M2E Too! Mellick's Multimedia EduBlog
The M2E Too! Blog by Larry Mellick, MD, presents important clinical pearls using multimedia.

By its name, M2E Too! acknowledges that it is one of many emergency medicine blogs, but we hope this will serve as a creative commons for emergency physicians.

Thursday, December 1, 2016

Hemiplegic Migraine and Paraspinous Cervical Injections with Bupivacaine

I recently treated a patient with hemiplegic migraines successfully with bupivacaine cervical injections, a novel therapeutic technique using paraspinous cervical injections. The technique employs deep intramuscular injections of 1.5 mL of 0.5% bupivacaine bilaterally into the paraspinous muscles of the lower neck. (Read more in my October 2012 blog and see it demonstrated in a video at http://bit.ly/2ewC5n1.)

This headache and orofacial pain treatment was first described in 1996 by my twin brother, Gary Mellick, DO, a neurologist who did a pain fellowship. The exact mechanism is unknown, but the treatment appears to work centrally on the brain based on convincing observations. Evidence of central effects include resolution of cortical-related signs and symptoms such as nausea, photophobia, and allodynia. The first three cervical nerves that innervated the neck and scalp travel directly into the brain stem and the trigeminal caudate nucleus, a relay center important to other successful headache medications. This relay center in the brain stem also has synapses with cranial nerves 5, 7, 9, and 10 and antinociceptive centers such as the periaqueductal gray, nucleus raphe magnus, and the rostroventral medulla synapse, which have a profound antinociceptive effect. Neural connections to the cerebral cortex are also documented.

Until now, no actual physical evidence has documented central activity other than patient-reported relief of headache and nausea, photophobia, phonophobia, and allodynia. This recent pediatric patient with hemiplegic migraine demonstrated dramatic physical examination changes after the injection that were undeniable. He had been admitted before after presenting with right-sided headache and left-sided hemiplegia, but this time had other known complications of this condition when he came to the ED: He was altered and only slightly responsive to painful stimuli. Because this 12-year-old basketball player was quite tall for his age, four health care providers were required to lift him from the wheelchair to the gurney because he was incapable of assisting or following directions.

I consulted with his parents, and we decided to try the bilateral cervical injections with bupivacaine. The patient demonstrated only a slight painful response to the first injection, but he was able to have a conversation with his father and move all four extremities 15 minutes after the injections. He was able to stand shortly after that, but still had difficulty walking because of residual left-sided weakness. He was admitted for further evaluation and observation.

Hemiplegic migraine has two forms, the familial hemiplegic migraine and the sporadic hemiplegic migraine. The familial form is dominantly inherited, and genetic studies have implicated mutations in the genes that encode proteins involved in ion transportation. This type of migraine headache is usually accompanied by an aura featuring a motor deficit and at least one other symptom such as aphasia, vertigo, tinnitus, or visual and sensory problems. Protracted motor deficit, confusion, coma, and seizures or status epilepticus can also occur during a severe crisis. Diagnosis of this condition is made by the process of elimination. The patient, however, may simplify the situation by presenting with the diagnosis already established. Other family members, usually first- and second-degree relatives, may have been previously diagnosed with this condition.

My patient's two older brothers also have the condition. The neurologic deficit is real and may last for minutes to hours. Prolonged speech deficits and residual motor weakness can occur depending on which cerebral hemisphere is involved. Headaches develop during or after the deficit and are often accompanied by typical migraine signs and symptoms. Severe crises, however, can present with altered mental status and even a Glasgow coma score of 3. Patients also can experience hyperthermia (41°C), respiratory failure, major confusion, agitation, hallucinations, vomiting with the risk of aspiration, and seizures, including partial or generalized status epilepticus.

Workup includes documenting absence of hypoglycemia, a battery of standard laboratory tests and toxicology screens, and CT scan and MRI. A lumbar puncture is recommended in the presence of fever and altered mental status. Other potential studies include an EEG, ECG, and chest x-ray.​

This was the first hemiplegic migraine patient I had ever treated with cervical injections, and the outcome of headache relief and subsequent neurologic recovery was clinically dramatic. This patient's response provided further evidence supporting the centrally acting mechanism of this therapeutic intervention.

mellick migraine.JPG

This 12-year-old with hemiplegic migraine could not even walk upon arrival at the ED, but could raise his arms and move his legs 15 minutes after a bupivacaine cervical injection. Watch a video of that and of his father explaining his history.​