Examination of the dizzy patient should include a search for neurological signs and symptpms and careful observation for nystagmus. Most neurological signs and symptoms are markers of dizziness of central origin. However, some of them represent vestibular or other neurological imbalances that cause dizziness. Nystagmus could also represent central or peripheral vestibular imbalances that cause dizziness. Careful examination can also help in discriminating psychogenic (functional) dizziness.
The Barany society has established international diagnostic criteria for nine vestibular disorders so far. The Japanese society of equilibrium research (JSER) developed the diagnostic criteria for five vestibular disorders in 2017, three of which overlap with those of the Barany Society. Thus, both domestic and international diagnostic criteria should be considered in Japan. In addition, some cases may meet the diagnostic criteria of more than one disease. The increasing number of diagnostic criteria makes it difficult for doctors to consider all of them within the limited amount of time available in outpatient settings. Therefore, we developed a system using Microsoft Excel to comprehensively determine whether the symptoms and signs of a patient meet the diagnostic criteria for multiple vestibular disorders, by inputting information from a questionnaire and examination findings. The diseases whose diagnostic criteria were included were Meniere's disease, delayed endolymphatic hydrops, vestibular neuritis, and benign paroxysmal positional vertigo in the 2017 revision of JSER, and Meniere's disease, vestibular migraine, vestibular paroxysmia, persistent postural-perceptual dizziness, bilateral vestibulopathy, presbyvestibulopathy, and hemodynamic orthostatic dizziness/vertigo in the Barany society. The questionnaire was designed to allow patients to answer multiple-choice questions regarding vestibular symptoms, the distinction between paroxysmal and non-paroxysmal vertigo, number of attacks, duration of attacks, provoking or aggravating factors, auditory symptoms, presence of migraine, and other accompanying symptoms. The system can be easily installed in a medical terminal and is expected to contribute to the efficiency of diagnosis and treatment of vestibular disorders.
The stepping test is a dynamic equilibrium function test that evaluates the rotation angle, the transition angle, the transition distance, and the presence of abnormal body sway during 50 or 100 steps taken in the same position with the eyes closed. Although this test is widely used as a part of evaluation of the equilibrium function, previous studies have reported that the deviated side in the stepping test was not correlated with the impaired side in the caloric test. In this study, we evaluated the correlation between the results in the caloric test and VEMP testing with those of the stepping test, in order to evaluate the usefulness of the stepping test to determine the impaired vestibular function side.
The subjects were 38 patients who visited our department and underwent vestibular testing, including the caloric test and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) testing. The correlations between the rotation angle, transition angle and transition distance in the stepping test and the CP% in the caloric test and asymmetry ratio (AR) in cVEMP/oVEMP testing were determined.
There was no significant correlation between the rotation angle, transition angle or transition distance and canal paresis (CP) % in the caloric test or the AR in VEMP. The results suggest that vestibular function exerts little effect on the deviation in the stepping test. The stepping test is still being researched in terms of its usefulness for evaluating the dynamic equilibrium function and the results should be analyzed individually for each case and type of disease. The vestibular function of a patient undergoing the stepping test should be evaluated comprehensively by using multiple types of examinations.
Romberg's sign is an important finding sign that is elicited to screen for the possibility of peripheral vestibular disorders, and the Romberg quotient in stabilometry is the numerical equivalent of the Romberg sign.
In this study, we analyzed the rates of abnormalities of six parameters (the outer circumference area of the sway movement, rectangular area, root means square area, total length of the sway movement, maximum diameter of the left-to-right movement, and maximum diameter of the anterior to posterior movement) to evaluate the Romberg quotient in patients with dizziness, including those with peripheral vestibular diseases.
Subjects stood on the stabilometer with both feet close together in an eyes-open or eyes-closed condition for 1minute each. The sampling frequency was 100Hz. We used the software for stabilometry analysis reported by Asai et al. We calculated the normal values of the six parameters determining the Romberg quotient based on the data in a healthy control group that consisted of 260 healthy adults without ear diseases or dizziness. In this study, we divided the patients into two study groups. Study group I consisted of 91 dizzy patients with peripheral vestibular disorders, while study group II consisted of 54 dizzy patients without peripheral vestibular disorders.
Among the parameters determining the Romberg quotient, the enveloped area, rectangular area, and total length of the sway path seemed to be the most suitable to screen for peripheral vestibular disorders. In particular, the enveloped area could be expected to be useful for distinguishing peripheral vestibular disorders from other disorders. On the other hand, the percentage of subjects with an abnormal root mean square area might be higher among dizzy patients without peripheral vestibular disorders.
A 26-year-old man who developed ataxia of gait and stance after surgery for a suprasellar tumor (juvenile xanthogranuloma) was referred to our outpatient department (Juntendo Univ.) 18 months after the onset of truncal ataxia. Neurological examinations revealed marked truncal ataxia, dysarthria and gaze-evoked nystagmus towards the left side. He had mild dysmetria in all four extremities and dysdiadochokinesia. MRI of the brain showed marked atrophy of the cerebellar vermis and hemispheres and manifest dilation of the fourth ventricle. Serology revealed high titers (1: 1280) of IgG antibodies against EBV capsid antigen (EBV-VCA), but a negative result for EBV-VCA IgM. Examination of the CSF revealed no cells, a glucose level of 56 mg/dl, and a protein level of 30 mg/dl. The CSF tested negative for oligoclonal bands and myelin basic protein. On ENG, gaze-evoked nystagmus was observed at the primary eye position and during leftward gaze in light, but was intermingled with abnormal eye movements such as saccadic intrusions (square wave jerks, double saccadic pulses) in the dark. Both horizontal and vertical pursuits were deteriorated, with remarkable saccadic pursuit. Horizontal OKN was poorly induced. Both horizontal and vertical saccade tests revealed hypermetria in both directions, followed by postsaccadic ocular drift (glissade). Based on these findings along with the finding of atrophy of the vermis on MRI, we considered that the lesions involved not only the vermis and fastigial nucleus, but also the middle portion of the cerebellum, such as the tonsil, uvula, and a part of cerebellar hemisphere (VII). Although MRI did not reveal any other remarkable findings in the brainstem, several nuclei such as the medial vestibular nucleus, nucleus prepositus hypoglossi, the interstitial nucleus of Cajal, and the cell groups of the paramedian tracts could be also suspected as responsible lesions.
When deprived of vision, pilots may experience spatial disorientation, a false perception of position, motion and/or altitude. Spatial disorientation is recognized as one of the most important causes of aircraft mishaps. A better understanding of how the human body interacts and interprets the environment of flight is important, as it can help secure control of a flight and prevent loss of spatial orientation and the attendant aviation mishaps.