Nerve Facial Palsy Tester Procedure

Traumatic head injury with facial palsy

Bismillahirhmanirahim

Introduction

·         Incidence of cranial nerve injury among head trauma patients ranges between 5 and 23 percent

·         The CNI (olfactory nerve), CNVII (facial nerve), and CNVIII (acoustic nerve) cranial nerves are the ones most frequently affected.

·         The facial nerve (CN VII) :most commonly damaged motor cranial nerve. [6]

·         Lower motor neuron facial palsy type.

Facial nerve (CNVII)

·         Primary motor cortex (above parietal lobe).

·         Emerges from brainstem between pons and medulla

·         Existing from stylomastoid foramen

·         Enters the parotid gland.

·         Two main divisions.

Traumatic injuries to the facial nerve

·         By site:

o   Extracranial

o   Intratemporal

o   Intracranial

·         By type of trauma:

o   Penetrating

o   Non-penetrating

o   Iatrogenic

Extracranial facial nerve injury

·         Injured at any point after its exit from temporal bone at the stylomastoid foramen.

·         Causes:

o   Laceration

o   stab wounds

o   gunshots

o   soft tissue avulsion

o   contusion

·         Temporal division:

o   Protect cornea from eyelid weakness

·         Mandibular division:

o   Prevent drooling resulting from lower lip weakness

o   If primary repair is not possible in first 3 days, the optimal time for repair may be at 21 days after injury

Intratemporal facial nerve injury

·         Disrupting

o   bony

o   membranous labyrinth

o   the inner ear

o   facial nerve

·         Non-penetrating injury

o   Transverse fracture (hearing loss)(20%)

o   Longitudinal fracture(50%)

o   Mixed fracture

·         Penetrating injury

o   Gunshot or stab wound

o   Suspicion of vascular injury of sigmoid or lateral sinus, jugular vein or carotid system.

·         Most commonly occurs during

o   Resection of an acoustic neuroma

o   Tumor of the cerebellopontine angle (CPA)

o   Iatrogenic

Facial Nerve lesion

·         Forehead muscle function receives bilateral innervations from the motor cortex

·         Lower face receives contralateral innervation from the motor cortex

Distinguish level of Facial Nerve lesion

·         Upper Motor Neuron (UMN) /Central type

o   Paresis over contralateral side, lower part of face.

o   Unless bilateral lesion, does not affect forehead

o   Mouth paralysis is overcome by emotional expression

·         Lower Motor Neuron (LMN) /peripheral type

o   Paresis over ipsilateral forehead and lower face

o   Bell’s palsy

Facial Motor Exam

·         Forehead and Upper lid innervations

o   Eyebrow elevation

§  Occipitofrontalis, frontalis part

o   Bridge of the nose wrinkling

§  Procerus

o   Frowning

§  Corrugator supercilii

o   Tight Closing of the eyes

§  Orbicularis oculi

·         Lower Face innervations

o   Lip closing

§  Orbicularis oris

o   Cheek compression

§   Buccinator

o   Natural smile

§  Levator anguli oris

·         General grading procedures:

o   F: functional; appears normal or only slight    impairment

o   WF: weak functional; moderate impairment that  

·         affects the degree of active motion

o   NF: nonfunctional; severe impairment

o   0: Absent

wallahuaklam...