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It is especially important to take the patient's history carefully and to perform neuro-ophthalmological and neuro-otological examinations when a patient ambiguously reports feeling "dizzy".
The history and the clinical examination should first differentiate between peripheral vestibular and central vestibular forms of vertigo.
Other additional laboratory tests are in most cases of less clinical importance.
Most disorders of the oculomotor system, the peripheral or central vestibular systems, and the control of stance and posture can be identified during a careful examination, even without recording the eye movements. These disorders can also be attributed topographically to the correct site. The following figures illustrate details of the examination procedure, the essential findings, and their interpretation. The important questions to be asked in the neuro-ophthalmological examination are the following:

1. Does a spontaneous nystagmus (e.g., upbeat nystagmus due to a medullary lesion or horizontal-rotatory nystagmus in vestibular neuritis), or positioning nystagmus (e.g., BPPV) occur?

2. Are there signs of vestibular disorders or disorders of the ocular motor system (e.g., double vision, saccadic pursuit, slowed or dysmetrical saccades, gaze-evoked nystagmus) or other neurological symptoms (e.g., facial paresis, perioral paresthesias, dysarthrophonia, dysphagia) that indicate a central origin of the disorder?
Examination procedure for the oculomotor and vestibular systems
Type of examination Check for  
Determine:  
Body and head posture
 		tilt or turn of the head / body
postural anomaly
Position / motility of the eyes:
Position of the eyes during gaze straight ahead
Cover test
Examination of the eyes in eight final positions (binocular and monocular)
 
primary misalignment, spontaneous misalignment, fixation misalignment, nystagmus of horizontal, vertical or torsional direction determine the range of eye movements, check end-point
Gaze-holding function:
 
Gaze in a 10-40 degree horizontal direction or 10-20 degree vertical direction and back to zero degrees
Smooth

Smooth pursuit:
Horizontal and vertical
  
 
gaze-evoked nystagmus: horizontal rebound nystagmus

 


smooth or saccadic pursuit or
     
Saccades:
 
Horizontal and vertical saccades when looking around and when directed at targets
 
 
 
 
 

latency, speed, accuracy, and conjugate movements

 
 
 

 
 
Optokinetic nystagmus (OKN):
Horizontal and vertical nystagmus when looking at an optokinetic drum or tape   


inducible, beating direction, and phase (reversal?)
 

 
Peripheral vestibular function:
Clinical testing of the vestibulo-ocular reflex (VOR) Halmagyi's head-impulse test: rapid turns of the head while fixating stationary target
unilateral or bilateral peripheral vestibular lesion
Fixation suppression of the vestibulo-ocular reflex:
Turns of the head while fixating a spot moving with the same velocity
 disturbance of fixation suppression
   

 
Examination with Frenzel's glasses:

Gaze straight ahead, to the right, to the left, downwards, upwards and head-shaking test


Eye movements induced by changes in middle-ear pressure (with Politzer balloon)

spontaneous nystagmus



signs of perilymph fistulas


 

Positioning maneuver (with Frenzel's glasses):
To the left and to the right in head-hanging position, during turns around the longitudinal axis of the body
 positioning nystagmus, central positional nystagmus

  
 
Stance and posture control:
Romberg test
Simple and more difficult balance and gait tests: with open or closed eyes, "tandem Romberg", with or without reclination of the head, with or without distracting maneuvers (tracing numbers on the patient's skin, doing math) 		swaying, tendency to fall

 
 
functional components



 
Additional laboratory tests
Psychophysical determination of the subjective visual vertical tilt of the visual vertical
   
Photography of the fundus of the eye
 eye rotation in the roll plane
Electronystagmography


 Electrodes placed on the face allow recording of horizontal and vertical eye movements.
  Rotatory chair and drum system, in which patients are rotated while sitting in a motor-driven chair; the rotation induces eye movements, which are then recorded.
  By means of caloric testing the responsiveness and functioning of the horizontal canals can be determined for each side separately.
 

First, a lesion of the eardrum must be excluded. Then caloric testing is performed by tilting the patient's head 60 degrees upward so that the horizontal canal is approximately vertical and thus maximally responsive to the test. Each of the external auditory canals is individually irrigated with 30° C cool and 44° C warm water. At the same time the horizontal and vertical eye movements are recorded by electronystagmography.

Video-oculography This non-invasive and well-tolerated technique allows recording of the eye movements within the range of +40°. The simple 2D measurement is routinely performed and is widely used for outpatients. An additional recording in the third plane (to measure eye torsion) is only possible with certain devices.
Posturography To determine posture and balance control, a force-measuring platform is used to measure body sway. An inherent physiological postural instability also causes body sway in healthy persons. It may be intensified by the presence of other conditions, e.g., vestibular disorders.
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