Randomized trial of transcranial direct current stimulation for poststroke dysphagia.

OBJECTIVE: We evaluated whether transcranial direct current stimulation (tDCS) is able to enhance dysphagia rehabilitation following stroke. Besides relating clinical effects with neuroplastic changes in cortical swallowing processing, we aimed to identify factors influencing treatment success. METHODS: In this double-blind, randomized study, 60 acute dysphagic stroke patients received contralesional anodal (1mA, 20 minutes) or sham tDCS on 4 consecutive days. Swallowing function was thoroughly assessed before and after the intervention using the validated Fiberoptic Endoscopic Dysphagia Severity Scale (FEDSS) and clinical assessment. In 10 patients, swallowing-related brain activation was recorded applying magnetoencephalography before and after the intervention. Voxel-based statistical lesion pattern analysis was also performed. RESULTS: Study groups did not differ according to demographic data, stroke characteristics, or baseline dysphagia severity. Patients treated with tDCS showed greater improvement in FEDSS than the sham group (1.3 vs 0.4 points, mean difference = 0.9, 95% confidence interval [CI] = 0.4-1.4, p < 0.0005). Functional recovery was accompanied by a significant increase of activation (p < 0.05) in the contralesional swallowing network after real but not sham tDCS. Regarding predictors of treatment success, for every hour earlier that treatment was initiated, there was greater improvement on the FEDSS (adjusted odds ratio = 0.99, 95% CI = 0.98-1.00, p < 0.05) in multivariate analysis. Stroke location in the right insula and operculum was indicative of worse response to tDCS (p < 0.05). INTERPRETATION: Application of tDCS over the contralesional swallowing motor cortex supports swallowing network reorganization, thereby leading to faster rehabilitation of acute poststroke dysphagia. Early treatment initiation seems beneficial. tDCS may be less effective in right-hemispheric insulo-opercular stroke. Ann Neurol 2018;83:328-340.

Pharyngeal electrical stimulation can modulate swallowing in cortical processing and behavior - magnetoencephalographic evidence.

BACKGROUND: The act of swallowing is a complex neuromuscular function that is processed in a distributed network involving cortical, subcortical and brainstem structures. Difficulty in swallowing arises from a variety of neurologic diseases for which therapeutic options are currently limited. Pharyngeal electrical stimulation (PES) is a novel intervention designed to promote plastic changes in the pharyngeal motor cortex to aid dysphagia rehabilitation. In the present study we evaluate the effect of PES on cortical swallowing network activity and associated changes in swallowing performance. METHODS: In a randomized, crossover study design 10min of real (0.2-ms pulses, 5Hz, 280V, stimulation intensity at 75% of maximum tolerated threshold) or sham PES were delivered to 14 healthy volunteers in two separate sessions. Stimulation was delivered via a pair of bipolar ring electrodes mounted on an intraluminal catheter positioned in the pharynx. Before and after each intervention swallowing capacity (ml/s) was tested using a 150ml-water swallowing stress test. Event-related desynchronization (ERD) of cortical oscillatory activity during volitional swallowing was recorded applying whole-head magnetoencephalography before, immediately after and 45min past the intervention. RESULTS: A prominent reduction of ERD in sensorimotor brain areas occurred in the alpha and beta frequency ranges immediately after real PES but not after sham stimulation (p<0.05) and had faded after 45min. Volume per swallow and swallowing capacity significantly increased following real stimulation only. CONCLUSION: Attenuation of ERD following PES reflects stimulation-induced increased swallowing processing efficiency, which is associated with subtle changes in swallowing function in healthy subjects. Our data contribute evidence that swallowing network organization and behavior can effectively be modulated by PES.

Discontinuous versus Continuous Weaning in Stroke Patients.

