Choice of pain proceduresᵃ
Unilateral pain | Bilateral or midline pain | Bilateral or midline pain | Bilateral or midline pain |
Head, face, neck, UE | Pain at or below C5 dermatome | Below diaphragm | Above diaphragm |
DBS | Cordotomyᵇ | Spinal IT narcotics ⬇️ commissural myelotomy | Intraventricular narcotics |
Stereotactic mesencephalotomy | Cordotomyᵇ | Spinal IT narcotics ⬇️ commissural myelotomy | Intraventricular narcotics |
- ᵃabbreviations: IT = intrathecal; UE or LE = upper or lower extremity
- ᵇcordotomy (open or percutaneous) if pain is unresponsive to or too high for spinal IT narcotics
Techniques for other conditions include:
Electrical stimulation
- DBS:
- Targets include thalamus and periaqueductal or periventricular Gray matter
Direct drug administration into the CNS
- Different routes: CNS narcotic administration
- Spinal
- Epidural or intrathecal
- Intraventricular
- Different agents:
- Local anesthetics
- Narcotics (without motor, sensory, or sympathetic impairment seen with local anesthetics)
Lesioning
- Intracranial ablative procedures:
- Cingulotomy:
- Theoretically reduces the unpleasant affect of pain without eliminating the pain.
- Must be done bilaterally,
- Intolerable pain usually recurs after ≈ 3 mos. 10– 30% develop flattened affect
- Medial thalamotomy:
- No longer used (presented for historical reasons).
- Controversial.
- Was used for some for nociceptive cancer pain.
- Performed stereotactically
- Stereotactic mesencephalotomy
- Indication
- For unilateral head, neck, face, and/or UE pain.
- Use MRI to create lesion 5mm lateral to Sylvian aqueduct at the level of the inferior colliculus.
- Unlike spinal cordotomy, the lesion is not near any motor tracts.
- Main complication is diplopia due to interference with vertical eye movement, often transient
- Spinal ablative surgical procedures
- Cordotomy:
- Open
- Percutaneous
- Cordectomy
- Commissural myelotomy: for bilateral pain
- Punctate midline myelotomy: for relief of visceral cancer pain
- Dorsal root entry zone lesion
- Dorsal rhizotomy: not useful for large areas of involvement
- Dorsal root ganglionectomy (an extraspinal procedure)
- Sacral cordotomy: for patients with pelvic pain who have colostomy and ileostomy. A ligature is tied around the dural sac below S1 nerve roots
- Sympathectomy:
- Indication
- Causalgia/Complex regional pain syndrome (CRPS)
Peripheral nerve procedures
- Nerve block:
- Neurolytic: injection neurodestructive agents (e.g. phenol or absolute alcohol) on or near the target nerve
- Nonneurolytic: using local anesthetics, sometimes in combination with corticosteroids
- Neurectomy:
- (e.g. intercostal neurectomy for pain due to infiltration of chest wall by malignancy). Performed open or percutaneously with radiofrequency lesion. May sacrifice motor function with mixed nerves
- Peripheral nerve stimulators:
- Rarely discussed
Neuroanatomy and Neuropsychology of Pain
- Reference: Khalid 2017
Surgical approaches for the management of neuropathic pain
Procedure | Description |
DREZ lesions | DREZ lesioning can be thought of as a treatment for pain that is believed to be confined to a unilateral limb. The Lissauer tract is a key pathway that conducts nociceptive information at least two segments above and below the DREZ (hence pain could be arising up to two segments above or below an involved dermatomal segment). If dorsal root fibers are avulsed, as commonly seen in pain associated with brachial or lumbar-sacral plexus trauma anatomy is more difficult and complications more likely. Lesions that inadvertently are placed too far laterally and injure the corticospinal tract, resulting in permanent ipsilateral weakness below the lesion. Alternatively, if lesions deviate too medially from the DREZ, ipsilateral loss of proprioception and light touch may occur due to dorsal column injury |
Anterolateral cordotomy | The spinothalamic tract lies just anterior to the dentate ligament and near the anterolateral surface of the cord, while the corticospinal tract is just posterior. The anterior spinal artery is a significant vascular structure whose midline position must be appreciated and avoided during open transection of the spinothalamic tract. Lesioning the spinothalamic tract removes pain below the level of the lesion, but levels of adequate pain control are several levels below the lesion. Good candidates are patients who experience severe pain that originates from cancer involving the pelvis, leg, hip, and lower trunk. Those with nonmalignant pain syndromes are not ideal due to the recurrence rate of pain within a few years or the emergence of new central neuropathic pain (burning dysesthesia below the level of the lesion). Complications are urinary retention or incontinence, permanent dysesthesia, transient hemiparesis, and respiratory complications (cervical cordotomies). Mirror pain is a unique complication of open thoracic cordotomies in patients with cancer in which a similar pain develops contralaterally within weeks to months after the cordotomy. Other complications that are shared with open dural procedures and laminectomies include possible mechanical spinal instability, CSF leak, and meningitis |
Midline myelotomy (commissurotomy) | In patients with bilateral lower extremity pain and, in particular, with involvement of the pelvis and lower abdominal organs, a single lesion disconnecting the anterior commissure through a lower thoracic approach has been quite effective in relieving severe refractory pain. The typical patient is one with pelvic cancer or sarcoma that invades bilateral structures in the pelvis and lower extremities. Loss of bowel and bladder function, and proprioception with relative preservation of motor function (leg weakness in one third) may be acceptable in this group who may otherwise be bedridden with severe pain. The risks of respiratory and sympathetic damage (fibers located near the central gray matter) in creating a mid to upper cervical midline myelotomy are likely the reasons why this technique has not been used much for upper trunk and arm pain |
Mesencephalic tractotomy | Mesencephalic tractotomy has been successfully used for the treatment of denervation pain, such as central dysesthesia, in the upper extremity, head, or neck. Potential candidates are those who fail medical management, neuromodulation, intrathecal infusions, and thoracic or cervical cordotomy, or those patients whose pain is from structures more superior than what cervical cordotomy can treat. In particular, neuropathic pain from head or neck malignancy could be a potential indication. Patients with chronic nonmalignant pain do not respond well to this technique. It involves a lesion of extralemniscal pathways lateral to the spinothalamic tract and medial lemniscus can result in relief of intractable pain without loss of sensation or dysesthesia |
Cingulotomy | Because the motivational-affective component of pain contributes to the fear, suffering, and anxiety of pain, cingulectomy and cingulotomy were proposed to treat this component of chronic pain. The anterior midcingulate cortex is implicated as an area of overlap between negative affect, pain, and cognitive control based on functional MR imaging and DTI studies. The first open resection of 4 cm of the anterior cingulate gyrus for intractable pain, called cingulectomy. Unilateral and bilateral cingulotomies that affect a larger volume of the cingulate fasciculus were subsequently developed, and more recently stereotactic cingulotomy. Its main benefit has been in malignant pain of the head and neck with associated sensations of respiratory distress, and for the discomfort of chronic dyspnea in a patient with malignant mesothelioma. Patients with significant preexistent mental disease, sociopathic personalities, or advanced age are generally not thought good candidates for cingulotomy |
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