Predictors of Pharyngeal Dysphagia in Patients with Parkinson's Disease.

BACKGROUND: Diagnosis of pharyngeal dysphagia in patients with Parkinson's disease is often difficult as reliable screening methods are lacking so far and clinical examination fails to adequately assess the pharyngeal phase of swallowing. OBJECTIVE: To identify clinical predictors indicating the presence of pharyngeal dysphagia in patients at risk. METHODS: We examined pharyngeal dysphagia in a large cohort of patients with Parkinson's disease (n = 200) divided in three clinical subtypes (tremor-dominant (TD), mainly bradykinetic (BK) and early postural instability and gait difficulty PIGD)) by using flexible endoscopic evaluation of swallowing. ANOVA-multivariance analysis and following t-tests as well as binary logistic regression analysis were performed to detect group differences and to identify clinical predictors for dysphagia. RESULTS: Statistically significant differences were found in the dysphagic group: age, male gender, disease duration, stage of the disease, Levodopa equivalent dose and higher scores on the Unified Parkinson's disease rating scale III and II, item 7. The PIGD subtype was affected more frequently than the TD and BK subtype. In a logistic regression model higher age (>63.5 years p < 0.05) and Levodopa equivalent dose (>475 mg, p < 0.01) were identified to be independent predictors for the presence of pharyngeal dysphagia. CONCLUSION: Particularly patients with an age > 63.5 years and a daily Levodopa equivalent dose >475 mg show an increased risk for pharyngeal dysphagia. These findings may partly be influenced by presbyphagia but are likely to represent disease progression. The PIGD subtype seems to be a risk factor due to more pronounced dyscoordination of oropharyngeal muscle movements.

Does higher sampling rate (multiband + SENSE) improve group statistics - An example from social neuroscience block design at 3T.

Multiband (MB) or Simultaneous multi-slice (SMS) acquisition schemes allow the acquisition of MRI signals from more than one spatial coordinate at a time. Commercial availability has brought this technique within the reach of many neuroscientists and psychologists. Most early evaluation of the performance of MB acquisition employed resting state fMRI or the most basic tasks. In this study, we tested whether the advantages of using MB acquisition schemes generalize to group analyses using a cognitive task more representative of typical cognitive neuroscience applications. Twenty-three subjects were scanned on a Philips 3 â€‹T scanner using five sequences, up to eight-fold acceleration with MB-factors 1 to 4, SENSE factors up to 2 and corresponding TRs of 2.45s down to 0.63s, while they viewed (i) movie blocks showing complex actions with hand object interactions and (ii) control movie blocks without hand object interaction. Data were processed using a widely used analysis pipeline implemented in SPM12 including the unified segmentation and canonical HRF modelling. Using random effects group-level, voxel-wise analysis we found that all sequences were able to detect the basic action observation network known to be recruited by our task. The highest t-values were found for sequences with MB4 acceleration. For the MB1 sequence, a 50% bigger voxel volume was needed to reach comparable t-statistics. The group-level t-values for resting state networks (RSNs) were also highest for MB4 sequences. Here the MB1 sequence with larger voxel size did not perform comparable to the MB4 sequence. Altogether, we can thus recommend the use of MB4 (and SENSE 1.5 or 2) on a Philips scanner when aiming to perform group-level analyses using cognitive block design fMRI tasks and voxel sizes in the range of cortical thickness (e.g. 2.7 â€‹mm isotropic). While results will not be dramatically changed by the use of multiband, our results suggest that MB will bring a moderate but significant benefit.

Action perception recruits the cerebellum and is impaired in patients with spinocerebellar ataxia.

Our cerebellum has been proposed to generate prediction signals that may help us plan and execute our motor programmes. However, to what extent our cerebellum is also actively involved in perceiving the action of others remains to be elucidated. Using functional MRI, we show here that observing goal-directed hand actions of others bilaterally recruits lobules VI, VIIb and VIIIa in the cerebellar hemispheres. Moreover, whereas healthy subjects (n = 31) were found to be able to discriminate subtle differences in the kinematics of observed limb movements of others, patients suffering from spinocerebellar ataxia type 6 (SCA6; n = 21) were severely impaired in performing such tasks. Our data suggest that the human cerebellum is actively involved in perceiving the kinematics of the hand actions of others and that SCA6 patients' deficits include a difficulty in perceiving the actions of other individuals. This finding alerts us to the fact that cerebellar disorders can alter social cognition.

