This paper reviews clinical, neuroanatomical, and neurophysiological studies that have implicated the cerebral cortex in the initiation and/or regulation of swallowing as well as related functions such as mastication. Cortical dysfunction has been reported to result in a variety of swallowing impairments. Furthermore, swallowing can be evoked and/or modulated by stimulation applied to restricted regions of the cortex. Neuroanatomical investigations and single neuron recording studies also provide some insights into the cortical structures, pathways, and mechanisms that may mediate deglutition.
"Orofacial motor dysfunctions such as dysphagia, dysarthria , impaired mastication and drooling are common clinical occurrences associated with sensorimotor cortex lesions (e.g., a stroke) and with altered sensory inputs such as those resulting from peripheral nerve damage (see Refs.   ). "
"Our study suggests that patients with right-sided strokes are less likely to recover swallowing than left sided strokes. Swallowing musculature is represented on the cortices of both hemispheres but displays interhemispheric asymmetry, independent of handedness, with larger representation on the right hemisphere for volitional swallowing [3,13,14,15,16,17]. Following stroke, dysphagia has been reported to be associated with a smaller pharyngeal representation on the intact hemisphere . "
[Show abstract][Hide abstract] ABSTRACT: Objective
To determine predictors of early recovery of functional swallow in patients who had gastrostomy (percutaneous endoscopic gastrostomy [PEG]) placement for dysphagia and were discharged to inpatient rehabilitation (IPR) after stroke.
A retrospective study of prospectively identified patients with acute ischemic and hemorrhagic stroke from July 2008 to August 2012 was conducted. Patients who had PEG during stroke admission and were discharged to IPR, were studied. We compared demographics, stroke characteristics, severity of dysphagia, stroke admission events and medications in patients who remained PEG-dependent after IPR with those who recovered functional swallow.
Patients who remained PEG dependent were significantly older (73 vs. 54 years, p=0.009). Recovery of swallow was more frequent for hemorrhagic stroke patients (80% vs. 47%, p=0.079). Age, adjusting for side of stroke (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.82-0.98; p=0.016) and left-sided strokes, adjusting for age (OR, 15.15; 95% CI, 1.32-173.34; p=0.028) were significant predictors of swallow recovery. Patients who recovered swallowing by discharge from IPR were more likely to be discharged home compared to those who remained PEG-dependent (90% vs. 42%, p=0.009).
Younger age and left-sided stroke may be predictive factors of early recovery of functional swallow in patients who received PEG. Prospective validation is important as avoidance of unnecessary procedures could reduce morbidity and healthcare costs.
Annals of Rehabilitation Medicine 08/2014; 38(4):467-75. DOI:10.5535/arm.2014.38.4.467
"Although the act of swallowing is thought to be mediated principally by brain stem mechanisms (Jean, 2001) converging evidence from electrophysiological, neuroimaging, and clinical studies indicates that the cerebral cortex also plays a fundamental role in the regulation of swallowing (Martin and Sessle, 1993; Miller, 1999). "
[Show abstract][Hide abstract] ABSTRACT: Swallowing is a complex motor event that is difficult to investigate in man by neurophysiological experiments. For this reason, the characteristics of the brain stem pathways have been studied in experimental animals.However, the sequential and orderly activation of the swallowing muscles with the monitoring of the laryngeal excursion can be recorded during deglutition. Although influenced by the sensory and cortical inputs, the sequential muscle activation does not alter from the perioral muscles caudally to the cricopharyngeal sphincter muscle. This is one evidence for the existence of the central pattern generator for human swallowing. The brain stem swallowing network includes the nucleus tractus solitarius and nucleus ambiguus with the reticular formation linking synaptically to cranial motoneuron pools bilaterally.Under normal function, the brain stem swallowing network receives descending inputs from the cerebral cortex. The cortex may trigger deglutition and modulate the brain stem sequential activity. The voluntarily initiated pharyngeal swallow involves several cortical and subcortical pathways. The interactions of regions above the brain stem and the brain stem swallowing network is, at present, not fully understood, particularly in humans.Functional neuroimaging methods were recently introduced into the human swallowing research. It has been shown that volitional swallowing is represented in the multiple cortical regions bilaterally but asymmetrically. Cortical organisation of swallowing can be continuously changed by the continual modulatory ascending sensory input with descending motor output.Significance: Dysphagia is a severe symptom complex that can be life threatening in a considerable number of patients. Three-fourths of oropharyngeal dysphagia is caused by neurological diseases. Thus, the responsibility of the clinical neurologist and neurophysiologist in the care for the dysphagic patients is twofold. First, we should be more acquainted with the physiology of swallowing and its disorders, in order to care for the dysphagic patients successfully. Second, we need to evaluate the dysphagic problems objectively using practical electromyography methods for the patients' management. Cortical and subcortical functional imaging studies are also important to accumulate more data in order to get more information and in turn to develop new and effective treatment strategies for dysphagic patients.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.