IV Ketamine Effect on Post-Concussional Migraine
In the course of treating an outpatient patient with intravenous ketamine for CRPS-Type 1, a salutary effect of the treatment on the patient’s post-concussional migraine was noted. The following case report chronicles the treatment.
GR, a 21-year-old right-handed male, was seen in consultation on referral from an anesthesia colleague, CMS. In July 2007, he had a 10-month history of a left shoulder and traumatic brain injury while at work. He was struck by a wooden palette in the left shoulder and head and developed problems with mobility in the left shoulder. This was surgically repaired, after which he developed hyperesthesia, allodynia, color and temperature changes, together with chronic daily burning and stabbing pain in the left upper extremity. Over the next few months, he developed a frozen shoulder with inability to use his left upper extremity at all. The fingers of his left hand were held in a contractured posture with severe pain upon simple opening. He also complained of a daily headache, throbbing in nature with nausea and photophobia.
He was initially referred to CMS for a Worker’s Compensation-based chronic pain management program and subsequently referred to one of the authors (JCK) for intravenous ketamine treatments for his CRPS-Type 1 symptoms.
After initial evaluation and examination, an intravenous line was placed in his right upper extremity at the antecubital fossa. Ketamine, 0.4 mg per kilogram [= 30mg], was infused over two hours. This reduced his number 10/10 pain severity down to 5/10. After a break for lunch, a repeat 2-hour IV ketamine infusion was performed using a dosage that was increased by 10% [0.44mg/kg, =35mg], and this further reduced pain to #0/10 in severity. Allodynia had reduced by about 75% after the first two ketamine infusions.
His #7/10 headache also was completely abolished on the first day. Pain returned to #7/10 by 4 hours after the end of the ketamine infusions on the first day. He did not fall asleep during the ketamine infusion, but described transient light-headedness symptoms lasting about 15 minutes.
The following day, he had awakened with #10/10 left arm pain and 5/10 headache. We tried a 2 hour infusion of IV lidocaine, 300 mg. This did not reduce his left upper extremity pain at all, but the headache decreased to #0/10. At this point, he was given two 2-hour sequential IV ketamine infusions [= 37.5mg and 45mg]. After these, he stated that his pain was entirely gone [#0/10] and he was observed to be able to open and close his left hand without pain. Allodynia in the left upper extremity was virtually undetectable.
Again, post-concussional headache was eradicated after IV ketamine infusions on the second day. Very transient “floating” feelings were described during the first 30 minutes of the first infusion and disappeared after about 10 minutes.
On the third day, GR described #5/10 left arm pain in the morning and #0/10 headache with a slight feeling of occipital tenderness on the left side. Two further IV ketamine infusions [0.5mg/kg], lasting 2 hours each, were performed at which point his pain was #0/10 in severity and no allodynia was seen in the left upper extremity. He was able to open and close his left hand without any pain.
No headache (#0/10) was reported on this day after IV ketamine. No side effects were reported by GR despite higher dosages used in the ketamine infusion.
Post-concussional migraines were eradicated with this three-day regimen of ketamine. To help in pain treatment and rehab, GR was instructed to use Ketamine, compounded in a nasal spray, 10 mg per spray (per 0.1 cc), and one spray every four to six hours around-the-clock. This allowed other aspects of his pain treatment and rehabilitation to be performed according to the pain program that he was enrolled in. He maintained his pain levels at less than 5/10 in severity with very little allodynia or hyperesthesia in the affected limb.
The dramatic results using sub-anesthetic doses of IV ketamine in CRPS-Type 1 in this case report mimic findings that have been published using this agent in this and other neuropathic pain conditions.1,2 At the doses employed, IV ketamine has fairly specific antagonist activity at NMDA type glutamate receptors. These receptors have been postulated to play a role in the maintenance of central sensitization, windup, and/or long-term potentiation in chronic pain disorders and perhaps in migraines as well. The virtual eradication of postconcussional migraine is an additional feature of success concerning this case report.
The data presented in this case report presents further evidence of the specific ability of IV ketamine to block ongoing neuropathic pain via antagonism of an NMDA–type glutamate receptors. Similar implications exist for this agent in blocking migraines and other headaches. One of the authors (JCK) has presented recent data on the ability of low-dose IV ketamine to successfully treat neuropathic pain and refractory migraines and headaches.1