Rainer Dziewas

Cervical artery dissection—clinical features, risk factors, therapy and outcome in 126 patients

Abstract.The highly variable clinical course of cervical artery dissections still poses a major challenge to the treating physician. This study was conducted (1) to describe the differences in clinical and angiographic presentation of patients with carotid and vertebral artery dissections (CAD, VAD), (2) to define the circumstances that are related to bilateral arterial dissections, and (3) to determine factors that predict a poor outcome. Retrospectively and by standardised interview, we studied 126 patients with cervical artery dissections. Preceding traumata, vascular risk factors, presenting local and ischemic symptoms, and patientoutcome were evaluated. Patients with CAD presented more often with a partial Horner’s syndrome and had a higher prevalence of fibromuscular dysplasia than patients with VAD. Patients with VAD complained more often of neck pain, more frequently reported a preceding chiropractic manipulation and had a higher incidence of bilateral dissections than patients with CAD. Bilateral VAD was significantly related to a preceding chiropractic manipulation. Multivariate analysis showed that the variables stroke and arterial occlusion were the only independent factors associated with a poor outcome. This study emphasises the potential dangers of chiropractic manipulation of the cervical spine. Probably owing to the systematic use of forceful neck-rotation to both sides, this treatment was significantly associated with bilateral VAD. Patients with dissection-related cervical artery occlusion had a significantly increased risk of suffering a disabling stroke.

Pneumonia in acute stroke patients fed by nasogastric tube

Background: Aspiration pneumonia is the most important acute complication of stroke related dysphagia. Tube feeding is usually recommended as an effective and safe way to supply nutrition in dysphagic stroke patients. Objective: To estimate the frequency of pneumonia in acute stroke patients fed by nasogastric tube, to determine risk factors for this complication, and to examine whether the occurrence of pneumonia is related to outcome. Methods: Over an 18 month period a prospective study was done on 100 consecutive patients with acute stroke who were given tube feeding because of dysphagia. Intermediate outcomes were pneumonia and artificial ventilation. Functional outcome was assessed at three months. Logistic regression and multivariate regression analyses were used, respectvely, to identify variables significantly associated with the occurrence of pneumonia and those related to a poor outcome. Results: Pneumonia was diagnosed in 44% of the tube fed patients. Most patients acquired pneumonia on the second or third day after stroke onset. Patients with pneumonia more often required endotracheal intubation and mechanical ventilation than those without pneumonia. Independent predictors for the occurrence of pneumonia were a decreased level of consciousness and severe facial palsy. The NIH stroke scale score on admission was the only independent predictor of a poor outcome. Conclusions: Nasogastric tubes offer only limited protection against aspiration pneumonia in patients with dysphagia from acute stroke. Pneumonia occurs mainly in the first days of the illness and patients with decreased consciousness and a severe facial palsy are especially endangered.

High-Normal Blood Pressure Is Associated With Poor Cognitive Performance

While the relation between systolic blood pressure (SBP) and vascular events is linear down to the high-normal range, the relation between SBP and cognition is less clear. We cross-sectionally assessed the relation between SBP and cognition in a cohort extending from mid- to late-life. From a total of 2200 community-dwelling individuals we recruited 377 aged 44 to 82 years (median: 64 years, 171 male) in the SEARCH-Health study (Systematic evaluation and alteration of risk factors for cognitive health). Participants were studied with a comprehensive neuropsychological test battery that provided, based on principal component analysis, 5 composite scores for cognition (learning and memory, attention and executive function, spatial skills, working memory, and verbal skills). Global cognition was calculated from the sum of the composite scores. SBP (corrected R2=0.007), education (corrected R2=0.203), age (corrected R2=0.102), and gender (corrected R2=0.011) explained one third of variance in global cognitive performance (P<0.001) on multivariate analyses. Moreover, the relation between SBP (based on 10 mm Hg-categories from <120 mm Hg to >170 mm Hg) and global cognitive performance was linear in this range of SBP-values, ie, even in the normotensive range (β=−0.110, P<0.05). Subgroup analysis showed that the association of SBP and cognition was driven by results in midlife (<60 years) individuals (β=−0.291, P<0.005). Thus, even in the normotensive range increasing systolic blood pressure is inversely related to cognition.

