Superior canal dehiscence syndrome
Superior canal dehiscence syndrome, a rare condition of the inner ear, occurs when there is a complete absence or thinning of the part of the temporal bone that overlies the semicircular canal of the vestibular system. As such, a “window” is created from the cranial vault into the inner ear, allowing sound and pressure waves to enter and influence the semicircular canals. Loud sounds, or pressure changes from sneezing, result in the abnormal movement of endolymph and the sensation of vertigo. Patients will present with nystagmus and vertigo that typically worsens with loud sounds or sudden movements. Pulsatile tinnitus, a feeling of fullness in the affected ear, and headache are common. A patient may describe hearing bodily sounds, such as cervical spine or eye movement, or hearing their own voice (autophony).
Central Causes of Vertigo
Central vertigo occurs secondary to disorders that affect the brain stem or cerebellum. With most causes of central vertigo (vertibrobasilar insufficiency being the exception), changes in position do not provoke the sensation of vertigo.
Vertigo is a common symptom in patients with migraine headaches. Patients may describe episodes of constant vertigo, positional vertigo or dizziness. Vertigo may occur concurrently with the headache or independently. Some patients complain of vertigo lasting from several minutes to 2 hours, whereas others experience vertigo lasting longer than 24 hours.5 Patients with a migraine will typically describe the headache as unilateral, pulsatile and lasting from 4 to 72 hours. Other symptoms of migraine headache include photophobia (increased sensitivity to light), phonophobia (increased sensitivity to sound), nausea and vomiting.
Patients with multiple sclerosis can present with vertigo lasting from hours to days to weeks. The patient will usually describe a sensation of vertigo that is not particularly intense or debilitating, and often there is nystagmus that is more impressive than the vertigo described by the patient.
Mal de debarquement syndrome
Mal de debarquement (French for “disembarkation sickness”) syndrome is a rare disorder that usually occurs after a long flight, car trip, sea cruise or any other event that results in sustained motion. Patients will describe a persistent sensation of swaying or rocking, as if they were on a boat. Other symptoms include anxiety, dizziness, visual disturbances, headaches and confusion. Ear complaints such as tinnitus, fullness or pressure may also be described. The syndrome is most common in women in their 40s, and symptoms can last from months to years, with the average length of symptoms being about 3.5 years.6
Cerebellar hemorrhage and infarct
An intracerebellar hemorrhage can produce symptoms such as vertigo and ataxia (lack of muscle coordination). Patients often describe the vertigo as a perception of side-to-side or front-to-back motion. These patients will typically have unstable gait and poor hand-eye coordination in addition to the more traditional signs and symptoms consistent with stroke.
Brain tumors affecting the cerebellum, either directly from within or by increasing pressure on the tissue, can lead to gradual onset of vertigo that is often unrelenting in nature. Symptoms are generally more subtle and can be associated with motor and coordination difficulties.
Vertebrobasilar insufficiency (VBI) is a term used to describe a transient decrease of perfusion in the posterior circulation of the brain, which supplies blood to the cerebellum, medulla, pons and midbrain. This results in a transient ischemic attack (TIA). VBI affects men, usually in their 70s and 80s, twice as often as women.7 Symptoms of VBI can vary depending on which portions of the brain are experiencing decreased blood flow, but vertigo can occur if the brain stem is involved. Vertigo and other symptoms can last from minutes to hours, but commonly resolve within 24 hours. Unlike other causes of central vertigo, VBI may be provoked by turning the head, if doing so partially occludes the vertebral artery. Other signs and symptoms include dysarthria, diplopia, dysphagia, and even near-syncope or loss of consciousness if there is a sufficient loss of brain stem circulation.