Vestibular diseases are sometimes associated with comorbid psychiatric conditions, such as anxiety and depression. These conditions often exacerbate the bodily symptoms of vestibular patients, e.g., dizziness and vertigo. In such cases, treatment not only for the organic vestibular diseases, but also for the comorbid psychiatric conditions is important for relieving the bodily symptoms. Diagnosis of anxiety/depression should be based on the diagnostic criteria, however, psychological assessments using questionnaires are helpful as a screening tool in the clinical setting. In this review, several questionnaires for psychiatric assessments, including HADS (Hospital Anxiety and Depression Scale), SDS (Self-rating Depression Scale), STAI (State Trait Anxiety Inventory), MAS (Manifest Anxiety Scale), CMI (Cornel Medical Index), POMS (Profile of Mood States), and SRS-18 (Stress Response Scale-18), are described in brief, including the targeted diagnoses (anxiety, depression, mood, or stress), normal ranges of scores, and clinical usefulness in the vestibular research. These questionnaires should be used not only for patients with suspected psychiatric disorders, but also for those in seemingly normal mental health, since the latter patients also sometimes show abnormal responses to the questionnaires. In addition, psychiatric questionnaires are also useful for evaluating the treatment outcomes.

　The video Head Impulse Test (vHIT) is a novel test that allows evaluation of the functions of the semicircular canals, including of the vertical semicircular canals. vHIT has many advantages over caloric testing; for example, it is both less invasive and less time-consuming than caloric testing. In addition, vHIT allows evaluation of the functions of the semicircular canals in patients with lesions in the external or middle ear, as the semicircular canal functions in this test are evaluated by recording the head and eye movements during the vestibulo-ocular reflex (VOR). It is important to evaluate vestibular functions for making appropriate treatment decisions. However, caloric testing might be inappropriate for patients with external or middle ear pathologies, as in these patients, stimulation with cold water might not be transmitted appropriately to the horizontal semicircular canal; as examples, patients with cholesteatoma, otitis media with ANCA-associated vasculitis, acute otitis media, otitis media with effusion and facial nerve schwannoma have been cited. In this review, evaluation of the functions of the semicircular canals in patients with middle ear pathologies by vHIT are described.

　Direction-changing positional nystagmus is commonly observed in patients with benign paroxysmal positional vertigo of the horizontal semicircular canal type. There are two types, namely, attenuating geotropic nystagmus and persistent apogeotropic nystagmus. The former is thought to be caused by canalolithiasis with the debris located in the horizontal semicircular canal and the latter is caused by cupulolithiasis with the heavy debris attached to the cupula of horizontal semicircular canal. In addition, there are rare cases of persistent direction-changing positional nystagmus, in which the nystagmus does not decay and is of long duration. The pathogenesis of this type of nystagmus is thought to involve a light cupula, because it is explained by the deflection of the cupula in the antigravity direction, but the precise mechanism is still unknown. We encountered a case of vestibular Meniere's disease with recurrent attacks of vertigo, in which the direction of nystagmus changed between the supine and prone positions, and stopped at about 90 degrees below the left and right ears.

　Fabry disease is an X-linked recessive disorder characterized by progressive lysosomal deposition of globotriaosylceramide (GL-3) in cells caused by a deficient activity of the enzyme α-galactosidase A (α-Gal A).

　Hearing loss, tinnitus, and dizziness are relatively common symptoms of Fabry disease.

　We report a case of Fabry disease in a 43-year-old man who presented with bilateral hearing disturbance, vertigo, and dizziness. We had regular hearing tests for about 10 years.

　Although the patient received enzyme replacement therapy, he developed deafness of sudden onset 3 years after the start of treatment.

　The auditory deterioration improved with steroid treatment, the patient's systemic symptoms gradually worsened, and he died less than 10 years after the first treatment.

　As in this case, enzyme replacement therapy exerts scarce effect on hearing in cases of Fabry disease. In the event of acute exacerbation of auditory symptoms, active steroid therapy should be administered.

　Otorhinolaryngologists should include Fabry disease in the differential diagnosis in patients presenting with unexplained sensorineural hearing loss associated with renal failure.

　Meniere's disease refers to a peripheral vestibular disorder characterized by recurrent vertigo and cochlear symptoms, and the underlying pathophysiology is thought to be endolymphatic hydrops. Vestibular migraine is a relatively new disease concept that manifests as recurrent vertigo, whose pathophysiology still remains unclear. Comparison of the physiological characteristics of these two diseases might help in elucidating the pathophysiology of vestibular migraine, and in this paper, the similarities and differences between the two diseases are described from the viewpoint of the findings of physiological examination.