Towards a Basic Endoscopic Assessment of Swallowing in Acute Stroke – Development and Evaluation of a Simple Dysphagia Score

Background and Purpose: Dysphagia is an important complication of acute stroke with a reported incidence of up to 76%. The purpose of this investigation was to develop and to evaluate an endoscopic scoring system which has the potential to guide dysphagia management in acute stroke patients. Methods: A fiberoptic endoscopic evaluation of swallowing (FEES) was carried out in 100 patients within 72 h of stroke onset. During endoscopic examination, the secretion status was evaluated, and the patient was successively given standard volumes of puree consistency, liquids and soft solid food. Penetration and aspiration was assessed using a 5-point scale. Results: Nearly 80% of patients showed penetration or aspiration during FEES. These events occurred more frequently with liquids and soft solid food than with puree. Penetration or aspiration at any stage of examination predicted failure at the subsequent food consistency. Furthermore, key findings of endoscopic evaluation were predictive of the need for later orotracheal intubation. Based on these observations a score was developed that grades stroke-related dysphagia according to the risk of penetration or aspiration of the different food consistencies tested. Assessment of interrater reliability by means of 25 additional endoscopic examinations resulted in excellent agreement between three investigators, reflected by a ĸ coefficient of 0.89. Conclusion: Stroke-related dysphagia may effectively be graded using a simple endoscopic scoring system. The usefulness of this screening protocol with respect to patient outcome and intercurrent complications has to be studied in prospective clinical trials.

Functional oropharyngeal sensory disruption interferes with the cortical control of swallowing

BackgroundSensory input is crucial to the initiation and modulation of swallowing. From a clinical point of view, oropharyngeal sensory deficits have been shown to be an important cause of dysphagia and aspiration in stroke patients. In the present study we therefore investigated effects of functional oropharyngeal disruption on the cortical control of swallowing. We employed whole-head MEG to study cortical activity during self-paced volitional swallowing with and without topical oropharyngeal anesthesia in ten healthy subjects. A simple swallowing screening-test confirmed that anesthesia caused swallowing difficulties with decreased swallowing speed and reduced volume per swallow in all subjects investigated. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of the individual SAM data was performed using a permutation test.ResultsThe analysis of normal swallowing revealed bilateral activation of the mid-lateral primary sensorimotor cortex. Oropharyngeal anesthesia led to a pronounced decrease of both sensory and motor activation.ConclusionOur results suggest that a short-term decrease in oropharyngeal sensory input impedes the cortical control of swallowing. Apart from diminished sensory activity, a reduced activation of the primary motor cortex was found. These findings facilitate our understanding of the pathophysiology of dysphagia.

Generalized arteriopathy in patients with cervical artery dissection

Objective: To make an ultrastructural comparison of superficial temporal artery (STA) biopsy specimens from patients with spontaneous cervical artery dissection (sCAD) and controls. Methods: The authors used light microscopic examination of semithin sections and electron microscopic examination of ultrathin sections of STA biopsy specimens from patients with sCAD and controls. Results: STA biopsy specimens from patients with sCAD taken around the time of the dissection showed a zone of connective tissue weakening with fissuring at the junction between the tunica media (TM) and the tunica adventitia (TA) in seven of nine specimens and erythrocyte infiltration in eight of nine specimens but in none of the control specimens. Light microscopy demonstrated transparent circular spots that, on electron microscopy, turned out to represent erythrocytes and other cellular components at different stages of degradation. Occasionally, scattered immune cells were found in specimens from patients with sCAD. In addition, smooth muscle cells of the synthetic phenotype, some of them showing extensive vacuolation were more common in the TM of STA biopsy specimens from patients with sCAD than in control specimens. Conclusions: Signs of tissue weakening along the TM/TA junction in STA biopsy specimens of patients with sCAD but not in controls suggest the presence of a generalized arteriopathy leading to impairment of the stability of the arterial wall in patients with sCAD. Limiting factors of the study are that some control biopsies were obtained from autopsies and that the anticoagulation status of patients and controls were not completely comparable.

The Safety of Fiberoptic Endoscopic Evaluation of Swallowing in Acute Stroke Patients

Background and Purpose— Fiberoptic endoscopic evaluation of swallowing (FEES) is an excellent method for the accurate examination of swallowing function in the acute phase of stroke. The present study investigates the safety of FEES related to patients characteristics in a setting of acute stroke care. Methods— A prospective study of FEES-associated complications was carried out in 300 acute stroke patients over a 1-year period. A neurologist and a speech-language pathologist of the stroke unit team performed FEES within a mean time interval of 1.9±0.8 days after stroke onset. A closely meshed monitoring of cardiovascular parameters was done during each examination. A discomfort rating was obtained from the patients. Results— In none of the 300 subjects any airway comprise, decrease in the level of consciousness, symptomatic bradycardia/tachycardia, laryngospasm, or epistaxis requiring special treatment was observed. The incidence of self-limiting nosebleeds was 6% and did not significantly differ in relation to major stroke types (ischemic versus hemorrhagic), acute treatment strategy (thrombolysis versus no thrombolysis), or secondary prevention regime (anticoagulant therapy versus antiplatelet drugs). Whereas no alterations in diastolic blood pressure were noted, statistically significant changes in systolic blood pressure, heart rate, and oxygen saturation occurred. However, these alterations did not cause any severe adverse event and were clinically judged as being mild. The assessment of comfort revealed an excellent tolerance of FEES in >80% of patients. Conclusion— This study demonstrates that FEES is a well-tolerated and safe method to assess swallowing function when performed by a speech-language pathologist and a neurologist in a stroke unit setting.

