A complete clinical history and a detailed clinical, otoscopic examination, audiogram tests, and complete blood count are mandatory in all children presenting with PFNP. In the absence of additional symptoms or specific findings on physical examination, the utility of further investigation is debatable. Manning et al. studied the causes of PFNP in 61 children and concluded that 50% of cases had Bell’s palsy, 14.8% had infections, 11.5% had injuries, and 3.3% had congenital problems. Grundfos et al. concluded that 84% of children had PFNP due to a specific etiology, and only 16% had Bell’s palsy as a diagnosis of exclusion. Particular causes of facial nerve palsy included injuries (24%), otitis media (16%), infections (12%), neoplasias (12%), and congenital anomalies (8%). In our study, no cause could be detected in 47.3% of the patients, infection was seen in 11(19.2%), a trauma in 6(10.5%), and others in 13(22.8%) were due to congenital, immune, neoplastic, Melkersson–Rosenthal syndrome, drugs toxicity and iatrogenic causes which were similar with Manning et al. results [23, 24].
A 10-year-old girl presented to our emergency department with facial immobility and an inability to close her eyes or move part of her mouth. Her symptoms started one day previously with severe pain in the shoulder and extremities. Physical examination revealed PFNP and mild bilateral weakness of the extremities, hypoesthesia, remarkable deep-sensation deficit in lower and upper extremities, and loss of Achilles reflex. Diagnosis of Guillain–Barre syndrome was established based on physical examination and electroneurophysiological findings. After the treatment, PFNP recovered within 3 months. There are also some reports in the literature regarding patients with GBS presenting only with PFNP without any other symptoms. Hence detailed examination is critical in every case of FNP .
Unilateral facial nerve palsy can be a rare presenting symptom of leukemia or leukemic relapse. In our study 1, patients were diagnosed with AML after developing PFNP. In his examination, paleness and proptosis and abnormal CBC findings were red flags. Typical MRI findings cannot exclude the diagnosis of leukemia or leukemic relapse. Developing a focal neurological deficit in a patient with known leukemia warrants rigorous investigation and close surveillance for possible central nervous system relapse. In neoplastic facial palsy, the prognosis depends on the type and stage of neoplasm, and the therapeutic protocol applied in each case. PFNP in our patient recovered within four months, and the patient had bone marrow transplantation [8, 26, 27].
Inappropriate treatment of acute otitis media can cause facial nerve palsy, mastoiditis, labyrinthitis. Ramsay Hunt syndrome is caused by the varicella-zoster virus (VZV) reactivation, which lies in the sensory ganglion after primary infection. The syndrome is characterized by facial nerve palsy associated with a painful vesicular eruption within the external auditory canal and vestibulocochlear dysfunction (sensorineural hearing loss, vertigo, nystagmus, and ataxia). EBV, CMV, and mycoplasma pneumonia are also among the infectious causes [6, 11, 14]. In our study, CMV, EBV, varicella-zoster, mycoplasma pneumonia, otitis media, otitis externa, and abscess led to PFNP in 11(19.2%) patients. Patients with PFNP caused by infections recovered within 0.5–3 months. Some cases such as Ramsey Hunt syndrome may have a worse prognosis. All these patients received a combination treatment of corticosteroid and acyclovir in herpes or VZV infection, corticosteroid and ceftriaxone in complicated otitis media, and gancyclovir in CMV. PFNP, due to infectious causes, recovered within three months with the support of 2 weeks of corticosteroid and physical rehabilitation till recovery. The ongoing COVID-19 pandemic has affected millions of people worldwide and revealed several neurological syndromes related to this infection. But no cases of PFNP due to SARS-CoV-2 could be detected in our center.
Generally, the prognosis of facial nerve palsy depends on the cause. When caused by perinatal injury, congenital facial nerve palsy has an excellent prognosis without treatment, while it is permanent when caused by congenital dysplastic structural reasons. In this case, paralysis can be partly improved with plastic surgery procedures. Patients with traumatic facial nerve palsy recover within 30 months, with better results when the paralysis is partial or treated with steroids, physiotherapy, or surgical procedures . In our study, the patient who had PFNP due to trauma recovered within seven months due to a mild injury, immediate surgical intervention, and extensive support of physical rehabilitation therapy were supplied. But PFNP in the patient with birth trauma didn't show any improvement. This situation could be due to the severe degree of birth trauma.
One of the rare reasons for FNP in children is hypertension. The ignorance of this etiological reason could lead to delayed diagnosis or even worsening hypertension due to the administration of steroids for idiopathic nerve palsy. Many authors recommend the measure of blood pressure in all patients with facial paralysis. It is essential to mention that we found several datasets that support PFNP as the first symptom of hypertension in children . In our study, hypertension was detected in any patients. But measuring blood pressure is essential in every issue of PFNP.