Subtle Esophageal Motility Alterations in Parkinsonian Syndromes: Synucleinopathies vs. Tauopathies.

BACKGROUND: Esophageal dysfunction is a frequent phenomenon in Parkinson's disease during all disease stages, but data about esophageal involvement in atypical parkinsonian syndromes as well as possible differences between alpha-synucleinopathies and tauopathies, including causative links to the origin of the dysfunction, are lacking so far. OBJECTIVE: To describe esophageal alternation patterns in different parkinsonian syndromes and to look for differences supporting the hypothesis of alpha-synuclein aggregation being linked to gastrointestinal impairment in parkinsonian syndromes. METHODS: We performed an analysis and comparison of esophageal high-resolution manometry examination parameters in n = 10 patients with Parkinson's disease, n = 10 patients with multiple system atrophy (both alpha-synucleinopathies), n = 10 patients with progressive supranuclear palsy (tauopathy), and n = 10 age-matched controls. Additionally, pharyngeal dysphagia was evaluated by an endoscopic examination of swallowing in all three patient groups. RESULTS: Statistically significant lower values for esophageal peristalsis and distal contractile integral were found for both groups of alpha-synucleinopathies (Parkinson's disease and multiple system atrophy) in comparison to the patients with tauopathy (progressive supranuclear palsy group), as well as the age-matched controls, where pathological pharyngeal findings were similar in all patient groups. CONCLUSIONS: Subtle esophageal motility alterations in parkinsonian syndromes seem to be limited to alpha-synucleinopathies, but are not measurable in tauopathies, indicating a causative connection between pathological alpha-synuclein aggregation in gastrointestinal tissues and esophageal involvement.

The causal role of the somatosensory cortex in prosocial behaviour.

Witnessing another person's suffering elicits vicarious brain activity in areas that are active when we ourselves are in pain. Whether this activity influences prosocial behavior remains the subject of debate. Here participants witnessed a confederate express pain through a reaction of the swatted hand or through a facial expression, and could decide to reduce that pain by donating money. Participants donate more money on trials in which the confederate expressed more pain. Electroencephalography shows that activity of the somatosensory cortex I (SI) hand region explains variance in donation. Transcranial magnetic stimulation (TMS) shows that altering this activity interferes with the pain-donation coupling only when pain is expressed by the hand. High-definition transcranial direct current stimulation (HD-tDCS) shows that altering SI activity also interferes with pain perception. These experiments show that vicarious somatosensory activations contribute to prosocial decision-making and suggest that they do so by helping to transform observed reactions of affected body-parts into accurate perceptions of pain that are necessary for decision-making.

Loss of sensory function in patients with idiopathic hand dystonia.

Former studies suggest an additional involvement of the sensory nervous system, beside the involuntary contractions of antagonist muscles, in idiopathic hand dystonia. We studied contact heat-evoked potentials and quantitative sensory testing (QST) in 10 patients suffering from idiopathic hand dystonia and 10 age-matched healthy controls. Cortical potentials recorded from the vertex (Pz) after contact heat stimulation of the volar forearm and the dorsum of the hand at a temperature of 51°C showed significantly reduced A-δ-amplitudes. Numerical pain ratings on the affected side in comparison to the unaffected side and to healthy controls were significantly reduced. QST results showed an impairment of the thermal detection thresholds, the mechanical pain sensitivity and the mechanical pain threshold at the affected body side of the patients. Our results suggest a loss of distinct sensory functions of the affected hand in comparison with the contralateral hand and to matched healthy subjects in patients suffering from idiopathic hand dystonia. For the first time, an extended loss of sensory function could be shown in patients suffering from idiopathic hand dystonia.