Coexistent Headache and Chronic Pain
Patients presenting with both headache and chronic pain may find that their condition provides a complexity that neither the clinical management of headache nor general management of pain is equipped to handle alone. The practical reality of today’s medicine is that there is little overlap between the two specialties. As a result, the patient may find great difficulty in finding a practice that will commit to the patient’s medical management. On the one hand, a headache specialist/neurology office may lack knowledge about pain literature or common pain complaints, may be uncomfortable with the demand/need of opiates for chronic pain, or may lack the procedures or time for frequent office calls and interactions that a typical pain patient requires. On the other hand, the pain management office may not be knowledgeable about unique headache/ migraine considerations in prescribing medications or find that initial evaluations for chronic pain are complicated by the overlay of headache.
Other concerns include the potential for misdiagnosis when, in actuality, brain disease is present. Yet despite the trepidation that these practitioners may have, patients with coexistent headache and chronic pain are common in the medical office and may be successfully managed. The following discussion provides insights into the variation of presentation and potential treatment modalities.
Chronic Intractable Headache
Every headache clinic has a small percentage of patients who are essentially intractable and are often referred to basic pain management with chronic narcotics as the primary form of treatment. This may include patients with chronic migraine, post-craniotomy patients, trigeminal neuralgia and other more obscure conditions. These are patients who have failed all the usual and customary forms of headache treatment. There is general agreement in the headache literature that opioids rarely conquer the problem of chronic headache entirely as tolerance and analgesic rebound issues intervene. Further, severe headaches may come through baseline chronic analgesic medications and these patients often require some breakthrough medication such as another opioid or a triptan.
There are major differences in opinion regarding the utility of chronic narcotics in these patients. On the downside, for example, Dr. Joel Saper, Director of the Michigan Headache Center, concluded in his long term study of 385 patients on chronic opiates for headache that only 26% had significant benefit after 3-5 years of therapy. About 50% of the 385 patients voluntarily discontinued the medications because of adverse effect or failure to benefit. These numbers, however, don’t negate what benefits the patients might have experienced for some period of time — 1-2 years, perhaps, or even six months. At times, all that physicians can do is offer solace and temporary relief of symptoms no matter what the eventual outcome may be.
On a more favorable note, Dr. Lawrence Robins has described his experience with 67 patients with refractory chronic daily headaches treated with Kadian, a 24 hour morphine preparation, and interviewed after 6 months of therapy with 40 mg a day dosing. 50% of these patients reported moderate to excellent relief after 6 months of therapy, a shorter treatment course than reported by Dr. Saper’s group, but nonetheless a significant patient benefit. Other studies employing methadone and controlled release oxycodone have shown moderate success.
A review of the major textbooks on headache in this area further demonstrates the reluctance by headache clinicians to utilize opioids in the headache patient. This reluctance, however, often fails to differentiate between headache sub-types and may deal with migraine and intractable chronic headache pain on an equal basis. There should be, for example, a completely different attitude toward treatment of the intractable headache following cervical surgery versus the typical common migraine sufferer. It has been recently noted that analgesic rebound — the principal concern over use of opioids — occurs in the migraine population but should not be considered a hazard of other headache types with the possible exception of ‘tension’ headache patients which are commonly comorbid with migraine. Addiction is also prominently mentioned in the majority of headache resources as a major hazard of opioid use when, in fact, that is not a frequent issue in the headache population.
It has been the author’s impression that many headache specialists will refuse to treat if the headache becomes intractable and, instead, send the patient to a pain specialist or pain clinic, where they will inevitably be treated with an opioid. The unwillingness to treat the intractable headache patient does not justify a lack of treatment for the pain patient nor negate the utility or necessity of treating these difficult, intractable patients with opioids.
The next most frequent disorder where headache and chronic pain intersect is the cervicogenic headache1 or headaches resulting from some variety of cervical pathology. These headaches are often traumatic or arthritic in origin. The basic cervicogenic headache tends to be posterior, usually one-sided, and triggered by movement or neck positioning with migrainous features being infrequent or minimal. Diagnostic blocks in the cervical region would be another helpful diagnostic clue. As with any variety of headache disorder, however, wide variations in features may occur.
One of the important variations on this theme would be cervical pain-induced migraine or the circumstance in which neck pain acts as the migraine trigger. Traumatic events may produce chronic pain and headache, depending on the pathology involved. Cervical pain and cervicogenic headaches are frequent as are ‘post-traumatic headache’ in general.2 Couch reported 37% of head injuries with cerebral injury and 52% of those with skull fracture developed ongoing headache disorders. Headaches developing in the context of head trauma are as variable as the injuries and the patients. They may take the form of migraine, ‘muscle contraction’, TMJ syndrome or cervicogenic headache. They may be brief or outlast all other apparent injuries. They may persist more than a year and run through all available treatments offered by neurology and headache specialists and yet be unimproved.
The next most frequent disorder where headache and chronic pain intersect is the cervicogenic headache1 or headaches resulting from some variety of cervical pathology.
Recent literature3 has confirmed the author’s observations that this is a common occurrence. Kaniecki reported neck pain as a frequent occurrence with migraine and often relieved along with the migraine pain using sumatriptan. It is a common occurrence in a typical headache practice to see post-traumatic headache patients with migraine features, responsive to migraine medications, or to see previous migraine disorders worsened by trauma.4 One likely explanation for the ability of cervical pain to trigger migraine is the extension of the nucleus caudalis of the trigeminal nerve, a major relay in the genesis of migraine, down to C2-4 in the cervical spine. Thus neck pain may charge up the migraine generators in the brain stem.