European Headache and Migraine Trust International Congress (EHMTIC)

LONDON – Chronic musculoskeletal complaints and chronic daily headache share a bidirectional causal relationship in which patients with either condition are predisposed over time to develop the other one, according to Dr. Lars J. Stovner.

This key finding from an impressively large, longitudinal, population-based Norwegian study has importance both for frontline clinicians as well as academic researchers, he said at the European Headache and Migraine Trust International Congress.

"From a practical point of view, one can say that if one has a patient with one of these common complaints, one should try hard to treat it not only to bring relief to the patient but to prevent the development of the other condition," said Dr. Stovner of the Norwegian University of Science and Technology, Trondheim.

The new observation of a bidirectional relationship between chronic musculoskeletal pain and chronic daily headache may also have import in terms of understanding the relevant pathophysiology. It suggests the disorders may share a common underlying cause.

"It says that chronic pain in the body is probably very much related to chronic headache. As we’ve heard elsewhere at this conference, they are both basically brain disorders," he continued.

Dr. Stovner presented data from two consecutive surveys conducted 11 years apart as part of the Nord-Trøndelag Health Study (HUNT). HUNT 2 included 51,383 adults queried in 1995-1997, of whom 26,197 completed the HUNT 3 questions regarding headache and chronic musculoskeletal pain at follow-up in 2006-2008.

Participants with chronic musculoskeletal complaints at baseline in HUNT 2 proved to have a 1.8-fold increased risk of developing chronic daily headache 11 years later in HUNT 3 compared with subjects without baseline chronic musculoskeletal pain, in a multivariate analysis adjusted for the known potential confounders of age, sex, anxiety, depression, and socioeconomic status.

Moreover, subjects with chronic daily headache but not chronic musculoskeletal pain in HUNT 2 had an identical adjusted 1.8-fold increased risk of developing chronic musculoskeletal pain in HUNT 3. The risk climbed to 2.7-fold when the analysis was restricted to individuals with widespread chronic musculoskeletal complaints in HUNT 3.

"Chronic daily headache and chronic musculoskeletal complaints are enormous public health problems. This is a huge population-based prospective study running for longer than 10 years," commented session cochair Dr. Zaza Katsarava of Evangelist Hospital in Unna, Germany. "The results clearly show there are no separate physiologic baskets for migraine and back pain; they are both part of an entire pain matrix that is impaired."

The HUNT study is supported by Norwegian governmental research funds. Dr. Stovner reported having no relevant financial conflicts.

LONDON – Chronic musculoskeletal complaints and chronic daily headache share a bidirectional causal relationship in which patients with either condition are predisposed over time to develop the other one, according to Dr. Lars J. Stovner.

This key finding from an impressively large, longitudinal, population-based Norwegian study has importance both for frontline clinicians as well as academic researchers, he said at the European Headache and Migraine Trust International Congress.

"From a practical point of view, one can say that if one has a patient with one of these common complaints, one should try hard to treat it not only to bring relief to the patient but to prevent the development of the other condition," said Dr. Stovner of the Norwegian University of Science and Technology, Trondheim.

The new observation of a bidirectional relationship between chronic musculoskeletal pain and chronic daily headache may also have import in terms of understanding the relevant pathophysiology. It suggests the disorders may share a common underlying cause.

"It says that chronic pain in the body is probably very much related to chronic headache. As we’ve heard elsewhere at this conference, they are both basically brain disorders," he continued.

Dr. Stovner presented data from two consecutive surveys conducted 11 years apart as part of the Nord-Trøndelag Health Study (HUNT). HUNT 2 included 51,383 adults queried in 1995-1997, of whom 26,197 completed the HUNT 3 questions regarding headache and chronic musculoskeletal pain at follow-up in 2006-2008.

Participants with chronic musculoskeletal complaints at baseline in HUNT 2 proved to have a 1.8-fold increased risk of developing chronic daily headache 11 years later in HUNT 3 compared with subjects without baseline chronic musculoskeletal pain, in a multivariate analysis adjusted for the known potential confounders of age, sex, anxiety, depression, and socioeconomic status.

