PubMed · 5286559
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
I M Sheppard, S M Sheppard. 1971. Denture occlusion.. https://doi.org/10.1016/0022-3913(71)90004-7
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
The inferior pharyngeal constrictor (IPC) muscle functions during swallowing, respiration, and vocalization. The most-caudal portion of the IPC is believed to be part of the functional upper esophageal sphincter (UES). We hypothesized that the caudal fibers of the human IPC may have enzyme-histochemical characteristics similar to those of the cricopharyngeus muscle, a major component of the UES. In this study, human IPC muscles obtained from autopsy were studied using Sihler's stain to examine innervation patterns, and using myofibrillar ATPase, NADH tetrazolium reductase (NADH-TR), and succinic dehydrogenase (SDH) techniques to investigate the distribution and oxidative capacity of the slow- (type I) and fast- (type II) twitch fibers in the muscle. The results showed that the human IPC consists of at least two neuromuscular compartments (NMCs): rostral and caudal. Each of the NMCs was innervated by a separate nerve branch derived from the pharyngeal branch of the vagus nerve. The rostral NMC is faster (39% type I, 61% type II) than the caudal NMC (70% type I, 30% type II). In addition, two histochemically-delineated fiber layers were identified in the human IPC: a slow inner layer (SIL) with predominantly type I fibers (66%), and a fast outer layer (FOL) with predominantly type II fibers (62%) (P < 0.01). However, the dimensions of both fiber layers and proportions of the muscle fiber types varied with the NMCs. Specifically, the ratio of the thickness of the SIL to FOL was approximately 2:1 for the caudal NMC and approximately 1:2 for the rostral NMC, respectively. In the SIL the type I fibers accounted for 84% for the caudal NMC and 69% and 44% for the lower and upper portions of the rostral NMC. In contrast, the type II fibers in the FOL accounted for 46% for the caudal NMC and 67% and 74% for the lower and upper portions of the rostral NMC, respectively (P < 0.01). The caudal NMC of the IPC shared histochemical characteristics with the cricopharyngeus muscle, in that it contained predominantly slow oxidative fibers. Overall, the caudal NMC and the SIL in the IPC had high NADH-TR and SDH activities. However, different patterns of oxidative enzyme activity were identified in both type I and type II fibers. This study provided histochemical evidence for the concept that the caudal NMC within the IPC contributes to the functional UES. In addition, the two histochemically-defined fiber layers in the IPC may be a specialized adaptation in humans to enable different upper-airway functions during respiration, swallowing, and speech.
BACKGROUND: Dysphagia occurs frequently in Parkinson's disease although patients themselves may be unaware of swallowing difficulties. Speech and language therapists in conjunction with nurses and dietitians use techniques that aim to improve swallowing and reduce the risk of choking, aspiration and chest infections. OBJECTIVES: ~Bullet~To compare the efficacy and effectiveness of non-pharmacological swallowing therapy for dysphagia versus placebo or no intervention in patients with Parkinson's disease. ~Bullet~To compare one form of non-pharmacological swallowing therapy for dysphagia with another in patients with Parkinson's disease. SEARCH STRATEGY: Relevant trials were identified by electronic searches of MEDLINE, EMBASE, CINAHL, ISI-SCI, AMED, MANTIS, REHABDATA, REHADAT, GEROLIT, Pascal, LILACS, MedCarib, JICST-EPlus, AIM, IMEMR, SIGLE, ISI-ISTP, DISSABS, Conference Papers Index, Aslib Index to Theses, the Cochrane Controlled Trials Register, the CentreWatch Clinical Trials listing service, the metaRegister of Controlled Trials, ClinicalTrials.gov, CRISP, PEDro, NIDRR and NRR; and examination of the reference lists of identified studies and other reviews. SELECTION CRITERIA: Only randomised controlled trials (RCT) were included. We did not examine any trials using drugs or surgery to treat the dysphagia. We did not examine any trials where part of the therapist's advice was to insert a nasogastric or percutaneous gastrostomy tube. DATA COLLECTION AND ANALYSIS: Not applicable. MAIN RESULTS: No randomised controlled trials or controlled trials were found that examined the efficacy of non-pharmacological swallowing therapy for the treatment of dysphagia in Parkinson's disease. However there is one large RCT currently recruiting patients that will compare 'chin down' posture with thickened liquids in the treatment of dysphagia. The main outcomes will be the rates of aspiration and pneumonia. REVIEWER'S CONCLUSIONS: There is currently no evidence to support or refute the efficacy of non-pharmacological swallowing therapy for dysphagia in Parkinson's disease. Large well designed placebo-controlled RCTs are required to assess the effectiveness of swallowing therapy for dysphagia in Parkinson's disease and reported according to CONSORT guidelines. Suitable outcome measures should be chosen so that the efficacy and effectiveness of non-pharmacological swallowing therapy can be assessed and an economic analysis performed. Outcomes which have meaning to patients and carers should be used wherever possible since they need to know the value of this therapy in practical terms. The patients should be followed for at least 6 months to determine the duration of any improvement.