although facial paralysis is fairly commonly encountered by ear , nose , and throat physicians , bilateral facial paralysis is very rare .
the frequency of facial paralysis is 2025 per 100,000 patients , but simultaneous bilateral facial paralysis occurs in only 1 in 5 million patients . simultaneous bilateral facial paralysis is considered present if the time elapsed from paralysis of one side to paralysis of the other side does not exceed 4 weeks . a differential diagnosis of bilateral facial paralysis must consider systematic , traumatic , neuromuscular , vascular , toxic , and infectious diseases and idiopathic causes .
we present 40-year - old male patient with bilateral facial paralysis caused by blunt head trauma .
the patient was followed up in our intensive care unit for 10 days , because of multiple traumas caused by the accident , and was referred to our clinic with a diagnosis of facial paralysis , hearing loss , and anosmia .
he was conscious , cooperative , and oriented . on physical examination , both tympanum membranes were intact . upon house - brackmann ( hb ) classification ,
hb grade 6 facial paralysis was observed on the right side and hb grade 5 on the left . upon audiometric testing ,
a slight sensorineural hearing loss ( snhl ) was evident on the right side with advanced mixed - type hearing loss on the left . on facial maxillary
computed tomography ( ct ) examination , multiple nondisplaced fracture lines were observed on the base of the right frontal sinus base , on the left frontal bone , on the zygomatic bone , and on both sides of the sphenoid bone . also , a transversely progressive fracture line was evident in both petrous temporal bones ( figures 1(a ) and 1(b ) ) .
as the facial paralysis had developed immediately after the accident and as total denervation was evident upon electromyography ( emg ) examination , a transmastoid facial decompression operation was performed on the right side in the third week after trauma .
the right side was graded hb 1 and the left side hb 2 at the 1-year follow - up ( figures 2(a ) and 2(b ) ) .
bilateral facial paralysis caused by bitemporal bone fracture is very rare , with seven cases reported to date ( table 1 ) . unlike unilateral facial paralysis ,
the most important causes of bilateral facial paralysis are trauma , infectious diseases ( infectious mononucleosis , syphilis , bilateral otitis media , herpes zoster , lyme disease , and meningitis ) , neurological diseases ( multiple sclerosis , neoplasms , or stroke ) , and other diseases , the aetiologies of which are uncertain ( guillain - barre syndrome , sarcoidosis , melkersson - rosenthal syndrome , and leukaemia ) .
trauma causes 5% of all facial paralysis , and 3% of cases are associated with temporal bone fractures , which can be divided into longitudinal , transverse , and mixed fractures .
the fracture lines of transverse fractures are vertical , running through the squamous petrous bone ; these constitute 10% of all temporal bone fractures . a total of 3050% of patients with transverse fractures present with facial paralysis and snhl .
such facial paralysis is rather serious , and the prognosis is very poor . in longitudinal fractures , the fracture lines lie parallel to the long axis of the temporal bone .
such fractures constitute 90% of all temporal bone fractures and , in 1025% of cases , are accompanied by facial paralysis .
, a fracture line exhibiting transverse progression was observed in both temporal bones , and facial paralysis was accompanied by snhl in the right ear and a mixed type of hearing loss in the left ear .
the technique explores the extent of facial nerve activity , and denervation of over 90% has been identified when electroneuronography ( enog ) was performed within 6 days of the trauma .
emg and high - resolution ct aid surgical decision - making for patients who are diagnosed late . in the present case emg test revealed that there were bilateral fibrillation potentials and no response after stimulation , which is a typical pattern of a complete degeneration of the nerve .
such patients may be divided into four groups : those suffering from neuropraxia , those suffering from axonotmesis , those suffering from neurotmesis , and those suffering from nerve injuries . in patients with neuropraxia , myelin sheath damage is evident but the axon is robust .
distal axons undergo wallerian degeneration after 7 days of injury , followed by axonal regeneration from intact nervous tissue .
if nerve incision is evident , it is necessary to place a nerve graft in the area in which the nerve incision has caused neural function to be lost . in our case
, we found that facial nerve integrity was in fact complete but that bone spicules had compressed the facial nerve .
the middle cranial fossa approach is used to treat not only longitudinal fractures , but also mixed and transverse fractures , combined with a transmastoid exploration technique .
we employed the latter technique in our patient ; we followed the fracture line and cleared bone spicules thereon .
fisch stated that an intraneural haematoma might compress a nerve in those with delayed paralysis and recommended urgent exploration .
watchful waiting for 3 - 4 weeks was suggested for patients with early - stage paralysis .
this was because the nerve was readily visualised ( oedema was present ) and because haematoma regression was often evident in those with early - stage paralysis .
the present case was diagnosed as complete bilateral facial paralysis at the first day of trauma .
he was operated upon in the third week of trauma after 10-day follow - up in the intensive care unit . in patients with facial paralysis
the use of synthetic tears and eye closure at night reduce the risk of keratitis .
traumatic bilateral facial paralysis is very rare and is often accompanied by serious fractures of the skull base . as patients with such fractures exhibit high levels of mortality , death may occur before diagnosis .
early diagnosis and treatment are vital in patients with bilateral facial paralysis . however , such patients may experience long stays in intensive care units , associated with delays in diagnosis , because facial asymmetry can not be evaluated if the facial paralysis is bilateral . in such situations
, it may be helpful to note that a patient can not close his or her eyes completely and that the eye globes move up or out ( the bell phenomenon ) when she or he is asked to close the eyes .
 bilateral facial paralysis caused by bilateral temporal bone fracture is a rare clinical entity , with seven cases reported in the literature to date . in this paper , we describe a 40-year - old male patient with bilateral facial paralysis and hearing loss that developed after an occupational accident . on physical examination , 
 house - brackmann ( hb ) facial paralysis of grade 6 was observed on the right side and hb grade 5 paralysis on the left . upon temporal bone computed tomography ( ct ) examination , a fracture line exhibiting transverse progression was observed in both petrous temporal bones . 
 our patient underwent transmastoid facial decompression surgery of the right ear . 
 the patient refused a left - side operation . 
 such patients require extensive monitoring in intensive care units because the presence of multiple injuries means that facial functions are often very difficult to evaluate . 
 therefore , delays may ensue in both diagnosis and treatment of bilateral facial paralysis . 
1. Introduction
2. Case Report
3. Discussion