LESIONS

A Guide to Localisation in Neurology

Case 21 - Facial numbness and hearing loss

Outcome

An MRI showed a right cerebellopontine angle mass. Imaging features suggested a vestibular schwannoma, with extension from the internal acoustic meatus.

The diagnosis was explained, including that this was a slow-growing lesion which had likely been present for some time.

A surveillance approach was taken at first. Interval imaging at 1 year showing minimal growth (1mm enlargement in each plane). While this was considered minor, she was given options - continued interval imaging surveillance, or radiotherapy. Radiotherapy would offer some control over lesion enlargement but pose a small (<5%) risk of worsening her symptoms, including causing facial weakness and worsening her hearing loss. It was also explained that it would not improve her existing symptoms - just attempt to slow tumour growth.

She chose to undergo stereotactic radiotherapy. She tolerated this well, but did develop troublesome neuralgic facial pain and dysaesthesia, treated with neuropathic pain medications.

At the time of writing she awaits a 1 year post-radiotherapy MRI scan, but remains neurologically stable.

1. Unilateral hearing loss is an important symptom in neurology, but is never due to a CNS lesion above the cochlear nuclei - the supranuclear projections are bilateral
2. The combination of sensorineural hearing loss with either V or VII dysfunction suggests a cerebellopontine angle (CPA) lesion, particularly a mass
3. The commonest CPA mass is vestibular schwannoma – which only rarely clinically affects nerve VII, despite it being distorted by the mass
4. Most vestibular schwannomas are managed with a conservative, watch-and-wait approach, but radiotherapy and surgery are sometimes considered, and patients are given the opportunity to make informed choices about their care