Pharyngolaryngeal Sensory Deficits in Patients with Middle Cerebral Artery Infarction: Lateralization and Relation to Overall Dysphagia Severity.

BACKGROUND: Dysphagia is a frequent and dangerous complication of acute stroke. Apart from a well-timed oropharyngeal muscular contraction pattern, sensory feedback is of utmost importance for safe and efficient swallowing. In the present study, we therefore analyzed the relation between pharyngolaryngeal sensory deficits and post-stroke dysphagia (PSD) severity in a cohort of acute stroke patients with middle cerebral artery (MCA) infarction. METHODS: Eighty-four first-ever MCA stroke patients (41 left, 43 right) were included in this trial. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardized protocol within 96 h after stroke onset. PSD was classified according to the 6-point fiberoptic endoscopic dysphagia severity scale. Pharyngolaryngeal sensation was semi-quantitatively evaluated by a FEES-based touch technique. RESULTS: PSD severity was closely related to the pharyngolaryngeal sensory deficit. With regards to lateralization of the sensory deficit, there was a slight but significant preponderance of sensory loss contralateral to the side of stroke. Apart from that, right hemispheric stroke patients were found to present with a more severe PSD. CONCLUSIONS: This study provides evidence that an intact sensory feedback is of utmost importance to perform nonimpaired swallowing and highlights the key role of disturbed pharyngeal and laryngeal afferents in the pathophysiology of PSD.

Flexible endoscopic evaluation of swallowing (FEES) for neurogenic dysphagia: training curriculum of the German Society of Neurology and the German stroke society.

BACKGROUND: Neurogenic dysphagia is one of the most frequent and prognostically relevant neurological deficits in a variety of disorders, such as stroke, parkinsonism and advanced neuromuscular diseases. Flexible endoscopic evaluation of swallowing (FEES) is now probably the most frequently used tool for objective dysphagia assessment in Germany. It allows evaluation of the efficacy and safety of swallowing, determination of appropriate feeding strategies and assessment of the efficacy of different swallowing manoeuvres. The literature furthermore indicates that FEES is a safe and well-tolerated procedure. In spite of the huge demand for qualified dysphagia diagnostics in neurology, a systematic FEES education has not yet been established. RESULTS: The structured training curriculum presented in this article aims to close this gap and intends to enforce a robust and qualified FEES service. As management of neurogenic dysphagia is not confined to neurologists, this educational programme is applicable to other clinicians and speech-language therapists with expertise in dysphagia as well. CONCLUSION: The systematic education in carrying out FEES across a variety of different professions proposed by this curriculum will help to spread this instrumental approach and to improve dysphagia management.

Neural correlates of rate-dependent finger-tapping in Parkinson's disease.

Functional imaging demonstrated hemodynamic activation within specific brain areas that contribute to frequency-dependent movement control. Previous investigations demonstrated a linear relationship between movement and hemodynamic response rates within cortical regions, whereas the basal ganglia displayed an inverse neural activation pattern. We now investigated neural correlates of frequency-related finger movements in patients with Parkinson's disease (PD) to further elucidate the neurofunctional alterations in cortico-subcortical networks in that disorder. We studied ten PD patients (under dopaminergic medication) and ten healthy subjects using a finger-tapping task at three different frequencies (1-4 Hz), implemented in an event-related, sparse sampling fMRI design. FMRI data were analyzed by means of a parametric approach to relate movement rates and regional BOLD signal alteration. Compared to healthy controls, PD patients showed higher tapping response rates only during the lower 1 Hz condition. FMRI analysis revealed a rate-dependent neural activity within the supplemental motor area, primary sensorimotor cortex, thalamus and the cerebellum with higher neural activity at higher frequency conditions in both groups. Within the putamen/pallidum, an inverse neural activity and frequency response correlation could be observed in healthy subjects with higher BOLD signal responses in slow frequencies, whereas this relationship was not evident in PD patients. We could demonstrate similar behavioral responses and neural activation patterns at the level both of frontal and cerebellar areas in PD compared to healthy controls, whereas regions like the putamen/pallidum appear to be still dysfunctional under medication regarding frequency-related neural activation. These findings may, potentially, serve as a neural signature of basal ganglia dysfunctions in frequency-related task requirements.

[Consensus paper--adequate medication for neurologic and geriatric patients with dysphagia]. / Konsensuspapier--Bedarfsgerechte Medikation bei neurologischen und geriatrischen Dysphagie-Patienten.