Fiberoptic Endoscopic Dysphagia Severity Scale Predicts Outcome after Acute Stroke

Background and Purpose: Fiberoptic endoscopic evaluation of swallowing (FEES) is a suitable method for dysphagia assessment after acute stroke. Recently, we developed the fiberoptic endoscopic dysphagia severity scale (FEDSS) for acute stroke patients, grading dysphagia into 6 severity codes (1 to 6; 1 being best). The purpose of this study was to investigate the impact of the FEDSS as a predictor of outcomes at 3 months and intermediate complications during acute treatment. Methods: A total of 153 consecutive first-ever acute stroke patients were enrolled. Dysphagia was classified according to the FEDSS, assessed within 24 h after admission. Intermediate outcomes were pneumonia and endotracheal intubation. Functional outcome was measured by the modified Rankin Scale (mRS) at 3 months. Multivariate regression analysis was used to identify whether the FEDSS was an independent predictor of outcome and intercurrent complications. Analyses were adjusted for sex, age and National Institutes of Health Stroke Scale (NIH-SS) on admission. Results: The FEDSS was found to predict the mRS at 3 months as well as but independent from the NIH-SS. For each additional point on the FEDSS, the likelihood of dependency at 3 months (mRS ≥ 3) raised by ∼50%. Each increase of 1 point on the FEDSS conferred a more than 2-fold increased chance of developing pneumonia. The odds for the necessity of endotracheal intubation raised by a factor of nearly 2.5 with each additional point on the FEDSS. Conclusions: The FEDSS strongly and independently predicts outcome and intercurrent complications after acute stroke. Thus, a baseline FEES examination provides valuable prognostic information for the treatment of acute stroke patients.

Time-Dependent Hemispheric Shift of the Cortical Control of Volitional Swallowing

An important part of the cortical processing of swallowing takes place in the sensorimotor cortex, predominantly in the left hemisphere. However, until now, only deglutition related brain activation with low time resolution exceeding a time interval of 1 s has been reported. In this study, we have examined the chronological sequence of cortical swallowing processing in humans by means of high temporal resolution magnetoencephalography (MEG). The cortical MEG activity was recorded during self‐paced volitional swallowing in 10 healthy subjects. Data were analyzed using synthetic aperture magnetometry and the group analysis was performed using a permutation test. Swallowing‐related muscle activity was recorded by electromyography. Within the time interval of 1 s of the most pronounced muscular swallowing execution, the MEG analysis revealed neural activation in the primary sensorimotor cortex. During the first 600 ms, only left hemispheric activation was found, bihemispheric activation during the next 200 ms and a right hemispheric activation during the last 200 ms. Thus, our results demonstrate a time‐dependent shift of neural activation from left to right sensorimotor cortex during deglutition with left hemispheric dominance in the early stage of volitional swallowing and right hemispheric dominance during its later part. Hum Brain Mapp 2009.

Tactile thermal oral stimulation increases the cortical representation of swallowing

BackgroundDysphagia is a leading complication in stroke patients causing aspiration pneumonia, malnutrition and increased mortality. Current strategies of swallowing therapy involve on the one hand modification of eating behaviour or swallowing technique and on the other hand facilitation of swallowing with the use of pharyngeal sensory stimulation. Thermal tactile oral stimulation (TTOS) is an established method to treat patients with neurogenic dysphagia especially if caused by sensory deficits. Little is known about the possible mechanisms by which this interventional therapy may work. We employed whole-head MEG to study changes in cortical activation during self-paced volitional swallowing in fifteen healthy subjects with and without TTOS. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of individual SAM data was performed using a permutation test.ResultsCompared to the normal swallowing task a significantly increased bilateral cortical activation was seen after oropharyngeal stimulation. Analysis of the chronological changes during swallowing suggests facilitation of both the oral and the pharyngeal phase of deglutition.ConclusionIn the present study functional cortical changes elicited by oral sensory stimulation could be demonstrated. We suggest that these results reflect short-term cortical plasticity of sensory swallowing areas. These findings facilitate our understanding of the role of cortical reorganization in dysphagia treatment and recovery.