Predictive factors of involuntary weight loss in patients with smell and taste disorders

BACKGROUND

Chemosensory dysfunction (olfaction, taste, and trigeminal) affects quality of life, potentially impacting eating behaviors. We investigated which factors are associated with weight loss in patients with smell and taste disorders.

METHODS

Retrospective study of consecutive adult patients seen in the smell and taste clinic during a 10-year period. Patients were asked about smell, flavor and taste impairment. Psychophysically, smell was assessed with Sniffin' Sticks, flavor with a retronasal test, and taste with Taste Strips.

RESULTS

A total of 554 patients (313 females) were included with a median age of 51 years (IQR 23). Seventy-six (13.7%) reported involuntary weight loss (median 6 kg, IQR 6) due to chemosensory disorders. The odds of losing weight were 2.1 times higher when patients reported subjective changes in flavor perception. Parosmia was a significant predictor of weight loss. Patients with symptoms lasting longer than two years were less likely to present with weight loss. Post-traumatic chemosensory dysfunction was a significant predictor of losing weight. On psychophysical testing, the probability of a patient losing weight increased by 8% for every 1-unit reduction in Taste Strips score.

CONCLUSION

Factors associated with weight loss were self-reported changes in flavor perception, parosmia, duration of symptoms for less than two years, head injury, and psychophysically measured low Taste Strips score. These data help to identify patients at risk of weight loss from smell or taste impairment.

Can MRI predict olfactory loss and improvement in posttraumatic olfactory dysfunction?

BACKGROUND

Although most patients with post-traumatic olfactory dysfunction (PTOD) undergo MRI, there is no consensus about its diagnostic or prognostic value. The aims were: 1) to classify the extent of post-traumatic neurodegeneration; 2) to determine its relationship with chemosensory dysfunction (smell, taste, trigeminal); and 3) to establish whether MRI can predict olfactory improvement.

METHODOLOGY

We conducted a retrospective cohort study based on a series of 56 patients with PTOD. All patients underwent validated psychophysical tests of their smell, taste, and trigeminal functions, otorhinolaryngologic evaluation, and MRI. An experienced radiologist blinded to patient data evaluated 40 chemosensory-relevant brain regions according to a four-point scale (0=no lesion to 3=large lesion). Follow up data after 4 years (on average) were available in 46 patients.

RESULTS

The cluster analysis showed 4 brain lesion patterns that differed in lesion localization and severity. They are associated with diagnostic categories: anosmia, hyposmia and normosmia. Two clusters were highly specific for anosmia (100% specificity)and could accurately predict this condition (100% positive predictive value). No clusters were associated with trigeminal or taste dysfunction. Regarding improvement, 72.7% of patients in the cluster with mild lesions experienced subjective and measurable olfactory improvement whereas this was only the case in 21.7-37.5% of patients with larger lesions. The odds of subjective smell improvement were 5.9 times higher in patients within the milder cluster compared to larger ones.

CONCLUSIONS

The analysis of brain lesions in PTOD allows corroboration of smell test results and prediction of subjective and measurable improvement.

Trigeminal cold receptors and airflow perception are altered in chronic rhinosinusitis

BACKGROUND

In chronic rhinosinusitis (CRS), nasal obstruction can often be explained by anatomical deformities, polyps, or congested nasal mucosa. However, in cases with little deformity or inflammation, perceived nasal obstruction may result from reduced airflow perception caused by an alteration of the intranasal trigeminal system. The aim of this study was to assess this association.

METHODOLOGY

We performed a prospective case-control study of 15 CRS patients, 18 patients with a deviated nasal septum (DNS) and 16 healthy controls. We assessed olfactory function using the Sniffin' Sticks test and Visual Analog Scales (VAS). We used the Trigeminal Lateralization Task (TLT) with eucalyptol and cinnamaldehyde to examine intranasal trigeminal function. Further, we assessed nasal patency with Peak Nasal Inspiratory Flow and VAS. Finally, we measured protein levels of trigeminal receptors (TRPM8, TRPA1 and TRPV1) and inflammatory markers (IL-13, INF-y and eosinophils) in CRS and DNS patients' mucosal biopsies using Western Blots.

RESULTS

CRS patients had significantly lower olfactory function than DNS and healthy controls. They also had significantly lower TLT scores for eucalyptol than both other groups. CRS patients had significantly lower nasal patency than controls; for DNS patients this was limited to subjective measures of nasal patency. In line with this, CRS patients exhibited significantly higher levels of sTRPM8-18 than DNS patients.

CONCLUSIONS

Intranasal trigeminal function is decreased in CRS patients, possibly due to the overexpression of short isoforms of TRPM8 receptors.

Position paper on olfactory dysfunction: 2023

BACKGROUND

Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process.

