xRead - Olfactory Disorders (September 2023)

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relative to one another for each etiology of smell dys function, and why some patients with many of these comorbidities and risk factors continue to have nor mal smelling ability. This is an area for potential future research. C Inherent predisposition of cranial nerve dysfunction when exposed to viruses Viruses such as influenza, measles, mumps, rubella, varicella zoster, and herpes simplex virus infection play a crucial role in causing cranial nerve dysfunction, including PVOL, trigeminal chemosensory dysfunc tion, sudden sensorineural hearing loss, and vocal fold paresis/paralysis. 1627,254 Pathophysiology of other cranial neuropathies has been shown to involve neuroinflam mation, apoptosis, and destruction of neurons, which is similar to PVOL in that it has been documented that neuroinflammation of the olfactory nerves or epithelium leads to neuronal injury and morphological alteration of both the OB and cortex. 254,1084,1628,1629 Jitaroon et al 1630 reported a higher incidence of cra nial neuropathies in patients with PVOL than in a con trol group. Additionally, a family history of neurologic dis eases, such as dementia, AD, and stroke, was also shown to be a potential risk factor for having both PVOL and other cranial neuropathies. When considering these neu rologic associations, there may be an inherent genetic vul nerability or susceptibility to neuropathy in some indi viduals or families. Theories as to what would cause this susceptibility range from a genetic propensity to mount an aggressive localized or systemic inflammatory response to a viral attack or other underlying genetic mechanism, versus a common familial exposure to environmental risk factors. More research in this area would help us under stand potential risk factors that have not previously been explored. D Discussion of protective and supportive measures 1 risks Patients with smell loss should be counseled regarding safety issues associated with OD. Surveys of patients with hyposmia or anosmia found that the degree of olfac tory impairment correlated with the frequency of haz ardous events associated with loss of smell. These incidents included burning of food or pots and pans associated with cooking, inability to smell a fire or smoke, failure to smell Control of environmental and food-related

a natural gas leak, or ingestion of spoiled food or toxic substances. 65,67 The percentage of patients who reported experiencing a hazardous event related to their smell loss ranged from 22% to 24% for those with mild hyposmia to 39% to 45% with anosmia, three times the rate of those with normosmia. 65,67 In addition, patients with impaired olfac tion reported concern related to these safety issues, which impacted their QOL. 62 Olfactory testing was included in the US NHANES of adults, wherein of those aged ≥ 70 years, 20.3% were unable to correctly identify smoke and 31.3% failed to correctly identify natural gas odor. 1631 Patients should receive information regarding their risks for hazardous events related to their smell loss as well as recommendations for safety measures. Family mem bers or housemates should be made aware of the limita tions of the patient’s ability to smell or detect hazardous odors or spoiled food in order to assist with safety con cerns. Smoke detectors should be installed and tested twice a year throughout the house as well as near the kitchen in case of risk of burning food or fires. For those with natu ral gas or propane in the home, gas leak alarms should be installed in furnace rooms, near fireplaces, and near gas stoves, as someone with anosmia would be unable to smell the mercaptan additive in the gas. These gas leak alarms differ from carbon monoxide alarms, which will not detect a gas leak. Finally, those with anosmia or severe hyposmia should be aware of the risk of ingesting spoiled food and utilize expiration dates or label foods with dates when stor ing them. 2 Nutritional monitoring Binge-eating disorder is the most prevalent eating disor der, with 2% to 4% of the general population afflicted. While some patients meet criteria of obesity, attacks of binge eating might also occur in patients with AN result ing in weight loss or that are able to maintain a normal weight. 1632 Sensory influences on food choices may still be under rated despite the sense of smell playing a primary role in flavor perception. 1633,1634 Several additional eat ing disorders have been associated with altered olfactory capacities. 871,946 Alternatively, OD may alter eating behav iors and food appreciation. 1635–1637 In individuals with food avoidance, this disorder might be sensory-related, specif ically to aspects of flavor perception (including smell, taste, texture, and color). 1638 While sensory-specific sati ety does not seem to be different in patients with OD, 1639 altered eating behaviors in OD may include distortion of food intensity, 1637 decreased pleasure in novel food, 1640 over-salting, 1641 and tendency to spicy dishes. 1636 Weight gain has been reported for patients with anosmia, in