Which investigations should be considered in a patient with suspected labyrinthitis to rule out other causes of vertigo?

In a patient with suspected labyrinthitis, initial investigations should focus on clinical assessment to exclude other causes of vertigo, particularly central causes such as stroke or vestibular schwannoma. Urgent referral or admission is warranted if there are red flag features including sudden onset vertigo with neurological signs, new unilateral hearing loss, or severe persistent symptoms ¹.

Basic investigations include a thorough history and clinical examination, including otoscopy and audiometry to assess for hearing loss or asymmetry, which may suggest alternative diagnoses like Meniere's disease or vestibular schwannoma ¹,³.

Imaging is indicated if central causes are suspected or if there is asymmetric sensorineural hearing loss. Magnetic resonance imaging (MRI) of the internal auditory meati is recommended to exclude cerebellopontine angle lesions such as vestibular schwannoma, especially if there is unilateral hearing loss or localising neurological signs ¹,³.

Neuroimaging with MRI, magnetic resonance angiography (MRA), or computed tomography (CT) should be considered urgently if there are features suggestive of a central cause, such as normal head impulse test, direction-changing nystagmus, skew deviation, new headache, or focal neurological deficits ¹,⁴.

Additional bedside tests like the HINTS (head impulse, nystagmus, test of skew) examination can help differentiate peripheral from central vertigo in acute vestibular syndrome, guiding the need for urgent imaging and specialist referral ¹,⁴.

Laboratory tests are generally not required unless systemic causes are suspected. Vestibular rehabilitation may be considered after diagnosis to aid recovery ².

In summary, to exclude other causes of vertigo in suspected labyrinthitis, consider clinical assessment, audiometry, otoscopy, and urgent MRI if central signs or asymmetric hearing loss are present, alongside specialist referral as indicated ¹,²,³,⁴.