Temporal Bone Trauma: Temporal Bone Trauma October 12, 2005 Steven T. Wright, M.D. Matthew Ryan, M.D.


Temporal Bone Trauma: Temporal Bone Trauma Wide spectrum of clinical findings Knowledge of the anatomy is vital to proper diagnosis and appropriate management


Incidence and Epidemiology: Incidence and Epidemiology Motorized Transportation 30-75% of blunt head trauma had associated temporal bone trauma Penetrating Trauma More dismal prognosis Barotrauma Inner ear decompression sickness The 'bends' Perilymphatic fistula Blast Injuries


Evaluation and Management: Evaluation and Management ATLS Airway Breathing Circulation H andamp; P Thorough head andamp; neck examination


Physical Examination: Physical Examination Basilar Skull Fractures Periorbital Ecchymosis (Raccoon’s Eyes) Mastoid Ecchymosis (Battle’s Sign) Hemotympanum


Physical Examination: Physical Examination Tuning Fork exam Pneumatic Otoscopy Flaccid TM Nystagmus


Imaging: Imaging HRCT MRI Angiography/ MRA


Longitudinal fractures: Longitudinal fractures 80% of Temporal Bone Fractures Lateral Forces along the petrosquamous suture line 15-20% Facial Nerve involvement EAC laceration


Transverse fractures: Transverse fractures 20% of Temporal Bone Fractures Forces in the Antero-Posterior direction 50% Facial Nerve Involvement EAC intact


Temporal Bone Trauma: Temporal Bone Trauma Hearing Loss Dizziness/Vertigo CSF Otorrhea Facial Nerve Injuries


Hearing Loss: Hearing Loss Formal Audiometry vs. Tuning Fork 71% of patients with Temporal Bone Trauma have hearing loss TM Perforations CHL andgt; 40db suspicious for ossicular discontinuity


Hearing Loss: Hearing Loss Longitudinal Fractures Conductive or mixed hearing loss 80% of CHL resolve spontaneously Transverse Fractures Sensorineural hearing loss Less likely to improve


Hearing Loss: Hearing Loss Tympanic Membrane Perforations Ossicular fracture or discontinuity Hemotympanum Treatment: Observation Otic solutions may only mask CSF leaks


Dizziness: Dizziness Fracture through the otic capsule or a labyrinthine concussion Difficult diagnosis- bed rest, obtundation, sedation Treatment: reserved for vomiting, limitation of activity Vestibular suppressants Allow for maximal central compensation


Dizziness: Dizziness Perilymphatic Fistulas SCUBA diver with ETD Fluctuating dizziness and/or hearing loss Tullio’s Phenomenon Management Conservative treatment in first 10-14 days 40% spontaneously close Surgical management for persistent vertigo or hearing loss Regardless of visualization of fistula site, the majority of patients get better


Dizziness: Dizziness Inner Ear Decompression Sickness Too rapid an ascent leads to percolation of nitrogen bubbles within the otic capsule. Greater than 30 ft…. Decompression stages upon ascent are needed


Dizziness: Dizziness BPPV Acute, latent, and fatiguable vertigo Can occur any time following injury Dix Hallpike Epley Maneuver


CSF Otorrhea: CSF Otorrhea Acquired Postoperative (58%) Trauma (32%) Nontraumatic (11%) Spontaneous Bony defect theory Arachnoid granulation theory


Temporal bone fractures: Temporal bone fractures Longitudinal 80% of Temp bone fx Anterior to otic capsule Involve the dura of the middle fossa


Temporal bone fractures: Temporal bone fractures Transverse 20% of Temp bone fx High rate of SNHL due to violation of the otic capsule 50% facial nerve involvement


Testing of Nasal Secretions: Testing of Nasal Secretions Beta-2-transferrin is highly sensitive and specific 1/50th of a drop Gold top tube, may need to send a sample of the patients serum also. Found in Vitreous Humor, Perilymph, CSF Electronic nose has shown early success Faster (andlt;24hrs) Very Accurate


Imaging CSF Otorrhea: Imaging CSF Otorrhea High resolution CT Convenience Speed CT Cisternography MRI Heavily weighted T2 Slow flow MRI MRI cisternography


Imaging: Imaging Slow flow MRI Diffusion weighted MRI Fluid motion down to 0.5mm/sec Ex. MRA/MRV


Treatment of CSF Otorrhea: Treatment of CSF Otorrhea Conservative measures Bed rest/Elev HOBandgt;30 Stool softeners No sneezing/coughing +/- lumbar drains Early failures Assoc with hydrocephalus Recurrent or persistent leaks


Treatment of CSF Otorrhea: Treatment of CSF Otorrhea Brodie and Thompson et al. 820 T-bone fractures/122 CSF leaks Spontaneous resolution with conservative measures 95/122 (78%): within 7 days 21/122(17%): between 7-14 days 5/122(4%): Persisted beyond 2 weeks


Temporal bone fractures: Temporal bone fractures Meningitis 9/121 (7%) developed meningitis. Found no significant difference in the rate of meningitis in the ABX group versus no ABX group. A later meta-analysis by the same author did reveal a statistically significant reduction in the incidence of meningitis with the use of prophylactic antibiotics.


