Smoking Susceptibility in Canadian Adolescent Electronic-Cigarette Users.

Background: E-cigarette use is increasing among Canadian youth, with experimentation especially prevalent among never-smoking youth. Among this group, there is concern e-cigarette use contributes to future initiation of smoking through a gateway effect. However, e-cigarette use and smoking share many common risk factors; a postulated mechanism to explain the apparent causal pathway from e-cigarette use to smoking initiation in previously smoking-naïve youth. A better understanding of the relationships between smoking susceptibility and e-cigarette use among never-smoking youth is needed. Purpose/objectives: The primary aim of this study was to gain a deeper understanding of the risk factors associated with smoking susceptibility in youth who have recently used e-cigarettes. Methods: This study used data (n = 40,363) from the 2018/2019 Canadian Student Tobacco Alcohol and Drug Use Survey (CSTADS) to compare the risk factor profiles of susceptible and non-susceptible never-smoking e-cigarette users, as well as susceptible and non-susceptible never-smoking youth who have never used an e-cigarette. Results: E-cigarette use, independent of susceptibility status, was associated with a sociodemographic and behavioral risk factor profile likely to confer a higher risk of initiating smoking. Among e-cigarette users, smoking susceptibility was associated with more smoking risk factors. Conclusions/importance: Study findings support a common risk-factor model, rather than e-cigarette use itself, to explain differences in the likelihood of smoking initiation among e-cigarette users. E-cigarette use and smoking initiation may be interchangeable outcomes amongst those with smoking risk factors. The risks of e-cigarette use, and their regulatory status, need to be balanced with their potential as harm reduction tools.

A Case of Ophthalmic Branch Trigeminal Neuralgia in the Emergency Department.

This case report describes a middle-aged patient with a past history of migraine headaches, who presented to the emergency department with a new onset of headaches around his left eye that were different from the pattern and character of his usual migraine headaches. The pain was severe, brief, and stabbing in nature, lasting only seconds, and occurring over intervals of a few minutes. His vital signs, including glucose, were normal. He had no constitutional symptoms, a normal neurological examination, and a normal head, eyes, ears, nose, and throat examination. The painful paroxysms could not be elicited on palpation of his face, head, or oral mucosa. His blood investigations were reported as within normal limits. He was not using alcohol or any illicit drugs and was not taking any medication. A diagnosis, with supportive imaging, of ophthalmic branch trigeminal neuralgia (TN) was made. His pain responded well to treatment with carbamazepine. TN is characterized by brief and intermittent lancinating pain with or without a constant background level of pain in the sensory distribution of one or more branches of the trigeminal nerve. There are three main causes for TN: idiopathic, the classical type resulting from neurovascular compression, and the secondary type typically due to multiple sclerosis, a space-occupying lesion, or a skull base abnormality. The mandibular and maxillary branches are most affected and can often be affected simultaneously. Ophthalmic branch TN is relatively rare. Virtually all of TN cases are unilateral and most are the classical type. Distinguishing TN from other cephalalgias, ocular pain, dental pain, or other pathology is critical to a proper diagnosis and initiation of effective therapy. Identifying trigger zones is important and carries a high diagnostic yield; however, they may be anatomically difficult to access, or in a refractory period during a physical examination. Physicians should be aware of several red flags associated with a suspected case of TN. Carbamazepine is the first-line treatment for TN, capable of reducing pain in 90% of patients. Failure to respond to medication requires further investigation and/or specialist referral. Untreated or unrecognized TN can have significant impacts on a patient's quality of life.

The effects of nicotine stimulus and response expectancies on male and female smokers' responses to nicotine-free electronic cigarettes.

BACKGROUND: Electronic cigarettes (e-cigarettes) have been reported to reduce tobacco craving and withdrawal; however, the mechanisms underlying these effects have not been elucidated. METHODS: This study examined the contributions of nicotine stimulus and response expectancies to responses to nicotine-free e-cigarettes in 21 e-cigarette naïve smokers (12 male). Participants completed two randomized experimental sessions in which they administered a nicotine-free e-cigarette. During one session they were informed that the e-cigarette contained nicotine and during the other session they were informed that the e-cigarette was nicotine-free. Participants completed subjective assessments before and immediately after sampling ten puffs from the e-cigarette and were then invited to earn additional puffs using a computerized progressive ratio task. Prior to their enrolment in the study, participants provided an estimate of the relative importance of the nicotine content of e-cigarettes for craving relief. RESULTS: Instructions that the e-cigarette contained nicotine were found to reduce both intention to smoke (p=0.017) and withdrawal-related (p=0.018) craving, regardless of a-priori reported beliefs regarding the relative importance of nicotine. Nicotine content instructions were also found to be associated with a shorter latency to self-administration (p=0.005); however, a Sex×Instructions×Response Expectancy interaction (p=0.008) revealed that this effect was specific to women who had strong a-priori nicotine content craving relief expectations. Neither nicotine content instructions nor response expectancies impacted the number of puffs self-administered. CONCLUSIONS: Findings suggest that nicotine content expectations contribute to smokers' responses to e-cigarettes, and that a-priori beliefs about nicotine effects may be especially important in women.