Moreover, subjects with chronic daily headache but not chronic musculoskeletal pain in HUNT 2 had an identical adjusted 1.8-fold increased risk of developing chronic musculoskeletal pain in HUNT 3. The risk climbed to 2.7-fold when the analysis was restricted to individuals with widespread chronic musculoskeletal complaints in HUNT 3.

"Chronic daily headache and chronic musculoskeletal complaints are enormous public health problems. This is a huge population-based prospective study running for longer than 10 years," commented session cochair Dr. Zaza Katsarava of Evangelist Hospital in Unna, Germany. "The results clearly show there are no separate physiologic baskets for migraine and back pain; they are both part of an entire pain matrix that is impaired."

The HUNT study is supported by Norwegian governmental research funds. Dr. Stovner reported having no relevant financial conflicts.

LONDON – Chronic musculoskeletal complaints and chronic daily headache share a bidirectional causal relationship in which patients with either condition are predisposed over time to develop the other one, according to Dr. Lars J. Stovner.

This key finding from an impressively large, longitudinal, population-based Norwegian study has importance both for frontline clinicians as well as academic researchers, he said at the European Headache and Migraine Trust International Congress.

"From a practical point of view, one can say that if one has a patient with one of these common complaints, one should try hard to treat it not only to bring relief to the patient but to prevent the development of the other condition," said Dr. Stovner of the Norwegian University of Science and Technology, Trondheim.

The new observation of a bidirectional relationship between chronic musculoskeletal pain and chronic daily headache may also have import in terms of understanding the relevant pathophysiology. It suggests the disorders may share a common underlying cause.

"It says that chronic pain in the body is probably very much related to chronic headache. As we’ve heard elsewhere at this conference, they are both basically brain disorders," he continued.

Dr. Stovner presented data from two consecutive surveys conducted 11 years apart as part of the Nord-Trøndelag Health Study (HUNT). HUNT 2 included 51,383 adults queried in 1995-1997, of whom 26,197 completed the HUNT 3 questions regarding headache and chronic musculoskeletal pain at follow-up in 2006-2008.

Participants with chronic musculoskeletal complaints at baseline in HUNT 2 proved to have a 1.8-fold increased risk of developing chronic daily headache 11 years later in HUNT 3 compared with subjects without baseline chronic musculoskeletal pain, in a multivariate analysis adjusted for the known potential confounders of age, sex, anxiety, depression, and socioeconomic status.

Moreover, subjects with chronic daily headache but not chronic musculoskeletal pain in HUNT 2 had an identical adjusted 1.8-fold increased risk of developing chronic musculoskeletal pain in HUNT 3. The risk climbed to 2.7-fold when the analysis was restricted to individuals with widespread chronic musculoskeletal complaints in HUNT 3.

"Chronic daily headache and chronic musculoskeletal complaints are enormous public health problems. This is a huge population-based prospective study running for longer than 10 years," commented session cochair Dr. Zaza Katsarava of Evangelist Hospital in Unna, Germany. "The results clearly show there are no separate physiologic baskets for migraine and back pain; they are both part of an entire pain matrix that is impaired."

The HUNT study is supported by Norwegian governmental research funds. Dr. Stovner reported having no relevant financial conflicts.

LONDON – Depression in patients with episodic migraine is an independent risk factor for transformation of their headache pattern into far more burdensome chronic migraine, according to data from the landmark American Migraine Prevalence and Prevention study.

"The study indicates that we need to look for depression in patients with episodic migraine or chronic migraine. We need to take it seriously and address this issue with patients – make the referral to a psychiatrist or treat them yourself if you’re comfortable with that. And the depression should be addressed as a problem separate from the headaches," Dr. Sait Ashina said at the European Headache and Migraine Trust International Congress.

AMPP study participants who had episodic migraine and depression were 1.65-fold more likely to progress to chronic migraine within the next year than were nondepressed participants who had episodic migraine, in an analysis extensively adjusted for potential confounding variables, reported Dr. Ashina of Albert Einstein School of Medicine, New York.