BACKGROUND: The incidence for dysphagia amounts to 44-50% in nursing homes. Dysphagia is one of the main reasons for pneumonia in elderly. METHOD: Consensus paper. RESULTS AND CONCLUSIONS: For the advisory board consisting of 2 physicians, 2 pharmacists, a speech therapist, and a respresentative of nursing service it is common understanding that for the ideal maintenance and support of patients with dysphagia an interdisciplinary approach is crucial. Despite high clinical relevance of dysphagia the basic knowledge of this field is often underdeveloped. Specific and validated screening procedures for dysphagia have to be developed and implemented into the relevant guidelines. Specifically in this field an active and discipline spanning risk management should find its way into stationary geriatric care and nursing homes. Just as important is the provision of necessary patient information on the progress of the disease, on therapeutic actions and possible diet forms in a dysphagia pass. Additionally, the mentioned disciplines require an online risk screening (for dysphagia) of the pharmacist concerning the overall medication as well as information of galenic properties like facts regarding the possibility of crushing, portioning or tube feeding of the prescribed medication. In this way health risks due to administration errors concerning the medication can be significantly reduced for this patient group. Adequate oral liquids for adapted application of drugs are missing so far.

Neural correlates of temporal auditory processing in developmental dyslexia during German vowel length discrimination: an fMRI study.

This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in two experimental conditions. In the temporal, but not in the phonological condition, hemodynamic brain activation was observed bilaterally within the anterior insular cortices in both groups and within the left inferior frontal gyrus (IFG) in controls, indicating that the left IFG and the anterior insular cortices are part of a neural network involved in temporal auditory processing. Group subtraction analyses did not demonstrate significant effects. However, in a subgroup analysis, participants performing low in the temporal condition (all dyslexic) showed decreased activation of the insular cortices and the left IFG, suggesting that this processing network might form the neural basis of temporal auditory processing deficits in dyslexia.

Slowly progressive Foix-Chavany-Marie syndrome as a precursor of a primary progressive aphasia.

Foix-Chavany-Marie syndrome (FCMS) is a rare neurological condition usually associated with bilateral ischemic lesions of the anterior frontoparietal operculum. Here, we present a patient with slowly progressive FCMS owing to focal brain atrophy who developed a language disorder similar to that seen in a primary progressive aphasia.

Prediction of outcome in neurogenic oropharyngeal dysphagia within 72 hours of acute stroke.

BACKGROUND: Stroke is the most frequent cause of neurogenic oropharyngeal dysphagia (NOD). In the acute phase of stroke, the frequency of NOD is greater than 50% and, half of this patient population return to good swallowing within 14 days while the other half develop chronic dysphagia. Because dysphagia leads to aspiration pneumonia, malnutrition, and in-hospital mortality, it is important to pay attention to swallowing problems. The question arises if a prediction of severe chronic dysphagia is possible within the first 72 hours of acute stroke. METHODS: On admission to the stroke unit, all stroke patients were screened for swallowing problems by the nursing staff within 2 hours. Patients showing signs of aspiration were included in the study (n = 114) and were given a clinical swallowing examination (CSE) by the swallowing/speech therapist within 24 hours and a swallowing endoscopy within 72 hours by the physician. The primary outcome of the study was the functional communication measure (FCM) of swallowing (score 1-3, tube feeding dependency) on day 90. RESULTS: The grading system with the FCM swallowing and the penetration-aspiration scale (PAS) in the first 72 hours was tested in a multivariate analysis for its predictive value for tube feeding-dependency on day 90. For the FCM level 1 to 3 (P < .0022) and PAS level 5 to 8 (P < .00001), the area under the curve (AUC) was 72.8% and showed an odds ratio of 11.8 (P < .00001; 95% confidence interval 0.036-0.096), achieving for the patient a 12 times less chance of being orally fed on day 90 and therefore still being tube feeding-dependent. CONCLUSIONS: We conclude that signs of aspiration in the first 72 hours of acute stroke can predict severe swallowing problems on day 90. Consequently, patients should be tested on admission to a stroke unit and evaluated with established dysphagia scales to prevent aspiration pneumonia and malnutrition. A dysphagia program can lead to better communication within the stroke unit team to initiate the appropriate diagnostics and swallowing therapy as soon as possible.

Neuromagnetic oscillations and hemodynamic correlates of P50 suppression in schizophrenia.

