Spinocerebellar degeneration (SCD) is a group of neurodegenerative disorders with cerebellar ataxia as the cardinal clinical sign. Among the types of SCD, spinocerebellar ataxia type 6 (SCA6) shows characteristic neuro-otological signs and symptoms distinct from other types of SCD. The characteristic features include gaze-evoked nystagmus, usually in the horizontal direction, vertigo or oscillopsia, and downbeat positioning nystagmus, which can be observed when the patient's position is quickly changed from the sitting to the supine position. The underlying genetic abnormality in SCA6 is an expansion of trinucleotide CAG repeats in the α1A-calcium channel gene, which is most abundantly expressed in the cerebellar Purkinje cells. Observation of the characteristic nystagmus and documentation of vertigo or oscillopsia in patients with ataxia suggests the possibility of SCA6.

　A 66-year-old female presented with a history of sudden profound sensory neural hearing loss in her right ear from 61 yo and left fluctuating hearing loss from 64 yo. The clinical picture suggested a diagnosis “contralateral delayed endolymphatic hydrops.” However, 3T-MRI with tympanic administration of Gd showed no penetration of Gd into the inner ear on either side, and 3T-MRI with intravenous administration of Gd also showed no evidence of endolymphatic hydrops. Her left-side hearing gradually worsened to profound hearing resulting at 68 yo. When we performed cochlear implantation surgery for the profound hearing loss in her left ear, we found that the round window niche and basal turn of the membranous labyrinth were filled with granulation tissue, which was thought to be caused by some form of labyrinthitis. It is unusual, and noteworthy that this case of labyrinthitis initially showed a clinical course similar to that of delayed endolymphatic hydrops. In this paper, we would like to emphasize the necessity of excluding labyrinthitis in the differential diagnosis of hearing fluctuation fluctuating hearing loss and vestibular disorders, including delayed endolymphatic hydrops.

　Symptoms in Ménière's disease (MD) usually start in middle age, predominantly between 30 and 50 years of age. Classical MD is rarely found in children and reports are scarce. In general, the frequency of occurrence of MD in children is only 0.4-7.0% of that in adults. Here, we selected 7 cases of juvenile MD and 1 case of delayed endolymphatic hydrops (DEH) among 57 pediatric patients with vertigo who were referred to the neuro-otological clinic of Aichi Medical University Hospital between January 2015 to December 2017. The children varied in age from 13 to 18 years (mean, 14.6 years). The 8 patients comprised 1 male and 7 females. Diagnosis of MD was based on the criteria of the Japan Society for Equilibrium Research for Meniere's Disease. The clinical features of the juvenile MD patients were as follows. Most MD patients complained of intensive frequent headache, ear fullness, nasal symptoms and sleep disorder except vertigo, especially were needed for treatment of headache.

　Among the 7 MD patients with fluctuating hearing loss, 5 showed a positive response to the glycerol test. Based on this finding, benign paroxysmal vertigo (BPV) was distinguished from migraine-related dizziness and other pathologies.

　In general, juvenile MD patients often complain of persistent headache, whereas dizziness and hearing loss usually show good progress. Actually, all of our cases showed hearing improvement, but the vertiginous attacks persisted for a long period of time in 2 cases, and transtympanic ventilation was subsequently performed. Following this, the frequency of vertigo reduced in one case, but remained unchanged in the other.

　In juvenile MD, insomnia and refusal to attend school can occur due to dizziness, frequent headaches and other symptoms; therefore, interventions such as child psychiatry referral and counseling may be necessary, depending on the case.

