This is what it looks like
Today’s post is a two week follow up on my report of my personal experience with Vestibular Neuritis. I came in to my office at 48 hours into the episode to document the obvious nystagmus, measure the effects of fixation and gaze angle, and measure functional changes in my Vestibular Ocular Reflex (VOR).
As you will see from the graphs below, I was able to document left beating nystagmus following Alexander’s Law. That means that the nystagmus was direction fixed (all left beating), was suppressed by fixation (at 48 hours I still could not supress entirely, but the decrease was obvious), and the nystagmus increased in velocity (from 13 degrees per second spontaneous to 15 degress per second in gaze left), and decreased (to zero) in right gaze.
My initial rotational chair test largely reflects the spontaneous left beating nystagmus as a profound asymmetry to the right. Symmetry is a measure of left beating nystagmus (typically generated by chair rotation to the left) compared to measure of right beating nystagmus (typically generated by chair movement to the right). In my case, there was no right beating nystagmus to measure due to the right hypofunction, and there was persistent, spontaneous nystagmus whether the chair was moving or not. The process of cerebellar clamp is seen as there is a significant reduction in gain of the VOR at slower speeds.
Finally, my vHIT results were consistent with my informal Head Impulse test described in the last post. You will note that when I moved quickly to the left, I was able to maintain visual contact with the target by making an eye movement that was equal and opposite of my head movement. When I moved quickly to the right, the eye movement was reduced (as noted in the decreased gain graph on the right), and I exhibited frequent overt saccades (the little blips occurring after the head stopped moving).
So, my preliminary head in the bucket while spinning and vomiting self exam was correct. As I have said many times, when you see a patient in the sudden onset acute stage of vertigo, you do need to be more concerned about worrisome pathology, but the ability to determine the cause is easier if you know what to look for. I will be back with periodic updates as I go through vestibular rehabilitation and the central compensation process. Wish me luck!