UCT researcher goes out on a limb to deal with 'phantom' pain

09 October 2017 - 13:43 By Claire Keeton
Pain researcher and physiotherapist, Maxwell Katleho Limakatso, with Nico Oosthuizen - who suffers from phantom limb pain.
Pain researcher and physiotherapist, Maxwell Katleho Limakatso, with Nico Oosthuizen - who suffers from phantom limb pain.
Image: Esa Alexander

University of Cape Town physiotherapist and award-winning pain researcher‚ Maxwell Katleho Limakatso‚ has showed how simple therapies can dramatically reduce phantom limb pain among patients who have undergone amputation‚ in a new study he is conducting in Cape Town.

The clinical trial is treating patients from Khayelitsha and Somerset and Victoria Hospitals.

The younger patients with amputations tended to have lost limbs in traumatic accidents‚ while conditions like diabetes were more likely to be the cause of amputations in older patients.

Diabetes patients expect their burning pain to disappear after amputation but often they still feel it.

Limakatso said: “Pain is all in the brain‚ an output of the brain. With very cheap treatments that stimulated the brain‚ some patients said their pain dropped from being 10/10 to zero/10.”

This is the first time a clinical trial on phantom limb pain using Graded Motor Imagery of the brain has been done in Africa.

The imagery programme demonstrated that reactivating the shrunken region of the brain that had controlled the missing limb caused that region - the cortical representation of the limb - to grow and the phantom pain to drop.

The severity of the pain was related to the extent to which that region had shrunk‚ prior research has found.

To stimulate the brain region controlling the missing limb‚ Limakatso used three steps: training left-right discrimination‚ imagined movements with sensory input‚ and finally mirror visual feedback.

“During mirror visual feedback‚ the visual reflection of the intact limb looks like the missing limb and that’s what the brain sees. Even though‚ for example‚ we know we see a reflection of our right hand moving (while the missing left hand is hidden)‚ our brain interprets this visual reflection as the left hand and this activates the shrunken region therefore regaining its territory in the brain.”

He said: “After six weeks our patients’ pain scores were zero. We followed up at three months‚ and the positive results were still maintained. We will follow up at six months in November.”

The therapies they used on the trial were cheap and “anybody could do them anywhere”‚ Limakatso said.

The UCT researcher said some patients with mysterious phantom limb pain were relieved to learn that this pain stemmed from their brain and not bewitchment.

“One person said he could not see his leg‚ but he could feel pain in that missing leg. Unable to get a solid explanation‚ he thought the pain was punitive and somebody had bewitched him‚” Limakatso said.

He won the best free-paper award at the PainSA conference in May for presenting a systematic review titled: The Effects of Graded Motor Imagery and its Components on Phantom Limb Pain and Disability in Upper and Lower Limb Amputees.