Clinical Review

Girl, 6, With Facial Weakness

Clinician Reviews. 2011 January;21(1):14, 16-18

References

1. House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985;93(2): 146-147.

2. Finsterer J. Management of peripheral facial nerve palsy. Eur Arch Otorhinolaryngol. 2008;265(7):743-752.

3. Lunan R, Nagarajan L. Bell’s palsy: a guideline proposal following a review of practice. J Paediatr Child Health. 2008;44(4):219-220.

4. Blosser CG, Reider-Demer M. Neurologic disorders. In: Burns CE, Dunn AM, Brady MA, et al, eds. Pediatric Primary Care. 4th ed. St. Louis: Saunders Elsevier; 2008:634-672.

5. Singhi P, Jain V. Bell’s palsy in children. Semin Pediatr Neurol. 2003;10(4):289-297.

6. Tiemstra JD, Khatkhate N. Bell’s palsy: diagnosis and management. Am Fam Physician. 2007;76(7):997-1002.

7. Lorch M, Teach SJ. Facial nerve palsy: Etiology and approach to diagnosis and treatment. Pediatr Emerg Care. 2010;26(10):763-769.

8. El-Hawrani AS, Eng CY, Ahmed SK, et al. General practitioners’ referral pattern for children with acute facial paralysis. J Laryngol Otol. 2005;119(7):540-542.

9. Shargorodsky J, Lin HW, Gopen Q. Facial nerve palsy in the pediatric population. Clin Pediatr (Phila). 2010;49(5):411-417.

10. Wang CH, Chang YC, Shih HM, et al. Facial palsy in children: emergency department management and outcome. Pediatr Emerg Care. 2010;26(2):121-125.

11. Evans AK, Licameli G, Brietzke S, et al. Pediatric facial nerve paralysis: patients, management and outcomes. Int J Pediatr Otorhinolaryngol. 2005;69(11):1521-1528.

12. Lockhart P, Daly F, Pitkethly M, et al. Antiviral treatment for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev. 2009;(4):CD001869.

13. Grogan PM, Gronseth GS. Practice parameter: steroids, acyclovir, and surgery for Bell’s palsy (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2001;56(7):830-836.

14. Khine H, Mayers M, Avner JR, et al. Association between herpes simplex virus-1 infection and idiopathic unilateral facial paralysis in children and adolescents. Pediatr Infect Dis J. 2008;27(5):468-469.

15. Tsai HS, Chang LY, Lu CY, et al. Epidemiology and treatment of Bell’s palsy in children in northern Taiwan. J Microbiol Immunol Infect. 2009;42(4):351-356.

16. Cha CI, Hong CK, Park MS, Yeo SG. Comparison of facial nerve paralysis in adults and children. Yonsei Med J. 2008;49(5):725-734.

17. Linder TE, Abdelkafy W, Cavero-Vanek S. The management of peripheral facial nerve palsy: “paresis” versus “paralysis” and sources of ambiguity in study designs. Otol Neurotol. 2010;31(2):319-327.

18. Rahman I, Sadiq SA. Ophthalmic management of facial nerve palsy: a review. Surv Ophthalmol. 2007;52(2):121-144.

19. Skogman BH, Croner S, Odkvist L. Acute facial palsy in children: a 2-year follow-up with focus on Lyme neuroborreliosis. Int J Pediatr Otorhinolaryngol. 2003;67(6):597-602.

20. Siegler RL, Brewer ED, Corneli HM, Thompson JA. Hypertension first seen as facial paralysis: case reports and review of the literature. Pediatrics. 1991;87(3):387-389.

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Acquired FNP is two to four times less common in children than adults, with an estimated prevalence of 2.7 per 100,000 patients younger than 10. Children account for only a small proportion of subjects in published studies that address diagnosis and management of FNP.³ While the presentation of FNP is much the same in adults and children, some notable differences in etiology exist.^2,3,7-9 Infectious, traumatic, or neoplastic causes of FNP are more common among children than adults and must be distinguished from idiopathic FNP.^7,9-11

Decisions regarding diagnostic testing, pharmacologic treatment, and referral must be guided by the history and physical exam, neurologic exam, and clinical judgment. Being able to identify or exclude alarming causes of FNP, such as neoplasm, will aid the primary care practitioner in treatment and referral practices for this condition.