Pediatric temporal bone fractures: Pediatric temporal bone fractures Much lower incidence (10:1, adult:pedi) Undeveloped sinuses, skull flexibility otorrheaandgt;andgt; rhinorrhea Prophylactic antibiotics did not influence the development of meningitis.


CSF Otorrhea Surgical Management: CSF Otorrhea Surgical Management Surgical approach Status of hearing Meningocele/encephalocele Fistula location Transmastoid Middle Cranial Fossa


Overlay vs Underlaytechnique: Overlay vs Underlay technique Meta-analysis showed that both techniques have similar success rates Onlay: adjacent structures at risk, or if the underlay is not possible


Technique of closure: Technique of closure Muscle, fascia, fat, cartilage, etc.. The success rate is significantly higher for those patients who undergo primary closure with a multi-layer technique versus those patients who only get single-layer closure. Refractory cases may require closure of the EAC and obliteration.


Facial Nerve Injuries: Facial Nerve Injuries Loss of forehead wrinkles Bell’s Phenomenon Nasal tip pointing away Flattened Nasofacial groove


Facial Nerve Anatomy: Facial Nerve Anatomy


Facial Nerve Injuries: Facial Nerve Injuries Initial Evaluation is the most important prognostic factor Previous status Time Onset and progression Complete vs. Incomplete


House Brackman Scale: House Brackman Scale


Electrophysiologic Testing: Electrophysiologic Testing NET: Nerve Excitability Test MST: Maximal Stimulation Test ENoG: Electroneurography Goal is to determine whether the lesion is partial or complete? Neuropraxia: Transient block of axoplasmic flow ( no neural atrophy/damage) Axonotmesis: damage to nerve axon with preservation of the epineurium (regrowth) Neurotmesis: Complete disruption of the nerve ( no chance of organized regrowth)


Nerve Excitability TestMaximal Stimulation Test: Nerve Excitability Test Maximal Stimulation Test Stimulating electrodes are placed and a gross movement is recorded Not as objective and reliable andgt;3.5mA difference suggests a poor prognosis for return of facial function. Correlates with andgt;90% degeneration on ENoG


Electroneuronography: Electroneuronography Most accurate, qualitative measurement Sensing electrodes are placed, a voluntary response is recorded Accurate after 3 days Requires an intact side to compare to Reduction of andgt;90% amplitude correlates with a poor prognosis for spontaneous recovery


Electromyography: Electromyography Electrode is placed within the muscle and voluntary movement is attempted. Normal Muscle is electrically silent. After 10-14 days, the denervated muscle begins to spontaneously fire: Diphasic/Polyphasic potentials: Good Loss of voluntary potentials: Bad


Facial Nerve InjuriesWHO GETS TREATMENT?: Facial Nerve Injuries WHO GETS TREATMENT? Conservative treatment candidates Surgical treatment candidates


Facial Nerve Injuries: Facial Nerve Injuries Chang andamp; Cass Medline search back to 1966 Individually reviewed each article 1) Understand the pathophysiology of facial nerve damage in temporal bone trauma. 2) What is the effect of surgical intervention on the ultimate outcome of the facial nerve. 3) Propose a rational course for evaluation and treatment.


Facial Nerve InjuriesChang & Cass: Facial Nerve Injuries Chang andamp; Cass Pathophysiology based on findings by Fisch and Lambert and Brackmann: Where? Perigeniculate, Labyrinthine, and meatal segments Concern over findings of endoneural fibrosis and neural atrophy proximal to the lesions In an untreated human specimen found intraneural edema and demyelinization that extended proximally to the meatal foramen How? Longitudinal Fractures 15% transection 33% bony impingement, 43% hematoma Transverse Fractures 92% transection


Does Facial Nerve decompression result in superior functional outcomes compared with no treatment?: Does Facial Nerve decompression result in superior functional outcomes compared with no treatment? Not enough human data! Boyle-monkey: prophylactic epineural decompression in complete paralysis did not improve recovery of facial nerve function after induced complete paralysis Kartush: Prophylactic decompression of the meatal segment during acoustic neuroma decreased the incidence of delayed paralysis Adour: compared patients with complete paralysis found: Equal outcome with observation vs. decompression without nerve slitting Worse outcome with decompression with nerve slitting


Does Facial Nerve decompression result in superior functional outcomes compared with no treatment?: Does Facial Nerve decompression result in superior functional outcomes compared with no treatment? Many difficulties in Study designs, controls, etc, but they made some rough estimates: 50% of patients who undergo facial nerve decompression obtain excellent outcomes The true efficacy of facial nerve decompression surgery for trauma remains uncertain


Conservative Treatment Candidates: Conservative Treatment Candidates Chang and Cass Present with Normal Facial Function regardless of progression Incomplete paralysis and no progression to complete paralysis Less than 95% degeneration by ENoG Most data comes from Bell’s palsy/tumor studies by Fisch.