BACKGROUND: An increasing number of stroke patients have to be supported by mechanical ventilation in intensive care units (ICU), with a relevant proportion of them requiring gradual withdrawal from a respirator. To date, weaning studies have focused merely on mixed patient groups, COPD patients or patients after cardiac surgery. Therefore, the best weaning strategy for stroke patients remains to be determined. METHODS: Here, we designed a prospective randomized controlled study comparing adaptive support ventilation (ASV), a continuous weaning strategy, with biphasic positive airway pressure (BIPAP) in combination with spontaneous breathing trials, a discontinuous technique, in the treatment of stroke patients. The primary endpoint was the duration of the weaning process. RESULTS: Only the 40 (out of 54) patients failing in an initial spontaneous breathing trial (T-piece test) were included into the study; the failure proportion is considerably larger compared to previous studies. Eligible patients were pseudo-randomly assigned to one of the two weaning groups. Both groups did not differ regarding age, gender, and severity of stroke. The results showed that the median weaning duration was 10.7 days (±SD 7.0) in the discontinuous weaning group, and 8 days (±SD 4.5) in the continuous weaning group (p < 0.05). CONCLUSIONS: To the best of our knowledge, this is the first clinical study to show that continuous weaning is significantly more effective compared to discontinuous weaning in mechanically ventilated stroke patients. We suppose that the reason for the superiority of continuous weaning using ASV as well as the bad performance of our patients in the 2 h T-piece test is caused by the patients' compliance. Compared to patients on surgical and medical ICUs, neurological patients more often suffer from reduced vigilance, lack of adverse-effects reflexes, dysphagia, and cerebral dysfunction. Therefore, stroke patients may profit from a more gradual withdrawal of weaning.

Evidence for adaptive cortical changes in swallowing in Parkinson's disease.

Dysphagia is a relevant symptom in Parkinson's disease, whose pathophysiology is poorly understood. It is mainly attributed to degeneration of brainstem nuclei. However, alterations in the cortical contribution to deglutition control in the course of Parkinson's disease have not been investigated. Here, we sought to determine the patterns of cortical swallowing processing in patients with Parkinson's disease with and without dysphagia. Swallowing function in patients was objectively assessed with fiberoptic endoscopic evaluation. Swallow-related cortical activation was measured using whole-head magnetoencephalography in 10 dysphagic and 10 non-dysphagic patients with Parkinson's disease and a healthy control group during self-paced swallowing. Data were analysed applying synthetic aperture magnetometry, and group analyses were done using a permutation test. Compared with healthy subjects, a strong decrease of cortical swallowing activation was found in all patients. It was most prominent in participants with manifest dysphagia. Non-dysphagic patients with Parkinson's disease showed a pronounced shift of peak activation towards lateral parts of the premotor, motor and inferolateral parietal cortex with reduced activation of the supplementary motor area. This pattern was not found in dysphagic patients with Parkinson's disease. We conclude that in Parkinson's disease, not only brainstem and basal ganglia circuits, but also cortical areas modulate swallowing function in a clinically relevant way. Our results point towards adaptive cerebral changes in swallowing to compensate for deficient motor pathways. Recruitment of better preserved parallel motor loops driven by sensory afferent input seems to maintain swallowing function until progressing neurodegeneration exceeds beyond the means of this adaptive strategy, resulting in manifestation of dysphagia.

Magnetoencephalographic evidence for the modulation of cortical swallowing processing by transcranial direct current stimulation.

