Genetic counseling is part of the management of genetic syndromes, consisting of providing appropriate clinical and genetic information based on the diagnosis and comprehensive psychosocial support. In Japan, clinical geneticists and certified genetic counselors play leading roles in this process. Although genetic testing on affected patients could be performed by all clinicians, genetic counseling should be considered for all patients with genetic syndromes and their families for the purpose of managing the variety of psychosocial burdens they might be carrying. Congenital hearing loss is a good model in which genetic testing and subsequent genetic counseling have prevailed as standard medical activities covered by medical insurance.
The episodic vertigo of Meniere's disease is related to stress. Although the questionnaire method is useful in the evaluation of mental stress, it is hard to assess physical stress, in other words, fatigue. Human herpes virus-6 (HHV-6) and -7 (HHV-7) are the cause of Roseola infantum. Latent infection of those viruses is established in all Japanese adults, and viruses are re-activated and secreted into saliva under conditions of severe fatigue. Detection of HHV-6 DNA in saliva represents short-term fatigue which lasts for a week, and that of HHV-7 DNA indicates long-term fatigue which lasts for a month. Objective evaluation of fatigue is achieved by measurement of the levels of HHV-6 and 7 DNA in saliva. Patients who suffered from vertigo attacks within a week were divided into two groups, namely Meniere's disease with depression (D (+) Meniere) and without depression (D (-) Meniere), using questionnaires and investigation of mental problems. Saliva samples were collected, and viral DNA was amplified with the Loop mediated isothermal amplification method using specific primers as reported previously. HHV-7 DNA was detected at the high rate of 89% in the D (-) Meniere group, whereas it was 17% in the D (+) Meniere group, and 0% in healthy subjects. HHV-6 DNA was also detected at a higher rate of 64% in the D (-) Meniere group compared with 17% in the D (+) Meniere group and 33% in healthy subjects. A high rate of virus DNA in saliva indicated accumulated fatigue in Meniere's disease patients.
In the present study, we examined the temperature of aural air stimulation that was equivalent to aural stimulation with water at 20°C in the caloric test. In 10 ears of 5 healthy volunteers, the maximum slow phase eye velocities (MSPEVs) of nystagmus induced by aural stimulation with air at 22°C, 46°C and 16°C were the same as those with water at 30°C, 44°C and 20°C, respectively. These findings suggest that caloric stimulation with air at 16°C is equivalent to that with water at 20°C that is commonly used in the caloric test in Japan. The MSPEVs of nystagmus induced by aural stimulation with air at 16°C were over 20°/sec in all ears except one, in which the MSPEV was 19.7°/sec. The criteria of canal paresis where the MSPEV of caloric nystagmus induced by aural stimulation with water at 20°C is less than 20°/sec can be used in the caloric test with aural air stimulation at 16°C.
Most acoustic neuromas (ANs) arise from the superior or inferior vestibular nerve. In our previous study, we demonstrated that the presence of vestibular disorders could cause unstable gait in patients with an AN. The purpose of this study was to investigate the influence of vestibular nerve function on head movements during walking. Fifteen patients (5 males, 10 females; mean age: 52.9±11.4 years old; mean height: 162.2±8.6cm) with unilateral AN were enrolled in this study. Nine healthy subjects (4 males, 5 females; mean age: 60.1±8.5 years old; mean height: 162.7±8.1cm) served as controls. All patients underwent ocular vestibular evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests. Subjects were asked to walk at a comfortable speed with eyes open or closed. Head movements during walking were analyzed with a 3-dimentional motion analysis system. For the vestibular test results, the percentages of abnormal oVEMP, cVEMP, and caloric responses were 66.7% (10/15), 66.7% (10/15), and 73.3% (11/15), respectively. The oVEMP test results correlated well with the caloric test results. In comparison with horizontal head movements of normal subjects, those of AN patients, especially with abnormal oVEMPs in the eyes closed condition, were greater. Vertical head rotations (pitch movements) of AN patients, especially those with abnormal cVEMPs, were greater than those of normal subjects. These results suggest that the dysfunction of the vestibular nerve in patients with an AN could affect head stability during walking.
Instead of examination under Fresnel lenses, infrared videonystagmography is now commonly used in cases of nystagmus. Nystagmus images are stored on a video recorder or a computer, and the information of the head positions is also saved using voice in the video. The method using voice is a simple way to record positions of the head, because it needs no additional hardware. However, judgment of the head position is difficult during playback if it is started from the middle of the recorded nystagmus images, which forces the examining clinician to continue to talk about the position of the head during the entire examination. We developed a motion sensor device and related software to record information about the position of the head which we have been using in our clinic since 2010. Recently the price and size of integrated circuitry, such as sensors, have fallen dramatically, concomitantly with improved performance. Even as amateurs, we can assemble a motion sensor device with a small number of parts and cheaply. Herein we explain how to make the motion sensor device and related software, which generate data on head animation from the sensor, correlate these data with the nystagmus images before saving them, and enable us to utilize the recorded images in various ways.
Cases of recurrent benign paroxysmal positional vertigo (BPPV) were evaluated retrospectively to examine the affected semicircular canal, the pathophysiology (canalithiasis or cupulolithiasis), and the affected side. The subjects were 152 patients with recurrent BPPV out of 571 consecutive BPPV patients treated at one clinic over a period of 10 years and 5 months. The subjects had up to 5 BPPV recurrences and there were 260 recurrences in total. Of these, 97 (37%) affected the same ear and the same canal and were caused by the same pathophysiology; 93 (36%) occurred on the same side, but affected a different canal and/or were caused by a different pathophysiology; 11 (4%) occurred on the same side, but affected a different canal and were suspected to have been caused by a different pathophysiology; 43 (17%) affected the contralateral side; and 16 (6%) were suspected to have affected the contralateral side. The affected side was defined as the side on which a deposit of otoliths detached from the utriculus. The affected canal and the pathophysiology were also defined based on a lesion with otolith deposits. Our results showed that about 75% of recurrent BPPV cases occur on a fixed side on which otoliths are likely to be detached, while 25% may have a general risk factor such as osteoporosis that can cause detachment of otoliths from the utriculus on both sides. About one-third of recurrent BPPV cases affected the same ear and canal, and were caused by the same pathophysiology; and another one-third occurred in the same ear and affected different canals and/or had a different pathophysiology. These findings suggest that a preference for head position during sleep may be related to the lesion site in which otoliths are deposited.