Single Limb Myoclonus and Unresponsiveness after General Anesthesia

[Aether2000]

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Could use some ideas on this one-
27 year old without ever having sedation or general anesthesia previously with a completely normal history and physical exam except being overweight but not obese. She was given fentanyl 100mcg, midazolam 2mg, propofol 160mg for induction- uncomplicated nasal intubation for oral surgery excision of two teeth. The anesthetic was 20min with Sevofluorane used for maintenance. These were the only medications she received.
On emergence she developed right upper extremity rhythmic clonus with primary motor activity in the wrist and rotation of the hand. The clonus was sustained and did not significantly wax or wane over 30 minutes. She had been extubated as she was bucking on the ETT and had no neuromuscular blockers given, however she failed to regain consciousness, respond to verbal commands or painful stimuli. The eyes were open and responsive to light, but there was no tracking, no blinking, and the lid lash reflex was absent. No other significant findings on physical exam. During the surgery the pulse was 105-135 but did not become extremely tachycardic and was never bradycardic. ETCO2 averaged 32-40 for the surgery. On transfer to the emergency department (6 min away) via ambulance, she began to respond to my voice by rotating her head on arrival in the ER. Within 2 hours all symptoms of unconsciousness resolved. A CT of the brain that night was normal and the next morning, EMG and MRI of the brain were normal. All labs were normal. Next day, no sequelae. The only memory she has was awakening when being removed from the emergency vehicle when being transported into the EMR. I have heard of myoclonus from anesthetics (propofol) and perhaps from Sevo. I am not familiar with an hour and a half of the symptoms of myoclonus in only one extremity and unresponsiveness.

Any ideas?

 

[sevoflurane]

Sounds like epilepsy.

 

[Hoya11]

Could use some ideas on this one-
27 year old without ever having sedation or general anesthesia previously with a completely normal history and physical exam except being overweight but not obese. She was given fentanyl 100mcg, midazolam 2mg, propofol 160mg for induction- uncomplicated nasal intubation for oral surgery excision of two teeth. The anesthetic was 20min with Sevofluorane used for maintenance. These were the only medications she received.
On emergence she developed right upper extremity rhythmic clonus with primary motor activity in the wrist and rotation of the hand. The clonus was sustained and did not significantly wax or wane over 30 minutes. She had been extubated as she was bucking on the ETT and had no neuromuscular blockers given, however she failed to regain consciousness, respond to verbal commands or painful stimuli. The eyes were open and responsive to light, but there was no tracking, no blinking, and the lid lash reflex was absent. No other significant findings on physical exam. During the surgery the pulse was 105-135 but did not become extremely tachycardic and was never bradycardic. ETCO2 averaged 32-40 for the surgery. On transfer to the emergency department (6 min away) via ambulance, she began to respond to my voice by rotating her head on arrival in the ER. Within 2 hours all symptoms of unconsciousness resolved. A CT of the brain that night was normal and the next morning, EMG and MRI of the brain were normal. All labs were normal. Next day, no sequelae. The only memory she has was awakening when being removed from the emergency vehicle when being transported into the EMR. I have heard of myoclonus from anesthetics (propofol) and perhaps from Sevo. I am not familiar with an hour and a half of the symptoms of myoclonus in only one extremity and unresponsiveness.

Any ideas?

Agree with sounds like a seizure. That is a short, light, rough anesthetic on a 27 year old patient (probably with some type of mental problems). Maybe she was light and in combination with the sevo and an underlying brain problem, and she seized. Could also be just a very strange wake-up with in-between/unconscious activity being the observed clonus.

 

[Aether2000]

My first thought was also a Jacksonian seizure. The EEG was normal the next day and she had no history of seizure activity. How bizarre!

 

[lobelsteve]

What side was the extraction done on? Was local anesthetic used as well?

 

[Planktonmd]

This a seizure followed by a postictal phase.
The 30 minutes duration of the convulsions is probably why the postictal phase was so profound.
The normal EEG next day does not rule that out.

 

[Promethean]

It isn't epilepsy unless she has more than 1 unprovoked seizure.

You can't call this one an unprovoked seizure. She was exposed to some potent CNS agents. Did one or more lower her seizure threshhold just enough?

You say those were the only meds she received, but is that really true? Are you only thinking about meds administered by the anesthesiologist? So the surgeon did not administer ANY local? That seems odd. I would expect that lidocaine would be administered, at least, for post-op pain management. How much lidocaine? Did she get a larger than appropriate dose, or was it maybe accidentally administered into a vein? There are a range of strengths available, and if the wrong vial were chosen, or if it made it into systemic circulation too quickly, or if she happened to be especially sensitive, lidocaine would be enough to cause her to seize.

Even if she didn't get that med, she could have an idiopathic sensitivity to one of the agents that you listed above. Usually, general anesthetics make seizure less likely, but that isn't always the case for everyone.

 

[Promethean]

http://anesthesiology.pubs.asahq.org/article.aspx?articleid=1944222

 

[Aether2000]

She did have a small amount of local 2% lidocaine. I suppose seizure activity would be possible but I have never seen a Jacksonian seizure with lidocaine- all those I have witnessed were generalized. Thanks for the insight and the thoughts!