Can an active lifestyle offset the relationship that poor lifestyle behaviours have on frailty?

OBJECTIVE: To examine the association of lifestyle behaviours (LSB) with physical activity (PA) and frailty; also, to examine if associations differ by sex and age. METHODS: 24,828 individuals [49.6 ± 17.6 years (range: 20-85), 51.6 % female] from the National Health and Nutrition Examination Survey (cycles 2009-2018) were included. Individuals were divided into Active (≥150 min/week of moderate-to-vigorous physical activity (MVPA)) and Inactive (<150 min/week MVPA) based on self-reported PA. Frailty was measured by a 46-item Frailty Index (FI). LSB consisted of stationary time, sleep, diet quality, and alcohol and smoking habits. LSB was summed into a score [0-5]. Linear regression models were used with each LSB in isolation and the summed LSB with frailty. RESULTS: There were 7,495 (30.1 %) Active and 17,333 (69.8 %) Inactive individuals. The FI was lower in the Active participants (Active: 0.10 ± 0.08; Inactive: 0.15 ± 0.12; p < 0.01). A worse LSB score was associated with an increased FI in all behaviours but females who binge drink and smoke (p-all>0.14). For inactive individuals, all LSBs were associated with an increased FI except those who binge drink and male smokers (p = 0.08). There was a significant association between increased summed LSB and an increased FI (ß range: Active, 0.024-0.037; Inactive, 0.028, 0.046. p-all<0.01); the Active group had a lower FI at every age group than the Inactive group (p < 0.001). CONCLUSION: PA was associated with a lower FI even among those with a poor LSB score. This association is dependent on age, with older individuals reporting a stronger association.

Knee-high compression socks minimize head-up tilt-induced cerebral and cardiovascular responses following dynamic exercise.

In healthy individuals during a non-exercised state, knee-high compression socks (CS) may reduce the magnitude of lower limb venous pooling during orthostasis but are not effective at minimizing the incidence of pre-syncopal symptoms. However, exaggerated reductions in cerebral blood flow velocity (CBV) and cardiac stroke volume (SV) occur during passive head-up tilt (HUT) testing following dynamic exercise. It is unknown if CS can minimize post-exercise HUT-induced decrements in CBV and SV in this population. To test the hypothesis that CS will attenuate the reductions in SV and CBV during 60° HUT following 60 minutes of moderate-intensity (60% VO2 peak) cycling exercise. Ten healthy volunteers (22.6 ± 2.1 years, 24.1 ± 2.5 kg/m2 ) completed pre- and post-exercise 15-minute HUT tests during randomized CS and Control (no CS) conditions. Changes in blood pressure (finger plethysmography), SV (Modelflow® method), and CBV (Transcranial Doppler) were measured during HUT and preceding supine rest periods. Pre-exercise HUT-induced similar (all, P > .47) reductions in SV (Control; -23.1 ± 11.5%, CS; -20.5 ± 10.9%) and CBV (Control; -18.1 ± 6.3%, CS; -15.3 ± 9.0%). However, larger post-exercise decreases in SV and CBV during HUT were observed in the Control versus CS condition. Specifically, CS attenuated the drop in SV (Control: -32.9 ± 5.6%, CS: -24.3 ± 11.6%; P = .01) and CBV (Control: -25.1 ± 5.8%, CS: -17.6 ± 7.8%; P = .02) during the post-exercise HUT test. These results indicate that CS attenuated HUT-induced reductions in SV and CBV following moderate-intensity cycling exercise and suggest that CS may be an effective countermeasure to reduce the incidence of post-exercise syncope in vulnerable populations.

Evolution of cerebral infarct volume assessed by diffusion-weighted magnetic resonance imaging.

BACKGROUND: Knowledge of the natural evolution of ischemic brain lesions may be a crucial aspect in the assessment of future stroke therapies. OBJECTIVE: To establish daily changes of ischemic cerebral lesion volume using diffusion-weighted magnetic resonance imaging. DESIGN: Prospective cohort study. SETTING: Referral center. PATIENTS AND METHODS: Serial magnetic resonance imaging scans were performed in consecutive untreated stroke patients. The baseline scan was obtained within 48 hours after symptom onset; subsequent scans, 12 to 48 hours, 3 to 4 days, 5 to 7 days, and 30 days after baseline. Lesion volumes were measured on each scan by 2 independent observers. MAIN OUTCOME MEASURE: Daily change in lesion volume. RESULTS: A total of 112 magnetic resonance imaging scans were obtained in 24 patients. An early increase in lesion volume was seen in all patients. Maximum lesion volume was reached at a mean of 74 hours. Lesion volumes increased by a mean (+/- SEM) of 21% +/- 12% during day 2 and 10% +/- 12% during day 3. No significant change occurred during day 4. During days 5, 6, and 7, statistically significant mean (+/- SEM) decreases of 6% +/- 8%, 3% +/- 4%, and 4% +/- 5%, respectively, were observed. CONCLUSIONS: Ischemic lesions follow a relatively consistent pattern of growth during the first 3 days and subsequent decrease in size. These data in conjunction with data regarding the evolution of lesion volume during the first 24 hours after symptom onset may be useful in the design of pilot studies of therapies for acute stroke.