Behavioral and electrophysiological data indicate compromised stimulus suppression in schizophrenia. The physiological basis of this effect and its contributions to the etiology of the disease are poorly understood. We examined neural and metabolic measures of P50 suppression in 12 patients with schizophrenia and controls. First, whole-head magnetoencephalography (MEG) assessed amplitudes of left- and right-hemispheric evoked responses and induced oscillations. Secondly, functional magnetic resonance imaging (fMRI) measured the hemodynamic responses to pairs of beeps with a short interval (500ms) as compared with those with a long interval (1500ms). The suppression of alpha power (8-13Hz) time-locked to the stimuli was negatively correlated with the suppression of evoked components and the hemodynamic measures. Remarkably, the suppression of alpha power was reduced in the patients already prior to stimulus onset. Conceivably, alpha oscillations play a central role in stimulus adaptation of neuronal networks and reflect an active mechanism for sensory suppression. The reduced stimulus suppression in schizophrenia seems to be in part due to impaired generation of alpha oscillations in the auditory cortex, resulting in higher metabolic demand as detected by fMRI. Delayed recovery of alpha rhythm may reflect an impaired gating function and contribute to sensory and cognitive deficits in schizophrenia.

Do we have a "mental syllabary" in the brain? An FMRI study.

The present study combines functional magnetic resonance imaging (fMRI) and reaction time (RT) measurements to further elucidate the influence of syllable frequency and complexity on speech motor control processes, i.e., overt reading of pseudowords. Tying in with a recent fMRI-study of our group we focused on the concept of a mental syllabary housing syllable sized ready-made motor plans for high- (HF), but not low-frequency (LF) syllables. The RT-analysis disclosed a frequency effect weakened by a simultaneous complexity effect for HF-syllables. In contrast, the fMRI data revealed no effect of syllable frequency, but point to an impact of syllable structure: Compared with CV-items, syllables with a complex onset (CCV) yielded higher hemodynamic activation in motor "execution" areas (left sensorimotor cortex, right inferior cerebellum), which is at least partially compatible with our previous study. We discuss the role of the syllable in speech motor control.

Complementary image analysis of diffusion tensor imaging and 3-dimensional t1-weighted imaging: white matter analysis in amyotrophic lateral sclerosis.

INTRODUCTION: in order to obtain detailed information on disease-associated changes in the integrity of cerebral white matter (WM), complementary image analysis (CIA) was applied to patients with amyotrophic lateral sclerosis (ALS) and controls. METHODS: both diffusion tensor imaging and T1-weighted 3-dimensional data were analyzed with respect to WM microstructure and T1 signal intensity alterations, respectively, in a sample of 19 ALS patients. Covariate information was added in the form of clinical parameters. All results were obtained in one common analysis software environment (Tensor Imaging and Fiber Tracking). RESULTS: complementary analysis and display were performed for WM directionality and structure. Significant WM differences between ALS patients and controls were observed both in the motor system, that is, the bilateral corticospinal tracts, and in extramotor brain areas, in part correlating with clinical parameters. The performance of all analyses in one software environment enabled the synopsis of results obtained from various analyses. DISCUSSION/CONCLUSION: within the application of CIA to a neurodegenerative disease for the whole brain-based analysis of WM alterations together with clinical characteristics, it could be demonstrated that ALS was associated with WM changes within and outside the motor system.

The contribution(s) of the insula to speech production: a review of the clinical and functional imaging literature.

Skilled spoken language production requires fast and accurate coordination of up to 100 muscles. A long-standing concept--tracing ultimately back to Paul Broca--assumes posterior parts of the inferior frontal gyrus to support the orchestration of the respective movement sequences prior to innervation of the vocal tract. At variance with this tradition, the insula has more recently been declared the relevant "region for coordinating speech articulation", based upon clinico-neuroradiological correlation studies. However, these findings have been criticized on methodological grounds. A survey of the clinical literature (cerebrovascular disorders, brain tumours, stimulation mapping) yields a still inconclusive picture. By contrast, functional imaging studies report more consistently hemodynamic insular responses in association with motor aspects of spoken language. Most noteworthy, a relatively small area at the junction of insular and opercular cortex was found sensitive to the phonetic-linguistic structure of verbal utterances, a strong argument for its engagement in articulatory control processes. Nevertheless, intrasylvian hemodynamic activation does not appear restricted to articulatory processes and might also be engaged in the adjustment of the autonomic system to ventilatory needs during speech production: Whereas the posterior insula could be involved in the cortical representation of respiration-related metabolic (interoceptive) states, the more rostral components, acting upon autonomic functions, might serve as a corollary pathway to "voluntary control of breathing" bound to corticospinal and -bulbar fiber tracts. For example, the insula could participate in the implementation of task-specific autonomic settings such as the maintenance of a state of relative hyperventilation during speech production.

