In this article, we will discuss the Bedside Test used for Evaluation of Vertigo. So, let’s get started.
Bedside Test used for Evaluation of Vertigo
1. Visual fixation: The effect of visual fixation is tested at the bedside with an ophthalmoscope focussed on the optic disc of one eye while the patient covers and uncovers the other (fixating) eye. The intensity of the nystagmus and velocity of its slow phase are increased by covering the fixating eye in peripheral vestibular lesions. Dynamic visual acuity is a functional test for assessing vestibular function. Visual acuity is measured with head still and head rotation (back and froth). A drop in visual acuity during head motion of more than one line on a near chart or Snellen chart is abnormal and indicates vestibular dysfunction.
2. Caloric test: Caloric stimulation test is applied to each ear separately. The test is performed by making the patient in recumbent position and head flexed at 30°. Cold water stimulation normally induces horizontal nystagmus with slow phase towards the cold water stimulation and fast phase to the opposite side. Warm water stimulation has opposite effect. A reduced response indicates vestibular disorder on the same side. An inability to induce nystagmus with ice water denotes a ‘dead labyrinth’.
3. Head impulse test (vestibulo-ocular reflex): It is assessed by multiamplitude rapid head rotations. While patient fixes on a target, the head is rotated to right and left and look for nystagmus after rotation. If head impulse test is negative, the rotation is followed by nystagmus in the opposite direction (leftward nystagmus) after rightward rotation, if positive then to the same side of rotation.
4. Dix-Hallpike manoveuvre for benign positional paroxysmal vertigo (BPPV).
5. Auditory testing: It gives informations regarding the hearing loss or tinnitus or other auditory symptoms that accompany vertigo in peripheral nerve lesions. CNS disorders rarely accompany auditory symptoms.
Electronystagmography is done for recording the sponatoneus nystagmus for positional vertigo.
6. MRI imaging: If a central aetiology is suspected, MRI should be done.