Evolution of apparent diffusion coefficient, diffusion-weighted, and T2-weighted signal intensity of acute stroke.

BACKGROUND AND PURPOSE: Serial study of such MR parameters as diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), ADC with fluid-attenuated inversion recovery (ADC(FLAIR)), and T2-weighted imaging may provide information on the pathophysiological mechanisms of acute ischemic stroke. Our goals were to establish the natural evolution of MR signal intensity characteristics of acute ischemic lesions and to assess the potential of using specific MR parameters to estimate lesion age. METHODS: Five serial echo-planar DWI studies with and without an inversion recovery pulse were performed in 27 patients with acute stroke. The following lesion characteristics were studied: 1) conventional ADC (ADC(CONV)); 2) ADC(FLAIR); 3) DWI signal intensity (SI(DWI)); 4) T2-weighted signal intensity (SI(T2)), and 5) FLAIR signal intensity (SI(FLAIR)). RESULTS: The lesion ADC(CONV) gradually increased from low values during the first week to pseudonormal during the second week to supranormal thereafter. The lesion ADC(FLAIR) showed the same pattern of evolution but with lower absolute values. A low ADC value indicated, with good sensitivity (88%) and specificity (90%), that a lesion was less than 10 days old. All signal intensities remained high throughout follow-up. SI(DWI) showed no significant change during the first week but decreased thereafter. SI(T2) initially increased, decreased slightly during week 2, and again increased after 14 days. SI(FLAIR) showed the same initial increase as the SI(T2) but remained relatively stable thereafter. CONCLUSION: Our findings further clarify the time course of stroke evolution on MR parameters and indicate that the ADC map may be useful for estimating lesion age. Application of an inversion recovery pulse results in lower, potentially more accurate, absolute ADC values.

Yield of diffusion-weighted MRI for detection of potentially relevant findings in stroke patients.

OBJECTIVE: To determine whether diffusion-weighted imaging (DWI) could identify potentially clinically relevant findings in patients presenting more than 6 hours after stroke onset when compared with conventional MRI. METHODS: MRI with both conventional (T2 and proton density images) and echoplanar imaging (DWI and apparent diffusion coefficient maps) was performed 6 to 48 hours after symptom onset (mean, 27 hours) in 40 consecutive patients with acute stroke. All acute lesions were identified first on conventional images, then on DWI, by a neuroradiologist who was provided with the suspected lesion location, based on a neurologist's examination before imaging. Abnormalities were rated as potentially clinically relevant if they were detected only on DWI and 1) confirmed the acute symptomatic lesion to be in a different vascular territory than suspected clinically, 2) revealed multiple lesions in different vascular territories suggestive of a proximal source of embolism, or 3) clarified that a lesion, thought to be acute on conventional imaging, was not acute. RESULTS: The initial clinical impression of lesion localization was incorrect in 12 patients (30%). Clinically significant findings were detected by DWI alone in 19 patients (48%). DWI demonstrated the symptomatic lesion in a different vascular territory than suspected clinically or by conventional MRI in 7 patients (18%) and showed acute lesions in multiple vascular distributions in 5 patients (13%). In 8 patients (20%), DWI clarified that lesions thought to be acute on conventional MRI were actually old. CONCLUSION: In patients imaged 6 to 48 hours after stroke onset, DWI frequently provided potentially clinically relevant findings that were not apparent on conventional MRI.

Basilar artery stenosis: clinical and neuroradiographic features.

INTRODUCTION: Although basilar artery stenosis (BAS) is an important cause of posterior circulation stroke, few reports detail the clinical and neuroradiological features of patients with BAS. METHODS: A retrospective review of symptomatic BAS patients who were evaluated by our Stroke Center. RESULTS: Twenty-eight patients were followed-up for a median of 16 months. Transient ischemic attacks (TIAs) specific for posterior circulation involvement were common (12/19 patients with TIA), were often multiple, and frequently preceded a posterior circulation stroke. The proximal (13/28) and mid (10/28) basilar arteries were the most common sites of stenosis. Brain infarction most often affected the pons, but also frequently involved the cerebellum and thalamus. Concomitant vertebral artery disease was prevalent (12/18 patients who underwent conventional cerebral angiography). Stroke mechanisms included artery to artery embolus, basilar branch disease, and hypoperfusion. The same-territory recurrent stroke rate was 8.2% per year. Most patients in the series were treated with warfarin. No patients suffered a recurrent stroke while on a therapeutic dose of warfarin (international normalized ratio [INR], 2.0 to 3.0). Angioplasty was performed in 6 patients. CONCLUSIONS: The same-territory stroke recurrence rate was 8.2% per year. Warfarin (INR, 2.0 to 3.0) appeared to be effective in preventing recurrent strokes. Angioplasty of the basilar artery was technically feasible. Symptomatic BAS typically affected the proximal and mid-basilar artery and most often caused infarction in the pons. The mechanisms for stroke were heterogeneous. TIAs frequently preceded a posterior circulation stroke.

