Functional Flashcards
Trigeminal Neuralgia Types
Burchiel Classification
Type I - more than 50% sharp and stabbing pain, with pain free intervals (better prognosis)
Type II - more than 50% constant and burning type pain
Trigeminal Neuralgia Facts
Commonly V2 and V3
Tx CARBAMAZEPINE first line
80% get relief with meds
by 16 yrs only 50% still have relief
lots of side effects
Phenytoin for acute attack
Baclofen may be adjunctive medication with AED
Trigeminal Neuralgia Ablative Options
Radiofrequency Rhizotomy – 55 to 80 deg C
97% have immediate pain relief and numbness
60 mos (5y) 57%
180 mos (15y) 42%
Balloon Rhizotomy
Glycerol Rhizotomy
Radiosurgery Target TN 3 to 8 mm ant to pons 70 to 90 Gy latency to pain relief about 1 month 12 mos 75% pain free 5 years 41% 10 years 25%
MVD Facts
Best for Type I TN (classical TN)
Greater Longevity and lower incidence of facial numbness and anesthesia dolorosa than other treatments
Lateral or 3q Prone
BAER
Retrosig approach
- take off CSF, coagulate vein (petrosal)
- find CN VII and VIII, then work rostrally
- place felt to pad the nerve from vascular structures
One study with 8 year follow up had 80% pain free rate
Trigeminal Neuralgia PEARLS
Classic TN respons to treatment with carbamazepine but side effects may be intolerable, particularly as disease progresses
MVD is the most durable surgical therapy, one risk is hearing loss or CN injury
Percutaneous procedurs and SRS can be considered for patients who cannot tolerate MVD
Nociceptive Pain
Pain caused by direct tissue damage
broken bone
burn
etc
this is a PROTECTIVE function, alerting us to danger
Neuropathic Pain
Pain from damage to the NERVOUS SYSTEM
No apparent functional benefit
Describe burning, tingling, shooting, crawling types of pain, as well as allodynia (perception of an ordinary stimulus as painful)
Phantom Limb Pain MS Related Pain Post Stroke Pain Brachial Plexus Avulsion injury Spinal Cord Injury Parkinson Pain
Dorsal Root Entry Zone Lesion (DREZ)
For ROOT AVULSION INJURIES
Can do open or percutaneous
- Open, midline, do lami, open dura
- inspect cord for area of nerve root avulsion
Can do DREZ with knife/bipolar OR a RFL probe
RFL probe set to 75 deg C for 15-20 seconds
- insert about 2mm into cord, in line with the sensory rootlets, about 1 to 1.5 mm apart.
- typical case requires 40 to 60 lesions
- angle probe about 30deg inward
Cordotomy
Tx of Unilateral Cancer Pain
Involves cutting the lateral Spinothalamic Tract
Open or Percutaneous
- Common technique now is percutaneous at C1-2
- Spinal needle, get CSF, do pyelogram to see cord and DENTATE LIGMENT (key landmark)
- cordotomy probe then put in through the spinal needle
- can stimulate before lesioning
Myelotomy
Tx of VISCERAL CANCER PAIN
best for intractable visceral pain in the pelvic or abdominal region
Punctate midline myelotomy (PMM)
- RFL lesions in the poster midline to disrupt the midline posterior column visceral pathway
Complications…
paresthesias
bowel and bladder issues
Cingulotomy
Has been tried for numerous pain syndromes and OCD.
Now most useful for RARE patients who have severe pain that has no other treatment option, such as thalamic infarct (Dejerine Roussy syndrome) or post stroke pain.
Done with stereotactic lesioning of the cingulate gyrus.
- entry 9.5 cm above nasion, 1.5 cm off midline.
- electrode placed into cingulate (STEALTH) with tip 5mm above roof of lateral ventricle and 5mm lateral to midline.
- lesion 80 deg C for 2 minutes for each side
72% improved pain
Complications…
aphasia, hemiparesis, hemorrhage, incontinence, confusion
Spinal Cord Stimulator Indications
Failed Back Syndrome Complex Regional Pain Syndrome Type I (CRPS1) PVD with limb ischemia pain Spinal Stenosis Some Neuropathic Pain Syndromes
Generally T8-T10 for FBSS related Pain
Spinal Cord Stimulator Outcomes
PROCESS TRIAL
RCT of SCS and Typical pain mgmt
52 SCS, 48 medical mgmt
of 52… 17% did not have a successful trial and thus were not implanted
- successful trial is >80% paresthesia coverage and/or 50% or more leg pain relief
For pets who got SCS…
at 12 mos,, 48% had good relief (>50% reduction in leg pain)
and only 18% had good relief in medical group
Compared to conventional mgmt, SCS can improve pain relief and QOL, functional capacity, and patient satisfaction
SCS Pearls
SCS is efficacious for FBSS, refractory angina pectoris, CRPS1, and peripheral vascular dz with leg ischemia
All patients need MRI (rule out surgical pathology) as well as NEUROPSYCH evaluation
Preop MRI, removal of the spinous process below the level of the laminotomy, and dissection under the lamina with the Woodson prior to lead placement help reduce the risks of surgery
Baclofen Withdrawal Sx
Itchy
Bitchy
Twitchy
Hallmarks of WD are diaphoresis, pruritus, hyperthermia, hypo or hypertension, seizures.
