6. Epidemiology and DemographicsEpidemiology and Demographics
- Incidence of approx 4 in
100,000
- Majority of cases occur
spontaneously
- Slight female
predominance
- Over age 50
7. Age of Onset
0
5
10
15
20
25
30
2nd 3rd 4th 5th 6th 7th 8th 9th
Decade
More than 70% of patients with TN are over 50
years of age at the time onset
8. - Pain typically consists of
lancinating paroxysms
- Mostly in Second &
Third trigeminal
divisions
- Right side most often
involved
- Pain attack is
stereotyped
- Symptom free between
attacks
- Lasts for several years if
left untreated.
11. The pain of TN……
- Paroxysmal attacks
- Electric shock like quality
- Sudden onset & severe in
intensity facial grimace
- Duration btw 1 sec and 2 min
- Instantaneous electric shock
sensation that’s over in much
less than a sec – ‘lightning
bolt’
- Symptom free btw attacks.
12. Pain is commonly evoked by stimuli
including washing, shaving, smoking,
talking and/or brushing the teeth
(trigger factors) and frequently occurs
spontaneously. The pains usually remit
for variable periods.”
14. Etiology and Pathogenesis
• Dental pathosis
• Excessive traction
• Allergic
• Ischemia
• Mechanical trauma like aneurysms
• Compression distortion phenomenon
• Anomalies of superior cerebellar artery
• Secondary lesion
15.
16. Clinical Presentation and
Physical Findings
Diagnosis of TN based on
distinctive signs &
symptoms.
Consists of 5 major clinical
features that define the
diagnosis of TN
17. ICHD Criteria for Classical TN (13.1.1)
A. Paroxysmal attacks of pain lasting from a fraction of a
second to 2 minutes, affecting one or more divisions of
the trigeminal nerve and fulfilling criteria B and C
B. Pain has at least one of the following characteristics:
1. intense, sharp, superficial or stabbing
2. precipitated from trigger areas or by trigger factors
C. Attacks are stereotyped in individual patient.
D. There is no clinically evident neurological deficit.
E. Not attribute to another disorder.
18. ICHD Criteria for Symptomatic TN (13.1.2)
A. Paroxysmal attacks of pain lasting from a fraction of a
second to 2 minutes, with or without persistence of aching
between paroxysms, affecting one or more divisions of
trigeminal nerve and fulfilling criteria B and C.
B. Pain has at least one of the following characteristics:
1. Intense, sharp, superficial or stabbing
2. Precipitated from trigger areas or by trigger factors.
C. Attacks are stereotyped in individual patient.
D. A causative lesion, other than vascular compression, has
been demonstrated by special investigations and/or
posterior fossa exploration.
20. Diagnostic testingDiagnostic testing
Diagnostic brain imaging toDiagnostic brain imaging to
visualize anatomicvisualize anatomic
landmark around trigeminallandmark around trigeminal
ganglion and CPAganglion and CPA
CT, MRI – to rule out CPACT, MRI – to rule out CPA
lesions and to visualizelesions and to visualize
subtle vascular anomaliessubtle vascular anomalies
causing compressioncausing compression
21. Imaging in Trigeminal Neuralgia
In patients with types 1 and 2 trigeminal
neuralgia (TN1 and TN2) one can
identify:
– Presence of (NVC)
– Degree of NVC
– Nature
– Location
Findings can be confirmed during MVD
25. Adverse Effects of AEDs
Cognitive changes
Sedation
Nystagmus, ataxia, diplopia,
dizziness
Nausea, vomiting, headache
Allergic reaction
– Up to 7% with CBZ
– Some cross-reactivity between
CBZ and PHT
27. Advantages of MVD
ONLY non-destructive
procedure.
Low risk of facial sensory
loss.
ONLY operation that
addresses vascular
compression
28. Disadvantages of MVD
Requires major surgery
MVD is generally associated
with more risks than
percutaneous procedures or
radiosurgery like CSF leak
More costly
32. Surgical Technique
Exposure of CPA
Visualization of trigeminal nerve
– Visualize the ENTIRE nerve from it’s
exit from the pons to it’s exit laterally
from the CPA
Decompression
– Mobilize and “pad” arteries
– Coagulate and divide veins
33. Operative Findings
Arterial compression
– Superior cerebellar artery
(SCA) – most common
– AICA
– PICA
– Vertebrobasilar artery
Venous compression
– More common with atypical
TN
Combined arterial and
venous compression
37. Repeat MVD for Recurrent TN
All procedures used to initially treat TN
CAN be effective for recurrent TN
Less than 1/3 of patients undergo repeat
MVD
Lower success rates
Findings: New compressive vessel.
Higher incidence of perioperative
morbidity
– Increased risk of cranial nerve palsy
– Increased incidence of facial numbness (8%)
and/or facial dysesthesias
43. Decision-Making in TN
When should surgery be considered?
– Success/failure of medical therapy
– Frequency of recurrences
– Duration of symptoms
Which operation should be done?
– Age and health of patient
– Willingness to except facial sensory
loss
– Previous procedures for TN
– Desires of patient
– Experience of surgeon