Swallowing is a complex neuromuscular task that is processed within multiple regions of the human brain. Rehabilitative treatment options for dysphagia due to neurological diseases are limited. Because the potential for adaptive cortical changes in compensation of disturbed swallowing is recognized, neuromodulation techniques like transcranial direct current stimulation (tDCS) are currently considered as a treatment option. Here we evaluate the effect of tDCS on cortical swallowing network activity and behavior. In a double-blind crossover study, anodal tDCS (20 min, 1 mA) or sham stimulation was administered over the left or right swallowing motor cortex in 21 healthy subjects in separate sessions. Cortical activation was measured using magnetoencephalography (MEG) before and after tDCS during cued "simple", "fast" and "challenged" swallow tasks with increasing levels of difficulty. Swallowing response times and accuracy were measured. Significant bilateral enhancement of cortical swallowing network activation was found in the theta frequency range after left tDCS in the fast swallow task (p=0.006) and following right tDCS in the challenged swallow task (p=0.007), but not after sham stimulation. No relevant behavioral effects were observed on swallow response time, but swallow precision improved after left tDCS (p<0.05). Anodal tDCS applied over the swallowing motor cortex of either hemisphere was able to increase bilateral swallow-related cortical network activation in a frequency specific manner. These neuroplastic effects were associated with subtle behavioral gains during complex swallow tasks in healthy individuals suggesting that tDCS deserves further evaluation as a treatment tool for dysphagia.

Standardized endoscopic swallowing evaluation for tracheostomy decannulation in critically ill neurologic patients.

OBJECTIVES: Decisions regarding tracheostomy tube removal after mechanical ventilation often depend on the physician's individual experience because evidence-based practice guidelines are still scarce, especially for critically ill neurologic patients. In these patients, the prevalence of aspiration is high and regarded as an important contributor to decannulation failure. The presence of severe neurological deficits may, however, give clinicians the subjective impression that a tracheostomy tube is still necessary although decannulation may actually be safe. It is therefore crucial to test swallowing function reliably prior to decannulation in this patient population. DESIGN: Prospective observational study. SETTING: University hospital, neurological ICU. PATIENTS: One hundred tracheostomized patients with acute neurologic disease completely weaned from mechanical ventilation. INTERVENTIONS: An endoscopic protocol evaluating readiness for decannulation and a conventional clinical swallowing examination were carried out by separate, experienced practitioners blinded to each other's decisions. Patient management always followed the decision made with endoscopy. MEASUREMENTS AND MAIN RESULTS: Practitioners' decannulation decisions (yes/no) reached with both assessments were compared. Decannulated patients were monitored throughout their stay for complications related to tube removal. Endoscopy was performed successfully in all subjects without any complications. Following the protocol, the tracheostomy tube was successfully removed in 54 patients, whereas according to the clinical swallowing examination, only 29 patients would have been decannulated at that point. Only one patient needed recannulation due to respiratory problems, resulting in a failure rate of 1.9%. CONCLUSIONS: In neurologic patients, speech-language pathologists' impressions about the patient's state when clinically assessing indirect variables of swallowing function often lead to the unnecessary prolongation of cannulation time. Endoscopic evaluation has the advantage of objectively visualizing the patient's ability to manage secretions directly and allows for faster but, nonetheless, safe decannulation. The endoscopic protocol proposed here is a safe, efficient, and objective bedside tool to guide decannulation decisions.

Sensorimotor cortical activation in patients with sleep bruxism.

Sleep bruxism is assumed to be triggered by a dysfunctional subcortical and cortical network. This study investigates sensorimotor cortical activation in patients with sleep bruxism during clenching and chewing. Nine polysomnographically diagnosed patients and nine healthy control subjects underwent magnetoencephalography (MEG). During clenching and chewing, patients with bruxism revealed significantly larger event-related desynchronization in the somatomotor area (Brodmann area 4) than healthy subjects. Group differences in the muscle activity were ruled out by electromyography (EMG) assessments during MEG. This result might be regarded as a consequence of increased sensorimotor cortical representation of the tongue and chewing musculature due to an enhanced parafunctional muscle activity in bruxers potentially triggered by occlusal factors. Alternatively, a secondary activation of cortical structures during sleep bruxism in the context of an activated network of subcortical and cortical structures might lead to increased cortical representation of the chewing musculature via use dependent plasticity.

Cortical swallowing processing in early subacute stroke.