Whole brain-based analysis of regional white matter tract alterations in rare motor neuron diseases by diffusion tensor imaging.

Different motor neuron disorders (MNDs) are mainly defined by the clinical presentation based on the predominance of upper or lower motor neuron impairment and the course of the disease. Magnetic resonance imaging (MRI) mostly serves as a tool to exclude other pathologies, but novel approaches such as diffusion tensor imaging (DTI) have begun to add information on the underlying pathophysiological processes of these disorders in vivo. The present study was designed to investigate three different rare MNDs, i.e., primary lateral sclerosis (PLS, N = 25), hereditary spastic paraparesis (HSP, N = 24), and X-linked spinobulbar muscular atrophy (X-SBMA, N = 20), by use of whole-brain-based DTI analysis in comparison with matched controls. This analysis of white matter (WM) impairment revealed widespread and characteristic patterns of alterations within the motor system with a predominant deterioration of the corticospinal tract (CST) in HSP and PLS patients according to the clinical presentation and also in patients with X-SBMA to a lesser degree, but also WM changes in projections to the limbic system and within distinct areas of the corpus callosum (CC), the latter both for HSP and PLS. In summary, DTI was able to define a characteristic WM pathoanatomy in motor and extra-motor brain areas, such as the CC and the limbic projectional system, for different MNDs via whole brain-based FA assessment and quantitative fiber tracking. Future advanced MRI-based investigations might help to provide a fingerprint-identification of MNDs.

The role of the unaffected hemisphere in motor recovery after stroke.

The contribution of the ipsilateral (nonaffected) hemisphere to recovery of motor function after stroke is controversial. Under the assumption that functionally relevant areas within the ipsilateral motor system should be tightly coupled to the demand we used fMRI and acoustically paced movements of the right index finger at six different frequencies to define the role of these regions for recovery after stroke. Eight well-recovered patients with a chronic striatocapsular infarction of the left hemisphere were compared with eight age-matched participants. As expected the hemodynamic response increased linearly with the frequency of the finger movements at the level of the left supplementary motor cortex (SMA) and the left primary sensorimotor cortex (SMC) in both groups. In contrast, a linear increase of the hemodynamic response with higher tapping frequencies in the right premotor cortex (PMC) and the right SMC was only seen in the patient group. These results support the model of an enhanced bihemispheric recruitment of preexisting motor representations in patients after subcortical stroke. Since all patients had excellent motor recovery contralesional SMC activation appears to be efficient and resembles the widespread, bilateral activation observed in healthy participants performing complex movements, instead of reflecting maladaptive plasticity.

The contribution of mesiofrontal cortex to the preparation and execution of repetitive syllable productions: an fMRI study.

Clinical data indicate that the brain network of speech motor control can be subdivided into at least three functional-neuroanatomical subsystems: (i) planning of movement sequences (premotor ventrolateral-frontal cortex and/or anterior insula), (ii) preparedness for/initiation of upcoming verbal utterances (supplementary motor area, SMA), and (iii) on-line innervation of vocal tract muscles, i.e., motor execution (corticobulbar system, basal ganglia, cerebellum). Using an event-related design, this functional magnetic resonance imaging (fMRI) study sought to further delineate the contribution of SMA to pre-articulatory processes of speech production (preceding the innervation of vocal tract muscles) during an acoustically paced syllable repetition task forewarned by a tone signal. Hemodynamic activation across the whole brain and the time courses of the responses in five regions of interest (ROIs) were computed. First, motor preparation was associated with a widespread bilateral activation pattern, encompassing brainstem structures, SMA, insula, premotor ventrolateral-frontal areas, primary sensorimotor cortex (SMC), basal ganglia, and the superior cerebellum. Second, calculation of the time courses of BOLD ("blood oxygenation level-dependent") signal changes revealed the warning stimulus to elicit synchronous onset of hemodynamic activation in these areas. However, during 4-s intervals of syllable repetitions SMA and cerebellum showed opposite temporal activation patterns in terms of a shorter (SMA) and longer (cerebellum) latency of the entire BOLD response-as compared to SMC, indicating different pacing mechanisms during the initial and the ongoing phase of the task. Nevertheless, the contribution of SMA was not exclusively restricted to the preparation/initiation of verbal responses since the extension of mesiofrontal activation varied with task duration.

