Pain Flashcards
A 37-year-old gentleman is experiencing severe pain in his left arm following a motorcycle accident in which he suffered traumatic brachial plexus avulsion. Now two years later, the patients continues to have a flail arm with no evidence of return of function. Medical therapy has failed to relieve his symptoms. Which of the following is the BEST treatment for this patients pain?
A. Lesion of dorsal root entry zone
B. Neurotization of denervated segments
C. Neurectomy at affected segments
D. Implant spinal cord stimulator
E. Implant morphine pump
A. Lesion of dorsal root entry zone
Dorsal root entry zone lesion successfully treats brachial plexus avultion pain 50-70% of cases in the long term. It is one of the few ablative procedures with long term benefit in nonmalignant pain. It should be reserved for patients who do not have any evidence of recovery of function ove rthe long term. Neurotization procedures are unlikely to add any benefit at this late stage. In addition, they would not treat the patients pain and are reserved for restoration to useful function. Similarly, neurotization surgery does not addres the source of the pain which appears to be in the dorsal rootentry zone. Intrathecal morphine does not offer any benefit, as pain of this type tends to be unresponsive to opiates. Electrical stimulation is also unlikely to work, as it requires intregity of the nervous system in order to facilitate conduction of the electrical impulses.
A 48 year old man who has undergone five operations on his lumbar spine aftera work-related injury comes to your clinic complaining of severe low back pain. He is taking 300mg/day of oral morphine is on duragesic path. He states that pain relief is inadequate with these medications and that over the last five years his need for these medications has risen dramatically. Which of the following BEST describes this patients behavior?
A. Narcotic addiction
B. Narcotic tolerance
C. Narcotic withdrawl
D. Malingering
B. Narcotic tolerance
Chronic use of oral opioids is almost always associated with tolerance. In some cases, the tolerance may be therapy limiting. However, addiction-or chemical dependence- is defined as phychological depemdence, and should be differentiated from tolerance. Umlike patients exhibiting tolerence to opioids, chemically-dependent patients tipically seek multiple medication from multiple prescribers, and often fail to mantain stable relationships with their physicians. Intrathecal narcotic therapy does not obviate tolerence and certainly does not prevent addiction.
A 56-year-old man present with severe pain in the right arm secondary to extensive invasion of the brachial plexus from a pancoast tumor. His pain extends from the shoulder region and involves the entire arm and hand. Due to his underlying malignancy. His oncologist has estimated his life expectancy to be less than 3 month. Which of the following represent the BEST approach for management of his pain?
A. Spinal cord stimulation
B. C1-2 percutaneous cordotomy
C. Intrathecal opiates
D. Dorsal root entry zone lasion
E. Dorsal rhizotomy
B. C1-2 percutaneous cordotomy
Percutaneous C1-2 cordotomy is an excellent procedure for treatment of cancer pain located at or below the C5 dermatomal level for patients with a limited life expecntacy. Cordotomy often procedures immediate pain relief and often allows significant reduction in oral opiates. An intrathecal pump could be considered, but in a patient with a life expectancy of less than 3 month, there devices are not cost effective. Moreover, there is the requirement for ongoing maintenance and refill of the pump. Spinal cord stimulation is not typically utilized for the management of cancer pain and, in any event, would not be indicated in someone with such a limited life expectancy. Dorsal rhizotomy for cancer pain is limited to cases in which the tumor has not spread into a large area. In order to achieve effective pain relief in the entire upper extremity, a rhizotomy extending from C4 through T3 to T4 would be required, most likely leaving the patients with a non fungsional extremity. DREZ lesioning is not customarily indicated for cancer pain.
Placement of a spinal cord stimulator lead percutaneously has been attempted but failed due to epidural scar formation. In order to treat the patients lower extremity neuropathic pain, you decide to perform a surgical lead placement. The most appropriate level for laminectomy is
A. C1-2
B. T10-11
C. T7-8
D. L2-3
B. T10-11
Placement of spinal cord stimulator for relief of lower extremity pain should be performed over the lumbal enlargement of the spianl cord, which is approximately at the T10-T11 level. This are affords the highest likelihood of stimulating the dorsal aspect of the spinal cord with minimal stimulation of the dorsal root. Stimulating below the tip of the spinal cord is therefore not helpful. Similary, stimulating the spinal cord above the lumbar enlargement is likely to be associated with significant radicular stimulation with minimal dorsal at this site may yield stimulation within the lower extremities as well, it is less pronounced than the stimulation in the arms.
You see a patients in your clinic with complete quadriplegia secondary to spinal cord injury at C6. He is complaining of severe rectal pain. On physical examination, he has compete anesthesia below C7. Which one of the following is the BEST treatment option?
A. Spinal cord stimulation
B. Thoracic cordotomy
C. Deep brain stimulation
D. Amitriptyline and/or carbemazapine
E. Intrathecal morphine pump
D. Amitriptyline and/or carbemazapine
This patients rectal pain is likely a manifestation of his spinal injury. Such pain is poorly responsive to spinal cord stimulation. In addition, intrathecal morphine therapy is unlikely to be successful and should not be tried in the absence of attempts at medical therapy. A surgical cordotomy does not address midline visceral pain. The literature regarding deep brain stimulation for such pain is relatively sparse. Use of antidepressants (such as amitriptyline) and anticonvulsants (such as carbemazapine) is assosiated with some success in treating neurophatic pain syndromes including those assosiated with a complete neurological injury.
