The symptoms are usually acute appearing within 48 hours and they include lower facial paralysis on one side of the face, reduced secretion of tears, posterior auricular pain, increased sensitivity to sound (hyperacusis), disorders in taste, pain in the ear, inability to close the eye lids, facial muscle weakness, eye pain, blurred vision and epiphora [6].

• Dysgeusia

  At the onset, 136 patients presented postauricular pain, 114 were affected by dry eye, and 94 reported dysgeusia. [ncbi.nlm.nih.gov]

  These findings are frequently accompanied by symptoms of neck, mastoid or ear pain, dysgeusia, hyperacusis or altered facial sensation. These associated symptoms are present in 50–60%23 and are reassuring for the diagnosis of Bell's palsy. [jnnp.bmj.com]

  Incomplete sensory regeneration Dysgeusia or ageusia (impairment or loss of taste, respectively) may occur with incomplete regeneration of the chorda tympani. [emedicine.com]

• Muscular Atrophy

  تؤثر أساساً في الجهاز العصبي المركزي Huntington's disease - Spinocerebellar ataxia ( Friedreich's ataxia, Ataxia telangiectasia, Hereditary spastic paraplegia ) Spinal muscular atrophy : Werdnig-Hoffman disease - Kugelberg-Welander disease - Fazio Londe [marefa.org]

• Osteopenia

  Thus, the authors of the AAN updated guideline recommend that early corticosteroid therapy be offered to patients who do not have contraindications, such as brittle diabetes mellitus, morbid obesity, osteopenia, and a previous history of corticosteroid [web.archive.org]

• Hyperacusis

  Dry mouth was present in 54 patients (19.7%), facial pain, hyperlacrimation, aural fullness, and hyperacusis represented a smaller percentage of the reported symptoms. [ncbi.nlm.nih.gov]

  Typically, presentation is with facial distortion, loss of taste, hyperacusis and a watery eye. [gpnotebook.co.uk]

  Initial presentation may be pain around the ear or surrounding areas May be associated with hyperacusis Prodrome of ear pain and dysacusis may be present Physical manifestations of Bell's Palsy. http://www.facialpalsy.org.uk/imagebank/2/4/7/247.jpg Differential [pedclerk.bsd.uchicago.edu]

  Additional Bell's palsy symptoms may include: Pain in or behind the ear Numbness of the affected side of the face Increased sensitivity to sounds (hyperacusis) Altered taste on half of the front part of the tongue Inability to fully close the eyelids [allaboutvision.com]

  Twitching or weakness of the muscles in the face Other symptoms that may occur: Dry eye, which may lead to eye sores or infections Dry mouth Headache if there is an infection such as Lyme disease Loss of sense of taste Sound that is louder in one ear (hyperacusis [nlm.nih.gov]

• Otalgia

  Some patients also report general malaise in the first few days on onset, as well as some pain in the region of the ipsilateral mastoid (known as otalgia), but many of patients have no otalgia or malaise. [physio-pedia.com]

  Chronic otitis media usually presents in an ear with chronic discharge ( otorrhea ), or hearing loss, with or without ear pain ( otalgia ). [marefa.org]

  Signs and symptoms Signs and symptoms of Bell palsy include the following: Acute onset of unilateral upper and lower facial paralysis (over a 48-hr period) Posterior auricular pain Decreased tearing Hyperacusis Taste disturbances Otalgia Weakness of the [emedicine.com]

• Postauricular Pain

  If patients suffer from postauricular pain, pharmacopuncture and cupping is utilized. [ncbi.nlm.nih.gov]

  At the onset, 136 patients presented postauricular pain, 114 were affected by dry eye, and 94 reported dysgeusia. [hindawi.com]

  Prolonged pain is also a predictor of worse outcome. [jnnp.bmj.com]

• Lacrimation

  They should be applied to make up for the lack of lacrimation. The use of external eyelid weights have also proven to be beneficial. [symptoma.com]

  In conjunction with a review of the literature, this case suggests that this phenotype carries with it a greater risk of serious complications affecting the eyelids and lacrimal gland. [ncbi.nlm.nih.gov]

  The parasympathetic secretomotor fibers supply the submandibular and sublingual salivary glands, the lacrimal glands and the glands of the nose and palate. [flexikon.doccheck.com]

