Weight Reduction due to Stroke-Induced Dysgeusia

Bilateral hypogeusia and food aversion due to lacunar infarct in the right dorsomedial pontine tegmentum

A 70-year-old right-handed housewife suffered an acute loss of taste, an unpleasant change in the taste of foods and liquids, and a strong aversion to all kinds of food due to a small lacune in the right dorsomedial pontine tegmentum. Eating became so unpleasant that she lost 7 kg in three weeks. Olfaction and the sensibility of the tongue were spared. The right medial longitudinal fascicle, the central tegmental tract, or both, were injured by the tegmental lesion. A discrete right-sided lesion in the upper pontine tegmentum may cause a reversible syndrome consisting of bilateral hypogeusia which is more severe ipsilaterally.

Using Animal Models to Determine the Role of Gustatory Neural Input in the Control of Ingestive Behavior and the Maintenance of Body Weight

INTRODUCTION

Decades of research have suggested that nutritional intake contributes to the development of human disease, mainly by influencing the development of obesity and obesity-related conditions. A relatively large body of research indicates that functional variation in human taste perception can influence nutritional intake as well as body mass accumulation. However, there are a considerable number of studies that suggest that no link between these variables actually exists. These discrepancies in the literature likely result from the confounding influence of a variety of other, uncontrolled, factors that can influence ingestive behavior.

STRATEGY

In this review, the use of controlled animal experimentation to alleviate at least some of these issues related to the lack of control of experimental variables is discussed. Specific examples of the use of some of these techniques are examined.

DISCUSSION AND CONCLUSIONS

The review will close with some specific suggestions aimed at strengthening the link between gustatory neural input and its putative influence on ingestive behaviors and the maintenance of body weight.

Aroma and taste perceptions with Alzheimer disease and stroke

Chemosensory disorders of smell or taste in humans have been attributed to various physiological and environmental factors including aging and disease conditions. Aroma and taste greatly condition our food preference, selection and, consumption; the decreased appetite in patients with known neurodegenerative diseases may lead to dietary restrictions that could negatively impact nutritional and health status. The decline in olfactory and gustatory systems in patients with Alzheimer disease and various types of stroke are described.

Altered taste and stroke: a case report and literature review

Patients with altered taste perception following stroke are at risk for malnutrition and associated complications that may impede recovery and adversely affect quality of life. Such deficits often induce and exacerbate depressive symptomatology, which can further hamper recovery. It is important for clinicians and rehabilitation specialists to monitor stroke patients for altered taste perception so that this issue can be addressed. The authors present the case of a patient who experienced an isolated ischemic infarct affecting a primary cortical taste area. This case is unusual in that the isolated injury allowed the patient to remain relatively intact cognitively and functionally, and thus able to accurately describe her taste-related deficits. The case is further used to describe the relevant neurological taste pathways and review potential taste-related therapies.

Altered taste and stroke: a case report and literature review

Patients with altered taste perception following stroke are at risk for malnutrition and associated complications that may impede recovery and adversely affect quality of life. Such deficits often induce and exacerbate depressive symptomatology, which can further hamper recovery. It is important for clinicians and rehabilitation specialists to monitor stroke patients for altered taste perception so that this issue can be addressed. The authors present the case of a patient who experienced an isolated ischemic infarct affecting a primary cortical taste area. This case is unusual in that the isolated injury allowed the patient to remain relatively intact cognitively and functionally, and thus able to accurately describe her taste-related deficits. The case is further used to describe the relevant neurological taste pathways and review potential taste-related therapies.

[Bilateral ageusia caused by right thalamic infarction]

A 58-year-old man noticed left hemiparesis at 01:00 pm on a particular day in March 2006. Because his symptoms developed gradually, he was referred to the emergency room of our hospital at 05:00 pm and was admitted with the diagnosis of cerebral infarction. While he presented slight left hemiparesis involving the face, impairment of sensation was not apparent. Diffusion-weighted magnetic resonance imaging of the head showed a high-intensity area in the ventromedial area in the right thalamus. The patient was treated with anticoagulant and edaravone, and his symptoms resolved on hospital day 3. When he began eating, he noticed that he was unable to distinguish tastes. On day 5, we performed taste examination using a commercial kit. The taste sensation on both sides of his tongue was severely affected, while the touch sensations in the mouth and olfaction were preserved. His symptoms improved spontaneously and resolved on hospital day 15. This is the second case report of bilateral ageusia caused by right thalamic infarction. Our study indicates the importance of the right thalamus in taste sensation involving both sides of the tongue.

