PARALISIA FACIAL PERIFÉRICA Prof. Dr. Ricardo F. Bento Professor Titular de Otorrinolaringologia Faculdade de Medicina da U.S.P.

VII PAR CRANIANO NERVO MISTO - 80% motor Funções fisiológicas

Fisiopatologia

Fisiopatologia da lesão NEUROPRAXIA AXONIOTMESE NEUROTMESE The temporal bone because of it’s particularities and complexity presents one rich pathophysiology that it’s very important in the knowledge of the diagnosis and treatment of the lesions

DIAGNÓSTICO Paralisia Central/Periférica Etiologia Topodiagnóstico Grau de Lesão do Nervo

Anamnese/ Exame físico

Topodiagnóstico

Exames Audiológicos Audiometria Tonal Impedânciometria

Electroneurography

Classificação IDIOPÁTICAS TRAUMÁTICAS INFECCIOSAS TUMORAIS METABÓLICAS CONGÊNITAS VASCULARES TÓXICAS

Idiopáticas Paralisia de Bell Síndrome de Melkerson-Rosenthal

TRATAMENTO Clínico: De 0 a 5 dias- Aciclovir: 30 mg/kg/d (3x/dia) Dexametazona: 8 mg/dia Fisioterapia Descompressão Cirúrgica

Traumáticas Fraturas Projéteis de arma de fogo Ferimentos Cortocontusos Traumas de Parto Iatrogênicas

Fisiopatologia / Fraturas Fratura Longitudinal ou Extralabiríntica 70 a 80 % das fraturas Causadas por impactos laterais (temporoparietais) A onda de fratura rompe a porção escamosa As previously said, the temporal bone is rich in vital internal and external structures. It is a compact bone that presents structures of different density; for example, the labyrinthic block is extremely hard. It contributes to common fracture lines and gunshot routes, as we will see ahead. First, let’s address the fracture mechanism of each type of fracturesd of the petrous bone: Longitudinal or extralabyrinthic fractures Amount to 70 to 80% of the fractures. They are caused by lateral impact (temporoparietal) and the wave of shock that spares the labyrinthic block (owing to its hardness) breaks the vertical squamous portion and the fracture curve follows the anterior cavity wall.

FRATURA LONGITUDINAL There may be three longitudinal fracture lines:

Fisiopatologia / Fraturas Transversal ou Translabiríntica 10 a 20 % das fraturas Impacto vertical ou occipital A onda de choque passa pelo foramem jugular extendendo-se anteriormente afetando a face interna do osso petroso. The transversal or translabyrinthic fractures amount to 10 to 20% of the fractures. They are caused by occipital or vertex impact,. The facial nerve is more frequently affected (60% of the cases) at two different levels:

FRATURA TRANSVERSAL The fracture wave causing a shock wave that comes from the occipital base and crosses the jugular foramen, extending anteriorly and exteriorly, and they affect the posterior-internal aspect of the petrous bone, normally rupturing the bone labyrinth at the level of the posterior semicircular canal and the vestibular aqueduct. The inner ear canal and the cochlea can also be damaged if the fracture line is further anteriorly.

Lesõs por arma de fogo Fisiopatologia FIREARM BULLETS Gunshots are normally very harmful and sometimes mortal, depending on caliber, distance of the gun from the impact site and point of entry. Bullets at close range, long distance or entering through the external auditory canal and mastoid are less mortal. If shot from short and middle distance, they are normally fatal if the caliber is 38 or greater. In addition to facial nerve direct lesions, there are affections on the labyrinthic block and vascular structures. The most common sites where the fragmented bullets are found are the mastoid tip and the stylomastoid foramen. The presence of the labyrinth in the center and top of the temporal bone, impeding the bullet's progression in the original direction and causing it to deviate to a more complacent region. The bullet's impact causes severe bone destruction and the burn lesion causes great loss of nerve tissue that often spreads through the reminiscent nerve.

Infecciosas Virais (Síndrome de Ramsay-Hunt) Bacterianas Inespecíficas (Otites) Bacterianas Específicas (Lyme, Lues, Tb)

Tumores Intrinsecos Extrinsecos

Congênitas

Tratamento Cirúrgico Precoce Descompressões Anastomoses do N. facial Anastomoses com outros nervos Cross Face

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enxerto

Hipoglosso Facial