Rapid recovery of poststroke cardiac autonomic dysfunction: Causes to be considered.

BACKGROUND AND PURPOSE: Acute stroke frequently causes cardiovascular-autonomic dysfunction (CAD). Studies of CAD recovery are inconclusive, whereas poststroke arrhythmias may wane within 72 h. We evaluated whether poststroke CAD recovers within 72 h upon stroke onset in association with neurological improvement or increased use of cardiovascular medication. METHODS: In 50 ischemic stroke patients (68 ± 13 years old) who-prior to hospital-admission-had no known diseases nor took medication affecting autonomic modulation, we assessed National Institutes of Health Stroke Scale (NIHSS) scores, RR intervals (RRIs), systolic and diastolic blood pressure (BP), respiration rate, parameters reflecting total autonomic modulation (RRI SD, RRI total powers), sympathetic modulation (RRI low-frequency powers, systolic BP low-frequency powers), and parasympathetic modulation (square root of mean squared differences of successive RRIs [RMSSD], RRI high-frequency powers), and baroreflex sensitivity within 24 h (Assessment 1) and 72 h after stroke onset (Assessment 2) and compared data to those of 31 healthy controls (64 ± 10 years). We correlated delta NIHSS values (Assessment 1 - Assessment 2) with delta values of autonomic parameters (Spearman rank correlation tests; significance: p < 0.05). RESULTS: At Assessment 1, patients were not yet on vasoactive medication and had higher systolic BP, respiration rate, and heart rate, that is, lower RRIs, but lower RRI SD, RRI coefficient of variance, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, RMSSDs, and baroreflex sensitivity. At Assessment 2, patients were on antihypertensives, had higher RRI SD, RRI coefficient of variance, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, RMSSDs, and baroreflex sensitivity but lower systolic blood pressure and NIHSS values than at Assessment 1; values no longer differed between patients and controls except for lower RRIs and higher respiration rate in patients. Delta NIHSS scores correlated inversely with delta values of RRI SD, RRI coefficient of variance, RMSSDs, RRI low-frequency powers, RRI high-frequency powers, RRI total powers, and baroreflex sensitivity. CONCLUSIONS: In our patients, CAD recovery was almost complete within 72 h after stroke onset and correlated with neurological improvement. Most likely, early initiation of cardiovascular medication and probably attenuating stress supported rapid CAD recovery.

High NIHSS values predict impairment of cardiovascular autonomic control.

BACKGROUND AND PURPOSE: Stroke is frequently associated with autonomic dysfunction, which causes secondary cardiovascular complications. Early diagnosis of autonomic imbalance prevents complications, but it is only available at specialized centers. Widely available surrogate markers are needed. This study tested whether stroke severity, as assessed by National Institutes of Health Stroke Scale (NIHSS) scores, correlates with autonomic dysfunction and thus predicts risk of autonomic complications. METHODS: In 50 ischemic stroke patients, we assessed NIHSS scores and parameters of autonomic cardiovascular modulation within 24 hours after stroke onset and compared data with that of 32 healthy controls. We correlated NIHSS scores with parameters of total autonomic modulation (total powers of R-R interval [RRI] modulation; RRI standard deviation [RRI-SD], RRI coefficient of variation), parasympathetic modulation (square root of the mean squared differences of successive RRIs, RRI-high-frequency-powers), sympathetic modulation (normalized RRI-low-frequency-powers, blood pressure-low-frequency-powers), the index of sympatho-vagal balance (RRI-LF/HF-ratios), and baroreflex sensitivity. RESULTS: Patients had significantly higher blood pressure and respiration, but lower RRIs, RRI-SDs, RRI coefficient of variation, square root of the mean squared differences of successive RRIs, RRI-low-frequency-powers, RRI-high-frequency-powers, RRI-total powers, and baroreflex sensitivity than did controls. NIHSS scores correlated significantly with normalized RRI-low-frequency-powers and RRI-LF/HF-ratios, and indirectly with RRIs, RRI-SDs, square root of the mean squared differences of successive RRIs, RRI-high-frequency-powers, normalized RRI-high-frequency-powers, RRI-total-powers, and baroreflex sensitivity. Spearman-Rho values ranged from 0.29 to 0.47. CONCLUSIONS: Increasing stroke severity was associated with progressive loss of overall autonomic modulation, decline in parasympathetic tone, and baroreflex sensitivity, as well as progressive shift toward sympathetic dominance. All autonomic changes put patients with more severe stroke at increasing risk of cardiovascular complications and poor outcome. NIHSS scores are suited to predict risk of autonomic dysregulation and can be used as premonitory signs of autonomic failure.

Status epilepticus in the elderly-A retrospective study on 120 patients.

PURPOSE: Status epilepticus (SE) is one of the most common neurological emergencies with a high incidence in the elderly. Major determinants of prognosis are patients' age, duration of SE and underlying etiology. We aimed identifying differences in clinical presentation of SE, etiologies and outcome between patients (pts.) sixty years or older (≥60) and younger than sixty (<60) years (yrs). METHODS: We retrospectively analyzed 120 patients (48 women) with SE admitted to the Neurological Intensive Care Unit (NICU), Department of Neurology, Paracelsus Medical University Salzburg, Austria between 1/2011 and 01/2013. KEY FINDINGS: Median age was 69 years (range 14-90) (63% ≥60yrs). Generalized tonic clonic SE was the most common SE type, whereas non convulsive SE with and without coma tended to occur more frequently in the elderly (33% ≥60 yrs. vs. 20%<60 yrs, Chi2=3.511, p=0.061). Preexisting history of epilepsy was more common in the younger age group (64% vs 41% p=0.014). An acute symptomatic cause of SE was identified in 25% (31/120), with cerebrovascular diseases being more frequent in the elderly (47% vs. 11%; p<0.01). Duration of SE did not differ between the age groups (p=0.63). Mortality was higher in elderly patients (31% vs. 7%, p=0.028, Chi Square=5.18) and moderate disability in younger patients (42% vs 17%; p=0.005, Chi Square=7.83). After Bonferroni correction only the higher rate of cerebrovascular etiologies in the elderly was statistically significant. SIGNIFICANCE: In the elder population, SE occurs more often in patients without preexisting epilepsy and is most frequently caused by cerebrovascular diseases. NCSE tends to be more frequent in the elderly and diagnosis is complicated by subtle clinical presentation. Even though comorbidities represent treatment limitations, in our sample no differences in choice of AED as well as dosage were observed between the age groups, reflecting a trend toward AEDs with more favorable adverse event profile in all patients. SE in older patients is associated with poorer outcome and higher mortality.