Nonfocal transient neurological attacks are related to cognitive impairment in patients with heart failure

Introduction Nonfocal transient neurological attacks (TNAs) are associated with an increased risk of future dementia, but it is unclear whether TNAs are also associated with concurrent cognitive impairment. We hypothesized that recent TNAs are related to worse cognitive functioning. We tested our hypothesis in patients with heart failure, as these patients are at risk of cerebral hypoperfusion, which might play a role in the etiology of TNAs. Methods We performed neuropsychological testing in all patients with heart failure enrolled in the Heart Brain Connection study. We assessed global cognition, attention-psychomotor speed, executive functioning, memory and language. All patients were interviewed with a standardized questionnaire on the occurrence of TNAs in the preceding 6 months. We studied associations between TNAs and cognitive functioning with linear and logistic regression analyses, adjusted for age, sex and education. We performed additional analyses in patients without previous stroke or TIA and in patients without brain infarction on MRI. Results Thirty-seven (23%) of 158 patients (mean age 70 years, 67% men) experienced one or more TNAs. Patients with a recent TNA were more likely to be impaired on≥1 cognitive domains than patients without TNAs [41% vs. 18%, adjusted odds ratio 4.6, 95% confdence interval (CI) 1.8–11.8]. Patients with TNAs performed worse than patients without TNAs on global cognition (mean diference in z scores −0.36, 95% CI −0.54 to −0.18), and on the cognitive domains attentionpsychomotor speed (mean diference −0.40, 95% CI −0.66 to −0.14), memory (mean diference −0.57, 95% CI −0.98 to −0.15) and language (mean diference −0.47, 95% CI −0.79 to −0.16). These associations were independent of cardiac output and volume of white matter hyperintensities. Subgroup analyses in patients without previous stroke or TIA or brain infarction on MRI (n=78) yielded comparable results, with the exception of the cognitive domain language, which was no longer diferent between patients with and without TNAs. Conclusion Among patients with heart failure, TNAs are associated with cognitive impairment, which warrants the need for more clinical awareness of this problem

A novel diffusion-tensor MRI approach for skeletal muscle fascicle length measurements.

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Techniques and applications of skeletal muscle diffusion tensor imaging : A review

Diffusion tensor imaging (DTI) is increasingly applied to study skeletal muscle physiology, anatomy, and pathology. The reason for this growing interest is that DTI offers unique, noninvasive, and potentially diagnostically relevant imaging readouts of skeletal muscle structure that are difficult or impossible to obtain otherwise. DTI has been shown to be feasible within most skeletal muscles. DTI parameters are highly sensitive to patient-specific properties such as age, body mass index (BMI), and gender, but also to more transient factors such as exercise, rest, pressure, temperature, and relative joint position. However, when designing a DTI study one should not only be aware of sensitivity to the above-mentioned factors but also the fact that the DTI parameters are dependent on several acquisition parameters such as echo time, b-value, and diffusion mixing time. The purpose of this review is to provide an overview of DTI studies covering the technical, demographic, and clinical aspects of DTI in skeletal muscles. First we will focus on the critical aspects of the acquisition protocol. Second, we will cover the reported normal variance in skeletal muscle diffusion parameters, and finally we provide an overview of clinical studies and reported parameter changes due to several (patho-)physiological conditions

Techniques and applications of skeletal muscle diffusion tensor imaging: A review

Diffusion tensor imaging (DTI) is increasingly applied to study skeletal muscle physiology, anatomy, and pathology. The reason for this growing interest is that DTI offers unique, noninvasive, and potentially diagnostically relevant imaging readouts of skeletal muscle structure that are difficult or impossible to obtain otherwise. DTI has been shown to be feasible within most skeletal muscles. DTI parameters are highly sensitive to patient-specific properties such as age, body mass index (BMI), and gender, but also to more transient factors such as exercise, rest, pressure, temperature, and relative joint position. However, when designing a DTI study one should not only be aware of sensitivity to the above-mentioned factors but also the fact that the DTI parameters are dependent on several acquisition parameters such as echo time, b-value, and diffusion mixing time. The purpose of this review is to provide an overview of DTI studies covering the technical, demographic, and clinical aspects of DTI in skeletal muscles. First we will focus on the critical aspects of the acquisition protocol. Second, we will cover the reported normal variance in skeletal muscle diffusion parameters, and finally we provide an overview of clinical studies and reported parameter changes due to several (patho-)physiological condition

Techniques and applications of skeletal muscle diffusion tensor imaging : A review

