You are trying to take your regular 30 minute nap, tossing and turning in your bed, or brushing your teeth and turning your head to grab the towel, suddenly you feel the world spinning before your eyes with every head tilt. The walls glide around you. Within 10 seconds, everything seems quite normal and in place as if you’ve been imagining the whole scenario when in reality you’re not. You’re thinking about how to find out the root cause of your dizziness and are failing to come to any conclusion. This minute disturbance is because of the malfunctioning system present in your inner ear called the vestibular system.
Inside the Vestibular System
We often discuss the five senses of the human body, ignoring the fact that balance never made it to the list. Balance is the one of the most important senses of the human body that can help create awareness about oneself. The vestibular apparatus comprises the semicircular canals and the otolith (sensory) organs. The sensory organs, called utricle and saccule are responsible for the detection of acceleration based movements. While the semicircular canals are responsible for the detection of rotational movements.
Vestibular lesions are divided into two distinct groups depending on their anatomical variations and characteristics, central and peripheral. Central lesions means the damage has occurred in the central nervous system or its parts and peripheral means outside the central nervous system such as inner ear structures.
Why is Vestibular Assessment Important?
When we talk about vestibular assessment, we confine ourselves to the use of dix-hallpipe solely. But in reality there is much more to the vestibular assessment. In order to answer this question: is this dizziness resulting from the inner ear, the brain or from an entirely different source? A physiotherapist may need to evaluate the patient more than once.
Yet there are chances of getting the diagnosis wrong which studies have reported that people with dizziness are misdiagnosed for years before the actual treatment even begins. The root cause and its accuracy is significant because not only it changes the whole dynamics of the plan of care but also helps in isolating what the therapist should not be doing on this specific patient.
Oftentimes, the body’s counteraction to the unsettled dizziness is frequently linked to rampant emotional stress because the nervous system stays on fight or flight mode for longer time periods. This prolonged stress and negative thoughts loop can cause an alarming impact on the body leading to the likelihood of serious medical problems.
How to Differentiate the Symptoms of Vestibular Compromise from Other Lesions?
VBI vs Vestibular System
One of the most common confusions that can occur during vestibular assessment is the presentation of symptoms. Even though the vertebrobasilar insufficiency is characterized as the temporary reduction in the blood flow to the brain via the basilar or vertebral artery, its symptoms are almost identical to those of the vestibular malfunctioning. VBI presents with 5Ds that include dizziness, diplopia, dysphagia, dysarthria and drop attacks that is sudden loss of muscular strength.
VBI may also persist with nystagmus, nausea and numbness typically on one side of the face or body. Unlike VBI, vestibular compromise presents with vertigo without blackouts, spinning, & swaying feeling usually with fast head movements such as rolling or moving eyes in busy visual fields along with autonomic nervous system variations. True vertigo doesn’t cause blackouts. These blackouts, often called syncope, occur due to sudden reduction in the blood flow or oxygen supply which is more common in the case of VBI.
Another distinguishing feature of VBI is the occurrence of ataxia known as lack of voluntary muscle control while walking leading to imbalance of the body.
Upper Cervical Spine Dysfunction vs Vestibular System
Another common condition that may mimic the symptoms of vestibular compromise is cervicogenic dizziness. It occurs due to the compromise of accessory nerve in the cervical plexus leading to dizziness, floating feeling leading to unsteadiness, headache and diplopia. These symptoms are triggered with sustained neck holding posture along with restricted range of motion with almost no to limited autonomic nervous system presentations.
How to find out the root cause of your dizziness? Parts of the assessment
A proper vestibular evaluation comprises 5 Major components. These include:
Nystagmus
It is characterized as involuntary, rhythmical, oscillatory movement of the eye(s) and is considered to be the most significant sign of vestibular evaluation. When it comes to describing the nystagmus, clinically we can distinguish it into:
- Direction of Motion – this includes its movement in horizontal, vertical or torsional aspect
- Amplitude – known by how far the nystagmus relocates
- Frequency – how many times it oscillates
When it comes to the types of nystagmus, it can be conflicted into three forms:
- Jerk Nystagmus – with slow drifting component and fast corrective component
- Pendular Nystagmus – with both drifting and corrective components being slow
- Mixed Nystagmus – with slow movement of both components when looking ahead and jerky in case of looking laterally
- Linear Drift Nystagmus – constant steady speed of drifting
- Gaze evoked Nystagmus – the drifting component is fast but corrective component is slow
- Congenital Nystagmus – both components are fast by birth
- Spontaneous Nystagmus – tested to rule out the lesion of Vestibular Ocular Reflex
The nystagmus can be clinically differentiated into different degrees of diagnosis such as first (appears when looking at fast component), second (when looking ahead) and third degree, with first being the weakest nystagmus and third being the strongest of all appearing when looking at the slow component. Apart from that, the characteristics of a nystagmus can help differentiate if the lesion is of central or peripheral origin. This means:
- Central – lesion in central pathways / doesn’t responds to gaze fixation or light dimming
- Peripheral – lesion of Cranial nerve VIII, Labyrinth / enhanced by darkness and suppressed by optic fixation
This information can help in ruling out whether the problem lies in the inner ear or is a major indicative of deadly stroke. It is also important to understand that the evaluation of specific type, degree and lesion of nystagmus serves as the critical barrier in ruling out the disease and problems with the VOR.
