The points of contact between the vestibular system and the trigeminal nerve remain an active area of research. Anatomically, several connections have been clearly identified, and these may play a role in the development of various disorders. Understanding these connections also proves to be extremely valuable from a clinical perspective. It is increasingly evident that the etiopathogenesis of various vestibular disorders is multifactorial. Therefore, knowledge of the points of interaction between the two systems can assist clinicians in patient assessment and, most importantly, in selecting the most appropriate therapeutic approach. This study is presented as a narrative review. A literature search was conducted to identify studies investigating the correlation between the trigeminal system and the vestibular system, as well as their respective characteristics, to provide a comprehensive overview. Since this is a narrative rather than a systematic review, no specific inclusion or exclusion criteria were applied. So, the aim of this study is to analyze these connections through a comprehensive review of the literature, trying to present a multidisciplinary approach to the topic, one that can involve both the neurologist and the otologist, in order to achieve a more refined management of clinical cases. To better understand their anatomical relationships, we begin by examining the embryological development of both the vestibular system and the trigeminal nerve. Finally, we present current knowledge on the trigeminal influence in certain vestibular disorders—particularly vestibular migraine—and, conversely, the vestibular system’s potential impact on trigeminal-related conditions.

Dietary supplements are products that are ingested in addition to the regular diet to provide additional health-promoting nutrients. Dietary supplements are defined and regulated differently in the European Union (EU) and the United States (US). A fundamental aspect, besides the one related to the composition of the various products on the market, is linked to their quality, both from a nutritional and a pharmacological point of view. Concerning the knowledge of the metabolic aspects, the analysis of the interference, as an inductive or an inhibitory effect, of the p450 enzyme on individual preparations of supplements, is crucial. In this study, we present the results of the interference analysis of a new nutraceutical product based on 38% Bergamot Polyphenolic Fraction BPF® (Citrus bergamia Risso et Poit.), Pomegranate (Punica granatum) and Citrus fruits (Citrus aurantium var. dulcis, Citrus maxima Burm. Merr, Citrus paradisi Macfad) extract with cytochrome p450, showing that the product has limited activity on the cytochromes involved in most of human drug metabolism. This nutraceutical product is to be considered safe and potentially useful in the context of multiple treatments, not interfering with the traditional chronic therapies of patients. These findings open the door to modern "pharma-grade" nutraceuticals, expanding the safety and quality profiles of these new products.

Hyperventilation induces metabolic changes that can elicit nystagmus (hyperventilation-induced nystagmus, HVIN) in various vestibular disorders, revealing vestibular imbalance and bringing out central or peripheral asymmetries. In acute unilateral vestibulopathy (AUVP, namely vestibular neuritis), hyperventilation can induce different patterns of nystagmus (excitatory, inhibitory, or negative), disclosing or modifying existing static vestibular asymmetries through its ability to invalidate compensation or increase peripheral excitability. In this context, we followed the evolutionary stages of HVIN in AUVP across 35 consecutive patients, with the goal of assessing alterations in the oculomotor pattern caused by hyperventilation over time. In the acute phase, the incidence of the excitatory pattern (and the strongly excitatory one, consisting of a reversal nystagmus evoked by hyperventilation) was significantly higher compared to the inhibitory pattern; then, a progressive reduction in the incidence of the excitatory pattern and a concomitant gradual increase in the incidence of the inhibitory one were observed in the follow-up period. Assuming the role of the ephaptic effect and the transient loss of vestibular compensation as opposing mechanisms, i.e., excitatory and inhibitory, respectively, the oculomotor pattern evoked by hyperventilation is the result of the interaction of these two factors. The data obtained allowed us to hypothesize an interpretative model regarding the pathogenetic aspects of responses evoked by hyperventilation and the etiologies of the disease: according to our hypotheses, the excitatory pattern implies a neuritic (viral) form of AUVP; instead, the inhibitory (and negative) one can be an expression of both the neuritic (viral) and vascular forms of the disease.