• Excessive Tearing

  Upon observation, the left upper and lower eyelids were drooping and the left eye had excessive tearing. Motion palpation indicated multiple fixations in the cervical spine. Laboratory studies showed a microcytic anemia. [ncbi.nlm.nih.gov]

  They can range from mild to severe and include Twitching Weakness Paralysis Drooping eyelid or corner of mouth Drooling Dry eye or mouth Excessive tearing in the eye Impaired ability to taste Scientists think that a viral infection makes the facial nerve [medlineplus.gov]

  This means that symptoms can also include drooling, excessive tearing, dryness of the eye or mouth, and ringing in the ear. [livescience.com]

• Lagophthalmos

  We speculate that corneal irritation caused by lagophthalmos contributes to the induction of blepharospasm. [ncbi.nlm.nih.gov]

  […] side of face Watering of eye (epiphora) Ocular exposure causes: redness, discomfort, pain, photophobia, reduced vision Signs Unilateral facial weakness including orbicularis oculi incomplete blink leads to corneal drying incomplete closure at night (lagophthalmos [college-optometrists.org]

  Also, a Bell’s palsy patient may need eye protection, as patients who are dealing with total facial paralysis sometimes struggle to close their eyes completely (lagophthalmos). [facialparalysisinstitute.com]

  Lagophthalmos (pronounced lag-op-thal-mus): This is an inability to close the affected eye, which if prolonged may result in eye dryness and/or corneal ulceration. [facialpalsy.org.uk]

• Eye Pain

  Eye drops for affected eye Medications such as steroids to reduce inflammation of nerve and decrease pain Surgery (in rare cases to improve appearance) Treatment of underlying viral infection [foundationforpn.org]

  Among the symptoms of Bell’s palsy are the following: paralysis or weakness on one side of the face, eye problems like drooping eyes, excessive tearing or dry eyes, pain inside or behind the ear, increased sensitivity to sound, drooling, and loss of taste [businessmirror.com.ph]

  […] ear, inability to close the eye lids, facial muscle weakness, eye pain, blurred vision and epiphora. [symptoma.com]

  Other symptoms may include: Inability to close the eye on the affected side Drooping of the affected side (within a few hours to overnight) Teariness or dryness of the affected eye Pain in or behind the ear on the affected side Sensitivity to sound Drooling [moveforwardpt.com]

• Facial Pain

  On initial presentation in physical therapy the patient had unilateral facial paralysis, ipsilateral regional facial pain and numbness, and a history of a gradual, progressive onset of symptoms. [ncbi.nlm.nih.gov]

  We address synkinesis, contractures of facial muscles, related facial pains, excessive tearing and dynamic facial asymmetry. [crystal-touch.nl]

  Karen Johnson, deputy CEO of Facial Palsy UK, said that nearly 30 per cent of people with Bell’s palsy don't make a full recovery and are left with facial pain and spasms. [telegraph.co.uk]

• Unilateral Facial Weakness

  Bell palsy is largely a diagnosis of exclusion, but certain features in the history and physical examination help distinguish it from facial paralysis due to other conditions: eg, abrupt onset with complete, unilateral facial weakness at 24 to 72 hours [ncbi.nlm.nih.gov]

  Bell's palsy is the most common cause of unilateral facial weakness. Pathogenesis Idiopathic, congenital, traumatic, and neoplastic causes can all acount for facial nerve palsy. [pedclerk.bsd.uchicago.edu]

• Trigeminal Neuralgia

  G51.0 ICD-10-CM Codes Adjacent To G51.0 G47.63 Sleep related bruxism G47.69 Other sleep related movement disorders G47.8 Other sleep disorders G47.9 Sleep disorder, unspecified G50 Disorders of trigeminal nerve G50.0 Trigeminal neuralgia G50.1 Atypical [icd10data.com]

  neuralgia - شلل بل - Thoracic outlet syndrome - Phantom limb - Mononeuropathy ( Carpal tunnel syndrome, Meralgia paraesthetica, Tarsal tunnel syndrome ) Polyneuropathies والاضطرابات الأخرى في الجهاز العصبي المحيطي Charcot-Marie-Tooth disease - Dejerine [marefa.org]

