Page 16 - Functional impairment and cues for rehabilitation of head and neck cancer patients -

Chapter 1
that the supine position it has to be performed in is not always feasible, especially for the HNC population, limiting compliance. As a solution, Yoon et al. developed the chin tuck against resistance exercise. For this exercise, the patient is seated in an upright position while tucking the chin against a rubber ball (47). For an effective gain of muscle strength, it is important to practice at 60-70% of the maximal 1 repetition maximum (48, 49). This means that during the course of an exercise program, as muscle strength increases, the resistance against which is exercised should be increased as well; an exercise principle known as progressive overload. While the chin tuck against resistance method tackles the uncomfortable position, it does not easily enable progressive overload. Multiple balls were used, but this is a rather crude and awkward way of increasing resistance. Also, the number of repetitions or contraction duration could be increased, but while this is effective for hypertrophy, it is less so for improving maximal strength (49). To tackle these problems, Kraaijenga et al. developed an exercise device based on the handheld TheraBite® (figure 3) (35-37). The device was modified in such a way that it enabled performing multiple active exercises (figure 4), targeting the suprahyoid, tongue, pharyngeal, and jaw opening musculature in a comfortable sitting position (50). Also, the device enables precise application and increase of exercise load. It is hypothesized that this combination will improve the effectiveness of conventional swallowing strength training. Results of two prospective studies on the SEA including healthy participants (n = 10) and patients with chronic, therapy-refractory dysphagia (n = 17) respectively, showed good compliance and feasibility as well as improved subjective and objective swallowing outcomes, after a training period of 6-8 weeks. One of the physiological questions remaining about the newly developed SEA was whether the relevant swallowing muscle groups targeted by this rehabilitation tool, as well as by the conventional exercises, are indeed activated. Adjustment of the (combination of ) exercises could be made if, for example, a relevant muscle group appears not to be sufficiently activated.
Figure 3 TheraBite® (left) and Swallow Exercise Aid (right).
Predicting feeding tube dependency
It is common knowledge that unused muscles lose mass and function; a phenomenon referred to as non-use atrophy and aptly summarized in the saying ’use it or lose it’. This reversibility principle also applies to the swallowing muscles (51). Therefore, maintaining oral intake during HNC treatment is believed to be beneficial for functional outcomes afterward (51, 52). Feeding tube dependency during CRT for advanced-stage head and neck cancer (HNC) is common; but still, a considerable proportion of patients can maintain their oral intake during CRT (53, 54). Reactive feeding tube (RFT) placement, i.e., placement of a feeding tube in response to excessive weight loss, dehydration, or aspiration, has a role in decreasing the incidence of
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