Diffusion tensor imaging (DTI) is increasingly applied to study skeletal muscle physiology, anatomy, and pathology. The reason for this growing interest is that DTI offers unique, noninvasive, and potentially diagnostically relevant imaging readouts of skeletal muscle structure that are difficult or impossible to obtain otherwise. DTI has been shown to be feasible within most skeletal muscles. DTI parameters are highly sensitive to patient-specific properties such as age, body mass index (BMI), and gender, but also to more transient factors such as exercise, rest, pressure, temperature, and relative joint position. However, when designing a DTI study one should not only be aware of sensitivity to the above-mentioned factors but also the fact that the DTI parameters are dependent on several acquisition parameters such as echo time, b-value, and diffusion mixing time. The purpose of this review is to provide an overview of DTI studies covering the technical, demographic, and clinical aspects of DTI in skeletal muscles. First we will focus on the critical aspects of the acquisition protocol. Second, we will cover the reported normal variance in skeletal muscle diffusion parameters, and finally we provide an overview of clinical studies and reported parameter changes due to several (patho-)physiological conditions

Muscle changes detected with diffusion-tensor imaging after long-distance running

Purpose To develop a protocol for diffusion-tensor imaging (DTI) of the complete upper legs and to demonstrate feasibility of detection of subclinical sports-related muscle changes in athletes after strenuous exercise, which remain undetected by using conventional T2-weighted magnetic resonance (MR) imaging with fat suppression. Materials and Methods The research was approved by the institutional ethics committee review board, and the volunteers provided written consent before the study. Five male amateur long-distance runners underwent an MR examination (DTI, T1-weighted MR imaging, and T2-weighted MR imaging with fat suppression) of both upper legs 1 week before, 2 days after, and 3 weeks after they participated in a marathon. The tensor eigenvalues (λ1, λ2, and λ3), the mean diffusivity, and the fractional anisotropy (FA) were derived from the DTI data. Data per muscle from the three time-points were compared by using a two-way mixed-design analysis of variance with a Bonferroni posthoc test. Results The DTI protocol allowed imaging of both complete upper legs with adequate signal-to-noise ratio and within a 20-minute imaging time. After the marathon, T2-weighted MR imaging revealed grade 1 muscle strains in nine of the 180 investigated muscles. The three eigenvalues, mean diffusivity, and FA were significantly increased (P < .05) in the biceps femoris muscle 2 days after running. Mean diffusivity and eigenvalues λ1 and λ2 were significantly (P < .05) increased in the semitendinosus and gracilis muscles 2 days after the marathon. Conclusion A feasible method for DTI measurements of the upper legs was developed that fully included frequently injured muscles, such as hamstrings, in one single imaging session. This study also revealed changes in DTI parameters that over time were not revealed by qualitative T2-weighted MR imaging with fat suppression. © RSNA, 2014 Online supplemental material is available for this article

Nonfocal transient neurological attacks in patients with carotid artery occlusion

Introduction: Nonfocal transient neurological attacks (TNAs) are episodes with atypical, nonlocalizing cerebral symptoms. We examined the prevalence of nonfocal TNAs, in patients with and without carotid artery occlusion (CAO). Methods: We included 67 patients with CAO and 62 patients without CAO. In both groups, patients had a history of transient ischemic attack (TIA) or nondisabling ischemic stroke in the anterior circulation that had occurred >6 months before inclusion. Patients without CAO did not have ipsilateral or contralateral carotid artery stenosis of ≥50%. All patients were interviewed with a standardized questionnaire on the occurrence of nonfocal TNA symptoms during the preceding six months. We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for the occurrence of ≥1 and ≥2 different nonfocal TNAs after adjustments for age, sex, systolic blood pressure and time interval between most recent TIA or ischemic stroke and administration of the questionnaire. Results: Forty-three of all patients (33%) had had one or more nonfocal TNAs in the preceding six months. Nonrotatory dizziness (24%) was reported most often. The prevalence of ≥1 nonfocal TNAs was not significantly different between patients with and without CAO (39% vs. 27%; adjusted RR 1.47, 95% CI 0.83–2.61), but the prevalence of ≥2 or more different nonfocal TNAs was higher in patients with CAO (16% vs. 3%; adjusted RR 4.77, 95% CI 1.20–18.98). In patients with CAO who also had a contralateral carotid or vertebral artery steno-occlusion, nonfocal TNAs occurred more often than in patients without any carotid or vertebral artery steno-occlusion (46% vs. 27%; adjusted RR 2.22, 95% CI 1.08–4.60 for ≥1 and 21% vs. 3%; adjusted RR 8.27, 95% CI 1.83–37.32 for ≥2 nonfocal TNAs). Conclusions: Patients with CAO more often experienced multiple nonfocal TNAs than patients without CAO