Oro‐facial impairment in stroke patients

Abstract

Stroke is considered one of the leading causes of death and acquired disability with a peak prevalence over the age of 80 years. Stroke may cause debilitating neurological deficiencies that frequently result in sensory deficits, motor impairment, muscular atrophy, cognitive deficits and psychosocial impairment. Oro-facial impairment may occur due to the frequent involvement of the cranial nerves' cortical representation areas, central nervous system pathways or motoneuron pools. The aim of this narrative, non-systematic review was to discuss the implications of stroke on oro-facial functions and oral health-related quality of life (OHRQoL). Stroke patients demonstrate an impaired masticatory performance, possibly due to reduced tongue forces and disturbed oral sensitivity. Furthermore, facial asymmetry is common, but mostly discrete and lip restraining forces are reduced. Bite force is not different between the ipsi- and contra-lesional side. In contrast, the contra-lesional handgrip strength and tongue-palate contact during swallowing are significantly impaired. OHRQoL is significantly reduced mainly because of the functional impairment. It can be concluded that impaired chewing efficiency, dysphagia, facial asymmetry, reduced lip force and OHRQoL are quantifiable symptoms of oro-facial impairment following a stroke. In the absence of functional rehabilitation, these symptoms seem not to improve. Furthermore, stroke affects the upper limb and the masseter muscle differently, both, at a functional and a morphological level. The rehabilitation of stroke survivors should, therefore, also seek to improve the strength and co-ordination of the oro-facial musculature. This would in turn help improve OHRQoL and the masticatory function, subsequently preventing weight loss and malnutrition.

Can you be too old for oral implants? An update on ageing and plasticity in the oro‐facial sensorimotor system

“…The extensive ongoing feedback and feedforward information provided by the oro‐facial somatosensory inputs to oSI, oMI and CMA is crucial for the preparation, execution, modulation and coordination of the many muscle activities involved in oro‐facial sensorimotor functions such as the positioning of the tongue to help place a food bolus between the teeth and the control of jaw muscles to regulate bite force during chewing (for review, see refs). The critical roles that these three cortical areas play in these functions are particularly evident, and clinically relevant, by way of the functional deficits that can occur in humans when a cortical injury (eg, stroke) affects these areas . Studies in laboratory animals have also shown that damage or experimentally induced inactivation of oM1, oS1 or CMA can disrupt chewing and swallowing and more simple voluntary oro‐facial movements, including the coordination of jaw, tongue and facial movements which is necessary for proper ingestion and transport of food and liquid from the mouth to the oesophagus (eg, refs).…”

“…Nutritional intake and associated ingestive functions may also be compromised in many elderly individuals by the loss of teeth which is particularly common in the elderly . These considerations may especially apply to institutionalised elderly individuals where chewing impairment may be associated with greater risk of mortality, and also apply to elderly persons with neurological problems (eg, stroke) or severe cognitive decline who may have more dental occlusal and related problems affecting their chewing ability …”

“…The importance to the elderly of plasticity of CNS areas in cognitive, emotional, attentional, memory and sensorimotor functions may have even broader implications in relation to oral and general health and rehabilitation. It has been estimated that 20% of senior adults are “orally disabled” because of tooth loss which as noted above may be associated with reduced masticatory efficiency and bite force and disrupted speech, and the prevalence of neurological disorders is also higher . There are several reports of associations between the state of the dentition and masticatory performance and cognitive functions in the elderly, and indeed, there is evidence suggesting that tooth loss and periodontitis represent potential risk factors for developing dementia, Alzheimer's disease and cognitive decline (for review, see refs).…”

“…The critical roles that these three cortical areas play in these functions are particularly evident, and clinically relevant, by way of the functional deficits that can occur in humans when a cortical injury (eg, stroke) affects these areas. [52][53][54] Studies in laboratory animals have also shown that damage or experimentally induced inactivation of oM1, oS1 or CMA can disrupt chewing and swallowing and more simple voluntary oro-facial movements, including the coordination of jaw, tongue and facial movements which is necessary for proper ingestion and transport of food and liquid from the mouth to the oesophagus (eg, refs 50,55 ).…”

“…Neuroplasticity refers to the lifelong capacity of the neural elements of the brain, and indeed, the nervous system in general, to continuously modify (strengthen or weaken) synaptic connections, forms new connections and re-wire neuronal circuits. These are achieved through structural and functional changes that occur in response to alterations of an intrinsic (eg, stroke) or extrinsic (eg, injury, training) nature and that may have a fast or slow onset and be short-lasting or long-lasting (for review, see refs 46,47,[54][55][56][57][58][59][60] ). The ability of CNS areas to undergo neuroplastic changes represents an integral process underlying functions as seemingly diverse as memory, cognition, somatosensation and sensorimotor functions.…”