CONCLUSIONS

We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

Efficacy of latanoprost as an adjunct to medical therapy for residual angle-closure glaucoma after iridectomy

Residual primary angle-closure glaucoma (PACG) after iridectomy is an important issue among Asians, especially Chinese. In this study, we tested the effectiveness of latanoprost as an intraocular pressure (IOP) lowering agent in cases of residual PACG. Twenty-six eyes of 26 PACG patients with persistently elevated IOP after iridectomy, despite treatment with conventional IOP lowering drugs (beta blockers and pilocarpine) were included. Latanoprost 0.005%, one drop daily, was added adjunctively to all eyes. Measurement of IOP at baseline and after the start of treatment with latanoprost indicated a significant IOP reduction. The IOP decreased by about 21% (p < 0.005) during the first 3 months, and showed a reduction of about 36% at the end of 1 year. At the 1-year follow up, the IOP was well controlled (below 20 mmHg) in all eyes. These findings show that, in combination with beta blockade and pilocarpine, latanoprost can ameliorate residual PACG after iridectomy and could potentially forestall the need for further therapeutic intervention.

Lipoprotein responses to fish, coconut and soybean oil diets with and without cholesterol in the Syrian hamster

Thirty-six young male Syrian hamsters were fed with test diets containing coconut oil, soybean oil or fish oil with and without 0.5% cholesterol for 6 weeks. Without dietary cholesterol supplementation, animals on the fish oil diet had significantly lower plasma total triglyceride (TG) and total cholesterol than those on the coconut oil or soybean oil diet. The decrease of TG was seen mainly in the very low density lipoprotein (VLDL) fraction. The degree of decrease in cholesterol was similar in all of the lipoprotein fractions. With 0.5% dietary cholesterol supplementation, there was no significant difference in plasma TG level among the three dietary groups. However, the fish oil group had significantly higher plasma cholesterol than the coconut oil and soybean oil groups. The increase of cholesterol was mainly in the VLDL and low density lipoprotein (LDL) fractions. In contrast to the plasma cholesterol level, the hepatic cholesteryl ester content was significantly lower in the cholesterol-supplemented fish oil group than in the coconut oil and soybean oil counterparts. The cholesterol-supplemented fish oil group showed higher liver microsomal acyl-coenzyme A:cholesterol acyltransferase activity than the other two groups, while there was no significant difference in the excretion of fecal neutral and acidic sterols among the three dietary groups.

Preoperative mitomycin-C subconjunctival injection and glaucoma filtering surgery

Intraoperative mitomycin-C application has been well accepted recently as a useful adjunctive procedure to enhance the filtering effect in glaucoma surgery. However, the exact dose of mitomycin-C left after such a procedure in the ocular tissue is variable and unclear. It is important to determine such residual because of potential long-term toxicity of mitomycin-C to the eye. Based on previous successful experience using preoperative mitomycin-C subconjunctival injection in the THC-YAG laser sclerostomy on rabbits, the effect of intraocular pressure (IOP) control and its clinical observation was studied in six eyes of six refractory and high risk glaucoma patients by subconjunctival 1.2 micrograms to 3.6 micrograms mitomycin-C injection 24 to 72 hours prior to classic, routine, limbal-based trabeculectomy surgery. After 18 months of satisfactory clinical observation of the first eye for IOP, functioning bleb appearance and smooth clinical course, the same procedure was used on an additional five eyes, with a follow-up period of more than five months. Average IOP was reduced from 27.8 mm Hg (range 24 to 34 mm Hg) preoperatively to 9.5 mm Hg (range 5 to 14 mm Hg) postoperatively, with a smooth clinical course. The advantages of such preoperative subconjunctival mitomycin-C injection are emphasized here.

Effects of timolol and acetazolamide on intraocular pressure elevation following argon laser iridotomy

To study the effect of hypotensive agents on intraocular pressure elevation following argon laser iridotomy, 0.5% timolol maleate topically and acetazolamide 125 mg orally were given in 39 eyes, one hour prior to laser iridotomy, with 29 eyes serving as the control. The mean pressure two hours after laser iridotomy was 18.9 +/- 7.2 mmHg in the control group and 12.8 +/- 3.9 mmHg in the pretreated group. Ocular pressure was elevated from the baseline pressure of the prelaser status in two eyes (5%) only in the timolol-acetazolamide treated group and in 16 eyes (55%) in the control group. The pressure elevation two hours after laser iridotomy was significantly less in the timolol-acetazolamide pretreated group.

Ocular hypotensive effects of N-demethylated carbachol on open angle glaucoma

Ocular hypotensive actions of N-demethylated carbachol hydrochloride (DMC) were studied in patients with open angle glaucoma; 1% pilocarpine hydrochloride solution was used as a reference. Although 1% pilocarpine seemed to be slightly more potent that 6% and 9% DMC solutions, DMC solutions were devoid of the noticeable side effects produced by pilocarpine. In all cases, maximum ocular hypotensive actions were observed six hours after the single-drop medication and were determined as 4.2, 4.6, and 4.8 mm Hg with 6% DMC, 9% DMC, and 1% pilocarpine, respectively.

Suspending agent effects on steroid suspension dissolution profiles

Dissolution profiles and particle-size analyses were determined for two lots of prednisolone acetate. The effects of common suspending agents on dissolution and particle-size distributions of these suspensions also were investigated. Lot-to-lot variation in the prednisolone acetate dissolution rate was observed and was apparently related to the percentage of fine particles within the distribution. Carboxymethylcellulose sodium inhibition of prednisolone acetate dissolution occurred with only one lot of raw material and seemed to be related to aggregation of the fine particles. Hydroxypropyl methylcellulose inhibited both prednisolone acetate lots and was observed with or without small particle aggregation. The dissolution variations observed have important implications in suspension formulation.