  Inheritance in such cases may be autosomal dominant with low penetration; however, which predisposing factors are inherited is unclear. [25] The family history may also be positive for other nerve, nerve root, or plexus disorders (eg, trigeminal neuralgia [emedicine.com]

• Cranial Nerve Involvement

  MRI should be considered for the following patients: decompressive surgery is being contemplated atypical signs and symptoms suggest another diagnosis may be possible: slow progressive palsy spasm preceding palsy multiple cranial nerves involved recurrent [radiopaedia.org]

  nerve involvement other than the facial nerve. [emdocs.net]

  Features suggestive of an upper motor neurone cause - eg, limb weakness, facial paraesthesia, other cranial nerve involvement, postural imbalance. [patient.info]

  paralysis associated with other cranial nerve involvement, or no sign of recovery after 3 months. [journals.sagepub.com]

The diagnosis of Bell’s palsy is usually made based on history and physical examination. However, investigations may be needed to exclude other conditions.

Laboratory tests

• Complete blood count
• Erythrocyte sedimentation rate
• VDRL test
• HIV screening
• Fasting blood glucose
• Thyroid function test
• CSF analysis

Imaging

• CT scan
• MRI

Other investigations that can be carried out include EMG, nerve conduction tests, blepharokymography and histology.

Most patients who suffer from this condition often recover spontaneously without treatment. However, treatment might be needed in some patients and also to accelerate recovery. Medical treatments include the use of corticosteroids, antiviral agents and a combination of the two.

The eye should also be protected with the use of artificial tears and ointments. They should be applied to make up for the lack of lacrimation. The use of external eyelid weights have also proven to be beneficial.

There is a place for physical therapy like facial exercises, neuromuscular retraining, and acupuncture in the treatment of Bell’s palsy [7]. Surgeries to manage this condition, though not commonly advocated, include facial nerve decompression and eyelid implants.

Close to 90% of patients recover in 3 months or less without any apparent disfigurement. There are three groups that the patients fall into based on their prognosis. The first group are those who recover completely from the lesion without any long-term complications and this is the group most patients fall into. The second group does not recover completely but they appear completely recovered to the inexperienced eye, most people in this group have had axonotmesis with interruption of the axons. The last group are those with permanent neurological damage, visible even to the inexperienced eye, and this group is made up mostly by the elderly [5].

Factors associated with poor prognosis include advanced age, complete paralysis and reduced taste or salivation on the affected side. Other factors are pain in the posterior auricular area and decreased lacrimation.

The cause of Bell’s palsy has not been fully understood, however, some factors have been associated with increased likelihood of developing the disease. The most implicated factor is exposure to cold like in chilly weathers and air-conditioned environments. Others include infection with herpes simplex virus, herpes zoster, Lyme disease, HIV, Epstein-Barr virus, cytomegalovirus, syphilis and mycoplasma. It could also result from microvascular disease like diabetes and hypertension and from other inflammatory causes, viral diseases and autoimmune diseases [2].

Bell’s palsy has an annual incidence of between 0.015% and 0.03%. It is most commonly seen during the winter months. It is the commonest cause of unilateral facial paralysis and it occurs more on the right side of the face. Bell’s palsy affecting both sides of the face is rare. It also has a higher incidence in people who have underlying medical conditions like diabetes, HIV and preeclampsia.

The incidence of Bell’s palsy increases with advancing age with the highest incidence seen in patients 65 years and over. It affects both male and female sexes equally, and there is no clear difference in the incidence for different races [3].

The exact way by which this condition occurs is still unclear. However, it is mostly agreed that due to ischemia and edema, there is compression of the facial nerve within the facial canal. Thee facial canal is a small hole in the temporal bone which the facial nerve goes through during its course. The exact way by which this edema or inflammation comes about is unclear.

The commonest site of compression of the facial nerve is at the meatal foramen which has a diameter that is less than 0.7mm. The labyrinthine segment, the first portion of the facial nerve goes through this foramen. Due to its constricted limits, it is rational that processes such as inflammation, compression, ischemia and demyelination will weaken nerve conduction at this site [4].