Moreover, a dose-response relationship was evident between depression severity and risk of progression from episodic to chronic migraine. That is, the nearly 1,400 AMPP participants with episodic migraine and moderate depression as defined by a Patient Health Questionnaire–9 (PHQ-9) score of 10-14 out of a maximum possible 27 had an adjusted 1.77-fold greater risk of converting to chronic migraine within the next year than did the 10,898 episodic migraine sufferers with no or mild depression, while the 656 with moderately severe depression as evidenced by a PHQ-9 score of 15-19 had a 2.35-fold increased risk, and the 420 individuals with a PHQ-9 score of 20-27 were at 2.53-fold increased risk.

The AMPP study is an ongoing longitudinal, population-based study in which 24,000 adults with severe headache were surveyed annually during 2004-2009. Dr. Ashina’s analysis involved nearly 13,500 participants who met criteria for episodic migraine in the 2005 or 2006 surveys. Transformation from episodic to chronic migraine within the next year occurred in 2.4% of the 2005 cohort and 2.2% of the 2006 group. Episodic migraine was defined in standard fashion as migraine headaches occurring on not more than 14 days per month averaged over the past 3 months, while chronic migraine entailed headaches on an average of 15 or more days per month.

The depression/migraine chronification analysis was adjusted for cutaneous allodynia, physician diagnosis of an anxiety disorder, headache pain intensity, headache frequency, migraine symptom score, use of antidepressant medications, headache-driven medication overuse, age, sex, body mass index, income, and health insurance status. The two strongest predictors of migraine chronification in the multivariate analysis proved to be depression and medication overuse involving triptans and/or opioids.

Dr. Ashina said that prior studies have established that depression and migraine are cotravelers, and that the relationship is bidirectional: That is, migraine is a risk factor for new-onset depression, and depression is a risk factor for new-onset migraine.

For example, one classic study conducted by some of the coinvestigators in Dr. Ashina’s current AMPP analysis showed a 2-year incidence of new-onset migraine of 9.3% in patients with major depression, compared with 2.9% in controls without major depression (odds ratio, 3.4). There also was a 2-year incidence of new-onset depression of 10.5% in migraineurs, compared with 2% in controls without migraine or other severe headache, for an odds ratio of 5.8 (Neurology 2003;60:1,308-12).

And in a combined analysis of two other studies, the prevalence of depression as defined using the PHQ-9 was 9.2% in the general population, 17.2% in persons with episodic migraine, and 30.2% in those with chronic migraine.

However, the relationship between depression and transformation of episodic to chronic migraine hasn’t previously been carefully looked at, which was the impetus for the AMPP analysis, he explained.

Back transitions from chronic to episodic migraine are known to be common, occurring in roughly one-quarter of patients with chronic migraine per year. Whether effective treatment of depression in chronic migraine patients promotes back transition to episodic migraine, or for that matter, whether antidepressant therapy in patients with episodic migraine reduces the risk of transformation to chronic migraine, are unanswered questions – and priorities for further research, in Dr. Ashina’s view.

At the international congress, Dr. Ashina received the prestigious Enrico Greppi Award from the Italian Society for the Study of Headaches for his research.

The AMPP study is funded by a grant from Ortho-McNeil Neurologics. Dr. Ashina’s analysis received supplemental funding in the form of a research grant from Allergan. He reported having served as a consultant to NeurogesX and Depomed.

LONDON – Depression in patients with episodic migraine is an independent risk factor for transformation of their headache pattern into far more burdensome chronic migraine, according to data from the landmark American Migraine Prevalence and Prevention study.

"The study indicates that we need to look for depression in patients with episodic migraine or chronic migraine. We need to take it seriously and address this issue with patients – make the referral to a psychiatrist or treat them yourself if you’re comfortable with that. And the depression should be addressed as a problem separate from the headaches," Dr. Sait Ashina said at the European Headache and Migraine Trust International Congress.

AMPP study participants who had episodic migraine and depression were 1.65-fold more likely to progress to chronic migraine within the next year than were nondepressed participants who had episodic migraine, in an analysis extensively adjusted for potential confounding variables, reported Dr. Ashina of Albert Einstein School of Medicine, New York.