PFNP, especially recurrent palsies, are uncommon disorder. In the literature, it was observed patients with recurrent PFNP, were diagnosed with celiac disease (CD) several months later. Because this observation and other neurological symptoms may be the only manifestation of atypical forms of CD. In our study, a 5-year-old girl suffered from CD for 12 months before developing PFNP for the first time; no other attacks were detected during follow-up [2, 4, 29]. Recurrent PFNP was seen in two cases, the first one was diagnosed as Melkersson–Rosenthal syndrome and the other one was considered idiopathic due to normal physical examination and laboratory and radiological test results except for B12 deficiency. Therefore this study cannot make causal inferences on the relation between B12 deficiency and PFNP. Nevertheless, there are many reported cases of neurological deficits due to B12 deficiency. One of these cases is a recurrent facial palsy in a 40-year-old woman who revealed primary Gougerot–Sjögren's syndrome. The onset of facial palsy has been linked with Gougerot–Sjögren's syndrome. The contribution of vitamin B12 deficiency is debatable in that case. So measuring B12 in cases of PFNP could be important, and thus supplying that patient with B12 could play a significant role in the treatment and prognosis .
Iatrogenic FNP cases are also reported. Complications can occur during mastoid surgery causing injury to the facial nerve. Early facial nerve exploration and neurolysis resulted in good facial nerve recovery. Some cases of PFNP secondary to superficial parotidectomy are also available in the literature [1, 2, 30]. In addition, bilateral facial nerve palsy secondary to the administration of high-dose paclitaxel was also reported in a woman with breast cancer . In our study, there is one case of PFNP due to iatrogenic reasons (during cochlear implant surgery). At the same time, our study revealed a case of PFNP after tacrolimus treatment in a patient with renal transplantation.
MRI is beneficial in identifying brainstem pathology. High-resolution computed tomography scanning is better for evaluating the infratemporal portion of the nerve, especially in traumatic cases. Contrast-enhanced magnetic resonance imaging can identify sections of affected nerve in idiopathic facial palsy, but this test is not indicated in most children. More recent techniques such as constructive interference in steady-state and 3D-magnetization-prepared rapid gradient echo can also be used to evaluate anatomical details of the inner ear and facial nerve. It should be indicated especially in patients presenting with atypical clinical findings and not improving as expected [6, 21].
Electrophysiological analyses of the facial nerve and the mimic muscles can assist in diagnosis, assess the lesion severity, and aid in decision-making. An acute facial palsy is a valuable tool for predicting recovery. The American Academy of Otolaryngology-Head and Neck Surgery Foundation guideline recommends electrodiagnostic testing only for cases of complete paralysis. In contrast, the German and the Spanish guidelines recommend electrodiagnostic for all patients with Bell’s palsy. Electrophysiological analyses were done in only 12 patients. This could be due to the lack of cooperation in children, Electrophysiological analyses may detect the presence of voluntary motor unit action potentials. In traumatic cases, this proves that the facial nerve has not been completely transected. This finding directly impacts the decision to explore the lesion site .
The treatment of idiopathic PFNP is controversial. The use of steroids early at the onset of palsy (within 72 h) improves the prognosis and chances of complete recovery. This theory has been conducted depending on studies in adults. In children, the clinical benefit of steroids has not been proven yet. This is possible because most children with PFNP with or without the use of steroids resulted in complete recovery. Many studies demonstrate that children generally have better outcomes. Some research revealed a beneficial effect of using a steroid. In a recent randomized, double-blind, and placebo-controlled research on 496 patients with Bell’s palsy after 3 months, 83% of the patients in the corticosteroid group recovered compared to 64% in the placebo group. The same study showed after 9 months of follow-up this proportion increased to 94% for the corticosteroid group and 82% for the placebo group. The researchers thought depending on the result of this research that the treatment with steroids within 3 days after onset profoundly improves the chance for complete recovery at 3 or 9 months. In another study on 147 patients with peripheral facial palsy 44% received corticosteroids, which did not significantly improve the outcome . In our study, steroid was started in 39 out of 57 patients, this could be due to a strong belief in the strong effects of steroids, and 46 of the children achieved full recovery under oral steroids or other required drugs according to the etiology within 1–7 months post-treatment.
Patients with Ramsay Hunt syndrome should be aggressively treated with intravenous administration of acyclovir plus steroids. Two recent reviews with acyclovir and steroids versus steroids alone, acyclovir versus steroids, and valacyclovir with steroids versus steroids. The study concluded that the results of all three trials were inconclusive about a short or long-term benefit and that a large, multicenter, randomized, controlled, and blinded study with a minimum follow-up of 1 year is required before a definite recommendation, however, acyclovir appears to be effective in patients with PFNP due to herpes zoster or VZV infection . In our study, CMV, EBV, varicella-zoster, mycoplasma pneumonia, otitis media, otitis externa, and abscess led to PFNP in 11(19.2%). Patients with PFNP caused by infections recovered within 0.5–3 months after treatment.
