Parosmia due to COVID-19 Disease: A 268 Case Series

Although parosmia is a common problem in the era of the COVID-19 pandemic, few studies assessed the demographic and clinical aspects of this debilitating symptom. We aimed to evaluate the socio-clinical characteristics and outcome of various options of treatment of individuals with parosmia due to COVID-19 infection. The study was conducted at two main Hospitals in the Ramadi and Tikrit cities, Iraq, on patients with a chief complaint of parosmia due to COVID-19 disease. The study involved 7 months (August 2020-February 2021). Detailed demographic and clinical characteristics and treatment options with their outcome were recorded and analyzed. Out of 268 patients with parosmia, there were 197 (73.5%) females. The majority were from age group ≤ 30 years (n = 188, 70.1%), housewives (n = 150, 56%), non-smokers (n = 222, 82.8%), and associated with dysgeusia (n = 207, 77.2%) but not associated with nasal symptoms (n = 266, 99.3%). All patients have complained of anosmia (89.9%) or hyposmia (10.1%). Troposmia was reported in the majority of participants. The majority of the patients were suffering from severe parosmia (65.7%). Around 3 quarters of the cases were presented in ≤ 4 months. Altered quality of life (AQL) was presented in 91.8% of subjects, and there was a significant association with the presence of dysgeusia and type and severity of parosmia. The smoking habit didn't show a significant association with AQL, the severity of parosmia, and the recovery rate. Most of the odor group was the most triggering stimuli eliciting parosmia, while, the sewage was the response odor in above 50% of the cases. The recovery rate was poor with olfactory training plus either tonics or local and systemic steroids. Parosmia due to COVID-19 infection is a common problem with poor results in the short-term treatment and follow-up. The AQL was seen in a greater proportion of patients and strongly associated with the presence of dysgeusia, type, and severity of parosmia.

The Effect of the Smell of Breast Milk and Non-Nutritious Sucking on Pain Behavioral Response and to First-Time Hepatitis B Vaccine in Term Newborns

Background: The issue of Pain Management finds special significance in infants who are unable to verbally express pain. Studies have shown that the use of non-pharmacological pain control techniques can be effective in reducing neonatal pain. The aim of this study was to compare the effects of olfactory stimulation (with breast milk) and non-nutritive sucking (with a pacifier) on the physiological and behavioral responses in term neonates to the hepatitis B vaccine. Methods: In this clinical trial, which was done in 2015 at the Nohom-e Dey Hospital of Torbat Heidariyeh, 90 eligible infants were randomly selected and divided into two intervention and one control groups. In the breast-milk odor group (n = 30), the neonates were exposed to the mother's odor during vaccination. In the non-nutritive sucking group (n = 30), a standard soft pacifier was used, whereas, in the control group (n = 30), no intervention was carried out. Data collection tools included demographic information forms and the Neonatal Pain Response Scale. Data were edited and analyzed using SPSS 20 software. Results: This study showed that there was a statistically significant difference between the mean scores of neonatal behavioral responses after intervention in the three groups (p <0.05). The mean behavioral response was 0.73 lower in the breast-milk odor group than in the control group, and the mean behavioral response in the non-nutritive sucking group was 0.6 lower than that of the control group. Conclusion: The results of the study showed that both olfactory stimulations with breast milk and non-nutritive sucking have a positive impact on neonatal pain reduction, nearly equally.

Odour-Evoked Memory in Dogs: Do Odours Help to Retrieve Memories of Food Location?

The ability of odors to spontaneously trigger specific memories has been widely demonstrated in humans. Although increasing evidence support the role of olfaction on dogs’ emotions and cognitive processes, very little research has been conducted on its relationship with memory in this species. The present study aimed at investigating the role of olfaction in the recall of detailed memories originally formed in the presence of a specific odor (i.e., vanilla). To test this, three groups of participants were trained with the same spatial learning task while a specific odor (i.e., vanilla) was dispersed in the testing room. Subjects were then divided in three experimental groups and after 24 h delay, they were presented with the same spatial task. The first group (Group 1) performed the task in the presence of a novel odor (i.e., control), whereas the second (Group 2) and the third group (Group 3) carried out the test in the presence of the vanilla odor and no odor (Group 3), respectively. After a brief delay, the test was presented again to the three groups of dogs: subjects of Group 1 were now tested in the presence of the vanilla odor, whereas the Group 2 was tested with the control odor. The Group 3 received no odor in both tests. A significant improvement of dogs’ performance was registered in the control-vanilla odors condition (Group 1), suggesting that the exposure to the odor presented at the encoding time would prompt the recall of spatial memories in dogs.

Analgesic Effect of Maternal Human Milk Odor on Premature Neonates: A Randomized Controlled Trial

Background: Two studies have demonstrated an analgesic effect of maternal milk odor in preterm neonates, without specifying the method of olfactory stimulation. Research aim: This study aimed to assess the analgesic effect of maternal milk odor in preterm neonates by using a standardized method of olfactory stimulation. Methods: This trial was prospective, randomized, controlled, double blinded, and centrally administered. The inclusion criteria for breastfed infants included being born between 30 and 36 weeks + 6 days gestational age and being less than 10 days postnatal age. There were two groups: (a) A maternal milk odor group underwent a venipuncture with a diffuser emitting their own mother’s milk odor and (2) a control group underwent a venipuncture with an odorless diffuser. The primary outcome was the Premature Infant Pain Profile (PIPP) score, with secondary outcomes being the French scale of neonatal pain—Douleur Aiguë du Nouveau-né (DAN) scale—and crying duration. All neonates were given a dummy. Results: Our study included 16 neonates in the maternal milk odor group and 17 in the control group. Neonates exposed to their own mother’s milk odor had a significantly lower median PIPP score during venipuncture compared with the control group (6.3 [interquartile range (IQR) = 5-10] versus 12.0 [IQR = 7-13], p = .03). There was no significant difference between the DAN scores in the two groups ( p = .06). Maternal milk odor significantly reduced crying duration after venipuncture (0 [IQR = 0-0] versus 0 [IQR = 0-18], p = .04). Conclusion: Maternal milk odor has an analgesic effect on preterm neonates.

Acquisition and Extinction of a Runway Response as a Function of a Between- or Within-Subjects Odor Condition

2 groups of albino rats received the same schedule of reward and nonreward (NNNRN), the same magnitude of reward, the same intertrial interval but differed in terms of odor conditions. Each S in a partial reinforcement, within- Ss group received all 5 daily trials before the second S received its first daily trial, etc. Tor Ss in a between- Ss, odor group, 4 other Ss received a given trial before the first S received its second trial, etc. Thus, the only difference between these groups was whether an S followed itself or other Ss. The results showed that during acquisition there was no difference in goal approach rate between the groups, but during extinction, the group of Ss receiving all trials before others were tested extinguished significantly faster than the group of Ss run 1 trial at a time in the start, run, and goal segments of the runway. The study points to important methodological considerations for odor control.