54. Trigeminal nerve (CN V)

Question 1

Function of CN V

Answer 1

Sensation of the face

Facial mus: Mastication

Question 2

Branches and its function

Answer 2

Ophthalmic (V1) (sensory –> afferent limb of corneal reflex)
Maxillary (V2) (sensory)
Mandibular (V3) (sensory/cutaneous & motor)

Question 3

What is trigeminal neuralgia?

Answer 3

Neuropathic disorder/syndrome, characterized by paroxysms of severe pain in the face, triggered by some tactile stimulus

Question 4

Treatment for trigeminal neuralgia

Answer 4

Surgical (percutaneous radiofrequency ablation and microvascular decompression) and medical (carbamazepine and other anticonvulsants)

Question 5

Affected areas w/trigeminal neuralgia

Answer 5

In front of the ear, in eye, lips, scalp, forehead, cheeks, mouth, jaw, side of the face
Any of the branches can be affected; rarely both side, mostly maxillary branch and mandibular

Question 6

Cause of trigeminal neuralgia

Answer 6

Result from compression of the trigeminal nerve root at the cerebellopontine angle. Most often by aberrant vascular loop.

Question 7

Diagnosis of trigeminal neuralgia

Answer 7

No laboratory, electrophysiologic, or radiologic testing is routinely indicated for the diagnosis. Only history and neurologic exam.

Question 8

Neurologic examination

Answer 8

Assess strength of jaw opening & palpate over the masseters bilaterally while jaw clenches.
Assess facial sensation by bilaterally gently touch over the forehead (V1), cheeks (V2) and jaw (V3).
To check the sensation function of cornea, touch with a cotton bud on the cornea, CN VII will demontrate the EFFERENT of the corneal reflex by blinking.