Smell and taste disorders in polyneuropathy: a prospective study of chemosensory disorders

Abstract

Objective – The aim of the study was to assess the occurrence and the frequency of chemosensory dysfunction in patients with polyneuropathy (PNP). Methods – We performed a prospective observational study. Olfactory function was assessed using the standardized ‘Sniffin’ Sticks’ test to measure odor threshold for phenyl ethyl alcohol, odor discrimination, and odor identification. Gustatory function was assessed using the standardized ‘taste strips’ test. In addition, we assessed etiology, neurophysiology, and severity of the PNP, and the patients’ comorbidities and medication. Results – A total of 53 consecutive patients were enroled (15 women, 38 men; mean age 61 years); 27 of them (51%) exhibited olfactory dysfunction and 23 of them (43%) gustatory dysfunction. Patients with diabetic PNP had significantly lower taste scores than patients with inflammatory, genetic, or idiopathic PNP. In addition, odor identification was negatively correlated with PNP severity. Conclusion – The applied bedside tests are useful to detect chemosensory dysfunction in patients with PNP. Chemosensory dysfunction is quite frequent in these patients.

Olfactory Dysfunction in Type 2 Diabetes Mellitus

“…In a study of 53 patients with polyneuropathy, 51% exhibited impaired sense of smell, and odor identification was negatively associated with the severity of polyneuropathy. 36 Diabetes or other metabolic perturbations were the etiology of polyneuropathy in 17% of the patients, while inflammatory (22.6%), genetic (7.5%), and idiopathic (52.8%) causes were quite frequent. 36 However, odor scores did not differ significantly among different etiology and neurophysiology subgroups.…”

Evaluation of olfaction and taste function in type 2 diabetic patients with and without peripheral neuropathy

“…Heckmann et al demonstrated that chemosensory testing identifies dysfunctions of taste and smell in 40% to 50% of patients with polyneuropathy. Odour identification was related to polyneuropathy severity; taste loss was most frequently found in patients with diabetic polyneuropathy …”

Pathophysiology of primary burning mouth syndrome with special focus on taste dysfunction: a review

“…Many patients with documented taste deficits fail to notice the loss of taste (Heckmann et al , ; Bartoshuk et al , ). Mild damage to one of the taste mediating nerves can lead to even intensification of both taste and tactile sensations, whereas damage to both chorda tympani and glossopharyngeal nerve leads to oral sensory loss (Bartoshuk et al , ).…”

“…Several clinical conditions or treatments such as otitis media, head and neck cancer, head trauma, middle ear surgery or tonsillectomy can cause taste nerve damage and taste dysfunction (Berteretche et al, 2008;Cowart, 2011;Bartoshuk et al, 2012). Taste disorders may also be a symptom of more widespread polyneuropathy (Heckmann et al, 2009). In one study, taste deficits were found to be related to dental nerve deafferentation: the greater the number of deafferented teeth, the higher the electrogustatometric thresholds (Boucher et al, 2006).…”