Pathophysiology
CN VII, the facial nerve, has a broad scope of function that incorporates both sensory and motor pathways. The brachial nerve portion of CN VII controls the muscles of voluntary facial expression. CN VII also autonomically innervates the lacrimal gland and submandibular gland and governs sensation from part of the ear as well as taste from the anterior two-thirds of the tongue.⁴

The precise pathophysiology involved in FNP remains an area of continuing debate, but infectious, vascular, immunologic, and genetic causes have been hypothesized.^7,12 Inflammation and subsequent nerve damage along CN VII caused by an infectious process is thought to be the most likely explanation for the pathogenesis of acquired FNP in both adults and children.^5,13

Herpes simplex virus 1 (HSV-1) has been suggested as the virus most commonly linked to FNP in both adults and children, but it is unlikely to be the sole cause.^5,6,9 Data from a three-year prospective study of FNP cases in children support a relationship between pediatric FNP and HSV-1 infection.¹⁴ Other infectious causes implicated in pediatric FNP are Lyme disease, Epstein-Barr, varicella zoster virus, rubella, coxsackie virus, adenovirus, and otitis media.^4,7,9

Presentation, History, and Physical Exam
Most children with idiopathic FNP will present with sudden-onset facial asymmetry and may have decreased tearing, loss of the conjunctival reflex (leading to difficulty closing the eye), an inability to hold the lips tightly together, and difficulty keeping food in the mouth. Complaints of otalgia, speech disturbances, hyperacusis, and altered sense of taste are common.^2,7 Recent occurrence of an upper respiratory infection is often reported in the history of a pediatric patient with FNP.^3,7,15,16

Idiopathic FNP is essentially a diagnosis of exclusion.^3,5 A meticulous history must be conducted, including any recent illnesses, trauma to the face or head, vaccines, rashes, and travel. Assessment of the head, eyes, ears, nose, and throat, and a careful neurologic history must be conducted to identify nonidiopathic causes of FNP (see Table 1^5-7,9). Facial weakness can progress from mild palsy to complete paralysis over one to two weeks⁵; therefore, a careful history of the progression of facial weakness should be ascertained and documented.^5,17

A full neurologic exam is essential. Cranial nerves I through XII should be evaluated; any malfunction of a cranial nerve other than CN VII could be indicative of a tumor or process other than idiopathic FNP. Assessment of facial nerve function is imperative, as this factor is the most important for predicting recovery; it can also aid in formulating a prognosis and directing treatment.^5,9,17

The House-Brackmann facial nerve grading system^1,2 is considered the gold standard for grading severity of facial paresis⁹ (see Table 2^1,2 ). A clear distinction between paresis (partial or incomplete palsy) and paralysis (complete palsy) must be made. Pediatric patients with an incomplete palsy have an improved chance of full recovery.^17,18

Any abnormalities in the peripheral neurologic exam should prompt further testing. FNP not involving the forehead musculature, gradual progression of paresis, and weakness in any extremity could be indicative of a central lesion. FNP has been the presenting symptom in various neoplastic processes, including leukemia, cholesteatoma, and astrocytoma.^3,7,9

Otitis media is a frequent cause of FNP among children.^9-11 Thus, a thorough examination of the ear canal, tympanic membrane, and hearing should be performed. The throat and oropharynx should be inspected, and the parotid gland palpated. Any swelling or abnormalities warrant further investigation.

Lyme disease presenting with FNP is more common in children than adults. This may be related to the increased likelihood for children to be bitten by ticks in the head and neck areas. Frequently, FNP associated with Lyme disease is bilateral—as often as 25% of the time.¹⁹ Headache, onset of symptoms during peak Lyme season, or bilateral FNP should raise the clinician’s suspicion for Lyme disease.^7,9,19