Continuous intracisternal and high cervical intrathecal bupivacaine analgesia in refractory head and neck pain.

BACKGROUND

The upper cervical component of the spinomesencephalic tract and cranial nerves V, VII (nervus intermedius), IX, and X are involved in mechanisms of acute and chronic pain from head and neck structures. To date there is no reliable method for relief of refractory pain (i.e., pain that cannot be relieved by conventional pharmacologic therapies) from these structures. Therefore, we explored continuous intracisternal infusion of bupivacaine for the treatment of refractory pain of the head and neck.

METHODS

Intracisternal catheters were inserted in 13 adults with refractory nonmalignant (n = 4) and malignant (n = 9) pain from the head, face, mouth, neck, and upper extremities; 0.5% plain bupivacaine was infused continuously at rates of 1-7 (median 1.5) mg/h with optional bolus doses of 0.5-2.0 mg 4-2 times/h. The efficacy was assessed from pain relief (daily VAS(max), VAS(min), and VAS(mean) scores 0-10), daily doses of intracisternal bupivacaine and total opioid (expressed as mg parenteral morphine-eq), amount of nocturnal sleep, and rates of adverse effects.

RESULTS

The 13 patients were treated for 3-182 days (median 37, total 712 days), 3 patients being treated at home for 10-112 days (median 88, total 210 days). In one patient, the efficacy of the treatment could not be estimated because of advanced senility. Eleven of the remaining 12 patients obtained acceptable pain relief with daily doses of intracisternal bupivacaine ranging from 20 to 118 mg (median 37 mg): VAS(mean) scores decreased from 7 to 2, mean pain relief increased for 30% to 80%, total opioid daily dose decreased from 53 to 36 mg parenteral morphine-eq, and nocturnal sleep increased from 2 to >6h (all figures are median values). Speech, eating, walking, and natural functions were generally not affected. Side effects such as tiredness and malaise, somnolence and sleep, feeling of coldness in the neck and skull base, transient post-spinal puncture headache, paresthesias, hoarseness, dysphagia, transient paresis of the upper/lower extremities, episodic miosis and conjunctival hyperemia, and transient orthostatic arterial hypotension were each observed in one or two patients. No patient presented clinical evidence of phrenic nerve paralysis. There was no nausea or vomiting. No persistent neurologic deficit or death could be attributed to the intracisternal pain treatment.

CONCLUSIONS

Continuous intracisternal infusion of bupivacaine may be a useful method in exceptional, well selected patients with refractory pain from the head and neck structures. Further studies are necessary to establish the indications and the safety of the method.