Spirulina or Arthrospira is a blue‐green alga that became famous after it was successfully used by NASA as a dietary supplement for astronauts on space missions. It has the ability to modulate immune functions and exhibits anti‐inflammatory properties by inhibiting the release of histamine by mast cells. Multiple studies investigating the efficacy and the potential clinical applications of Spirulina in treating several diseases have been performed and a few randomized controlled trials and systematic reviews suggest that this alga may improve several symptoms and may even have an anticancer, antiviral and antiallergic effects. Current and potential clinical applications, issues of safety, indications, side‐effects and levels of evidence are addressed in this review. Areas of ongoing and future research are also discussed.

Benign paroxysmal positional vertigo (BPPV) is one of the most common peripheral vestibular dysfunctions encountered in clinical practice. Although the treatment of BPPV is relatively successful, many patients develop recurrence after treatment. Our purpose is to evaluate the mean recurrence rate and risk factors of BPPV after treatment. A review of the literature on the risk factors of BPPV recurrence was performed. A thorough search was conducted using electronic databases, namely Pubmed, CINAHL, Academic Search Complete and Scopus for studies published from 2000 to 2020. Thirty studies were included in this review with 13,358 participants. The recurrence rate of BPPV ranged from 13.7% to 48% for studies with follow-up <1 year, and from 13.3% to 65% for studies with follow-up ≥2 years. Pathophysiologic mechanisms and implication of each of the following risk factors in the recurrence of BPPV were described: advanced age, female gender, Meniere’s disease, trauma, osteopenia or osteoporosis, vitamin D deficiency, diabetes mellitus, hypertension, hyperlipidemia, cardiovascular disease, migraine, bilateral/multicanal BPPV, cervical osteoarthrosis and sleep disorders. Patients with hyperlipidemia and hypertension had the highest recurrence rates of BPPV, 67.80% and 55.89%, respectively, indicating that vascular comorbidities increase the risk of BPPV recurrence. In addition, more than half of patients (53.48%) with diabetes mellitus and BPPV experienced recurrence of BPPV. Knowledge and awareness of risk factors for recurrence of BPPV are essential for the assessment and long-term prognosis of patients. Identification of these relapse risk factors may enhance the ability of clinicians to accurately counsel patients regarding BPPV and associated comorbidities.

To review the recent literature on the etiology and pathophysiology of vocal fold nodules in adults. Research regarding the etiology of vocal nodules over the past 2 years supports previous thinking regarding the central role of voice misuse, overuse, and phonatory trauma. Advanced modeling techniques have helped elucidate mechanisms by which this may occur such as vibration-induced rise in capillary pressures and varying fluid dynamics in the layered vocal fold structure. Contributory roles of personality traits, reflux, and allergy have also been hypothesized. Current research supports long-held beliefs that phonatory trauma is a central cause of vocal fold nodule formation. Innovative basic science research has unraveled mechanisms of traumatic damage and clinical research continues to identify crucial lifestyle behavior and contributing comorbid conditions that play a role in the pathogenesis of vocal fold nodules. The multifactorial etiology of vocal fold nodules requires a comprehensive history to identify contributing factors and a multidisciplinary approach to optimize treatment outcome.