Many of our patients with refractory migraine do not respond to first-line acute or preventive treatments, and, almost by definition, first- and second-line treatments have failed in the majority of patients on calcitonin gene-related peptide (CGRP) antagonist medications. Three studies this month highlight the efficacy of CGRP monoclonal antibody (mAb) and small-molecule medications in this population specifically.
Most headache specialists are familiar with the "standard" or PREEMPT onabotulinumtoxinA (Botox) paradigm used preventively for migraine. This protocol uses 155 units of onabotulinumtoxinA over 31 sites in seven muscle groups. OnabotulinumtoxinA vials typically come in 100 or 200 units, and when preparing onabotulinumtoxinA for patients who are being injected most providers are forced to discard most or all of the remaining 45 units. Anecdotally, some providers do inject the entire 200-unit vial, and the additional injection sites are either given in another standard protocol or in a follow-the-pain manner.
The study by Zandieh and colleagues followed 175 patients with chronic migraine who first received three injections of 150 units of onabotulinumtoxinA, then three injections of 200 units of this agent. The additional 50 units were injected into the temporalis and occipitalis muscles — the standard sites were used, but additional units were injected into each of the sites. The majority of patients experienced primarily frontal pain; the injections were not given in specific areas where more pain was manifesting.
The average number of headache days per month decreased significantly when the onabotulinumtoxinA dose was increased; patients tolerated the medication over the 3-month period as well. In practice, many providers use the additional units of onabotulinumtoxinA. This study argues that there is a minimal risk, and probably a potential significant benefit, when using up to 200 units every 3 months. Providers should, however, be aware that in rare instances, some insurances will only cover a 155-unit injection, and the use of additional units may jeopardize reimbursement for those plans.
Many patients anecdotally will use cold or heat as a treatment for acute migraine pain; however, the topical use of temperature has not been well studied for this purpose. Cold stimulus has, importantly, been known to be a trigger of migraine as well as other headache disorders classified in the International Classification of Headache Disorders, third edition (ICHD-3), including external cold stimulus headache and "brain freeze" or internal cold stimulus headache. Hsu and colleagues produced a meta-analysis and systematic review on the use of cold for acute treatment of migraine.
Six studies were found to be eligible for this review. The cold stimulus could be placed anywhere on the head, and the studies could have considered its use for any migraine-associated symptom. This includes headache, eye pain, nausea, or vomiting. The interventions used cold somewhat differently, including as ice packing, cooling compression, soaking, and as a rinse. Both randomized and nonrandomized trials were included in the systematic review; however, only randomized controlled trials were used for the meta-analysis.
The primary outcome evaluated by the authors was pain intensity; secondary outcomes were duration of migraine pain as well as associated symptoms (eg, nausea, vomiting). The meta-analysis revealed that cold interventions reduce migraine pain by 3.21 points on an analog scale, and this was found to be effective within 30 minutes. At 1-2 hours after the intervention, the effect was not seen to be significant. At 24 hours, the effect of cold intervention was marginal. Cold was not seen to significantly reduce nausea or vomiting at 2 hours after intervention.
Although cold treatments are commonly used by patients, there appears to be benefit only early in the onset of a migraine attack. Headache specialists typically recommend early treatment with a migraine-specific acute medication; however, the medication may take minutes to hours before taking effect. Cold can be recommended to patients during that intervening period, and it may help until the time that their acute medications take effect.
Chronic refractory migraine remains one of the most debilitating neurologic disorders and is a challenge even for the best trained neurologist or headache specialist. There are few headache centers with inpatient headache units around the United States, and those that remain use treatments that most neurologists are not familiar with. Schwenk and colleagues retrospectively reviewed the data of a major academic headache center and revealed impressive outcomes in this very difficult-to-treat population.
This study reviewed the outcomes of 609 consecutive patients admitted to the Thomas Jefferson University inpatient headache unit from 2017 to 2021. These patients all received continuous lidocaine infusions that were titrated according to an internal protocol that balanced daily plasma lidocaine levels, tolerability, and pain relief. Hospital discharge occurred when patients were pain-free for 12-24 hours or had a minimal response after 5 days of treatment. All patients had at least eight severe headaches per month for at least 6 consecutive months and had tried one to seven preventive medications, with the result of either intolerance or ineffectiveness.
The primary outcome was change from baseline to discharge pain level. Patients were admitted with an average score of 7.0 of 10 on admission and were discharged at a score of 1.0 of 10. Secondary outcomes were average pain at post-discharge appointment vs baseline (5.5 vs 7.0), number of monthly headache days at post-discharge appointment (22.5 vs 26.8), and current and average pain levels at the post-discharge appointment, which were both significantly lower as well. The most common adverse effect was nausea; others noted were cardiovascular changes, hallucinations or nightmares, sedation, anxiety, and chest pain.
This is an important retrospective on the effectiveness of an inpatient lidocaine protocol for refractory chronic migraine. When considering this population, especially if multiple lines of preventive and acute medications are not effective, referral to an academic inpatient headache center should definitely be considered. This patient population does not respond effectively to most treatment modalities, and this is cause to give them hope.