What are the diagnostic criteria for Vestibular Neuritis (VN) / Labyrinthitis (inflammation of the inner ear)?

From the Guidelines

Diagnosing vestibular neuritis or labyrinthitis requires a focused clinical approach based on symptoms and examination findings, prioritizing a careful history and physical examination to differentiate these conditions from other causes of vertigo, such as Ménière's disease, as outlined in the clinical practice guideline 1.

Key Diagnostic Considerations

• The diagnosis is primarily made through a careful history and physical examination, with particular attention to the timing, triggers, and associated symptoms of vertigo.
• Patients typically present with acute onset of severe vertigo, nausea, vomiting, and imbalance without hearing loss in vestibular neuritis, while labyrinthitis additionally includes hearing changes, as differentiated in Table 5 of the guideline 1.
• The head impulse test is a key diagnostic maneuver, showing a corrective saccade when the head is quickly turned toward the affected side.
• Nystagmus is typically horizontal with a rotatory component, beating away from the affected ear.

Additional Diagnostic Tests

• Laboratory tests are generally not helpful for diagnosis, though a complete blood count and metabolic panel may be ordered to rule out other causes.
• Imaging studies like MRI are not routinely needed but may be considered to exclude central causes if symptoms are atypical or persistent, as suggested by the guideline 1.
• Audiometry should be performed if hearing loss is present to distinguish labyrinthitis from vestibular neuritis.
• The Dix-Hallpike maneuver is typically negative in these conditions but helps rule out BPPV.
• Caloric testing may show reduced vestibular response on the affected side but is not required for initial diagnosis.

Management and Prognosis

• These conditions are typically self-limiting, with symptoms gradually improving over days to weeks as central compensation occurs.
• Clinicians should ask patients detailed/specific questions about the vertigo attacks, including the nature of the onset, duration of active vertigo, and concurrent otologic symptoms, to ensure accurate diagnosis and management, as recommended by the guideline 1.

From the Research

Diagnosing Vestibular Neuritis/Labyrinthitis

• The diagnosis of vestibular neuritis is based on the presence of abrupt true-whirling vertigo lasting for more than 24 hours, with no presence of cochlear symptoms and other neurological symptoms and signs 2.
• Various diagnostic tests such as the head impulse test, bithermal caloric test, and vestibular-evoked myogenic potential test are conducted to accurately diagnose vestibular neuritis 2.
• The key signs and symptoms of vestibular neuritis include rotatory vertigo with an acute onset lasting several days, horizontal spontaneous nystagmus, a pathologic head-impulse test toward the affected ear, and nausea 3.
• Vestibular neuritis is a diagnosis of exclusion, and relevant differential diagnoses include vestibular pseudoneuritis due to acute pontomedullary brainstem lesions or cerebellar nodular infarctions, vestibular migraine, and monosymptomatically beginning Ménière's disease 3.
• Recent advances in diagnostic evaluation include the use of bedside oculomotor findings to differentiate vestibular neuritis from stroke, and the implementation of cervical and ocular vestibular evoked myogenic potential, and video head impulse test in vestibular function testing 4.

Diagnostic Tests

• The head impulse test is used to assess the vestibuloocular reflex and can show an ipsilateral deficit in patients with vestibular neuritis 3.
• The bithermal caloric test is used to assess the function of the vestibular system and can help diagnose vestibular neuritis 2.
• The vestibular-evoked myogenic potential test is used to assess the function of the vestibular system and can help diagnose selective damage of the vestibular nerves 4.

Differential Diagnoses

• Vestibular pseudoneuritis due to acute pontomedullary brainstem lesions or cerebellar nodular infarctions should be considered in the differential diagnosis of vestibular neuritis 3.
• Vestibular migraine and monosymptomatically beginning Ménière's disease should also be considered in the differential diagnosis of vestibular neuritis 3.
• A thorough history and physical examination are essential in diagnosing common vestibular disorders presenting with vertigo 5.