS: In our cohort, PTSD was a common sequela among stroke survivors. We suggest that risk factors for PTSD development include stroke severity, white matter damage, and premorbid coping styles. Early identification of at-risk patients is key to effective treatment.

The Interrelation Between Chronic Headache, Cognitive Scores, and MRI Markers Among Stroke Survivors.

BACKGROUND: Migraine is known to mildly increase the risk for ischemic stroke and is associated with vascular MRI markers. However, the potential effect of chronic headache (CH) on stroke outcomes has not been studied. OBJECTIVE: We aimed to assess the interrelation between CH and post-stroke cognitive impairment. METHODS: Data from 455 patients with a first ever stroke from the TABASCO study was available. All patients underwent 3T brain MRI, blood analysis, and a serial cognitive assessment at baseline and 6, 12, and 24 months after. RESULTS: Eighty-five (18.7%) patients reported suffering from CH, of whom 53 (62.4%) reported symptoms of photophobia or nausea, and 34 (40%) reported an aura. CH was associated with female sex, lower prevalence of T2DM (p < 0.001), and lower HbA1C levels (p < 0.001). Multiple regression analysis, controlling for age, sex, education, vascular risk factors, and the presence of acute lesions in MRI, revealed that CH was an independent predictor of better cognitive scores 6, 12, and 24 months post-stroke (p = 0.015, p = 0.01, and p = 0.012, respectively). Stroke patients suffering from CH had also higher normalized gray, white matter, and thalamus volumes, and better white matter microstructural integrity (p < 0.001, p = 0.037, p < 0.001, p = 0.008, respectively)Conclusion:In this study, CH was consistently associated with better long term cognitive scores among post stroke subjects. These surprising findings may partially arise from the higher prevalence of T2DM among subjects without CH, that may represent the existence of chronic cerebrovascular disease, and may reflect mechanisms involving glucose metabolism.

Working status is related to post stroke/TIA cognitive decline: data from the TABASCO study.

BACKGROUND AND AIMS: Occupational status may influence physical and mental post-stroke outcomes. We aimed to evaluate the association between occupational status and type, or engagement in social and family activities, neuroimaging measures and cognitive decline (CD) in a prospective cohort of stroke patients. METHODS: We included 273 first-ever stroke survivors at working age. All patients underwent 3T MRI at admission, as well as clinical and cognitive assessments at admission, 6, 12 and 24 months thereafter. RESULTS: Ninty nine (36.3%) of the participants were unemployed prior to the stroke. Age, sex, work type, other comorbidities, stroke severity or location were not associated with return to work. Patients who returned to work (87.4%) had better cognitive results and less depressive symptoms than those who retired after the event. Pre-stroke unemployment was associated with diabetes mellitus, hypertension, dyslipidemia, depression, poorer cognitive scores and brain atrophy. During the follow-up, 11% developed CD. CD was more common among previously unemployed than employed participants (19.2% vs. 6.3%, p = 0.001). Multiple regression adjusted for risk factors, revealed that pre-stroke unemployment was an independent predictor of CD (HR, 3.0; 95% CI: 1.06-8.44). Furthermore, engagement in mentally stimulating jobs decreased the risk for CD. CONCLUSIONS: Pre-stroke unemployment and post-stroke work disruption were each associated with depression and poorer cognitive performance up to two years post-stroke, as well as with brain atrophy at admission. Retirement after the stroke may increase the risk of developing CD. These results highlight the importance of continued employment in preserving cognitive abilities among stroke survivors.

Neuroanatomical Risk Factors for Posttraumatic Stress Disorder in Recent Trauma Survivors.

BACKGROUND: Low hippocampal volume could serve as an early risk factor for posttraumatic stress disorder (PTSD) in interaction with other brain anomalies of developmental origin. One such anomaly may well be the presence of a large cavum septum pellucidum (CSP), which has been loosely associated with PTSD. We performed a longitudinal prospective study of recent trauma survivors. We hypothesized that at 1 month after trauma exposure the relation between hippocampal volume and PTSD symptom severity will be moderated by CSP volume, and that this early interaction will account for persistent PTSD symptoms at subsequent time points. METHODS: One hundred seventy-one adults (87 women, average age 34.22 years [range, 18-65 years of age]) who were admitted to a general hospital's emergency department after a traumatic event underwent clinical assessment and structural magnetic resonance imaging within 1 month after trauma. Follow-up clinical evaluations were conducted at 6 (n = 97) and 14 (n = 78) months after trauma. Hippocampal and CSP volumes were measured automatically by FreeSurfer software and verified manually by a neuroradiologist (D.N.). RESULTS: At 1 month after trauma, CSP volume significantly moderated the relation between hippocampal volume and PTSD severity (p = .026), and this interaction further predicted symptom severity at 14 months posttrauma (p = .018). Specifically, individuals with a smaller hippocampus and larger CSP at 1 month posttrauma showed more severe symptoms at 1 and 14 months after trauma exposure. CONCLUSIONS: Our study provides evidence for an early neuroanatomical risk factors for PTSD, which could also predict the progression of the disorder in the year after trauma exposure. Such a simple-to-acquire neuroanatomical signature for PTSD could guide early management as well as long-term monitoring.

Tegmen attenuation in patients with idiopathic intracranial hypertension is progressive.

OBJECTIVES: To prove that temporal bone tegmen attenuation in patients with idiopathic intracranial hypertension (IIH) is progressive. STUDY DESIGN: Retrospective blind study at a tertiary academic medical center. METHODS: Enrolled were medical records of patients with IIH that included at least two sequential computed tomography (CT) scans. The vertical distances between the floor of the middle fossa to the superior and lateral semicircular canals (SSC and LSC, respectively), to the scutum and minimal squama thickness were measured. The same measurements were made in scans of control subjects. The impact of demographics and metabolic variables including opening lumbar puncture (LP) pressure were evaluated. RESULTS: Twenty medical records were enrolled. Median age at diagnosis was 21 years; 16 were females. The median body mass index (BMI) was 32 kg/m2 . Initial LP pressure was 195 mm cerebrospinal fluid (CSF). The median time interval between CT scans was 58 months. A median attenuation of 0.35 mm and 0.25 mm over the right and left LSC and of 0.5 mm and 0.3 mm over the right and left scutum, was found, respectively. The thicknesses of the SSC and squama remained stable. No attenuation was present in controls. The opening pressure on initial LP (median 195 mm CSF), was positively correlated with the degree of tegmen attenuation, but the age at diagnosis and BMI were not. CONCLUSIONS: Tegmen attenuation may be progressive in patients with idiopathic increased intracranial pressure and correlated with the opening pressure on LP. Tegmen defects and CSF leak should be looked for in these patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 2020.