　Meniere's disease is characterized by unilateral vestibular dysfunction, which is not disease-specific. Positive results of tests for endolymphatic hydrops, such as the furosemide test and furosemide-loading VEMP are specific for the disease. Patients who showed unilateral canal paresis on caloric testing did not show lower VOR gain in the video head impulse test (vHIT), which is also specific for the disease.

　About 18%-42% of patients with vestibular migraine show unilateral dysfunction on caloric testing. Many patients with unilateral canal paresis on caloric testing did not show a low VOR gain on vHIT, similar to the case of Meniere's disease. The peak-to-peak amplitude of cVEMP and oVEMP may show a decrease. Some tests for endolymphatic hydrops show positive results.

　The findings could be summarized as follows; vestibular dysfunction is not uncommon in vestibular migraine. The tests show that endolymphatic hydrops could be associated with vestibular migraine, however, it is not clear if this is the cause or the result of the disease.

　The treatment tools for vertigo/dizziness are positioning maneuvers, medication, rehabilitation, intermittent pressure therapy, and surgery. Although many drugs are used, Kampo formulations are sometimes effective in the treatment of patients with vertigo/dizziness who are resistant to usual treatments or have comorbid psychiatric conditions. In Kampo medicine, the condition of a patient is evaluated based on the concept of yin-yang, deficiency-excess, cold-heat, exterior-interior, qi-blood-water, five viscera and location of the disease, which are difficult to understand and utilize for an otolaryngologist. In this report, we introduce some cases that were effectively treated with Kampo formulations based on the concept of deficiency-excess, and qi-blood-water and concomitant symptoms. While Kampo formulations are thought to be an effective tool, they should be used cautiously, because some cases of severe complications such as interstitial pneumonia and mesenteric phlebosclerosis have been reported.

　Several Japanese herbal medicines (Kampo), including Yokukansan, Yokukansankachimpihange, Shigyakusan, Kososan, Kamishoyosan, Kamikihito, Saikokaryukotsuboreito, Keishikaryukotsuboreito, Hangekobokuto, and Rikkunshito, are clinically used for patients with stress-related symptoms and diseases, according to the patient's constitution and symptoms (`Sho' in Oriental medicine). Kamikihito and Yokukansan are prescribed for the treatment of insomnia and neurosis in Japan. However, the precise mechanisms of actions of these products remain unclear. We investigated their possible antistress effects and involvement of oxytocin in the mechanisms of their actions in an animal model of stress. Oxytocin is a posterior pituitary hormone related to uterine contraction and milking. In recent years, its effects in the central nervous system-including its antistress effect-have been attracting interest. Oxytocin is reported to reduce stress levels via regulation of activities in the hypothalamic-pituitary-adrenal axis. Administration of Kamikihito or Yokukansan significantly increased the secretion of oxytocin in acute stress situations and exerted an antistress effect. Furthermore, the effects of these drugs were partially abrogated by administration of an oxytocin receptor antagonist. These results suggest that Kamikihito and Yokukansan have antistress activity and that increased oxytocin secretion may be involved in the mechanism underlying this effect. In clinical practice, the target candidates for these two drugs are different. Although both are used for irritability, anger and insomnia, Kamikihito is generally prescribed to patients who are physically weak, have weak digestive functions, or complain of mental anxiety. Yokukansan, on the other hand, is prescribed to patients with moderate physical strength, who are sensitive, and easily excited. These Kampo medicines may also be useful for stress-induced symptoms and illnesses.

　Descending information from the labyrinth to the spinal motoneurons is mainly conveyed through the vestibulospinal system, which consists of the lateral and medial vestibulospinal tracts. The lateral vestibulospinal tract (LVST) arises mainly from the lateral vestibular nucleus and descends ipsilaterally in the ventrolateral funiculus. It mainly receives input from the otolith organs, extends throughout the length of the spinal cord, and exerts excitation on the extensor muscles of the lower leg. Single LVST axons have multiple axon collaterals at different segments along the entire length of the spinal cord, thus playing an important role in maintaining the posture. In contrast, the medial vestibulospinal tract (MVST) originates in the descending, medial and lateral vestibular nuclei, and descends bilaterally in the ventromedial funiculus of the cervical cord. It conveys mainly semicircular canal inputs to the neck motoneurons, and single MVST axons have multiple axon collaterals terminating on neck motoneurons in different segments of the cervical spinal cord, thus playing an important role in the vestibulocollic reflex.