Moreover, a dose-response relationship was evident between depression severity and risk of progression from episodic to chronic migraine. That is, the nearly 1,400 AMPP participants with episodic migraine and moderate depression as defined by a Patient Health Questionnaire–9 (PHQ-9) score of 10-14 out of a maximum possible 27 had an adjusted 1.77-fold greater risk of converting to chronic migraine within the next year than did the 10,898 episodic migraine sufferers with no or mild depression, while the 656 with moderately severe depression as evidenced by a PHQ-9 score of 15-19 had a 2.35-fold increased risk, and the 420 individuals with a PHQ-9 score of 20-27 were at 2.53-fold increased risk.

The AMPP study is an ongoing longitudinal, population-based study in which 24,000 adults with severe headache were surveyed annually during 2004-2009. Dr. Ashina’s analysis involved nearly 13,500 participants who met criteria for episodic migraine in the 2005 or 2006 surveys. Transformation from episodic to chronic migraine within the next year occurred in 2.4% of the 2005 cohort and 2.2% of the 2006 group. Episodic migraine was defined in standard fashion as migraine headaches occurring on not more than 14 days per month averaged over the past 3 months, while chronic migraine entailed headaches on an average of 15 or more days per month.

The depression/migraine chronification analysis was adjusted for cutaneous allodynia, physician diagnosis of an anxiety disorder, headache pain intensity, headache frequency, migraine symptom score, use of antidepressant medications, headache-driven medication overuse, age, sex, body mass index, income, and health insurance status. The two strongest predictors of migraine chronification in the multivariate analysis proved to be depression and medication overuse involving triptans and/or opioids.

Dr. Ashina said that prior studies have established that depression and migraine are cotravelers, and that the relationship is bidirectional: That is, migraine is a risk factor for new-onset depression, and depression is a risk factor for new-onset migraine.

For example, one classic study conducted by some of the coinvestigators in Dr. Ashina’s current AMPP analysis showed a 2-year incidence of new-onset migraine of 9.3% in patients with major depression, compared with 2.9% in controls without major depression (odds ratio, 3.4). There also was a 2-year incidence of new-onset depression of 10.5% in migraineurs, compared with 2% in controls without migraine or other severe headache, for an odds ratio of 5.8 (Neurology 2003;60:1,308-12).

And in a combined analysis of two other studies, the prevalence of depression as defined using the PHQ-9 was 9.2% in the general population, 17.2% in persons with episodic migraine, and 30.2% in those with chronic migraine.

However, the relationship between depression and transformation of episodic to chronic migraine hasn’t previously been carefully looked at, which was the impetus for the AMPP analysis, he explained.

Back transitions from chronic to episodic migraine are known to be common, occurring in roughly one-quarter of patients with chronic migraine per year. Whether effective treatment of depression in chronic migraine patients promotes back transition to episodic migraine, or for that matter, whether antidepressant therapy in patients with episodic migraine reduces the risk of transformation to chronic migraine, are unanswered questions – and priorities for further research, in Dr. Ashina’s view.

At the international congress, Dr. Ashina received the prestigious Enrico Greppi Award from the Italian Society for the Study of Headaches for his research.

The AMPP study is funded by a grant from Ortho-McNeil Neurologics. Dr. Ashina’s analysis received supplemental funding in the form of a research grant from Allergan. He reported having served as a consultant to NeurogesX and Depomed.

LONDON – Depression in patients with episodic migraine is an independent risk factor for transformation of their headache pattern into far more burdensome chronic migraine, according to data from the landmark American Migraine Prevalence and Prevention study.

"The study indicates that we need to look for depression in patients with episodic migraine or chronic migraine. We need to take it seriously and address this issue with patients – make the referral to a psychiatrist or treat them yourself if you’re comfortable with that. And the depression should be addressed as a problem separate from the headaches," Dr. Sait Ashina said at the European Headache and Migraine Trust International Congress.

AMPP study participants who had episodic migraine and depression were 1.65-fold more likely to progress to chronic migraine within the next year than were nondepressed participants who had episodic migraine, in an analysis extensively adjusted for potential confounding variables, reported Dr. Ashina of Albert Einstein School of Medicine, New York.

