Disruption of the Obligatory Swallowing Sequence in Patients with Wallenberg Syndrome.

Although the sequence of events involved in swallowing varies among healthy adults, healthy adults demonstrate some consistent patterns, including opening of the upper esophageal sphincter (UES) prior to maximum laryngeal elevation (LE). Previous animal studies suggested that swallowing is regulated by a neuronal network in the medulla, and lateral medullary infarction, or Wallenberg syndrome, frequently causes dysphagia. This retrospective, observational, multicenter study aimed to determine if the sequence of swallowing events was disturbed in patients with Wallenberg syndrome compared with previously published reference data for healthy adults. The study subjects included 35 patients with Wallenberg syndrome admitted to three hospitals in Japan from 1/4/2009 to 31/3/2017. Sixteen timing events, including maximum LE and UES opening, and the intervals between events were measured. If the sequence of events was the same as in healthy adults, the interval value was positive, and if the sequence of events was opposite to that in healthy adults, the value was negative. The median interval from UES opening to maximum LE was - 0.02 s (range - 0.80 to 0.89, 95% CI - 0.14 to 0.10). About half of the Wallenberg cases showed negative values indicating that the sequence was reversed. These results suggest that lateral medullary infarction impairs the sequence of swallowing events.

Prediction of life-space mobility in patients with stroke 2 months after discharge from rehabilitation: a retrospective cohort study.

Purpose: To determine the predictors of life-space mobility among patients with stroke 2 months after discharge from a post-acute rehabilitation unit.Materials and methods: The study population was 1023 patients discharged from a post-acute rehabilitation unit in Japan. We assessed the relationships between life-space mobility 2 months after discharge and age, sex, length of hospital stay, cognition and motor function (Functional Independence Measure), severity of hemiparesis, falls efficacy, physical function (Timed Up and Go (TUG) test), walking distance ability and social support from family and friends.Results: Bivariate and multiple regression analyses showed that life-space mobility was predicted by sex, age, cognitive score at discharge, TUG score <15 s, length of hospital stay and falls efficacy at discharge. Taken together, these factors accounted for 54% of the variability in life-space mobility. A predictive formula was determined for clinical use.Conclusions: The predictive formula provides an objective measure of life-space mobility for stroke patients after discharge. The clinical application of this formula could help health care professionals working in stroke rehabilitation to prepare patients for discharge and to set concrete goals for in-hospital rehabilitation to improve life-space mobility after discharge.Implications for rehabilitationAccurate prediction of the prognosis for life-space mobility 2 months after discharge is useful in establishing clear goals for community-based rehabilitation.Long-term life-space mobility in the community is not only affected by physical function, but also by sex, age, cognitive ability and falls efficacy at discharge.Life-space mobility in female patients is affected by factors reflecting physical function, whereas life-space mobility in male patients is affected by both physical and cognitive function.Prediction of life-space mobility after stroke is important to determine unique mobility goals in rehabilitation and the required use of adaptive equipment after discharge (e.g., returning to work, engaging in a hobby or travelling beyond the immediate neighbourhood).

Symmetrical hemispheric priming in spatial neglect: a hyperactive left-hemisphere phenomenon?

Hemispheric rivalry models of spatial neglect suggest that the left hemisphere becomes hyperactive following right-hemisphere lesions since the two hemispheres normally exert an inhibitory influence on each other via callosal connections. Using a masked hemifield priming paradigm, we investigated whether the putative change in hemispheric balance involves other, higher-order abstract representational systems in spatial neglect. Participants consisted of 12 neglect patients with right-hemisphere damage and three groups of control participants, i.e., 12 young healthy controls, 10 age-matched healthy controls and 10 right-hemisphere patients without spatial neglect. In each trial, participants made semantic categorization about a centrally presented target word which was preceded by a masked prime flashed either to the left or right visual field. All three control groups exhibited strong left-hemisphere advantage in inhibitory syllabic priming, consistent with the known left-hemisphere dominance in lexical inhibition during reading. By contrast, neglect patients exhibited a symmetrical pattern of priming between the left and right visual fields. These results suggest that (1) the neglected hemifield can rapidly extract abstract information even from weak and normally non-perceptible visual stimuli, but that (2) the normal left hemispheric dominance in reading is absent in neglect patients probably because of the generalized hyperactivity of the left hemisphere. Our results demonstrate a covert behavioral change in spatial neglect which may reflect the altered inter-hemispheric balance in the bilateral word recognition system encompassing lexico-semantic memory.