Questions and Best Answers

Courses


Tag

INTRATEMPORAL COURSE OF FACIAL NERVE:     

  From internal acoustic meatus to stylomastoid foramen.

     A) MEATAL SEGMENT:  a. 8-10 mm.

          b. Within internal acoustic meatus.

     B) LABYRINTH SEGMENT:  a. 4 mm.

          b. From fundus of meatus to geniculate ganglion, where nerves takes a turn posteriorly forming “Genu”.

     C) TYMPANIC OR HORIZONTAL SEGMENT:  a. 11 mm.

          b. From Geniculate ganglion to just above the pyramidal eminence.

          c. Lies above oval window & below lateral semicircular canal.

     D) MASTOID OR VERTICAL SEGMENT:  a. 13 mm.

          b. From Pyramid to Stylomastoid foramen.

          c. Between Tympanic & mastoid segments is the 2nd Genu of nerve.

DESCRIBE THE RELEVENT TOPO DIAGNOSTIC TESTS:

These tests are useful in finding the site of lesion in paralysis of LMN.

  1. SCHIRMER TEST: It compares lacrimation of two sides.

A strip of filter paper is hooked in the lower fornix of each eye & amount of wetting of strip measured.

Decrease Lacrimation- Lesion proximal to geniculate ganglion as secretomotor fibres to lacrimal gland leave at the geniculate ganglion via greater superficial petrosal nerve.

  1. STAPEDIAL REFLEX: Lost in lesion above the nerve to stapedius.

Tested by tympanometry.

  1. TASTE TEST: Measured by a drop of salt or sugar solution placed on one side of the protruded tongue or by electro gustometry.

Impairment of taste- lesion above the Chorda Tympani.

  1. SUBMANDIBULAR SALIVARY FLOW TASTE: Measures functions of Chorda Tympani.

Polythene tubes are passed into both Whartan Ducts & drops of saliva counted during one minute period.

Decrease Salivation- Injury above Chorda Tympani.

;