Definition and Overview
Vestibular paroxysmia is a vestibular disease in which brief bouts of dizziness occur repeatedly due to pressure on the 8th cranial nerve, the vestibulocochlear nerve, by blood vessels. It is characterized by rotational or non-rotational dizziness that lasts from a few seconds to several minutes and repeats several times a day, and shares a neurovascular compression mechanism similar to trigeminal neuralgia.
The ICD-10 code applies H81.8 (Other disorders of vestibular function).
pathophysiology
Vestibular paroxysmia occurs when blood vessels, such as arteries, compress the vestibulocochlear nerve. When nerve myelin is damaged in a compressed area, abnormal electrical signal transmission occurs between nerve fibers and ectopic excitation occurs. These brief, repetitive nervous excitations appear as dizziness attacks. It is the same mechanism as other neurovascular compression syndromes such as trigeminal neuralgia and hemifacial spasm.
symptoms
The dizziness of a vestibular attack is brief, repetitive, and comes and goes suddenly.
Main symptoms:
- Brief rotational or non-rotational dizziness lasting from a few seconds to several minutes.
- Attacks that repeat several times, sometimes dozens of times a day
- Temporary tinnitus or hearing changes that may accompany a attack
- May be triggered by changes in head position or posture
- There are usually no symptoms between attacks
diagnosis
Clinical diagnostic criteria
The Bárány Society suggests that diagnostic criteria for vestibular paroxysmia include repeated brief dizziness attacks, spontaneous or in a specific position, and response to anticonvulsants. A history of brief and frequent dizziness attacks is the starting point for diagnosis.
High-resolution MRI
High-resolution magnetic resonance imaging (MRI) confirms the neurovascular contact between the vestibulocochlear nerve and blood vessels. However, because neurovascular contact can be observed even in people without symptoms, it is not diagnosed based on imaging findings alone.
treatment response
If dizziness attacks improve with low doses of carbamazepine or oxcarbazepine, this serves as evidence to support the diagnosis.
Differential diagnosis
- Vestibular neuritis: Dizziness that starts acutely and lasts for several days.
- Benign paroxysmal positional vertigo (BPPV): Rotational dizziness lasting several seconds when changing certain head positions.
- Meniere's disease: Recurrent dizziness lasting several minutes to several hours accompanied by hearing fluctuations and tinnitus.
- Vestibular migraine: Recurrent dizziness associated with headache
treatment
medication
Use carbamazepine or oxcarbazepine in low doses. This anticonvulsant reduces the frequency and intensity of dizziness attacks by stabilizing the abnormal activity of nerves overexcited by pressure. There are many patients who respond to drugs, so treatment response can be a clue to diagnosis. Adjust the dosage based on the effects and side effects.
Progress observation and control
If attacks are well controlled with medication, you can try adjusting or reducing the dose while watching the progress of symptoms. If the drug does not respond or is difficult to use due to side effects, consider other anticonvulsants.
Clinical implications
Vestibular paroxysmia is distinguished from other vestibular diseases by their unique characteristics of brief, repetitive dizziness and good response to anticonvulsants. Since neurovascular contact occurs even in asymptomatic patients, it is important to use clinical diagnostic criteria and treatment response together rather than diagnosing based on imaging findings alone.