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17 Articles in Volume 19, Issue #4
Analgesics of the Future: Inside the Potential of Nerve Growth Factor Antagonists
Best Practices Are Still Largely Undefined in Task Force Report
Brief Behavioral Interventions for Chronic Pain
Cervicogenic Headache: Diagnosis and Management
Chronic Headache and Central Pain Conditions
Considering Comorbidities When Selecting Medications for Pain (Part 4)
For APPs: How to Contribute to Clinical Research
Gabapentin and Suicidal Ideation: Is There a Link?
Intranasal Ketamine for the Relief of Cluster Headache
Letters: Slipping Rib Syndrome; Burning Leg Pain; CGRP Complications
Pain Assessment Tools for Malingering in Patients with Chronic Pain
Refractory Chronic Migraine: Mild, Moderate, or Severe
Should Probuphine be considered for MAT?
Special Report: The Abuse Potential of Gabapentin & Pregabalin
Tension-Type Headache: Evidence for Trigger Points
Treatment Alternatives for Migraine
Trigeminal Neuralgia: Current Diagnosis and Treatment Options

Refractory Chronic Migraine: Mild, Moderate, or Severe

Building off of his refractory chronic migraine scale for adults, the author proposes a rating scale for adolescents.
Pages 27-29

The International Headache Society defines chronic migraine as 15 headache days or more, occurring per month, for at least 3 months. There must be at least 8 days that are considered migrainous in nature.1 A subset of chronic migraine is known as refractory chronic migraine (RCM). The American Headache Society has proposed criteria for RCM which include failed adequate trials of at least two preventive medication classes, as well as poor response to abortive migraine medications.2 The European Headache Federation’s RCM criteria relies primarily on failed trials of preventive medications.3

The severity of RCM varies widely. For instance, a hypothetical mild RCM patient may be 20 years old and experience 8 months of daily headache with no comorbidities. A more severe case patient may be 55 years old and have experienced 40 years of around-the-clock headache, as well as multiple medical and/or psychiatric comorbidities. The clinical approaches to each patient would differ and, typically, there may be lower expectations of success in the severe case.

In general, most clinical drug trials in the migraine and headache field exclude patients with more severe refractory headache as these subjects are likely to increase the risk of failure. For these reasons, I have found it useful to differentiate between those patients with mild, moderate, or severe RCM when forming treatment plans.

Introducing a scale for both adults and adolescents to diagnose refractory chronic migraine. (Source: 123RF)

A Refractory Chronic Migraine Rating Scale

In 2012, I published on a refractory chronic migraine rating scale4 designed for use in the adult population, followed by a retroactive study in which I applied the scale to approximately 130 RCM patients. The scale consists of eight items, with 10 possible points. Points are added based on the patient's medical history as follows:

  • Refractory to preventive approaches = 2 points
  • Refractory to abortive medications = 2 points
  • Duration (# of years) of migraine occurrence; if greater than 10 years = 1 point
  • Number of headaches per month; if 25 or more days, on average = 1 point
  • Medical comorbidities (irritable bowel syndrome [IBS], temporomandibular joint disorder [TMD], fibromyalgia, chronic fatigue, chronic pelvic pain, painful bladder syndrome); if two or more are present = 1 point
  • Psychiatric comorbidities, whether a severe Axis I disorder (ie, an affective disorder) or any definite Axis II disorder (ie, a personality disorder), as defined by the Diagnostic and Statistical Manual of Mental Disorders = 1 point
  • Disability (work and/or home) = 1 point
  • Medication overuse headache (not simply medication overuse) = 1 point.

After totaling the points, the scale helps clinicians to categorize patients as follows:

  • 2 to 4 points = mild RCM
  • 5 to 7 points = moderate RCM
  • 8 to 10 points = severe RCM.

Results with the Adult Refractory Rating Scale

In the retrospective study, I used the scale to evaluate quality of life (QoL) and pain levels in 129 RCM patients (109 women, all over age 18) of the Robbins Headache Clinic over a 10-year period. Of the subjects, 18.5% of the patients were rated as mildly refractory, 52% as moderate, and 29.5% as severe.

Overall, QoL improved an average of 33% over the 10-year period. Within the mild RCM group, 66% reported at least a 30% improvement in QoL; improvement was 57% in the moderate group, and 61% in the severe group.

Improvement in pain scores was even more dramatic. Over the 10-year period, pain levels declined by at least 30% in 80% of the mild RCM group, by 72% in the moderate group, and by 71% in the severe group.

These results suggested that, over time, those with RCM may often improve their day-to-day function and reduce their pain. (Refer to Reference 4 for full study results.)

An Adolescent Rating Scale

I continue to use the adult scale today and now proposes an adolescent (ie, age 11 to 19) chronic migraine refractory scale. Points for the adolescent patient would be tallied as follows:

  • Refractory to preventives (which may include Botox) = 1 point
  • Refractory to abortives = 1 point
  • Headache occurrence greater than one year = 1 point
  • Number of headaches per month; if 25 or more days, on average = 1 point
  • Significant comorbidities; if at least one are present (IBS, TMD, fibromyalgia, or chronic fatigue) = 1 point
  • Psychiatric comorbidities: severe Axis I, or a strong indication that Axis II may be present = 1 point.
  • Disability defined as an inability to go to school for at least 2 months due to headache (either homebound, or a greatly modified schedule), or a significant decrease in functioning = 1 point
  • Severe family dysfunction, which may include a personality disorder pathology in the primary parent (usually the mother) = 1 point

With this scale, a total of 8 points would be possible, ranking as such:

  • 2 to 4 points = mild RCM
  • 5 to 6 points = moderate RCM
  • 7 to 8 points = severe RCM.

Reasoning of the Point System

In the adult scale, more weight was given to “refractory to preventives” and “refractory to abortives” than to the other items because refractoriness to medications is the primary component in the definition of RCM. However, this scale is a work in progress. Heavier weighting could be given to the number of days per month of headache. The number of years of headache could also warrant two points instead of one. If done, this would then raise the RCM scale’s total points to 12.

Medical comorbidities were included because they add to refractoriness and complicate treatment. Central sensitization syndromes (eg, fibromyalgia, IBS) were selected as these syndromes are frequently encountered among those with RCM. Psychiatric conditions were included as these may also complicate treatment. Only severe affective disorders were considered in the scale as milder anxiety or depression may not always substantially contribute to RCM. Disability issues are also often seen in patients with RCM. For adolescents with RCM, they may be missing months (or years) of school over time.5 Disability therefore needs to play a role in determining refractoriness.

Medication overuse headache (MOH) is often poorly defined and over-diagnosed as it may easily be conflated with simple medication overuse.6 At the same time, MOH can add to the difficulty in treating RCM patients, and should play some role in determining severity.

Conclusion

Refractory chronic migraine represents a small but important subset of chronic migraine patients. For clinical and research purposes, it may be helpful for a clinician to be able to determine the level of refractoriness. This categorization is especially important as the treatment approach and long-term goals for milder patients often differs from those with severe refractory cases. As demonstrated herein, a refractory scale helped to categorize adult RCM patients and I now propose a new scale that may be helpful in assessing adolescent patients along the same lines. A rating scale adapted to this lower age range may be helpful when establishing both short- and long-term care plans.

Last updated on: June 21, 2019
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