Dr.Dinesh.M.G Professor of Surgery J.J.M.M.C Davangere

1. Dr. Dinesh. M.G
Professor of Surgery
J.J.M.M.C.
Davangere

2. Nerve injuries
Histology of peripheral nerve

3. Nerve injury and regeneration
Seddon classification based on extent of damage to the
nerve fibre and sheath
 Neurapraxia
 Axons are not disrupted and nerve sheath is intact
 Nerve conductivity is temporarily lost
 Recovery is complete
 Axonotmesis
 Axons are disrupted and nerve sheath is intact
 Near complete recovery taking a longer time
 Neurotmesis
 Nerve is completely divided (axons and sheath)
 Partial recovery if nerve ends are approximated

4. Nerve injury and regeneration:
Axonotmesis

5. Nerve injury and Regeneration:
Axonotmesis
1. Wallerian degeneration
 Axon and myelin sheath distal
to injury break down.
2. Phagocytosis
 Macrophages clean out dead
axon. Surviving Schwann cells
proliferate and release factors
to stimulate axonal growth
3. Axon sprouting
 Schwann cells form
regeneration tube. Axon
sprouts multiple filaments.
4. When one filament contacts
target, the rest die off.
Connecting filament grows,
new myelin sheath forms.
Tinel’s sign is elicited at the site of
regeneration of axons

6. Nerve injury and regeneration:
Neurotmesis
 Neuromas

7. Nerve suturing
 Epineural repair
 Fascicular repair

8. Nerve grafting

9. Facial nerve palsy
Surgical anatomy
 Supplies mainly motor
fibres to muscles of facial
expression
 Chorda tympani branch
carries taste sensation
from anterior 2/3 of
tongue
 Upper facial muscles have
bilateral representation
from both hemispheres

10. Facial nerve palsy
Causes of facial nerve paralysis
 Upper motor neuron lesion
 Cerebrovascular accidents
 Tumours
 Infection
 Lower motor neuron lesions
 Fracture base of skull
 Malignant parotid tumour/ parotid gland surgery
 Otitis media
 Bell’s palsy
 Facial trauma
 Herpes zoster infection

11. Facial nerve palsy
 In LMN palsy
 No wrinkling of forehead
 Can not close eyes
 Flattened nasolabial fold
and drooping of angle of
mouth
 Deviation of angle of
mouth to the opposite side
 In UMN palsy
 Preservation of eye
closure and forehead
wrinkling

12. Bell’s palsy
 Acute paralysis of facial nerve related to inflammation &
swelling of facial nerve in facial canal
 Mostly unilateral
 May occur repeatedly
 May be associated with viral infection
Investigations
CT / MRI head to rule out intracranial lesions

13. Facial nerve palsy
Treatment
Medical management
 Prednisolone in high doses
 Antiviral drug(Acyclovir) if viral infection is suspected
Surgical management
 Lateral tarsorrhaphy to prevent exposure keratitis
 Primary repair of nerve
 Using a nerve graft from sural or great auricular nerve
 Nerve transfer of hypoglossal to facial nerve

14. Facial nerve palsy
Surgical treatment
Plastic surgery to improve resting state of face
 Face lift operation
 Insertion of slings of fascia lata
 Transplanting the insertion of temporalis muscle from
mandible to cheek to support the corner of mouth

15. Trigeminal neuralgia
(Tic Douloureux)
Anatomy

16. Trigeminal neuralgia
(Tic Douloureux)

17. Trigeminal neuralgia
(Tic Douloureux)
 Characterised by intermittent attacks of severe, sharp,
stabbing pain affecting the II and III division of
trigeminal nerve while I division(ophthalmic) is mostly
spared
 Seen in middle aged or elderly females
 Precipitated by
 Exposure to cold
 Chewing
 Brushing teeth
 Talking
 Touching specific points on face(trigger zones)

18. Trigeminal neuralgia
(Tic Douloureux)
 Aetiology not known in most cases
 Ectatic vascular loops are found to compress trigeminal nerve
in few cases
 Sometimes due to cerebello-pontine lesion(acoustic neuroma)
Investigations
 MRI to exclude cerebello-pontine lesions

19. Trigeminal neuralgia
(Tic Douloureux)
Treatment
Drug therapy
 Carbamazepine ( 600-1600
mg/day)
Operative treatment
 Trigeminal ganglion alcohol
injection
 Radiofrequency ablation of
trigeminal ganglion
 Trigeminal root section
 Microvascular
decompression of trigeminal
nerve root in the posterior
fossa

20. Thank you