Bell Palsy in Pregnancy

Bell palsy is acute idiopathic lower motor neurone facial paralysis, possibly from herpes simplex reactivation with oedema of the nerve in the fallopian canal. Incidence in pregnancy is about three to four times that of non pregnant women, peaking in the third trimester and first postpartum week.

• Risk increases with pregnancy induced hypertension, preeclampsia, gestational diabetes and obesity.
• Outcome is good, but complete palsy and preeclampsia predict poorer recovery.

Rapid onset over hours (peak within 72 hours) of unilateral facial weakness involving the forehead.

• Inability to close the eye, Bell phenomenon (eye rolls up), drooping mouth, loss of nasolabial fold, drooling, altered taste, hyperacusis, retroauricular pain.
• No limb weakness, no sensory loss in the limbs.
• Differential diagnosis: stroke (forehead sparing), Ramsay Hunt syndrome (ear vesicles), HIV related facial palsy, Lyme disease, otitis media or cholesteatoma, parotid tumour, sarcoidosis, Guillain Barre syndrome (bilateral), eclampsia related neurological disease, cerebral venous thrombosis, skull base tumour, diabetes.
• Complications: exposure keratopathy and corneal ulcer, synkinesis, contracture, crocodile tears, residual weakness, psychological distress, preterm delivery in severe hypertensive disease.

Clinical, after excluding other causes.

• Blood pressure, urine protein, glucose, HIV serology, VDRL or syphilis test, malaria test where endemic, full blood count.
• Otoscopy for vesicles and middle ear disease; check hearing.
• Neuroimaging (MRI without gadolinium or with caution) if forehead sparing, progression beyond 3 weeks, other cranial nerve involvement, bilateral palsy, or no improvement by 3 to 4 months.
• Document House Brackmann grade.

Early corticosteroid within 72 hours, eye protection and exclusion of hypertensive disease.

• Supportive: eye care is essential: lubricating drops (hypromellose 0.3 percent or carbomer) hourly while awake, ointment at night, tape or patch the eyelid for sleep, wear glasses outdoors. Gentle facial massage and physiotherapy. Reassure about recovery.
• Pharmacological: prednisolone 60 mg orally daily for 5 days then reduce by 10 mg daily over 5 days (total 10 days); alternative 50 mg daily for 10 days. Monitor glucose and blood pressure. For severe or complete palsy add aciclovir 800 mg orally five times daily for 7 days or valaciclovir 1 g three times daily for 7 days. Paracetamol 1 g for pain.
• Procedures: tarsorrhaphy or lid weight for persistent exposure; facial reanimation surgery for permanent deficit (after delivery); decompression rarely.
• Special groups: pregnancy, prednisolone and aciclovir are acceptable at these doses; check for gestational diabetes and preeclampsia at each visit; labour, mode of delivery follows obstetric indications; lactation, both drugs compatible; HIV positive, optimise antiretroviral therapy.
• Red flags: hypertension with proteinuria, headache or visual symptoms (preeclampsia), bilateral palsy, forehead sparing, other cranial nerve deficits, ear vesicles, progression beyond 3 weeks, no recovery by 3 months, eye pain or red eye.
• Follow-up: review at 1 week then every 2 to 4 weeks; antenatal blood pressure and urine checks; refer to ophthalmology for eye complications; ENT and neurology review if no improvement at 3 months. About 70 to 90 percent recover fully.