Evidence and Recommendations for Acute Stroke Rehabilitation from the Japan Stroke Society: Abridged Secondary Publication of the Japanese-language Version.

Objectives: In Japan, acute stroke rehabilitation has been expanding more steadily than previously with the nationwide establishment of primary stroke centers. However, Japan previously had no established guidelines for the rehabilitation. Consequently, rehabilitation programs and the provision systems for acute stroke varied among the facilities. To equalize and standardize acute stroke rehabilitation in Japan, it is necessary to develop clinical recommendations for rehabilitation. Therefore, the rehabilitation project team of the Japan Stroke Society aimed to develop the first recommendations for acute stroke rehabilitation in Japan. Methods: The recommendations are based on the results of a survey on the current status of acute stroke rehabilitation at primary stroke centers in Japan, which was completed in 2022, and on a literature review conducted by the rehabilitation project team. Results: The recommendations consist of 19 clinical questions regarding the following topics of acute stroke rehabilitation: (1) head elevation and mobilization training, (2) acute complications, (3) training time and frequency for acute stroke rehabilitation, (4) dysphagia in the acute phase, and (5) acute rehabilitation during pandemics of novel and re-emerging infections, particularly novel coronavirus disease 2019 (COVID-19). The team members agreed on all answers for these 19 clinical questions. Conclusions: These recommendations suggest broad principles of rehabilitative intervention in the acute phase of stroke. In the near future, it is expected that the dissemination of these recommendations will result in an increase in the quality of acute stroke rehabilitation in Japan.

Effect of attention on chewing and swallowing behaviors in healthy humans.

We examined how attention alters chewing and swallowing behaviors. Twenty-one healthy volunteers were asked to freely eat 8 g of steamed rice in three separate trials, and we obtained the average number of chewing cycles (N) and chewing duration (T) prior to the first swallow in each trial. We also conducted an N-limited test, in which participants chewed the food while independently counting the number of chewing cycles and swallowed the food when they reached N, and a T-limited test, in which they chewed the food for T sec and then swallowed. We recorded electromyograms (EMGs) from masseter and suprahyoid muscles and collected videoendoscopic images. In the N-limited test, chewing speed decreased, masseter muscle activity (area under the curve of the rectified EMG burst) per cycle increased, and suprahyoid muscle activity per cycle decreased. In the T-limited test, the chewing speed increased, muscle activities per cycle decreased, and the number of cycles increased. The occurrence frequency of bolus propulsion into the pharynx before swallowing was smaller in the N- and T-limited tests than in the free chewing test. Further, the whiteout time was longer in the T-limited test than in the free chewing test. Attentional chewing changes not only chewing but also swallowing behavior.

Involvement of hypoglossal and recurrent laryngeal nerves on swallowing pressure.

Swallowing pressure generation is important to ensure safe transport of an ingested bolus without aspiration or leaving residue in the pharynx. To clarify the mechanism, we measured swallowing pressure at the oropharynx (OP), upper esophageal sphincter (UES), and cervical esophagus (CE) using a specially designed manometric catheter in anesthetized rats. A swallow, evoked by punctate mechanical stimulation to the larynx, was identified by recording activation of the suprahyoid and thyrohyoid muscles using electromyography (EMG). Areas under the curve of the swallowing pressure at the OP, UES, and CE from two trials indicated high intrasubject reproducibility. Effects of transecting the hypoglossal nerve (12N) and recurrent laryngeal nerve (RLN) on swallowing were investigated. Following bilateral hypoglossal nerve transection (Bi-12Nx), OP pressure was significantly decreased, and time intervals between peaks of thyrohyoid EMG bursts and OP pressure were significantly shorter. Decreased OP pressure and shortened times between peaks of thyrohyoid EMG bursts and OP pressure following Bi-12Nx were significantly increased and longer, respectively, after covering the hard and soft palates with acrylic material. UES pressure was significantly decreased after bilateral RLN transection compared with that before transection. These results suggest that the 12N and RLN play crucial roles in OP and UES pressure during swallowing, respectively. We speculate that covering the palates with a palatal augmentation prosthesis may reverse the reduced swallowing pressure in patients with 12N or tongue damage by the changes of the sensory information and of the contact between the tongue and a palates. NEW & NOTEWORTHY Hypoglossal nerve transection reduced swallowing pressure at the oropharynx. Covering the hard and soft palates with acrylic material may reverse the reduced swallowing function caused by hypoglossal nerve damage. Recurrent laryngeal nerve transection reduced upper esophageal sphincter negative pressure during swallowing.