Moreover, a dose-response relationship was evident between depression severity and risk of progression from episodic to chronic migraine. That is, the nearly 1,400 AMPP participants with episodic migraine and moderate depression as defined by a Patient Health Questionnaire–9 (PHQ-9) score of 10-14 out of a maximum possible 27 had an adjusted 1.77-fold greater risk of converting to chronic migraine within the next year than did the 10,898 episodic migraine sufferers with no or mild depression, while the 656 with moderately severe depression as evidenced by a PHQ-9 score of 15-19 had a 2.35-fold increased risk, and the 420 individuals with a PHQ-9 score of 20-27 were at 2.53-fold increased risk.

The AMPP study is an ongoing longitudinal, population-based study in which 24,000 adults with severe headache were surveyed annually during 2004-2009. Dr. Ashina’s analysis involved nearly 13,500 participants who met criteria for episodic migraine in the 2005 or 2006 surveys. Transformation from episodic to chronic migraine within the next year occurred in 2.4% of the 2005 cohort and 2.2% of the 2006 group. Episodic migraine was defined in standard fashion as migraine headaches occurring on not more than 14 days per month averaged over the past 3 months, while chronic migraine entailed headaches on an average of 15 or more days per month.

The depression/migraine chronification analysis was adjusted for cutaneous allodynia, physician diagnosis of an anxiety disorder, headache pain intensity, headache frequency, migraine symptom score, use of antidepressant medications, headache-driven medication overuse, age, sex, body mass index, income, and health insurance status. The two strongest predictors of migraine chronification in the multivariate analysis proved to be depression and medication overuse involving triptans and/or opioids.

Dr. Ashina said that prior studies have established that depression and migraine are cotravelers, and that the relationship is bidirectional: That is, migraine is a risk factor for new-onset depression, and depression is a risk factor for new-onset migraine.

For example, one classic study conducted by some of the coinvestigators in Dr. Ashina’s current AMPP analysis showed a 2-year incidence of new-onset migraine of 9.3% in patients with major depression, compared with 2.9% in controls without major depression (odds ratio, 3.4). There also was a 2-year incidence of new-onset depression of 10.5% in migraineurs, compared with 2% in controls without migraine or other severe headache, for an odds ratio of 5.8 (Neurology 2003;60:1,308-12).

And in a combined analysis of two other studies, the prevalence of depression as defined using the PHQ-9 was 9.2% in the general population, 17.2% in persons with episodic migraine, and 30.2% in those with chronic migraine.

However, the relationship between depression and transformation of episodic to chronic migraine hasn’t previously been carefully looked at, which was the impetus for the AMPP analysis, he explained.

Back transitions from chronic to episodic migraine are known to be common, occurring in roughly one-quarter of patients with chronic migraine per year. Whether effective treatment of depression in chronic migraine patients promotes back transition to episodic migraine, or for that matter, whether antidepressant therapy in patients with episodic migraine reduces the risk of transformation to chronic migraine, are unanswered questions – and priorities for further research, in Dr. Ashina’s view.

At the international congress, Dr. Ashina received the prestigious Enrico Greppi Award from the Italian Society for the Study of Headaches for his research.

The AMPP study is funded by a grant from Ortho-McNeil Neurologics. Dr. Ashina’s analysis received supplemental funding in the form of a research grant from Allergan. He reported having served as a consultant to NeurogesX and Depomed.

LONDON – Brief low-temperature radiofrequency rhizolysis of the C-1 spinal nerve and C-2 and C-3 dorsal root ganglia was safe and effective for occipital neuralgia with migraine in a retrospective series of 10 patients.

"The pain reduction lasted for an average of 5½ months. That’s a longer duration of action than with nerve blockade alone," said Dr. Mollie M. Johnston of the headache research and treatment program at the University of California, Los Angeles (UCLA).

While the favorable initial clinical experience with this novel therapy is exciting, the broader significance of the findings lies in a resultant new appreciation of the C-1 nerve root as likely an important player in pain syndromes involving an orbital or periorbital distribution.

"The C-1 nerve root may be an important target for pain syndromes such as occipital neuralgia, migraine, and possibly cluster headache. This target may not be addressed by approaches currently in widespread use," she said at the European Headache and Migraine Trust International Congress.