Conservative Treatment Candidates: Conservative Treatment Candidates Brodie and Thompson All patients that presented with normal facial nerve function initially that progressed to complete paralysis recovered to a HB 1 or 2.


Surgical Candidates : Surgical Candidates Critical Prognostic factors Immediate vs. Delayed Complete vs. Incomplete paralysis ENoG criteria


Algorithm for Facial Nerve Injury: Algorithm for Facial Nerve Injury


Facial Nerve InjuriesChang & Cass: Facial Nerve Injuries Chang andamp; Cass What time frame is best to operate? Fisch-cats: Decompression of the nerve within a 12 day period resulted in 'excellent' functional recovery. Presumption was that it preserved endoneural tubules. (limits the damage to axonotmesis at worst) Limits the accuracy of your patient selection because EMG is not reliable until day 10-14.


Surgical Approach: Surgical Approach Medial to the Geniculate Ganglion No useful hearing Transmastoid-translabyrinthine Intact hearing Transmastoid-trans-epitympanic Middle Cranial Fossa Lateral to Geniculate Ganglion Transmastoid


Surgical Approach: Surgical Approach Chang andamp; Cass Histopathologic study Severe facial nerve injury results in retrograde axonal degeneration to the level of the labyrinthine and probably meatal segments


Surgical findings of greater than 50% nerve transection/damage: Surgical findings of greater than 50% nerve transection/damage Nerve repair via primary anastamosis or cable graft repair HB 1 or 2: 0% HB 3 or 4: 82% HB 5 or 6: 18%


Iatrogenic Facial Nerve Injuries: Iatrogenic Facial Nerve Injuries Mastoidectomy (55%) Tympanoplasty (14%) Bony Exostoses (14%) Lower tympanic segment is the most common location injury 79% were not identified at the time of surgery


Management of Iatrogenic Facial Nerve Injuries: Management of Iatrogenic Facial Nerve Injuries Green, et al. andlt;50% damage: perform decompression 75% had HB of 3 or better! andgt;50% damage: perform nerve repair No patients had better than a HB 3 Beware of local anesthetics General consensus: acute, complete, postoperative paralysis should be explored as soon as possible.


Emergencies: Emergencies Brain Herniation Massive Hemorrhage Pack the EAC Carotid arteriography with embolization


Bibliography: Bibliography Bailey, Byron J., ed. Head and Neck surgery- Otolaryngology. Philadelphia, P.A. J.B. Lippincott Co., 1993. Brodie, HA, Thompson TC. Management of Complications from 820 Temporal Bone Fractures. American Journal of Otology; 18: 188-197, 1997. Brodie HA, Prophylactic Antibiotic for Posttraumatic CSF Fistulas. Arch of Otolaryngology- Head and Neck Surgery; 123; 749-752, 1997. Black, et al. Surgical Management of Perilymphatic Fistulas: A Portland experience. American Journal of Otology; 3: 254-261, 1992. Chang CY, Cass SP. Management of Facial Nerve Injury Due to Temporal Bone Trauma. The American Journal of Otology; 20: 96-114, 1999. Coker N, Traumatic Intratemporal Facial Nerve Injuries: Management Rationale for Preservation of Function. Otolaryngology- Head and Neck Surgery; 97:262-269, 1987. Green, JD. Surgical Management of Iatrogenic Facial Nerve Injuries. Otolaryngolgoy- Head and Neck Surgery; 111; 606-610, 1994. Lambert PR, Brackman DE. Facial Paralysis in Longitudinal Temporal Bone Fractures : A Review of 26 cases. Laryngoscope; 94:1022-1026, 1984. Lee D, Honrado C, Har-El G. Pediatric Temporal Bone Fractures. Laryngoscope: vol 108(6). June 1998, p816-821. Mckennan KX, Chole RA. Facial Paralysis in Temporal Bone Trauma. American Journal of Otology; 13: 354-261, 1982. Savva A, Taylor M, Beatty C. Management of Cerebrospinal Fluid Leaks involving the Temporal Bone: Report on 92 Patients. Laryngoscope: vol 113(1). January 2003, p50-56 Thaler E, Bruney F, Kennedy D, et al. Use of an Electronic Nose to Distinguish Cerebrospinal Fluid from Serum. Archives of Otolaryngology; vol 126(1). Jan 2000, p71-74.