LESIONS

A Guide to Localisation in Neurology

Case 21 - Facial numbness and hearing loss

Case

A 55 year old woman presented with sensory disturbance in the right side of her mouth and face and hearing loss in her right ear.

The sensory disturbance began several months ago. It was exclusively right-sided. She likened it to a dental anaesthetic wearing off.

At first it affected the internal oral cavity, including the tongue – she had accidentally bitten the inner cheek and barely felt anything. It also affected the lips. It then progressed over months to affect the chin and external cheek. She had initially seen a dentist and no cause was found. The distribution then progressed to affect the face as high as the forehead, and if she touched herself in the affected regions she could barely feel anything.

She also had begun noticing ringing in her right ear and reduced hearing on that side. While talking on the phone she struggled to hear, and she now had to put the phone to her left ear. She had undergone audiometry testing, showing right-sided sensorineural hearing loss.

She also noted some deterioration in her balance. She remained ambulant but had fallen a few times. She did not report vertigo.

She had no headaches, visual disturbance, changes to speech or swallowing, or facial weakness. The limbs were intact, with no numbness, weakness or incoordination. She felt systemically well.

Her past medical history included mild asthma and gastro-oesophageal reflux.

On examination she had:

• Diminished touch and pinprick sensation in the right half of the face affecting all 3 trigeminal zones, with normal sensation over the mandibular angle and in the neck, and normal sensation in the back of the head
• Absent blink reflex when the right cornea was touched (i.e. neither eye blinked in response). The reflex was normal when the left cornea was tested.
• Weber and Rinne tests showed partial sensorineural hearing loss on the right

The rest of the exam was normal, including no facial weakness, normal eye movements, no limb abnormalities, and normal gait. On Romberg's testing she was able to stay upright though did sway a little more than with eyes open.