Bell’s palsy is a self-limiting neurological disease due to facial nerve paralysis resulting in the inability to control facial muscles on affected side. It is commonest cause for acute facial nerve paralysis.
As cause is not known and involves only one side, it’s known as an idiopathic unilateral facial nerve paralysis. Rarely (17%) it is bilateral. Syndrome is first described by Sir Charles Bell and hence named as Bell’s palsy.
Hallmark of disease is rapid onset of partial or complete paralysis that takes place overnight. Paralysis develops over one to three days with forehead involvement. Symptoms peaks over first week and gradually resolve over 3 weeks to 3 months.
Incidence is common at 40 years, in diabetes and during third trimester of pregnancy. It affects 10-30 per 100,000 peoples with equal occurrence among men and women and has no predilection for either side of face.
Cause for Bell’s palsy remains unidentified but close relationship is found to exist with infection by herpes simplex -1(HSV-1) and Varicella Zoster Virus (VSV). An inflammation of facial nerve in response to a virus results in swelling of nerve within narrow bony canal through which it travels. Swelling of facial nerve results in its compression, ischemia and demyelination result in paralysis.
Coping With Bell’s Palsy Effectively
Patient suffer from inability to close eyes and mouth on the involved side, sagging of lower eyelid, eye rolls upward on attempted closure, eye irritation due to lack of lubrication and constant exposure, decreased tear production, pooling of food and saliva on affected side and spilling from corner of mouth and feeling of numbness on paralysed side. Condition is painful.
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Incomplete eyelid closure with resultant dry eye is most common short-term complication, while permanent facial weakness with muscle contracture is uncommon long-term side effect of Bell’s palsy.
Diagnosis and Management of Bell’s Palsy
No specific laboratory tests detect Bell’s palsy. Diagnosis is done with clinical presentation and ruling out other possibilities.
Generally 70-80% cases with incomplete facial paralysis recover spontaneously without treatment. Those with complete paralysis should start treatment early within 3 days after onset for effective result, full recovery and complete recuperation. Therapy generally consists of:
Corticosteroid such as prednisone significantly improves outcome at 6 months. 10 days tapering dose is offered with starting of 60 mg/day. Anti-inflammatory property of steroid helps to reduce facial nerve inflammation and recover paralysis.
Due to possible role of virus in Bell’s palsy, antiviral are advice for good result. Acyclovir is administered as a 400mg five times a day for seven days, while valacyclovir is offered as 1gm three times a day for seven days.
Physiotherapy involves muscle re-education exercises which helps to maintain tone of affected facial muscles, stimulate facial nerve, prevents permanent contracture of paralysed muscles and restore normal movements. Application of heat reduces pain in affected muscle. Transcutaneous electrical stimulation is good for unresolved facial paralysis.
Persistent exposure makes eye dry, irritating and prone for infection, hence always moisten and clean eye with lubricating eye drops. Avoid dusty and sandy environment by wearing glasses. Apply a thin line of eye ointment into lower eyelid sac and patch eye with surgical adhesive tape at night time.
When there is no improvement with drugs or physiotherapy, smile reconstructive surgery restores smile of patient, tarsorrhaphy is done for permanent eyelid weakness and botox injection is advice to maintain facial symmetry. Approaching Bell’s palsy with these ways will definitely give excellent result.
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