Amyotrophic lateral sclerosis (ALS) patients with impaired swallowing show loss of taste perception, according to a new study. This problem is greater in patients requiring a feeding tube.
The findings also suggested that using a device reproducing original food flavor may improve the patients’ quality of life.
The study, “Taste changes in amyotrophic lateral sclerosis and effects on quality of life,” was published in the journal Neurological Sciences.
Impaired swallowing, or dysphagia, is experienced by most ALS patients. A soft diet may be used but patients often complain about its taste, a problem that is aggravated in people requiring an enteral tube (ET) for nutrition. However, no study has evaluated changes in taste perception in patients with ALS.
The team from Italy assessed whether taste perception changes in ALS patients with dysphagia, exploring psychological and quality-of-life consequences. The scientists also studied whether using a device that provides flavors of natural meals improves quality of life. This device, previously tested in healthy volunteers, enables patients to perceive flavors without the need to swallow.
A total of 32 patients (mean age 63 years; 19 men) attending inpatient and outpatient services at the NeuroMuscular Omniservice (NEMO) Clinical Center, in Milan, Italy, were recruited between July and December 2017. Mean disease duration was 59 months; 21 patients required non-invasive ventilation, and nine had a tracheostomy for breathing.
All underwent physical and neurological examinations at baseline. Presence of dysphagia was assessed with the swallowing sub-item in the ALS Functional Rating Scale-Revised (ALSFRS-R). The patients were then divided into two sub-groups — those fed by ET (11 patients, mean age 60 years) and those following a specific oral diet (21, mean age 64 years).
A set of questionnaires was used to determine the impact of taste changes on patients’ psychological status and quality of life. Specifically, section one assessed the degree of interest in flavors in the general study population and specifically in patients on ET feeding. The presence of excessive salivation and/or gastric pyrosis, or heartburn, were also analyzed.
Section two addressed loss or alteration of taste, smell or both. Section three adapted a pre-existing questionnaire to determine the impact of dysphagia on quality of life in two parts. The first evaluated physical function — chewing, swallowing, speech, taste, saliva, and appearance — and social-emotional function — anxiety, mood, pain, activity, and recreation. The second part investigated the three most significant problems as reported by patients. The last section evaluated the ability to identify the presented flavors and their degree of pleasantness.
Then, researchers applied the device, providing flavors to each participant’s tongue for 20 seconds. Both the neurologist administering the flavors and the psychologist responsible for the questionnaires were unaware of responses to questionnaires and reactions to the device.
The results showed that food perception was important for ALS patients, as 24 (75%) had a score of at least 75 (0-100) in the respective scale. Those on ET feeding also had high scores on the importance of food and flavor perception (mean scores equal to 91.77 and equal to 87.92, respectively).
Taste perception was reduced, particularly in the ET group, as eight of 11 patients (73%) reported a significant loss in taste, compared to only five of 21 patients (24%) fed orally.
Over 50% of patients considered swallowing, appearance and speech significant problems. All those on ET considered that swallowing impairment affected their quality of life, in contrast to only 29% on oral feeding.
Patients who were able to eat gave more importance to appearance (76%) and recreational activities (52%). Overall, the composite score for the physical function subscale was significantly lower in patients with ET (27.35) than in those able to eat (60.83).
All patients appreciated the device presenting flavors, which had no side effects. Those on ET feeding considered the essences more pleasant. The team found no differences in patients’ salivation and heartburn when pre- and post-device use were compared. All reported mild levels of saliva and none had heartburn.
“For the first time, our study revealed changes in taste perception in a cohort of ALS patients and the negative consequences that these changes have on psychological status and [quality of life],” the scientists stated.
However, they cautioned that longitudinal analyses are warranted to assess the device’s safety and efficacy.