What is Vertigo?
Vertigo is a sensation of spinning which can generally be described as “feeling dizzy”. Vertigo is a symptom rather than a disorder by itself, but it can also lead to other symptoms such as – tinnitus, which is a ringing sensation inside the ear, nausea, imbalance, headache, fullness in the ear, and nystagmus which is abnormal, involuntary, rapid eye movements. It is not to be confused with plain light-headedness, which usually have causes that unrelated to the balance system. Based on the duration of vertigo, accompanying signs and symptoms, as well as certain diagnostic tests, the cause of vertigo can be determined, and whether they are central or peripheral in nature.
Conditions that can lead to vertigo
Benign Paroxysmal Positional Vertigo (BPPV) is vertigo induced by abrupt changes in head position. It causes sudden, but brief episodes of mild to intense dizziness. The management includes certain repositioning procedures. Each position is held until any symptoms or nystagmus fades, and are usually effective after one to two sessions.
Vestibular neuritis and Labyrinthitis is the inflammation of the vestibular nerve or the inner ear labyrinth respectively. While vestibular neuritis causes only symptoms of vertigo, labyrinthitis causes cochlear symptoms such as hearing loss, and tinnitus.
Cholesteatoma is a benign growth that develops in the middle ear, behind the tympanic membrane. As the size of the growth increases, it can cause damage to the surrounding structures that can result in hearing loss, vertigo, and problems in the facial muscles. It can be caused either due to repeated middle ear infections, or due to poor eustachian tube function.
Meniere’s Disease is the result of abnormal endolymph build up in the inner ear, characterized by the 3 classical symptoms which are vertigo, tinnitus, and hearing loss. It is usually unilateral in nature and most often individuals do not experience symptoms in between episodes.
Perilymphatic fistula is a condition in which the perilymph from the fluid filled inner ear leaks into the air filled middle ear due to a tear or rupture in the round or oval windows. This fluid leakage causes pressure changes in your ear leading to balance and hearing problems. Other central conditions that can give rise to vertigo or imbalance include migraine, brainstem stroke, cerebellopontine angle tumors, and some demyelinating diseases such as multiple sclerosis.
Assessment of vertigo involves an informal assessment to assess if the cause is central or peripheral in nature, a general neurological assessment to look for important central symptoms of stroke, tumor, demyelination, and other pathologies of the nervous system, Vestibular Evoked Myogenic Potential, and Video Nystagmography.
Vestibular Evoked Myogenic Potential (VEMP) is a test for vestibular function done by stimulating the ear with high intensity acoustic stimuli and recording the muscle activity via electrodes. There are two types of VEMP – cervical VEMP (cVEMP) tests the saccule and inferior vestibular nerve, while the ocular VEMP (oVEMP) tests the utricle and superior vestibular nerve.
Videonystagmography (VNG) measures involuntary eye movements known as nystagmus. VNG uses infrared goggles to track the eye movements during positional changes and a variety of visual stimuli. These tests are valuable tools that assist in the diagnosis of vestibular and balance related disorders such as Meniere’s Disease, Superior Semicircular Canal Dehiscence (SSCD), etc.,