Dietary nitrate reduces blood pressure and cerebral artery velocity fluctuations and improves cerebral autoregulation in transient ischemic attack patients.

Accentuated blood pressure (BP) fluctuation and low cerebral blood flow (CBF) response to CO2 increase the risk of transient ischemic attack (TIA) recurrence and stroke in TIA patients. Improving cardio- and cerebrovascular function may reduce stroke risk. We found dietary nitrate lowered dynamic blood pressure variability (BPV) in rats and improved cerebrovascular CO2 reactivity in healthy individuals. In 30 TIA patients, we examined the effects of a 7-day supplementation of dietary nitrate (0.1 mmol·kg-1·day-1) on cerebrovascular function using a randomized, single-blinded, placebo-controlled study design. We hypothesized that 7-day dietary nitrate supplementation would decrease variabilities in BP and CBF and improve CBF-CO2 slope and cerebral autoregulation (CA). We assessed beat-to-beat middle cerebral artery blood velocity (MCAv; index of CBF) and BP at rest and during CO2 breathing. Transfer function analysis was performed on beat-to-beat MCAv and BP to determine CA parameters (gain, phase, and coherence). Irrespective of treatment, high- and low-frequency BP-MCAv gain and MCAv-CO2 slope increased 7 days following TIA onset, while low-frequency BPV decreased (P < 0.05 vs. baseline). At follow-up, dietary nitrate elevated plasma nitrate concentration by ~547% (P < 0.001) and moderately lowered BPV (d = 0.6, P = 0.011), MCAv variability (d = 0.7, P = 0.018), and BP-MCAv coherence (d = 0.7, P = 0.008) in the very-low-frequency range (0.02-0.07 Hz), while MCAv-CO2 slope and arterial stiffness were unaffected (P > 0.05). Concurrent with standard treatment, dietary nitrate supplementation reduces BP and CBF fluctuation and improves cerebral autoregulation in TIA patients, without affecting cerebrovascular CO2 reactivity.NEW & NOTEWORTHY We found dietary nitrate supplementation reduced blood pressure and brain blood flow fluctuations and improved the relationship between blood pressure and brain blood flow in transient ischemic attack patients. Meanwhile, dietary nitrate had no effects on the brain blood vessels' response to CO2. We attribute the improved brain blood flow stability to the improved myogenic control of blood pressure with dietary nitrate. Our findings indicate that dietary nitrate could be an effective strategy for stabilizing blood pressure and brain blood flow following transient ischemic attack.

Do clinical nurse specialist led stroke follow-up clinics reduce post-stroke hospital readmissions and recurrent vascular events?

BACKGROUND: Post-discharge stroke follow-up clinics intend to improve care and may reduce readmission. Pre-2013, there was no consistent post-stroke specialist follow up offered at Wellington Hospital. We tested whether the establishment of a clinical nurse specialist follow-up clinic reduced the 12-month readmission rate. METHODS: This is a sequential comparison of stroke patients admitted 1 year prior and 1 year after clinic establishment in 2013. The primary outcome was 12-month hospital readmission rate; main secondary outcomes were guideline adherence and recurrent vascular events. Patients were identified from hospital discharge records and underwent chart review. We adjusted results for differences in baseline characteristics. RESULTS: We identified 603 eligible patients; 288 pre- and 315 post-nurse clinic implementations. There was no difference based on study cohort in the 1-year readmission rate (adjusted odds ratio (aOR) = 1.14; 95% CI, 0.7-1.89; P = 0.583), or recurrent composite vascular events at 1 year (aOR = 1.56; 95% CI, 0.89-2.9; P = 0.159). When looking at clinic attendance as the main variable of interest, a pre-specified sub-group analysis, there was a significant difference in implementation of best medical therapy (aOR 2.66 (1.19-5.94); P = 0.017), and a trend towards reduction of vascular events and/or death at 1 year post discharge (aOR 0.53 (0.28-1.02); P = 0.056). CONCLUSIONS: There was no reduction in the 1-year hospital readmission or vascular event recurrence rate for patients admitted with stroke following the establishment of a specialist nurse-led stroke follow-up clinic. Actual clinic attendance, however, did appear to confer some benefit. This study suggests that more consistent and potentially earlier timed follow up is probably desirable.

Decompressive hemicraniectomy after malignant middle cerebral artery infarction: does hospital of origin matter?

Decompressive hemicraniectomy (DHC) has been shown to reduce mortality in malignant middle cerebral artery (MCA) infarction. Our primary objective was to compare 1-year mortality between patients receiving DHC for malignant MCA infarction at our institution based on hospital of origin. We retrospectively reviewed the medical records of all patients treated for malignant MCA infarction with DHC at our institution over a 3-year period. One-year mortality rates and time to surgery were comparable regardless of whether the patient first attended the tertiary referral centre or a peripheral centre.

Impact and implementation of a sustainable regional telestroke network.

BACKGROUND: Telestroke uses videoconferencing technology to allow off-site experts to provide stroke thrombolysis decision support to less experienced front line clinicians. AIM: To assess the impact of a new telestroke service on thrombolysis rates and door-to-needle times in participating provincial hospitals and service resources to aid transition to a sustainable telestroke service. METHODS: This is a sequential comparison of 'pre' (December 2015 to May 2016) and 'post' (June 2016 to December 2016) implementation outcomes. The main outcomes were thrombolysis rate and door-to-needle time. All patient data were captured prospectively in a central database. Data captured and analysed also included technical problems, consumer and clinician feedback, and additional service resources required. RESULTS: Over the study period, 164 telestroke assessments were completed, including the 'hub' hospital. Among the participating provincial hospitals, 21 of 343 patients (6.1%) were thrombolysed in the 6-months prior to June 2016 and 50 of 318 patients (15.7%) during the 6-month following implementation of telestroke; odds ratio 2.86 (95% confidence interval 1.68-4.89); P = 0.0001. Overall, mean (standard deviation) regional hospital door-to-needle time reduced from 79.6 (31.4) to 62.7 (23.3) min (P = 0.015). Videoconferencing failure occurred in 4.8% of cases. Consumer and clinician feedback was positive. The main resource challenge was doubling of out-of-hours neurologist workload. CONCLUSION: Telestroke was associated with a significant increase in thrombolysis rate and reduction in door-to-needle time in provincial hospitals indicating improved patient care. Quantification of the extra neurologist workload allowed for a seamless transition to 'business as usual' using a novel annual subscription funding and service model.