Pulsed-field gel electrophoresis is a useful tool in the monitoring of methicillin-resistant Staphylococcus aureus epidemic outbreaks in the intensive care unit.

We wished to determine how pulsed-field gel electrophoresis may be of use in monitoring methicillin-resistant Staphylococcus aureus (MRSA) outbreaks in the intensive care unit (ICU). A retrospective epidemiological analysis was conducted. All 27 ICU patients and 11 patients from other hospital wards from whom MRSA was isolated over a one year period were included in the study. Seventeen of the 27 ICU MRSA isolates were analysed by pulsed-field gel electrophoresis for clonality and compared with the 11 other hospital isolates genotypes over the same period. During three MRSA outbreaks, five MRSA genotypes were identified in ICU whilst the same five genotypes and three additional were found in the rest of the hospital. Pulsed-field gel electrophoresis analysis was useful in identifying clonality of ICU MRSA infections and establishing that they were imported from hospital wards, rather than arising de novo in ICU. We were further able to identify clonal clusters within the unit linked by temporal and geographical proximity, suggestive of cross-infection. Pulsed-field gel electrophoresis typing might be additionally useful in tracing the source of human and/or environmental factors if a genotype were persistently identified.

MRI abnormalities associated with partial status epilepticus.

OBJECTIVE: To report neuroimaging findings in patients with complex partial status epilepticus. BACKGROUND: During status epilepticus, neuroimaging may be used to exclude other neurologic conditions. Therefore, it is important to identify the neuroimaging features that are associated with status epilepticus. In addition, MRI characteristics may provide insight into the pathophysiologic changes during status epilepticus. METHODS: The history and neuroimaging examination results of three patients with complex partial status epilepticus were reviewed. Studies obtained during status epilepticus included diffusion-weighted MRI (DWI), MR angiography (MRA), postcontrast T1-weighted MRI, T2-weighted MRI, and CT. Follow-up MRI was obtained in two patients, and autopsy results were available for the third. RESULTS: Some of the MRI and CT findings during partial status epilepticus mimicked those of acute ischemic stroke: DWI and T2-weighted MRI showed cortical hyperintensity with a corresponding low apparent diffusion coefficient, and CT showed an area of decreased attenuation with effacement of sulci and loss of gray-white differentiation. However, the lesions did not respect vascular territories, there was increased signal of the ipsilateral middle cerebral artery on MRA, and leptomeningeal enhancement appeared on postcontrast MRI. On follow-up imaging, the abnormalities had resolved, but some cerebral atrophy was present. CONCLUSIONS: The radiologic characteristics of status epilepticus resemble those of ischemic stroke but can be differentiated based on lesion location and findings on MRA and postcontrast MRI. The MRI abnormalities indicated the presence of cytotoxic and vasogenic edema, hyperperfusion of the epileptic region, and alteration of the leptomeningeal blood-brain barrier. These changes reversed, but they resulted in some regional brain atrophy.

Diffusion-weighted MRI in transient global amnesia precipitated by cerebral angiography.

BACKGROUND: Transient global amnesia is a well-described complication of cerebral angiography. Speculation about the pathophysiology exists but is as yet unsubstantiated. Diffusion-weighted MRI is a new imaging technique that is very sensitive in detecting acute ischemia. Its use in the evaluation of transient amnesia precipitated by cerebral angiography has not previously been reported. CASE DESCRIPTION: A 44-year-old man underwent posterior circulation cerebral angiography for the investigation of episodic vertigo. Shortly after completion of the procedure, he was noted to have symptoms of transient global amnesia. Diffusion-weighted MRI at 6 and 44 hours after the procedure demonstrated increased signal in the right hippocampus and other areas within the posterior circulation bilaterally consistent with ischemia from emboli. Abnormalities on conventional MRI images performed at the same time points were noted only in retrospect. A follow-up MRI at 2 months was normal. CONCLUSIONS: Ischemia from cerebral emboli may cause transient global amnesia precipitated by cerebral angiography. Diffusion-weighted MRI may be useful in defining the pathophysiology.

Types of affective response to stroke.

Most studies of depression after stroke have included heterogeneous samples of patients. These studies have generally not qualified patients as to age, absence of neurologic, psychiatric, and substance abuse histories, and other complicating factors. Of 155 inpatient rehabilitation admissions after acute unilateral cerebrovascular accident, only 26 met the following strict criteria for inclusion: age older than 55 years, no history of or concomitant brain disease or injury, and no history of major affective, thought, or substance abuse disorder. Two examiners independently administered the Hamilton Depression Rating Scale, a mood adjective checklist, and a modified Mini-Mental State Examination to 20 subjects who agreed to participate. They also rated subjects on research diagnostic criteria for depression and obtained a dexamethasone suppression test for each subject. Eighteen subjects completed neuropsychologic evaluation. All evaluations were completed within six weeks of the patient's stroke. Subjects fell into four distinct clinical groups based on averaged data: (1) no affective symptoms, (2) verbal distress only, (3) vegetative symptoms only, and (4) a combined disorder with both distress and vegetative symptoms. The presence of verbal reports of distress, vegetative signs, or both were associated with longer hospital stays and greater neuropsychologic impairment.