View
257
Download
3
Category
Preview:
Citation preview
Trigeminal Neuralgia
By, Meera Ramesh
TIC DOULOUREUXFOTHERGILLS DISEASESUICIDE DISEASE
OCTOBER 7TH
INTRODUCTION
Disorder characterized by lancinating attacks of severe facial pain
Epidemiology and DemographicsEpidemiology and Demographics
- Incidence of approx 4 in 100,000
- Majority of cases occur spontaneously
- Slight female predominance
- Over age 50
Age of Onset
0
5
10
15
20
25
30
2nd 3rd 4th 5th 6th 7th 8th 9thDecade
More than 70% of patients with TN are over 50 years of age at the time onset
- 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.
Trigeminal Nerve Anatomy
Distribution of Pain by Division32
17 17 15 14
40.4
0
5
10
15
20
25
30
35
Percent
V2,3 V2 V1,2,3 V3 V1,2 V1 V1,3Trigeminal Division
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.
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.”
Trigger zones……
Etiology and Pathogenesis
• Dental pathosis• Excessive traction• Allergic• Ischemia• Mechanical trauma like aneurysms• Compression distortion phenomenon• Anomalies of superior cerebellar artery• Secondary lesion
Clinical Presentation andPhysical Findings
Diagnosis of TN based on distinctive signs & symptoms.
Consists of 5 major clinical features that define the diagnosis of TN
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.
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 stabbing2. 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.
Diagnosis of Trigeminal NeuralgiaALL FACIAL PAIN IS NOT TRIGEMINAL NEURALGIA!
Diagnostic testingDiagnostic testing Diagnostic brain imaging to Diagnostic brain imaging to
visualize anatomic visualize anatomic landmark around trigeminal landmark around trigeminal ganglion and CPAganglion and CPA
CT, MRI – to rule out CPA CT, MRI – to rule out CPA lesions and to visualize lesions and to visualize subtle vascular anomalies subtle vascular anomalies causing compressioncausing compression
Imaging in Trigeminal NeuralgiaIn 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
Right Trigeminal Nerve
Compressing vessel
Right Trigeminal Nerve
Compressing vessel
Pharmacological TreatmentAEDs– Tegretol (carbamazepine)
gold standard– Tripeptal (oxcarbazepine)– Dilantin (phenytoin)– Neurontin (gabapentin)– Lyrica (pregabalin)– Lamictal (lamotrigene)– Topamax (topirimate)– Gabatril (tiagabine)– Keppra (levateracitam)
TCAs– Elavil (amitriptyline)– Pamelor (nortriptyline)– Desipramine (norpramin)
Baclofen (lioresal)
Opioids
Adverse Effects of AEDs
Cognitive changesSedationNystagmus, ataxia, diplopia, dizzinessNausea, vomiting, headacheAllergic reaction – Up to 7% with CBZ– Some cross-reactivity between CBZ
and PHT
Surgical Treatment of TNMicrovascular decompression (MVD)Percutaneous ablative procedures– Radiofrequency thermal lesioning– Glycerol injection– Balloon compression
Stereotactic radiosurgery– Gamma knife– Linac-based
Peripheral ablative procedures (V1 and V2 pain)– Peripheral branch neurectomy– Alcohol neurolysis
Open destructive procedures– Partial sensory rhizotomy– Subtemporal ganglionectomy (Frazier-Spiller procedure)
Advantages of MVDONLY non-destructive procedure.Low risk of facial sensory loss.ONLY operation that addresses vascular compression
Disadvantages of MVD
Requires major surgery
MVD is generally associated with more risks than percutaneous procedures or radiosurgery like CSF leak
More costly
Surgical TechniquePositioningSkin IncisionRetromastoid craniectomyT-shaped dural opening
Surgical TechniqueExposure of CPAVisualization 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
Operative FindingsArterial compression– Superior cerebellar artery
(SCA) – most common– AICA– PICA– Vertebrobasilar artery
Venous compression– More common with atypical
TN
Combined arterial and venous compression
Operative Findings
Complications of MVDCerebellar injury <1%Infectious complications– Bacterial meningitis– Aseptic meningitis
CSF leak 0-4%Cranial nerve deficits– Diplopia– Sensory loss or dysesthesias 0.5-17%– Facial weakness 0.5-15%– Hearing loss <1 (0-19%)
StrokeMortality < 1%
Outcome Following Initial MVD(N=1204 patients)
0102030405060708090
Initial 1 yr 10 yrs
Excellent Partial Failure
Barker F, Jannetta P, Bissonette D, et.al.: NEJM, 1996
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 MVDLower success ratesFindings: New compressive vessel.Higher incidence of perioperative morbidity– Increased risk of cranial nerve palsy– Increased incidence of facial numbness (8%)
and/or facial dysesthesias
Percutaneous Procedures
Radiofrequency thermal lesioning
Glycerol injection
Balloon compression
Radiofrequency Lesioning
Glycerol Injection
Contrast in trigeminal cistern Contrast under temporal lobe
Balloon Compression
Radiosurgery for TN
Decision-Making in TNWhen 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
THANK YOU
Recommended