　Because bilateral posterior semicircular canal (PSCC)-type benign paroxysmal positional vertigo (BPPV) is rare, this condition appears to be diagnosed and treated mostly in large hospitals. This report is aimed at underscoring the possibility of diagnosis of bilateral PSCC-type BPPV even in small general ENT clinics. From January 2015 to June 2017, at our general ENT clinic, we encountered two patients who showed right torsional and upward nystagmus in the right Dix-Hallpike (DH) maneuver and left torsional and upward nystagmus in the left DH maneuver. We recorded digital videos of their positional nystagmus during the right and left DH maneuvers. From the video recordings, we could analyze the positional nystagmus of one patient off-line in a three-dimensional manner. The rotational axis of the positional nystagmus in the right DH maneuver was perpendicular to the plane of the right PSCC and that of the positional nystagmus in the left DH maneuver was perpendicular to the plane of the left PSCC. The positional nystagmus in the other patient was analyzed off-line in a two-dimensional manner. During both the right and left DH maneuvers, transient upward nystagmus was observed. Thus, positional nystagmus could be observed upon excitation of the right PSCC in the right DH maneuver and upon excitation of the left PSCC in the left DH maneuver. Both patients were cured by Epley maneuvers. Therefore, we diagnosed both patients as having had bilateral PSCC-type BPPV. During the study period, we encountered 511 patients with BPPV. The ratio of bilateral PSCC-type BPPV to classical BPPV in the patients was 0.39% (2/511), indicating a very low incidence. Thus, by careful observation of the positional nystagmus in both right and left DH maneuvers, bilateral PSCC-type BPPV can be diagnosed even in a small general ENT clinic.

　Vertigo/dizziness may interfere with the daily lives of the patients and have mental defect cause psychological problems. It is important to perform both objective and subjective assessments in patients with vertigo/dizziness. The purpose of this study was to explore differences in the handicap associated with dizziness and psychological problem among patients. During the 44-month period between July 2014 and February 2018, of a total of 275 patients hospitalized at the Vertigo/Dizziness Center at Nara Medical University Hospital, 172 patients, including 78 cases diagnosed as having Meniere's disease, 48 with BPPV, 31 with unilateral vestibular dysfunction, and 15 with sudden deafness, were included in this analysis. Subjects were assessed with the handicap questionnaire for dizziness, the Stress Response Scale (SRS), and the Self-Rating Depression Scale (SDS). Patients with Meniere's disease showed lower scores in items 2 and 3 of the handicap questionnaire as compared to patients with BPPV and those with unilateral vestibular dysfunction. The abnormal ratio of SRS was higher in patients with unilateral vestibular dysfunction; however, no significant differences were noted in the positive ratio of SDS among the groups. These results suggest that patients with BPPV may have limitation of physical activity under the influence of dizziness caused by changes in the head position. Many patients with unilateral vestibular dysfunction do not achieve vestibular compensation and develop psychological problems. It is important for patients with BPPV and those with unilateral vestibular dysfunction to undergo individualized vestibular rehabilitation programs.

　Past major earthquakes have been associated with an increase in the prevalence of vertigo or dizziness; the 2016 Kumamoto earthquakes on April 14 and 16 (JST, moment magnitude=7.0, Shindo 7 [Japanese seismic scale]) and the large numbers of aftershocks were no exception. Several months after the initial earthquake, significant outbreaks of vertigo or dizziness occurred over a large area surrounding the epicenter of the earthquake. However, it is unclear why major earthquakes cause these symptoms. After the major earthquake in Kumamoto, we conducted a questionnaire and medical records survey to investigate post-earthquake dizziness (PED). This survey covered a total of 575 subjects who complained of exacerbation of vertigo or dizziness after the earthquake and visited the hospital for follow-up before the scheduled dates. Our results showed that the number of patients with vertigo or dizziness who visited the hospital increased after the earthquake, and peaked between 2 and 4 weeks after the earthquake. The timing of onset of vestibular disorders varied according to the underlying disease. This study also suggested that earthquake-related psychological stress or stress resulting from earthquake evacuation could cause the onset of some vestibular disorders. We speculated that PED could be caused by stimulation of the vestibular and visual systems and bathyesthesia, psychological stress, potential effects of autonomic stress on the equilibrium function, and/or sensory mismatch. Our study could contribute to establishing PED as a new concept in the area of vestibular disorders.