Developing workable research methods: lessons from a pilot study with vulnerable participants and complex assessments

Following acute stroke, deterioration in nutritional status and weight loss is common; few studies have investigated this, perhaps due to difficulties with recruitment and completion of complex assessments with stroke patients. This study reports the feasibility of a study protocol to determine predictors of nutritional intake in stroke patients. The aim of the study was to test the feasibility of a protocol to measure taste and smell function, and explore links with dietary intake following stroke. Patients were recruited from one Acute Stroke Unit in 2007/8. Data were collected at three time-points and entailed standardised validated assessments of taste and smell function, diet, appetite and mood state. Recruitment of this vulnerable population to a demanding assessment schedule was challenging. Of a cohort of 166 admissions, six were recruited and complete data collected from four participants. Slow recruitment was largely due to exacting inclusion criteria and rapid hospital discharge. Those who completed all assessments reported the schedule as tolerable and acceptable. This study illustrated the difficulties of recruiting this vulnerable population. Identification of reasons for slow recruitment facilitated development of measures to address them. It was possible to format a complex and lengthy assessment schedule to be acceptable to vulnerable participants.

Recovery from long-lasting post-tonsillectomy dysgeusia

Transient post-tonsillectomy taste dysgeusia (PTD) is a common complaint. Long-lasting PTD is less frequent but has significant consequences on patients' quality of life, with some cases leading to medicolegal issues. Treatment options and knowledge about mechanisms and factors favoring PTD are limited. PTD may result from direct surgical injury, tongue compression, inflammatory processes or side effects of local anesthetics. Some authors also claim that dietary zinc deficiency plays a role in the development of PTD. Although this latter cause had not yet received a lot of attention, we report a case of a female patient who reported a 4-year PTD and recovered within 2 months after oral intake of zinc sulfate. This clinical observation, together with recent findings on significant improvement of taste disorders after zinc treatments for other causes, opens again the question of what extent zinc deficiency plays a role in PTD.

Transient hemiageusia in cerebrovascular lateral pontine lesions

Knowledge of human central taste pathways is largely based on textbook (anatomical dissections) and animal (electrophysiology in vivo) data. It is only recently that further functional insight into human central gustatory pathways has been achieved. Magnetic resonance imaging studies, especially selective imaging of vascular, tumoral, or inflammatory lesions in humans has made this possible. However, some questions remain, particularly regarding the exact crossing site of human gustatory afferences. We present a patient with a pontine stroke after a vertebral artery thrombosis. The patient had infarctions in areas supplied by the anterior inferior cerebellar artery and showed vertical diplopia, right sided deafness, right facial palsy, and transient hemiageusia. A review of the sparse literature of central taste disorders and food preference changes after strokes with a focus on hemiageusia cases is provided. This case offers new evidence suggesting that the central gustatory pathway in humans runs ipsilaterally within the pons and crosses at a higher, probably midbrain level. In patients with central lesions, little attention has been given to taste disorders. They may often go unnoticed by the physician and/or the patient. Central lesions involving taste pathways seem to generate perceptions of quantitative taste disorders (hemiageusia or hypogeusia), in contrast to peripheral gustatory lesions that are hardly recognised as quantitative but sometimes as qualitative (dysgeusia) taste disorders by patients.

Dysgeusia related to urinary obstruction from benign prostatic disease: a case control and qualitative study

Anecdotal reports suggest that dysgeusia may be related to a variety of systemic factors, including bladder outflow obstruction. This is a hospital-based case-controlled study involving 111 patients who were admitted to urological wards for transurethral resection of the prostate for benign prostatic disease with age- and sex-matched control of 137 subjects. We used a semi-structured questionnaire by a trained interviewer at admission (preoperative), at the postoperative period and at follow-up between 4-6 months (median 5 months). Analysis used unpaired t-test and chi(2) test. The incidence of dysgeusia was 22% in the study group and 13% in the control group (P=N.S.). However, strikingly, the dysgeusia in the study group was relieved promptly by relief of urinary obstruction in 100% of cases and did not return within the follow-up period. The mechanism of the dysgeusia associated with dysuria in benign prostatic disease is unknown, but we suggest that the dysgeusia could be from the stress of dysuria or due to a release of an unknown chemical from the urinary tract or an overflow of neural impulse from pontine/cortical micturition centres to the taste centres. An association between dysgeusia and dysuria has not been described before.

Taste Disorders in Acute Stroke

Background and Purpose— The aim of the study was to assess whether and how frequently patients with acute first-ever stroke exhibit gustatory dysfunction.

Methods— We performed a 1-year prospective observational study. Gustatory function was assessed using the standardized “taste strips” test. In addition, we assessed olfactory function, swallowing, stroke location, comorbidities, and the patients’ medication.

Results— A total of 102 consecutive patients were enrolled (45 female, 57 male; mean age, 63 years); 31 of them (30%) exhibited gustatory loss and 7 (6%) had lateralized impairment of taste function. Predictors of impaired taste function were male gender ( P =0.003), high National Institutes of Health Stroke Scale (NIHSS) score at admission ( P =0.009), coexisting swallowing dysfunction ( P =0.026), and a stroke of partial anterior circulation subtype (PACS) ( P =0.008). In particular, in hypogeusic patients the lesion was most frequently localized in the frontal lobe ( P =0.009). Follow-up examinations in 14 patients indicated improvement of taste sensitivity.

Conclusion— Taste disorders after stroke are frequent. A significant association was found for male gender, high NIHSS score, swallowing disorder, and PACS, particularly in the frontal lobe. Generally, taste disorders after stroke seem to have a good prognosis.