Three-dimensional analysis of eye movements using four times high-speed video camera

Differential diagnosis of vertigo and dizziness in the emergency department

CONCLUSIONS

To establish a system of differential diagnosis for vertigo/dizziness at the Emergency Department (ED), careful history-taking of complications and examinations of nystagmus should be helpful and therefore prepared by ED staff.

OBJECTIVES

Vertigo/dizziness could come from various kinds of organs for equilibrium, sometimes resulting in an emergency due to the central origin. In the present study, we checked patients' background data at the ED in advance of a definitive diagnosis at the Department of Otolaryngology and examined the significance of the correlation between the data and the diagnosis.

METHODS

We studied a series of 120 patients with vertigo/dizziness, who visited the Departments of Emergency and Otolaryngology between April 2011 and March 2012. At the ED, we first checked patients' backgrounds and carried out neurologic and neuro-otologic examinations. At the Department of Otolaryngology, we finally diagnosed all the patients according to the criteria and classified the origins of vertigo/dizziness into central and non-central diseases.

RESULTS

The ratio of patients with disease of central origin was 12.5% and that for non-central origin was 87.5%. The risk factors for cerebrovascular disease such as hypertension, heart disease, and diabetes were also the risk factors for central vertigo/dizziness by the chi-squared test. To predict a central origin for vertigo/dizziness, only gaze nystagmus was the significant factor by multivariate regression analysis.

Nystagmus as a sign of labyrinthine disorders--three-dimensional analysis of nystagmus

In order to diagnose the pathological condition of vertiginous patients, a detailed observation of nystagmus in addition to examination of body equilibrium and other neurotological tests are essential. How to precisely record the eye movements is one of the goals of the researchers and clinicians who are interested in the analysis of eye movements for a long time. For considering that, one has to think about the optimal method for recording eye movements. In this review, the author introduced a new method, that is, an analysis of vestibular induced eye movements in three-dimensions and discussed the advantages and limitations of this method.

Pathological localization of so-called posterior canal BPPV

OBJECTIVE

Based on the hypothesis that the origin of nystagmus is from the posterior canal (PC), the nystagmus in the head hanging and sitting position should be mirror images. To clarify the anatomical origin of positioning nystagmus in BPPV patients, we analyzed the positioning nystagmus of benign paroxysmal positioning vertigo (BPPV) patients three-dimensionally.

METHODS

Twenty-six patients with BPPV participated in this study. The positioning nystagmus was recorded in complete darkness from the patient's left eye by means of an infrared CCD camera. We performed three-dimensional analysis of nystagmus using video image analysis system (VIAS). Subsequently, the rotation axis of the 3D eye movements of the positioning nystagmus was calculated.

RESULTS

Among the 26 patients tested, 20 patients demonstrated the axes of nystagmus in good or relatively good alignment to the PC axis. However, in 11 of these 20 patients there was poor alignment of the axis of nystagmus in the sitting position to the PC axis. In addition, six patients showed axes of nystagmus with poor alignment to the PC in the head hanging position. Among them, two patients exhibited axes of nystagmus in good alignment with the anterior canal, in spite of diagnosis of these patients as PC BPPV by experienced examiner based on the positioning nystagmus test.

CONCLUSION

These results demonstrated that only one-third of patients who were diagnosed as BPPV, could be diagnosed as true BPPV which originates from a PC pathology. Besides the possibility that the pathology may originate from the AC, it is still unclear which part of the inner ear may be the candidate site of origin of the pathology of BPPV in the other 15 patients.