Facial palsy: when and why to refer for specialist care

ACUTE FLACCID FACIAL PARALYSIS

The critical distinction between AFFP and LFFP relates to the presence or absence of viable facial mimetic muscles. The exact time at which the facial muscles become non-receptive to re-innervation remains unknown; however, many would consider 12 months as the point when a patient would transfer into the LFFP group.³

The majority of patients with AFFP will have Bell’s palsy.⁴ The exact cause of Bell’s palsy is unknown, but it is thought to result from facial nerve swelling within the confines of the temporal bone. Eye care with lubricants and night-time taping is essential, and, in those presenting within 72 hours, commencing a 10-day course of 50 mg prednisolone is the only treatment shown to improve the long-term outcome.^4,5 Among those with Bell’s palsy, 83% will go on to fully recover facial movement if treated with prednisolone, with most showing improvement from 3 weeks onwards. Only 72% make a full recovery if not treated with steroids within 72 hours.⁵ The remainder will have some degree of long-term sequelae and fall into the LFFP or PPFP groups. Table 1 describes the timeframe and indication for referral among those with AFFP.

Careful clinical assessment for a painful vesicular rash in or around the ear, mouth, or scalp should alert the physician to the diagnosis of Ramsay Hunt Syndrome, where the addition of acyclovir to the course of steroids is necessary. Slow-onset paralysis or involvement of other nerves (for example, hearing or taste) should alert the clinician that skull base or parotid tumours are possible causes and warrant prompt investigation.

In those who do not have a complete return of facial movement after 3 months, several non-surgical and surgical treatment options can be provided through specialised facial palsy centres to improve long-term function and appearance. The ultimate objective is to restore movement within the patient’s native facial muscles, as transfer of muscles from other areas of the body can never accurately replicate the complex, synchronised movement of the facial mimetic muscles. To achieve this, intervention at around 6 months should be the target in those unlikely to spontaneously recover facial movements.

LONGSTANDING FLACCID FACIAL PARALYSIS

This group consists of those with both congenital and acquired causes of facial palsy persisting more than 12 months. Most will have established an ocular care regimen, but this should be checked at each clinical review. Among patients born with facial paralysis, early referral to the local paediatric service is essential to assess for potential causes of the facial palsy. Although unlikely, it should be checked that those with LFFP have undergone investigations to determine its aetiology.

Among those with LFFP, there is minimal potential for the patient’s native facial muscles to regain meaningful movement. As a result, referral to a specialised facial palsy centre should be made. Here, a multidisciplinary team (MDT) consisting of surgeons, facial physiotherapists, and psychologists can plan an optimal treatment strategy. The objectives are to achieve ocular protection, restore nostril opening, and restore resting and, where possible, dynamic facial symmetry. A myriad of options exist and it is essential that these patients are given access to review in these specialised MDTs.

POST-PARALYTIC FACIAL PALSY

A potential complication from the spontaneous neural regeneration that occurs following an insult to the facial nerve is PPFP. This typically comprises synkinesis (the development of unwanted facial movements), hypertonia (persistent tightness of the facial muscles), and hyperkinesis (exaggerated movements). All can have a significant impact on facial symmetry and confer significant psychological morbidity.

As a result, referral to secondary care is indicated. Facial physiotherapy plays an important role in managing these challenging cases and treatment with botulinum toxin to weaken the overactive muscles can carry significant benefit.⁶ Surgical options also exist that can be targeted at areas that may benefit from a more permanent solution.

WHERE TO REFER

Currently no standardised referral pathways exist that ensure patients with facial palsy are seen within an appropriate dedicated facial palsy service. A recent patient survey conducted by the charity Facial Palsy UK (FPUK) identified that over 50% of patients with facial palsy referred to secondary care were not sent to a service that was able to manage their case and required subsequent referral onwards (unpublished Facial Palsy UK data, January 2019). This is likely a result of the patient not being referred to a dedicated facial palsy service. FPUK is in the process of developing a list of recognised facial palsy services across the country to aid primary care physicians in selecting an appropriate location to refer patients on to (https://www.facialpalsy.org.uk/).

FACIAL PALSY SERVICES

A comprehensive facial palsy service should comprise facial physiotherapists, psychologists, ear, nose, and throat (ENT), ophthalmology, and reconstructive surgeons within their core team, with additional access to neurology and neurodiagnostic services. Currently the onus is on those working within specialised facial palsy teams to work with local fundholders to better define and establish clear pathways for appropriately referring those with facial palsy to secondary care.

CONCLUSION

Although most patients with facial paralysis have Bell’s palsy, some will require input from teams specialised in managing those with facial palsy. Timely referral to such facilities can improve the patient’s long-term outcome by enhancing the function within the individual’s native facial musculature. In those with longstanding facial paralysis, or the sequelae associated with aberrant nerve regeneration, a breadth of treatment options exist that can be tailored to each patient following review within a specialised facial palsy team.