The C-1 nerve root has traditionally not been thought of as having a significant sensory function because it doesn’t have dermatomal or cutaneous branches. But recent cadaveric studies have demonstrated that up to half of individuals have C-1 dorsal root ganglia, which typically lie medial to the dural root sleeve and inferior to the vertebral artery. Moreover, persons without C-1 dorsal root ganglia often have C-1 rootlets joining the spinal accessory nerve (J. Neurosurgery 2011;115:929-33). These cadaveric findings suggest a sensory function for the C-1 nerve root; however, until Dr. Johnston’s study, the pain referral pattern associated with this sensory function wasn’t known.

It’s well established that the dorsal rami of the C-2 and C-3 nerve roots contribute to the auricular nerve, the greater and lesser occipital nerves, and the third occipital nerve. These nerves are known to send sensory input from the occipital region to the periauricular region, the vertex, the C-2 and C-3 facet joints, and the cervical musculature, which is why they, too, were targeted for rhizolysis, Dr. Johnston explained.

The novel treatment for occipital neuralgia she and her coworkers have developed at UCLA entails a two-step neurosurgical procedure. First comes fluoroscopically guided provocation testing at the C-1 through C-3 level, followed by blockage of the nerve roots with anesthetic plus steroids. In a later separate procedure, the surgeon performs brief low-temperature radiofrequency rhizolysis.

Dr. Johnston presented a retrospective series of 10 patients with the distinctive, burning electricaltype pain of occipital neuralgia, 6 of whom also had migraine. The patients with migraine experienced orbital or periorbital pain referral upon direct stimulation at the C-1 level; those without migraine did not.

Nine of 10 patients had a positive nerve block, with either transient or sustained pain relief. The seven patients who didn’t experience sustained pain relief as a result of C-1, -2, and -3 nerve blockade subsequently underwent brief low-temperature radiofrequency rhizolysis. Four of the seven responded with a greater than 50% reduction in pain, headache days, and need for rescue medications; their responses lasted for an average of 5.5 months. The other three patients had a lesser response or no response.

No side effects or complications occurred as a consequence of the procedure. Future controlled studies are planned.

Dr. Johnston reported having no relevant financial disclosures.

LONDON – Brief low-temperature radiofrequency rhizolysis of the C-1 spinal nerve and C-2 and C-3 dorsal root ganglia was safe and effective for occipital neuralgia with migraine in a retrospective series of 10 patients.

"The pain reduction lasted for an average of 5½ months. That’s a longer duration of action than with nerve blockade alone," said Dr. Mollie M. Johnston of the headache research and treatment program at the University of California, Los Angeles (UCLA).

While the favorable initial clinical experience with this novel therapy is exciting, the broader significance of the findings lies in a resultant new appreciation of the C-1 nerve root as likely an important player in pain syndromes involving an orbital or periorbital distribution.

"The C-1 nerve root may be an important target for pain syndromes such as occipital neuralgia, migraine, and possibly cluster headache. This target may not be addressed by approaches currently in widespread use," she said at the European Headache and Migraine Trust International Congress.

The C-1 nerve root has traditionally not been thought of as having a significant sensory function because it doesn’t have dermatomal or cutaneous branches. But recent cadaveric studies have demonstrated that up to half of individuals have C-1 dorsal root ganglia, which typically lie medial to the dural root sleeve and inferior to the vertebral artery. Moreover, persons without C-1 dorsal root ganglia often have C-1 rootlets joining the spinal accessory nerve (J. Neurosurgery 2011;115:929-33). These cadaveric findings suggest a sensory function for the C-1 nerve root; however, until Dr. Johnston’s study, the pain referral pattern associated with this sensory function wasn’t known.

It’s well established that the dorsal rami of the C-2 and C-3 nerve roots contribute to the auricular nerve, the greater and lesser occipital nerves, and the third occipital nerve. These nerves are known to send sensory input from the occipital region to the periauricular region, the vertex, the C-2 and C-3 facet joints, and the cervical musculature, which is why they, too, were targeted for rhizolysis, Dr. Johnston explained.