Facial nerve injury in Bell’s palsy usually occurs near or at the geniculate ganglion, peripheral to the nerve’s nucleus. There is associated autonomic and gustatory abnormalities accompanying the motor paralysis if the injury occurs proximal to the geniculate ganglion. The same effects are seen if they occur between the geniculate ganglion and the origin of the corda tympani, but the lacrimal glands are spared. If it occurs at the stylomastoid foramen, there is only facial paralysis.

There is no documented way to prevent Bell’s palsy. However, lifestyle changes that reduce the risk of acquiring risk factors like HIV, diabetes and hypertension could be beneficial.

Bell’s palsy is named after Sir Charles Bell, a Scottish anatomist who first described the disease. It results from an injury to the motor neuron of the facial nerve and is self-limiting in over 80% of cases. Symptoms usually subside over a period of three months [1].

Definition

Bell’s palsy is a condition that leads to weakness of one side of the face and it is caused by injury to the facial nerve.

Cause

The cause of Bell’s palsy is unclear but the following factors have been known to contribute to development of the condition. They are exposure to cold, herpes simplex virus, herpes zoster, HIV, cytomegalovirus, sarcoidosis, Lyme disease and Epstein–Barr virus.

Signs and symptoms

Symptoms of Bell’s palsy mainly affect one half of the face and they include drooping of the face, drooping of the eyelid, altered taste sensation, lack of tears in the eye, increased sensitivity to sound, drooling, inability to make facial expressions like smiling [8].

Diagnosis

Diagnosis of Bell’s palsy is mainly made one the bases of the presenting symptoms, although some tests might be needed to exclude other conditions. Such tests include blood tests for infection, glucose, HIV and syphilis. Imaging tests like CT scan and MRI may also be required. Some nerve conduction tests may also be carried out.

Treatment

Treatment involves the use of corticosteroids, antivirals, artificial tears and ointments. Physical therapies to train the muscles of the face are also beneficial. In some cases, surgery on the facial nerve or the eyelids would be beneficial [9] [10].

1. Anderson P. New AAN guideline on Bell's palsy. Medscape Medical News. November 7, 2012. Accessed November 12, 2012.
2. Holland NJ, Weiner GM. Recent developments in Bell's palsy. BMJ. Sep 4 2004;329(7465):553-7.
3. Mutsch M, Zhou W, Rhodes P, Bopp M, Chen RT, Linder T, et al. Use of the inactivated intranasal influenza vaccine and the risk of Bell's palsy in Switzerland. N Engl J Med. Feb 26 2004;350(9):896-903.
4. Murakami S, Mizobuchi M, Nakashiro Y, Doi T, Hato N, Yanagihara N. Bell palsy and herpes simplex virus: identification of viral DNA in endoneurial fluid and muscle. Ann Intern Med. Jan 1 1996;124(1 Pt 1):27-30.
5. Unlu Z, Aslan A, Ozbakkaloglu B, Tunger O, Surucuoglu S. Serologic examinations of hepatitis, cytomegalovirus, and rubella in patients with Bell's palsy. Am J Phys Med Rehabil. Jan 2003;82(1):28-32.
6. Kim YH, Choi IJ, Kim HM, Ban JH, Cho CH, Ahn JH. Bilateral simultaneous facial nerve palsy: clinical analysis in seven cases. Otol Neurotol. Apr 2008;29(3):397-400.
7. Cardoso JR, Teixeira EC, Moreira MD, Fávero FM, Fontes SV, Bulle de Oliveira AS. Effects of exercises on Bell's palsy: systematic review of randomized controlled trials. Otol Neurotol. Jun 2008;29(4):557-60.
8. Baugh R, Basura G, Ishii L, Schwartz S, Drumheller C, Burkholder R, et al. Clinical Practice Guideline: Bell's Palsy. Otolaryngol Head Neck Surg November 2013 vol. 149 no. 3 suppl S1-S27. 
9. Hato N, Yamada H, Kohno H, Matsumoto S, Honda N, Gyo K, et al. Valacyclovir and prednisolone treatment for Bell's palsy: a multicenter, randomized, placebo-controlled study. Otol Neurotol. Apr 2007;28(3):408-13.
10. de Almeida JR, Al Khabori M, Guyatt GH, Witterick IJ, Lin VY, Nedzelski JM, et al. Combined corticosteroid and antiviral treatment for Bell palsy: a systematic review and meta-analysis. JAMA. Sep 2 2009;302(9):985-93.