Symptoms of migraine aura may resemble those of multiple sclerosis (MS) relapse, and some MS drugs may cause headache.
STOWE, VT—Migraine and multiple sclerosis (MS) can have similar symptoms and often are comorbid diseases, according to Angela Applebee, MD, who spoke at the Headache Cooperative of New England’s 22nd Annual Headache Symposium. Neurologists should know which MS therapies can contribute to headache and which migraine drugs to prescribe with caution if a patient is taking certain new MS therapies, said Dr. Applebee, Assistant Professor of Neurology at the University of Vermont in Burlington.
The Link Between Migraine and MS
“The most convincing study of the link between migraine and MS” is the Nursing Health Study, said Dr. Applebee. That prospective study, during which investigators at New York University sent surveys to 116,000 nurses from 1989 to 1995, found that patients with migraine had a 39% higher risk of developing MS than nonmigraneurs. The absolute risk of developing MS was 0.15% higher, which means that migraine is a modest predictor of MS. Stronger predictors of MS include factors such as DRB1*1501 haplotype or history of infectious mononucleosis.
The study also found that patients with MS had a 33% greater chance of being diagnosed with migraine during follow-up. This difference was nonsignificant, however, said Dr. Applebee.
Differentiating Between Migraine Aura and MS Relapse
Migraine aura and MS relapse may have similar symptoms, but several principles can help neurologists distinguish between the two. First, aura tends not to last as long as MS relapse. In general, migraine aura lasts from five to 60 minutes, with the exception of the rare hemiplegic migraine variant. In MS relapse, on the other hand, new or worsening previous symptoms usually occur for 24 hours. “When I’m doing a history on a new patient, I’m trying to determine whether the symptom is always there, or whether it comes and goes, to help determine whether it could be a relapse or an aura,” Dr. Applebee explained.
Second, the symptoms of migraine aura tend to be consistent, but those of MS relapse tend to vary. A stress such as an infection, however, can cause an MS relapse characterized by a recurrence of old symptoms.
Also, each occurrence of migraine usually is related to the same areas of the brain. In contrast, each MS relapse, by definition, affects a different area of the brain than the previous MS relapse had affected. “If the optic nerve is first involved [in a relapse], another area of the brain should be next involved,” said Dr. Applebee. “Different areas of the brain don’t have to be involved in migraine,” she added.
Between 20% and 30% of auras entail visual and sensory disturbance. If an MS relapse entails a visual disturbance, it tends to include the symptoms of optic neuritis, such as pain when moving the eye and cloudy vision. MS relapses also may be associated with nystagmus or diplopia, said Dr. Applebee.
Drugs for MS May Cause Headache
Several drugs used to treat MS may cause headache. Natalizumab, a once-per-month infusion, can cause a postinfusion headache that lasts 24 hours before resolving itself completely. “If you premedicate prior to the infusion, this tends not to be an issue, and I haven’t seen that patients with migraine are more predisposed to having headaches with natalizumab,” advised Dr. Applebee.
Interferon therapies, which are given by subcutaneous or intramuscular injection, sometimes cause flulike symptoms that last from three to six months after the start of therapy. “If you teach patients to premedicate prior to their injections, it can minimize the flulike symptoms,” said Dr. Applebee. “Patients with migraine tend to have more difficulty in controlling their migraines when they first go on interferon therapy.” This difficulty, however, is not a contraindication for using interferon therapies in these patients, she added.
A patient with MS also may experience headache for the first four weeks after starting to take fingolimod, which the FDA approved in 2010. After four weeks, the headache usually resolves itself. Initiating treatment with fingolimod sometimes causes a pounding headache in patients with no previous history of headache. The drug also may make it difficult for patients with migraine to control their headache, but pulse steroids can provide relief, said Dr. Applebee.
Monitoring Fingolimod Use in Patients With Comorbid Cardiac Problems
Because fingolimod acts on the S1P1 receptors, patients may have a decreased heart rate within the first six hours of their first dose of the drug. The drug may lead to first- and second-degree heart block.
“When we dose these patients, we do a baseline ECG in our office, monitor them for six hours with vitals every hour, and then have a second ECG performed prior to exit,” noted Dr. Applebee. Patients with abnormal ECGs should be admitted to the hospital to ensure that they can tolerate the medication, she observed.