Intersubject variability in the analysis of diffusion tensor images at the group level: fractional anisotropy mapping and fiber tracking techniques.

INTRODUCTION: Diffusion tensor imaging (DTI) provides comprehensive information about quantitative diffusion and connectivity in the human brain. Transformation into stereotactic standard space is a prerequisite for group studies and requires thorough data processing to preserve directional inter-dependencies. The objective of the present study was to optimize technical approaches for this preservation of quantitative and directional information during spatial normalization in data analyses at the group level. METHODS: Different averaging methods for mean diffusion-weighted images containing DTI information were compared, i.e., region of interest-based fractional anisotropy (FA) mapping, fiber tracking (FT) and corresponding tractwise FA statistics (TFAS). The novel technique of intersubject FT that takes into account directional information of single data sets during the FT process was compared to standard FT techniques. Application of the methods was shown in the comparison of normal subjects and subjects with defined white matter pathology (alterations of the corpus callosum). RESULTS: Fiber tracking was applied to averaged data sets and showed similar results compared with FT on single subject data. The application of TFAS to averaged data showed averaged FA values around 0.4 for normal controls. The values were in the range of the standard deviation for averaged FA values for TFAS applied to single subject data. These results were independent of the applied averaging technique. A significant reduction of the averaged FA values was found in comparison to TFAS applied to data from subjects with defined white matter pathology (FA around 0.2). CONCLUSION: The applicability of FT techniques in the analysis of different subjects at the group level was demonstrated. Group comparisons as well as FT on group averaged data were shown to be feasible. The objective of this work was to identify the most appropriate method for intersubject averaging and group comparison which incorporates intersubject variability of the directional information.

Contribution of the anterior insula to temporal auditory processing deficits in developmental dyslexia.

Developmental dyslexia has been assumed to arise from general auditory deficits, compromising rapid temporal integration both of linguistic and nonlinguistic acoustic stimuli. Because the effort of auditory temporal processing of speech and nonspeech test materials may depend on presentation rate, fMRI measurements were performed in dyslexics and controls during passive listening to series of syllable and click sounds, using a parametric approach. Controls showed a decrease of hemodynamic brain activation within the right and an increase within the left anterior insula as a function of the presentation rate both of click as well as syllable trains. By contrast, dyslexics exhibited this profile of hemodynamic responses under the nonspeech condition only. As concerns syllables, activation in dyslexics did not depend on presentation rate. Moreover, a subtraction analysis of hemodynamic main effects across conditions and groups revealed decreased activation both of the left and right anterior insula in dyslexics compared to controls during application both of click and syllables. These results indicate, in line with preceding studies, that the insula of both hemispheres is involved in auditory temporal processing of nonlinguistic auditory stimuli and demonstrate, furthermore, that these operations of intrasylvian cortex also extend to the linguistic domain. In addition, our data suggest that the anterior insula represents an important neural correlate of deficient temporal processing of speech and nonspeech sounds in dyslexia.

Dysphagia due to unilateral infarction in the vascular territory of the anterior insula.

We describe a patient who suddenly developed dysphagia for liquids as the sole manifestation of stroke. Magnetic resonance imaging (MRI) revealed a right-sided infarction of the superior part of the anterior insula and a small portion of the adjacent medial frontal operculum. These findings confirm the role of the anterior insula as a critical area in humans with regard to the origin of dysphagia.

Diagnosis and treatment of bulbar symptoms in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease of the motor system. Bulbar symptoms such as dysphagia and dysarthria are frequent features of ALS and can result in reductions in life expectancy and quality of life. These dysfunctions are assessed by clinical examination and by use of instrumented methods such as fiberendoscopic evaluation of swallowing and videofluoroscopy. Laryngospasm, another well-known complication of ALS, commonly comes to light during intubation and extubation procedures in patients undergoing surgery. Laryngeal and pharyngeal complications are treated by use of an array of measures, including body positioning, compensatory techniques, voice and breathing exercises, communication devices, dietary modifications, various safety strategies, and neuropsychological assistance. Meticulous monitoring of clinical symptoms and close cooperation within a multidisciplinary team (physicians, speech and language therapists, occupational therapists, dietitians, caregivers, the patients and their relatives) are vital.