The novel treatment for occipital neuralgia she and her coworkers have developed at UCLA entails a two-step neurosurgical procedure. First comes fluoroscopically guided provocation testing at the C-1 through C-3 level, followed by blockage of the nerve roots with anesthetic plus steroids. In a later separate procedure, the surgeon performs brief low-temperature radiofrequency rhizolysis.

Dr. Johnston presented a retrospective series of 10 patients with the distinctive, burning electricaltype pain of occipital neuralgia, 6 of whom also had migraine. The patients with migraine experienced orbital or periorbital pain referral upon direct stimulation at the C-1 level; those without migraine did not.

Nine of 10 patients had a positive nerve block, with either transient or sustained pain relief. The seven patients who didn’t experience sustained pain relief as a result of C-1, -2, and -3 nerve blockade subsequently underwent brief low-temperature radiofrequency rhizolysis. Four of the seven responded with a greater than 50% reduction in pain, headache days, and need for rescue medications; their responses lasted for an average of 5.5 months. The other three patients had a lesser response or no response.

No side effects or complications occurred as a consequence of the procedure. Future controlled studies are planned.

Dr. Johnston reported having no relevant financial disclosures.

LONDON – Brief low-temperature radiofrequency rhizolysis of the C-1 spinal nerve and C-2 and C-3 dorsal root ganglia was safe and effective for occipital neuralgia with migraine in a retrospective series of 10 patients.

"The pain reduction lasted for an average of 5½ months. That’s a longer duration of action than with nerve blockade alone," said Dr. Mollie M. Johnston of the headache research and treatment program at the University of California, Los Angeles (UCLA).

While the favorable initial clinical experience with this novel therapy is exciting, the broader significance of the findings lies in a resultant new appreciation of the C-1 nerve root as likely an important player in pain syndromes involving an orbital or periorbital distribution.

"The C-1 nerve root may be an important target for pain syndromes such as occipital neuralgia, migraine, and possibly cluster headache. This target may not be addressed by approaches currently in widespread use," she said at the European Headache and Migraine Trust International Congress.

The C-1 nerve root has traditionally not been thought of as having a significant sensory function because it doesn’t have dermatomal or cutaneous branches. But recent cadaveric studies have demonstrated that up to half of individuals have C-1 dorsal root ganglia, which typically lie medial to the dural root sleeve and inferior to the vertebral artery. Moreover, persons without C-1 dorsal root ganglia often have C-1 rootlets joining the spinal accessory nerve (J. Neurosurgery 2011;115:929-33). These cadaveric findings suggest a sensory function for the C-1 nerve root; however, until Dr. Johnston’s study, the pain referral pattern associated with this sensory function wasn’t known.

It’s well established that the dorsal rami of the C-2 and C-3 nerve roots contribute to the auricular nerve, the greater and lesser occipital nerves, and the third occipital nerve. These nerves are known to send sensory input from the occipital region to the periauricular region, the vertex, the C-2 and C-3 facet joints, and the cervical musculature, which is why they, too, were targeted for rhizolysis, Dr. Johnston explained.

The novel treatment for occipital neuralgia she and her coworkers have developed at UCLA entails a two-step neurosurgical procedure. First comes fluoroscopically guided provocation testing at the C-1 through C-3 level, followed by blockage of the nerve roots with anesthetic plus steroids. In a later separate procedure, the surgeon performs brief low-temperature radiofrequency rhizolysis.

Dr. Johnston presented a retrospective series of 10 patients with the distinctive, burning electricaltype pain of occipital neuralgia, 6 of whom also had migraine. The patients with migraine experienced orbital or periorbital pain referral upon direct stimulation at the C-1 level; those without migraine did not.

Nine of 10 patients had a positive nerve block, with either transient or sustained pain relief. The seven patients who didn’t experience sustained pain relief as a result of C-1, -2, and -3 nerve blockade subsequently underwent brief low-temperature radiofrequency rhizolysis. Four of the seven responded with a greater than 50% reduction in pain, headache days, and need for rescue medications; their responses lasted for an average of 5.5 months. The other three patients had a lesser response or no response.

No side effects or complications occurred as a consequence of the procedure. Future controlled studies are planned.

Dr. Johnston reported having no relevant financial disclosures.