Romberg Test
A screening tool used to evaluate the proprioception of a person by testing vision, proprioception and vestibular system independently. To perform:
- Ask the patient to stand straight with both hands on the sides, feet together
- Compensate the balance with eyes open first and then continue with eyes closed
- When the patient can’t compensate his/her balance with eyes closed this further helps us in indicating the lesion – Swaying to the one side is Peripheral lesion & overall instability is indicative of Central lesion
- If the person is able to hold the balance while being in a state of closed eyes, progress to sharpened romberg’s. To perform:
- Ask the patient to stand with one heel in front of the toes of another foot and arms folded across his/her chest
- The inability of the patient to perform this test indicates the impairment of vestibular apparatus.
Within the romberg test, we can understand different working conditions helpful to formulate which dependent system is malfunctioning. If we:
- Move from wide base of support to narrow BOS that is, feet apart to close together, we’re activating the antigravity muscles, can be helpful in indicating somatosensory loss and inability to hold feet together even with eyes open can also be significant for cerebellar lesion finding
- Move from wide base of support to narrow (patient can perform this accurately) with the addition of eyes closed, we can rule out if the person is dependent on the vision to hold/carry out the test.
Gait & Balance
Gait cycle or the normal walking pattern comprises 2 phases with 8 instances in total and it is known to be the most significant aspect of assessment. Physiotherapists can observe the gait pattern and rule out hundreds of lesions within a blink of an eye. This is why walking is a part of exercise regimen and can be helpful in diagnosing as well as rehabilitation tools. In order to classify a normal gait the following two conditions should be met:
- Amount of degree of freedom / all muscles moving freely to perform the respective gait cycle
- Bilateral symmetry of swing and stance phase / Quantification of angle
However, if the patient has gone through any severe injury, fracture or is a case of Osteoarthritis, he will not be presenting the required symmetrical assessment. Instead, the stance angle of the affected side will be relatively shorter with swing of the normal side longer than usual, sometimes resulting in hip hike to compensate for the injury patterns. To asses:
- Ask the patient to walk on a straight like with eyes fixed on a target
- Close the eyes and follow the same straight pathway
- Deviation from the straight pathway to one side indicates defect of the peripheral system. The deviation will be on the affected side.
Balance can be assessed with tandem stance or semi tandem stance, standing on the foam surface with eyes open & then progressing to eyes closed. It is indicative of how much we rely on our vision, our joints or our inner ear to hold us upright during every activity of life. Balance assessment is most beneficial when it comes to older adults as it can be helpful in ruling out the fall risk efficacy, helping is in beating down the injuries even before they occur.
Barany Past Pointing Test
Is a maneuver used to indicate the malfunctioning of vestibular ocular reflex and vestibular spinal reflex. The VOR acts as a window between the vestibular system and the nervous system. The VOS, on the other hand, functions to balance the body with movements and tilts in posture. Past pointing is essential in order to differentiate if there is any mismatch between the functioning of the inner ear and movement of the body in response to it. To perform:
- Ask the patient to touch his/her index finger with the therapist’s index finger with eyes open and then ask him to perform the same procedure with eyes closed ( with eyes open you can easily drift towards the target subconsciously )
- Test is positive when the patient finds difficulty in performing the maneuver with his eyes closed
Hallpike dix Maneuver
The last and final most important component of the vestibular assessment is the infamous hallpike dix test. To Perform:
- Ask the patient to be seated on the couch
- Hold the patient’s head and turn it to 45° right
- Place the patient in supine and hang his head 30° in extension
- Hold for 30 seconds with each movement to observe the eyes for nystagmus and ask the patient to not close his eyes
- Repeat the test with head turned to left and then again with head hanging position
One major criteria for the hallpike dix maneuver to be functional is the ability to hold the neck in extension without any restriction. Any patient that presents with a restricted range of motion of the neck, shouldn’t be forced to undergo this test.
What happens when the cause isn’t the inner ear at all?
While the vestibular system could be the major reason as to why you’re experiencing dizziness, however, it is not necessarily the only system to be blamed for. Most people with a previous history of stroke can report the feeling of dizziness throughout their recovery phase. It is therefore, necessary to have a thorough detailed neurological assessment with an insight on the complete guide to stroke recovery with diagnosis and assessment. The same caution applies to various other progressive neurological disorders such as ALS and spinal cord injury. It is important to understand the core points in order to differentiate between them and have a solid diagnosis before progressing to any treatment.
The Population Everyone Overlooks
Vestibular issues are not only subjective to elderly population. It can also occur in children with special needs such as down syndrome and may go years without any proper assessment or diagnosis. It is important to understand that such children might be undergoing multiple issues that are being neglected by doctors just because they can’t explain them well. It is significant to raise awareness of people with Down syndrome and the value of diversity and opportunity for all are brought to the public’s attention.
Recovery Expectations
Once the fountainhead of the issue has been discovered, treatment is surprisingly successful. The main lesson over here is to understand that dizziness is not something that you can sleep on, and like any signal in the body, it needs a proper evaluation rather than speculation. Canalith repositioning maneuvers can resolve the BPPV in three or more sessions. With that gaze stabilisation exercises and postural stability programs can be used as a layer of rehabilitation, build confidence in movement and take away the fear of falling.
This article has been written by a Physical Therapist and provides general guidance on physical health & exercise. While it is grounded in professional expertise, it is not a substitute for individualized medical advice. If you are experiencing pain, specific symptoms, or have an underlying medical condition, please book a 1 on 1, 30 minute consultation with our expert physical therapist for a personalized assessment & tailored recommendations.