The Key to a Proper Diagnosis in Vestibular Disorders
Vestibular disorders vary in intensity of symptoms and their duration as well as patient’s ability to manage them. In our office, we see patients that often come undiagnosed or with specific diagnosis listed on PT prescription. As clinicians, we always have to perform our own evaluation to determine which condition can be the reason of patient’s discomfort. It is important to determine whether symptoms begun rapidly or maybe they developed over the course of time. Also the location of the symptoms during the day and their onset related to certain daily events is important to establish. For example patients with Benign Paroxysmal Positional Vertigo (BPPV) will have symptoms of sudden onset of spinning that is usually brief but almost always appear during laying down, rolling in bed or looking up. This is related to gravitational position change of inner ear canals that manifest with vertigo as the pathway of fluid within the canal is disturbed by dislodged crystals (otoconia). Therefore it is very important to ask patient whether symptoms appear sometimes or only while laying down in bed or at night with rolling.
In BPPV, which is the most common vestibular disorder, otoconia should be located within the utricle (which is the other part of vestibular system located below canals). Instead, they have repositioned to canal system and now disturb the flow of the fluid located within them. Without displaced otoconia, canal’s receptors under normal circumstances detect just a fluid movement and pass this signal through vestibular nerve to other areas including brainstem and eye muscles. With BPPV, signal is disturbed on one or possibly both sides and information that brain receives is incorrect, resulting in involuntary eye movement (nystagmus) that triggers vertigo. So now we know that we deal with the condition of positional character and that this only happens with gravitational position change.
Very often patients feel vertigo that is rapid and lasts longer then few seconds. it is also triggered by head turns towards any directions, not only gravity related. It lasts only for a day or two and is relieved by rest or laying down. There are few clinical diagnoses that can be responsible for this. Most common is vestibular neuritis or labyrinthitis. Vestibular neuritis is an inflammatory proces of the portion of vestibular nerve (cranial nerve number 8). Labyrinthitis is caused by inflammation of vestibular system itself. With these conditions onset is also sudden but is not related always to gravitational position change, but rater than movement of the head toward various directions. Symptoms also increase when patient is deprived of room light, as in dark environment peripheral vestibular system is the most challenged.
With central vestibulopaties that are caused by problems related to central nervous system, onset can be very rapid too. It is increased by head rotations but also includes falls and inability to maintain balance mainly when room light is present. This is often not present with conditions related to inner ear itself.
Proper diagnostics should always include through interview and when needed diagnostic imaging to rule out certain conditions that can be easily detected with the use of MRI or CT Scan. It also needs to contain clinical testing, including vestibular function testing performed by ENT Doctors or Neurologists. Physical Therapist that specializes in vestibular rehabilitation should be able to screen patient for symptoms that are not necessarily related to vestibular apparatus and include cardiovascular or orthopedic disorders.
In our clinic, we alway take time to make sure we can help patient, therefore we block our schedule for 1 hour to make sure we can assist 100%. We will always implement appropriate intervention that is customized for patients symptoms as each vestibular disorder is treated differently.
My next blog with give focus to various treatment techniques to target different vestibular disorder ensuring fast recovery that is tolerable to patient.
Dr. Bart Roman, PT DPT
Certified Vestibular Rehabilitation Therapist