Could unlearning “learned non-use” after a stroke be this fast?
Warning: technical jargon ahead
Stroke unpredictably affects basic sensory and motor functions. Rehabilitation methods are typically tailored and delivered by specialists.(1)(2) For some stroke patients, the lost use of an impaired limb results from a “learned” behavior. the non-use may improve through repetitive training.(3) Called “locked-in syndrome”, a stroke in the main movement control centers in the brain leaves the person unable to move any part of their body.(4)(5)
Could the therapy help recover any function after being “locked-in” for 14 years?
In development studies, PhotoMed’s team included people with disorders that they expected would not improve. The software and hardware engineers were looking for failures that might help find boundaries for PhotoMed’s therapy. Machine-learning techniques combed the data to improve the treatment algorithm.
The studies recorded functional improvements that might occur during first few visits. Patients reported that it was “easier” to move while PhotoMed’s therapy was being applied. Newly resumed functions could continue to improve in the absence of additional therapy.
14-years prior, Josephine had a massive stroke in her brain stem that left her in a “locked in” state. She could voluntarily only raise and lower her left eye. Up for yes. Down for no. Josephine was fully awake, aware, and had normal sensory functions throughout her body.
Josephine is quick to tell a joke if you’ve got a few extra minutes for her to spell each letter by signaling with her eye.
She enrolled in one of PhotoMed’s studies without expectation of improvement. The team wondered, could a few visible photons awaken movement? Probably not. Everyone agreed. It seemed useless to video fingers that hadn’t moved for more than a decade. Talk about an embarrassing missed opportunity.
Within 5 minutes of PhotoMed’s therapy to her fingers and elbow, Josephine reported that she could see her fingers move under her command for the first time. The motion was barely visible to others in the room.
4 days later, Josephine returned. She was eager to demonstrate movement of her fingers and wrist. (21 seconds)
The recording show that her fingers were straighter than might have been expected. Flexion-contracture typically leads to a clenched fist. What might be going on for 14 years.
What might happen if she tried to talk?
Consistent with other stroke and spinal cord injury patients, Josephine reported that it was easier to move when PhotoMed’s therapy was turned on. She and her husband, Winston, asked to try therapy on her face and mouth. Nothing visible happened right away. Josephine reported that her tongue felt more flexible and moved to where she intended.
Then she decided to make speech sounds. At first her breath seemed too weak for anyone else to hear. However, her sounds grew stronger within minutes. This video shows her progress by the end of the visit. (1:06)
Over the next few weeks, Josephine’s speech efforts appeared to recruit her diaphragm. She could laugh (rapid diaphragm action) and to breathe more deeply.
Perhaps most important to Josephine, the time between suctioning her mouth and tracheostomy tube increased from 10 minutes to an hour or more.
We don’t know how Josephine could respond to PhotoMed’s therapy after 14 years. Could her impaired function result from “learned non-use”?
A Historical Note
Edward Taub, PhD, coined the term “learned non-use” in 1972. He developed “constraint induced therapy” to help stroke affected parts to move again. With Dr. Taub’s permission, we link to one of his papers. (3)
(1) https://www.ninds.nih.gov/disorders/patient-caregiver-education/fact-sheets/post-stroke-rehabilitation-fact-sheet Post-Stroke Rehabilitation Fact Sheet
(2) https://www.ninds.nih.gov/Disorders/All-Disorders/Stroke-Information-Page Stroke Information Page
(3) https://www.ncbi.nlm.nih.gov/pubmed/17039223 The learned non-use phenomenon: implications for rehabilitation
(4) https://rarediseases.org/rare-diseases/locked-in-syndrome/ Locked-in syndrome
(5) https://rarediseases.info.nih.gov/diseases/6919/locked-in-syndrome Locked-in syndrome