Other Causes for Dizziness
All central signs must be tested for before a diagnosis of BPPV can be made. This includes testing the Oculomotor, Balance and Vestibular Ocular Reflex systems, as well as screening for Vertebral Artery Insufficiency and Upper Cervical instabilities.
Treatment for dizziness with central involvement includes an education and exercise based program, along with some manual therapy dependent on the each patient’s specific problems. Generally, three main principle methods of exercise are prescribed to each patient; Gaze Stabilisation, Balance and Habituation.
Gaze Stabilisation exercises are prescribed when Oculomotor insufficiencies are found during assessment. They are used to improve eye control during head movements, therefore improving the clarity of the patient’s vision. Patients will often report issues with reading or focusing on objects when moving about. E.g. Oculomotor retraining exercises will generally consist of repeated head movements, while the patient attempts to fixate on a stagnant object.
Balance exercises are designed specifically to address each patient’s underlying balance issues. The exercises are to be challenging enough to incite some form of coordination strategy from the patient, but safe enough as to avoid injury. E.g. Balance exercises should include changes in base of support, visual input and involving one or more extra tasks, in order to increase the difficulty for patient’s.
Habituation exercises are prescribed when Vestibular Ocular Reflex (VOR) issues are found during assessment. Patients with VOR issues will report dizziness from self motion (moving around, especially with quick head movements or bending over) or from increased visual stimulus (shopping malls, action movies etc). The goal of habituation exercises is to reduce dizziness associated with these stimuli through repetitive provocation and resolution. Over time, the brain learns to ignore the abnormal signals it is receiving from the inner ear, in response to these stimuli. E.g. Patient views a video clip from someone else's point of view, moving through a busy shopping centre, while increasingly reducing their base of support as able.
Posterior Capsule Palpation
In neutral jaw position, it is very hard to palpate the posterior joint line and capsule. It is
important to have a good understanding of how tender to palpation the posterior capsule is,
as it can help differentiate the cause of pain between occlusal issues and poor motor control.
The best way to get to the posterior joint line is to laterally deviate the jaw to the other side,
which will cause the condyle to translate forward and expose both the posterior aspect and
anterior aspect of the joint. It is generally considered a tender area, so we are looking at
difference in pain left vs right or an exquisite pain response.
Pterygoid Strength Test
The Pterygoids role is to stabilise the condyle in the socket as it rotates and translates
forward and then to act as a decelerator when the jaw closes to guide the condyle back
into its resting place. Dysfunction of the pterygoids can lead to posterior capsular
impingements, compression of the neurovascular bundle, clicking or locking joints, ear pain
and extra tension in the masseters to compensate.
The patient should be able to comfortably move through left and right excursion with
resistance applied to the point of the chin without pain or discomfort. Also look for fatigue
signs such as tremors, neck involvement or tongue thrusting. If the Pterygoid is
dysfunctional, it is unlikely any other treatment will have a lasting effect as the jaw will
remain unstable. This is commonly linked with a failure of the Tongue Differentiation Test
and is a good indicator that the primary cause of pain or restriction is the jaw.
Tongue Differentiation Test
The tongue is responsible for maintaining breathing airways, moving food around in the mouth, swallowing and talking. It plays no role in moving the jaw. With bruxing, clenching or even headaches, it is quite common to use the tongue as a crutch to try to support the jaw and neck, which is an undesirable compensatory movement.
Your patient (and your good self) should be able to isolate your tongue function from their jaw muscles by placing their tongue on the roof of their mouth and then opening and closing their jaw. If this is achievable, then progress to lateral deviation left and right. The tongue needs to stay on the roof of the mouth, if they can’t do this, they need strategies to help break down their parafunction.
Upper Cervical Spine Range of Motion
C01 and C23 play an intricate role in cervicogenic headache and although a loss of range of motion is not definitively linked to headaches, it is a good indicator that it is involved. A simple screening test you can do in your clinic is differentiating how much movement C1-2 is contributing to rotation vs the rest of the cervical spine. Approximately 50% of neck rotation comes from C1-2, so if we gently block the neck at c3 and don’t allow any lower cervical spine movement, the patient should still be able to turn their head 45 degrees or so.
If the patient has a restriction in their upper cervical spine but can still turn their head over their shoulder, we know that they are using dysfunction compensatory movements to achieve this and unless addressed, will more than likely end up with degenerative joint disease, normally around the C5-6 segment.