By Chris Baraniuk
To Lori Lemon, the doctors all seemed flabbergasted. She had come in to the Mayo Clinic in Jacksonville, Florida, to have a lipoma – a growth of soft fatty tissue under the skin – removed from her elbow. She needed to have the area around the lump numbed for the procedure, but that was proving inexplicably difficult.
“All the ways and all the different medications that they had at their disposal – none of them worked,” she says. Steven Clendenen, an anaesthesiologist at the clinic, confirms her story. “The nerves were flooded with local anaesthetic and at the time it didn’t work,” he recalls. Her physicians might have been surprised, but Lemon wasn’t. She’d had this problem, local anaesthetic resistance, for as long as she could remember. The first time she remembers it coming up was decades ago at the dentists, when she was about seven.
I just kind of screamed and was in tears the whole time – Lori Lemon
“They started working on me and I, being obedient, I just raised my hand and let ’em know, ‘I can feel this’,” she says. Another injection of the local anaesthetic had no effect. “Finally I just kind of screamed and was in tears the whole time.”
Clendenen, who had seen first-hand the effects this resistance had on his patient, decided to investigate further. He found a handful of stories scattered in the medical literature concerning strange cases where patients claimed local anaesthetic had no effect on them. It turns out that no-one really knows what’s going on in these patients – either in terms of what mechanisms cause the resistance, or what the best remedy may be. But a new genetic study of Lemon and her family may set us on the path to discovering the answer.