Introduction: Current treatment of Meniere's disease is limited to prevention of attacks by reducing endolymphatic hydrops. There is no treatment that provides immediate relief during the vertigo episodes. Thus, animal model experiments are needed being conducted to identify curative treatments for Meniere’s disease. Although animal models of endolymphatic hydrops for Meniere's disease exist, there are no animal models in which vertigo can be induced. In the present study, a mouse model was created to induce irritative nystagmus.
Methods: Ten male C 57 B 6 J mice aged 7-11 weeks old were used. Nystagmus was induced by intratympanic injection of 0.2 ml of 3.4 M potassium chloride solution at 37℃ into the left ear. The head was elevated to 40° from the natural body position. Nystagmus in both eyes was recorded with an infrared camera, and the horizontal and vertical eye movements were analyzed using a novel method developed by us.
Results: All mice showed a change from irritative to paralytic nystagmus, as seen in patients with Meniere's disease. Irritative nystagmus appeared 6.22 ± 0.83 min after the intratympanic injection and lasted for 4.42 ± 0.72 min. Subsequently, the irritative nystagmus changed to paralytic nystagmus.
Conclusion: We were able to create a mouse model of vertigo, in which we induced nystagmus that changed from the irritative to the paralytic type. This animal model could be useful in the future to develop a curative treatment for vertigo attacks in patients with Meniere's disease presenting with irritative nystagmus.
