When should I refer a patient with cranial nerve palsy for specialist assessment or imaging?

Refer a patient with cranial nerve palsy for specialist assessment or imaging if:

• There is sudden-onset limb or facial weakness, as this may indicate stroke or transient ischaemic attack and requires urgent neurological assessment and imaging according to stroke pathways.
• There is rapidly progressive weakness of a single limb or hemiparesis within hours to days, which warrants investigation including neuroimaging using a suspected cancer pathway referral.
• There are persistent abnormal neurological signs such as facial numbness or other cranial nerve deficits, which may require neuroimaging and specialist assessment.
• Bell's palsy is complicated by symptoms of aberrant reinnervation (e.g., gustatory sweating or jaw-winking) developing 5 months or more after onset, suggesting need for neurological assessment.
• There is suspicion of other serious causes such as temporal arteritis (scalp tenderness or jaw claudication), which requires blood tests and specialist referral.

In uncomplicated Bell's palsy without other medical conditions, routine referral is not required but eye care advice should be given.

Overall, urgent referral and imaging are indicated when cranial nerve palsy is sudden, progressive, associated with other neurological signs, or refractory to treatment, to exclude serious underlying pathology including stroke, cancer, or inflammatory conditions.

References: NICE NG127