Subjective Vestibular Assessment

Original Editor - Jess Bell based on the course by Bernard Tonks
Top Contributors - Jess Bell and Kim Jackson

Introduction

As discussed here, there are a number of conditions that can cause dysfunction of the vestibular system. Examples of vestibular pathologies include:

• Vestibular labyrinthitis or neuritis (also termed neuronitis)
• Labyrinthine concussion (unilateral vestibular lesions (UVL) or bilateral vestibular lesions (BVL)) or post-concussion syndrome
• Benign paroxysmal positional vertigo (BPPV)
• Perilymphatic fistula
• Primary endolymphatic hydrops (Meniere’s disease)
• Secondary endolymphatic hydrops (traumatic, infections etc)
• Utricular dysfunctions
• Superior canal dehiscence syndrome (congenital, but trauma can also ‘activate’)
• Central vestibulopathies (sensory integration dysfunctions)
• Drug toxicity
• Persistent postural-perceptual dizziness (PPPD)
• Mal de Debarquement Syndrome (MdDS)

A detailed subjective and objective assessment is necessary when treating patients with vertigo or dizziness in order to determine the most effective treatment for each patient. This page will discuss the subjective evaluation in detail.

Subjective Evaluation

When taking a subjective history, the following questions should be asked:

• How long do the episodes of dizziness or vertigo last (i.e. seconds, minutes or hours)?
• Does the patient have vertigo or more generalised dizziness and disequilibrium (or both)?
• Has the patient had any medical investigations or been given a diagnosis?
• Does the patient have a history of head trauma or other precipitating factors?
• Does the patient experience symptoms with visual tasks or in complex, motion rich environments?

It is also important to consider the conditions or symptoms discussed below in the subjective interview.

Mal de Debarquement Syndrome (MdDS)

MdDS is a form of sensory integration dysfunction. If a patient complains of a rocking or swaying sensation (i.e. as if they are on a ship), MdDS should be considered in the differential diagnosis.

The vestibular system must be able to adapt to continuous passive motion – for example while travelling at sea - and then re-adapt when back on land. In MdDS, this re-adaptation does not occur. The symptoms of rocking / swaying persist sometimes for months and occasionally for years. Typically, MdDS patients feel better when they are in motion.

Motion Sickness

Asking about motion sickness in the subjective assessment of vestibular patients is relevant because a history of motion sickness indicates that:

• A patient’s central nervous system may choose strategies to manage sensory conflict that are not adaptive
• There is a sensory mismatch between vestibular and visual cues

Oscillopsia

Oscillopsia is the subjective illusion of visual motion  - it is caused by a malfunction of the vestibulo-ocular reflex (VOR). It can only occur when an individual’s eyes are open and it frequently presents with peripheral BVLs.

Floating, Swimming, Spinning Inside the Head

These symptoms are frequently associated with anxiety, depression and somatoform disorders. The vestibular system does not tend to cause these types of sensations.

Vertical Diplopia

Vertical diplopia is a type of double vision where the individual sees two images, which line up vertically:

• Symptoms disappear if either eye is closed
• It is often caused by skew eye deviation and is due to an otolith dysfunction or otolith processing issue

Vertigo

Vertigo is defined as the illusion of movement of self or of the environment. It is an entirely subjective phenomenon. If vertigo is related to a dysfunction of the vestibular system, it will be due to a sudden imbalance of tonic neural output.

Lightheadedness or Presyncope

These symptoms are related to orthostatic hypotension - they are not a vestibular symptom.

Symptom Provocation

It is important in the subjective interview to determine the circumstances which provoke symptoms. For example, find out if symptoms:

• Are provoked by certain movements of the head and body, or in situations where there is visual-vestibular-somatosensory mismatch
• Occur in busy, noisy and motion rich environments
• Are related to specific visual tasks and activities

For a summary of the key symptoms of dizziness and their underlying mechanisms, please see Table 1.

Table 1. Symptoms of Dizziness

Symptoms	Mechanisms
Disequilibrium - imbalance or unsteadiness while standing or walking	Loss of vestibulospinal, proprioceptive, visual, motor function, joint pain or instability and psychological factors
Lightheadedness or presyncope	Decreased blood flow to the brain
Sense of rocking or swaying as if on a ship (MdDS)	The vestibular system adapts to continuous, passive motion and must re-adapt once the environment is stable
Motion sickness	Visual-vestibular mismatch
Nausea and vomiting	Stimulation of medulla
Oscillopsia - illusion of visual motion	Spontaneous: acquired nystagmus Head-induced: severe, bilateral loss of VOR
Floating, swimming, rocking, and spinning inside the head	Anxiety, depression and somatoform disorders
Vertical diplopia	Skew-eye deviation
Vertigo - rotation, linear movement, tilt	Imbalance of neural activity to the vestibular cerebral cortex

Falls

Patients with UVLs do not tend to fall more than their age-matched peers. However, patients with BVLs are more at risk of falling:

• The risk of falling increases in those who have fallen more than twice in the past 6 months

Questions to ask include:

• Was the individual injured in the fall?
• When and how did the fall occur?
• Has the individual changed his / her lifestyle due to the fall?

Functional Status

Subjective Outcome Measurement

The Dizziness Handicap Inventory (DHI or DI) can be useful for both the subjective evaluation of vestibular patients and as an outcome measure. It enables the clinician to measure a patient’s perception of his / her disability - i.e. the impact of the dizziness on his / her quality of life. Items relate to functional, emotional and physical problems.

A score of 16 to 34 indicates the patient perceives his/ her dizziness as mild. A score of 36 to 52 suggests moderate symptoms and a score of over 54 suggests a perception that the dizziness is severe.

Psychosocial Status

Psychosocial status has to be considered as anxiety is known to have a disruptive influence on vestibular rehabilitation.

The Positive and Negative Affective Scale (PANAS) can be used for vestibular patients. It is a screening tool that can be used to assess the presence of anxiety or depression, but it is important to note that it does not indicate the cause of symptoms.

Cognitive Vestibular Interactions

Individuals with vestibular dysfunction might also present with cognitive dysfunction, including decreased memory, compromised concentration and impaired abilities when multitasking.

• There are projections of pathways from the vestibular system to the cortex
• A recent study by Brandt and colleagues suggested that “moving towards a concept of higher vestibular disorders” would be helpful
• This interaction between cognitive and vestibular dysfunction probably represents problems with sensory integration (visual, vestibular)

Summary

• A number of conditions can cause dizziness and vertigo symptoms
• It is essential to determine the nature and perceived severity of the patient's symptoms before conducting a thorough objective assessment
• The objective assessment of vestibular patients is discussed here