BACKGROUND: Dysphagia is a major complication in hemispheric as well as brainstem stroke patients causing aspiration pneumonia and increased mortality. Little is known about the recovery from dysphagia after stroke. The aim of the present study was to determine the different patterns of cortical swallowing processing in patients with hemispheric and brainstem stroke with and without dysphagia in the early subacute phase. METHODS: We measured brain activity by mean of whole-head MEG in 37 patients with different stroke localisation 8.2+/-4.8 days after stroke to study changes in cortical activation during self-paced swallowing. An age matched group of healthy subjects served as controls. Data were analyzed by means of synthetic aperture magnetometry and group analyses were performed using a permutation test. RESULTS: Our results demonstrate strong bilateral reduction of cortical swallowing activation in dysphagic patients with hemispheric stroke. In hemispheric stroke without dysphagia, bilateral activation was found. In the small group of patients with brainstem stroke we observed a reduction of cortical activation and a right hemispheric lateralization. CONCLUSION: Bulbar central pattern generators coordinate the pharyngeal swallowing phase. The observed right hemispheric lateralization in brainstem stroke can therefore be interpreted as acute cortical compensation of subcortically caused dysphagia. The reduction of activation in brainstem stroke patients and dysphagic patients with cortical stroke could be explained in terms of diaschisis.

Sleep characteristics, cognitive performance, and gray matter volume: findings from the BiDirect Study.

STUDY OBJECTIVES: Sleep is essential for restorative metabolic changes and its physiological correlates can be examined using overnight polysomnography. However, the association between physiological sleep characteristics and brain structure is not well understood. We aimed to investigate gray matter volume and cognitive performance related to physiological sleep characteristics. METHODS: Polysomnographic recordings from 190 community-dwelling participants were analyzed with a principal component analysis in order to identify and aggregate shared variance into principal components. The relationship between aggregated sleep components and gray matter volume was then analyzed using voxel-based morphometry. In addition, we explored how cognitive flexibility, selective attention, and semantic fluency were related to aggregated sleep components and gray matter volume. RESULTS: Three principal components were identified from the polysomnographic recordings. The first component, primarily described by apnea events and cortical arousal, was significantly associated with lower gray matter volume in the left frontal pole. This apnea-related component was furthermore associated with lower cognitive flexibility and lower selective attention. CONCLUSIONS: Sleep disrupted by cortical arousal and breathing disturbances is paralleled by lower gray matter volume in the frontal pole, a proposed hub for the integration of cognitive processes. The observed effects provide new insights on the interplay between disrupted sleep, particularly breathing disturbances and arousal, and the brain.

Dysphagia in Patients With Severe Coronavirus Disease 2019-Potential Neurologic Etiologies.

IMPORTANCE: Dysphagia is a common complication of critical illness, and many known risk factors are also present in critically ill coronavirus disease 2019 victims. OBJECTIVES: To investigate dysphagia in patients with severe coronavirus disease 2019. DESIGN SETTING AND PARTICIPANTS: In this case series, we report results of dedicated evaluation of swallowing function in six consecutive, tracheotomized coronavirus disease 2019 patients after they had survived acute respiratory distress syndrome and were weaned from the respirator. MAIN OUTCOMES AND MEASURES: Dysphagia was assessed with flexible endoscopic evaluation of swallowing. RESULTS: Three patients suffered from severe dysphagia and airway compromise precluding decannulation, whereas in the other, three swallowing was less critically impaired, and the tracheal cannula could be removed. Four patients presented with additional laryngeal dysfunctions not typically seen in acute respiratory distress syndrome survivors. CONCLUSION AND RELEVANCE: Dysphagia with impaired airway protection is a key feature in coronavirus disease 2019 acute respiratory distress syndrome survivors. Apart from critical illness polyneuropathy, coronavirus disease 2019-related involvement of the peripheral and central nervous system may contribute to swallowing impairment and laryngeal dysfunction.

Endoscopic characteristics and levodopa responsiveness of swallowing function in progressive supranuclear palsy.