Neuromyelitis optica presenting as acute bilateral ptosis.

Acute bilateral ptosis can be a hallmark of several serious neurological conditions. We present the first case of acute bilateral near-complete ptosis secondary to neuromyelitis optica spectrum disorder. We suggest that clinicians should consider this disorder among the differential diagnosis of acute bilateral ptosis, especially if there are other brainstem signs.

Long-Term Effect of Participation in an Early Exercise and Education Program on Clinical Outcomes and Cost Implications, in Patients with TIA and Minor, Non-Disabling Stroke.

Participation in exercise and education programs following transient ischemic attack (TIA) or minor stroke may decrease cardiovascular disease risk. The purpose of this study was to assess the long-term effect (3.5 years) of an exercise and education program administered soon after TIA or minor stroke diagnosis on clinical outcome measures (stroke classification and number, patient deaths, hospital/emergency department admission) and cost implications obtained from standard hospital records. Hospital records were screened for 60 adults (male, n = 31; 71 ± 10 years), diagnosed with TIA or non-disabling stroke, who had previously been randomised and completed either an 8-week exercise and education program, or usual care control. Follow-up clinical outcomes and cost implications were obtained 3.5 ± 0.3 years post-exercise. Participants randomised to the exercise and education program had significantly fewer recurrent stroke/TIAs (n = 3 vs. n = 13, Cohen's d = 0.79) than the control group (P ≤ 0.003). Similar finding were reported for patient deaths (n = 0 vs. n = 4, d = 0.53), and hospital admissions (n = 48 vs. n = 102, d = 0.54), although these findings were only approaching statistical significance. The relative risk (mean; 95%CI) of death, stroke/TIAs and hospital admissions were 0.11 (0.01 to 1.98), 0.23 (0.07 to 0.72) and 0.79 (0.57 to 1.09), respectively. Hospital admission costs were significantly lower for the exercise group ($9041 ± 15,080 NZD [~$6000 ± 10,000 USD]) than the control group ($21,750 ± 22,973 NZD [~$14,000 ± 15,000 USD]) during the follow-up period (P < 0.05, d = 0.69). The present study demonstrates the long-term patient benefit and economic importance of providing secondary prevention, exercise and education programs for patients with TIA and minor stroke. URL: http://www.anzctr.org.au/ ; Trial Registration Number: ACTRN12611000630910.

Stroke thrombolysis in New Zealand: data from the first 6 months of the New Zealand Thrombolysis Register.

The New Zealand National Stroke Network introduced a National Stroke Thrombolysis Register on the first of January 2015 to assist with quality assurance and continuous service improvement. In the first 6 months, there were 179 [75 women, mean (SD) age 69.9 (14) years] treated with stroke thrombolysis out of a total of 2,796 ischaemic stroke patients, giving a national thrombolysis rate of 6.4%. The median [Inter-quartile range (IQR)] onset-to-treatment time was 154 (125-190) minutes, and the median (IQR) door-to-needle time was 74.5 (55.7-105.0) minutes. The rate of symptomatic intracranial haemorrhage following thrombolysis was 4.4%. These results are similar to other international centres, and indicate an approximate doubling of the proportion of stroke patients treated with stroke thrombolysis since a 2009 national audit. However, there is need for on-going efforts to improve treatment rates and process efficiency, particularly door-toneedle times.

Hemodynamic variability and cerebrovascular control after transient cerebral ischemia.

We investigated if hemodynamic variability, cerebral blood flow (CBF) regulation, and their interrelationships differ between patients with transient ischemic attack (TIA) and controls. We recorded blood pressure (BP) and bilateral middle cerebral artery flow velocity (MCAv) in a cohort of TIA patients (n = 17), and age-matched controls (n = 15). Spontaneous fluctuations in BP and MCAv were characterized by spectral power analysis, and CBF regulation was assessed by wavelet phase synchronization analysis in the very low- (0.02-0.07 Hz), low- (0.07-0.20 Hz), and high-frequency (0.20-0.40 Hz) ranges. Furthermore, cerebrovascular CO2 reactivity was assessed as a second metric of CBF regulation by inducing hypercapnia with 8% CO2 inhalation followed by hyperventilation driven hypocapnia. We found that TIA was associated with higher BP power (group effect, P < 0.05), but not MCAv power (P = 0.11). CBF regulation (assessed by wavelet phase synchronization and CO2 reactivity) was intact in patients (all P ≥ 0.075) across both hemispheres (all P ≥ 0.51). Pooled data (controls and affected hemisphere of patients) showed that BP and MCAv power were positively correlated at all frequency ranges (R(2) = 0.20-0.80, all P < 0.01). Furthermore, LF phase synchronization index was a significant determinant of MCAv power (P < 0.05), while VLF and HF phase synchronization index, and TIA were not (all P ≥ 0.50). These results indicate that CBF stability and control is maintained in TIA patients, but BPV is markedly elevated. BPV attenuation may be an important therapeutic strategy for enhancing secondary stroke prevention in patients who suffer a TIA.