In patients unable to close their eyes, appropriate eye care is needed to help avoid corneal abrasions. This care can be provided by using artificial tears, sun protection, and rarely tarsorrhaphy. In our study, all patients received artificial tears and eye care. Additional measures such as acupuncture and moxibustion could be applied. Though only limited experience has been reported with acupuncture for Bell’s palsy , several studies provide increasing evidence for the beneficial effect of acupuncture and moxibustion as an adjunctive treatment of Bell’s palsy [30,31,32]. In our study, none of the patients received acupuncture and moxibustion.
There are only a few controlled trials present on the real effectiveness of physical therapy for facial palsies. In a randomized trial on 50 patients with Bell’s palsy and a mean HBS of IV, mime therapy, including auto massage, relaxation exercises, inhibition of synkinesis, coordination exercises, or emotional expression exercises, resulted in improvement of facial stiffness [35,36,37,38]. In our study, physical rehabilitation programs were provided to all patients.
Not all cases of PFNP have resulted in complete recovery. There are cases with poor outcomes, so in these patients, further methods of treatment are applied as pulsatile electrical current (transcutaneous electrical stimulation) particularly, in chronic facial nerve damage long-term electrical stimulation may be beneficial. In a study on 12 patients with chronic PFNP and 5 cases due to iatrogenic causes, such stimulation was applied. There was an improvement in these patients. The beneficial effect was due to the facilitation of re-innervation through electrical stimulation. Another further way of treatment in poor prognosis patients is transmastoid decompression. In a study on 58 patients with PFNP having denervation exceeding 95%, transmastoid decompression of the facial nerve resulted in significant improvement of the HBS. Gold weight Implantation into the upper eyelids is also applied in poor prognosis patients a study regarding gold implantation on 16 patients with lagophthalmos due to PFNP resulted in a significant reduction of lagophthalmos and improved corneal coverage of 100%. Facial nerve cable grafting is also another treatment method that is applied in poor prognosis. In a retrospective study of 27 patients undergoing facial nerve grafting who had the nerve grafted to a site distal to the mental foramen had a better outcome than those with anastomosis proximal to the meatal foramen. The subperiosteal facial suspension (face lifting) In an observational study on five patients with an HBS of III–V face lifting resulted in a marked improvement in four of them [39,40,41,42,43,44]. These further method generally were applied on adult patients, in our study non of these methods were approached.
Assessing the prognosis of facial nerve paralysis can be difficult, especially in children, even if the possibility of a complete functional recovery is greater in pediatric cases than in adult ones. Facial nerve palsy can improve up to 1 year later. Complete palsy, Absent recovery by 3 weeks, Age > 60 years, Severe pain Ramsey Hunt syndrome, Presence of conditions causing secondary facial nerve palsy, and Reduction of the compound muscle action potential > 50% are considered to be Indicators for poor prognosis. The grade is very important when determining the prognosis. Patients with partial paralysis have a better prognosis. The II-degree, according to the House–Brackmann scale, has a good outcome, while the III and IV degrees are associated with moderate residual dysfunctions. The V and the VI degrees, instead, have a poor possibility of recovery. It has been reported that in about 5% of cases, the affected side may develop residual sequelae like contractures, spasms, and synkinesis. The latter, in particular, affects symmetry and facial expressiveness. The most common synkinesis affects the eye and mouth muscles: during a voluntary movement of the mouth, for example, a smile, there could be an involuntary eye closure and vice versa. A similar phenomenon can occur with the autonomic fibers: for example, when eating, the activation of salivation also causes lacrimation (a phenomenon known as “crocodile tears”). No patient revealed such residual sequelae despite unrecovered 4 cases and partial recovery in 2 patients in our studies. In our study, the prognosis of PFNP is good with complete recovery in about 80.7% of the cases, 3.5% experienced some kind of improvement, and 7% remained with severe sequelae, our results are similar to Joseph et al. results that showed complete recovery in about 80% of the cases, 15% experienced some improvement 5% were with severe sequelae [34, 45, 46].
In conclusion, peripheral facial nerve palsy is a rare condition in children with different causes. It could be idiopathic, congenital, or due to infectious, traumatic, neoplastic, and immune reasons. So, when a child presents with facial palsy, a complete clinical history and a detailed clinical examination are recommended. Giving attention to the red flag is very important. Peripheral facial nerve palsy in children is considered to have a good prognosis.