Dysphagia is a frequent and early symptom in progressive supranuclear palsy (PSP) predisposing patients to aspiration pneumonia. Fiberoptic endoscopic evaluation of swallowing (FEES) has emerged as a valuable apparative tool for objective evaluation of neurogenic dysphagia. This is the first study using FEES to investigate the nature of swallowing impairment in PSP. Eighteen consecutive PSP patients (mean age 69.7 +/- 9.0 years) were included. The salient findings of FEES in PSP patients were compared with those of 15 patients with Parkinson's disease (PD). In 7 PSP patients, a standardized FEES protocol was performed to explore levodopa (L-dopa) responsiveness of dysphagia. Most frequent abnormalities detected by FEES were bolus leakage, delayed swallowing reflex, and residues in valleculae and piriformes. Aspiration events with at least one food consistency occurred in nearly 30% of PSP patients. Significant pharyngeal saliva pooling was observed in 4 PSP patients. We found no difference of salient endoscopic findings between PSP and PD patients. Endoscopic dysphagia severity in PSP correlated positively with disease duration, clinical disability, and cognitive impairment. No correlation was found with dysarthria severity. In early PSP patients, swallowing dysfunction was solely characterized by liquid leakage with the risk of predeglutitive aspiration during the oral phase of swallowing. Two PSP patients showed relevant improvement of swallowing function after L-dopa challenge. Chin tuck-maneuver, hard swallow, and modification of food consistency were identified as the most effective therapeutic interventions. In conclusion, FEES assessment can deliver important findings for the diagnosis and refined therapy of dysphagia in PSP patients.

Hereditary amyloidosis of the Finnish type in a German family: clinical and electrophysiological presentation.

Hereditary amyloidosis of the Finnish type (HAF, or familial amyloid polyneuropathy type IV) is an autosomal dominant disease that has been described most commonly in the Finnish population but has also been found in some other countries. Herein we report the first German family whose members suffer from this condition. There are no known Finnish ancestors. We performed clinical and electrophysiological examinations in 22 members of this family. All symptomatic family members suffered from facial palsy, and most of them had peripheral neuropathy. One patient had confirmed corneal lattice dystrophy. Additional symptoms were hypoglossal nerve involvement in 5 patients and oculomotor nerve palsy in 1 patient. The lips of all older patients appeared thickened. The causative G654A mutation in the gelsolin gene was found in all affected family members.

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. CONCLUSIONS: 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.

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.

Cortical compensation associated with dysphagia caused by selective degeneration of bulbar motor neurons.

According to recent neuroimaging studies, swallowing is processed within multiple regions of the human brain. In contrast to this, little is known about the cortical contribution and compensatory mechanisms produced by impaired swallowing. In the present study, we therefore investigated the cortical topography of volitional swallowing in patients with X-linked bulbospinal neuronopathy (Kennedy disease, KD). Eight dysphagic patients with genetically proven KD and an age-matched healthy control group were studied by means of whole-head magnetoencephalography using a previously established swallowing paradigm. Analysis of data was carried out with synthetic aperture magnetometry (SAM). The group analysis of individual SAM results was performed using a permutation test. KD patients showed significantly larger swallow-related activation of the bilateral primary sensorimotor cortex than healthy controls. In contrast to the control group, in KD patients the maximum activity was located in the right sensorimotor cortex. Furthermore, while in nondysphagic subjects a previously described time-dependent shift from the left to the right hemisphere was found during the one second of most pronounced swallow-related muscle activity, KD patients showed a strong right hemispheric activation in each time segment analyzed. Since the right hemisphere has an established role in the coordination of the pharyngeal phase of swallowing, the stronger right hemispheric activation observed in KD patients indicates cortical compensation of pharyngeal phase dysphagia.

Auditory temporal processing in healthy aging: a magnetoencephalographic study.

BACKGROUND: Impaired speech perception is one of the major sequelae of aging. In addition to peripheral hearing loss, central deficits of auditory processing are supposed to contribute to the deterioration of speech perception in older individuals. To test the hypothesis that auditory temporal processing is compromised in aging, auditory evoked magnetic fields were recorded during stimulation with sequences of 4 rapidly recurring speech sounds in 28 healthy individuals aged 20 - 78 years. RESULTS: The decrement of the N1m amplitude during rapid auditory stimulation was not significantly different between older and younger adults. The amplitudes of the middle-latency P1m wave and of the long-latency N1m, however, were significantly larger in older than in younger participants. CONCLUSION: The results of the present study do not provide evidence for the hypothesis that auditory temporal processing, as measured by the decrement (short-term habituation) of the major auditory evoked component, the N1m wave, is impaired in aging. The differences between these magnetoencephalographic findings and previously published behavioral data might be explained by differences in the experimental setting between the present study and previous behavioral studies, in terms of speech rate, attention, and masking noise. Significantly larger amplitudes of the P1m and N1m waves suggest that the cortical processing of individual sounds differs between younger and older individuals. This result adds to the growing evidence that brain functions, such as sensory processing, motor control and cognitive processing, can change during healthy aging, presumably due to experience-dependent neuroplastic mechanisms.

Measurement of pharyngeal sensory cortical processing: technique and physiologic implications.

BACKGROUND: Dysphagia is a major complication of different diseases affecting both the central and peripheral nervous system. Pharyngeal sensory impairment is one of the main features of neurogenic dysphagia. Therefore an objective technique to examine the cortical processing of pharyngeal sensory input would be a helpful diagnostic tool in this context. We developed a simple paradigm to perform pneumatic stimulation to both sides of the pharyngeal wall. Whole-head MEG was employed to study changes in cortical activation during this pharyngeal stimulation in nine healthy subjects. Data were analyzed by means of synthetic aperture magnetometry (SAM) and the group analysis of individual SAM data was performed using a permutation test. RESULTS: Our results revealed bilateral activation of the caudolateral primary somatosensory cortex following sensory pharyngeal stimulation with a slight lateralization to the side of stimulation. CONCLUSION: The method introduced here is simple and easy to perform and might be applicable in the clinical setting. The results are in keeping with previous findings showing bihemispheric involvement in the complex task of sensory pharyngeal processing. They might also explain changes in deglutition after hemispheric strokes. The ipsilaterally lateralized processing is surprising and needs further investigation.

Tactile thermal oral stimulation increases the cortical representation of swallowing.

BACKGROUND: Dysphagia 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. RESULTS: Compared 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. CONCLUSION: In 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.

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 > or = 3) raised by approximately 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.

Local sphere-based co-registration for SAM group analysis in subjects without individual MRI.

Synthetic aperture magnetometry (SAM) is a powerful MEG source localization method to analyze evoked as well as induced brain activity. To gain structural information of the underlying sources, especially in group studies, individual magnetic resonance images (MRI) are required for co-registration. During the last few years, the relevance of MEG measurements on understanding the pathophysiology of different diseases has noticeable increased. Unfortunately, especially in patients and small children, structural MRI scans cannot always be performed. Therefore, we developed a new method for group analysis of SAM results without requiring structural MRI data that derives its geometrical information from the individual volume conductor model constructed for the SAM analysis. The normalization procedure is fast, easy to implement and integrates seamlessly into an existing landmark based MEG-MRI co-registration procedure. This new method was evaluated on different simulated points as well as on a pneumatic index finger stimulation paradigm analyzed with SAM. Compared with an established MRI-based normalization procedure (SPM2) the new method shows only minor errors in single subject results as well as in group analysis. The mean difference between the two methods was about 4 mm for the simulated as well as for finger stimulation data. The variation between individual subjects was generally higher than the error induced by the missing MRIs. The method presented here is therefore sufficient for most MEG group studies. It allows accomplishing MEG studies with subject groups where MRI measurements cannot be performed.