Monday, April 11th, 2016
Which Recovers First After A Stroke – The Arm or The Leg? By Peter G Levine
“Which comes back first after a stroke, the arm or the leg?”
First-year OT and PT students know the answer to this question: the leg. However, the reasons driving the leg’s speedy recovery are not so simple.
Here are some reasons to rethink this “leg comes back first” perspective.
The Leg “Comes Back” First Because It Gets A Lot Of Help
The leg has two great aids that help it do its primary function immediately. Anyone who’s ever treated stroke survivors knows what they are: AFO’s and assistive devices (canes, walkers, etc.). So here’s your quiz: What are the analogues in the upper extremity? That is, what helps survivors immediately use the upper extremity in some sort of real world way?
Let’s focus the question on the basic grasp and release function of the hand. Primarily, the joints in the UE are designed to position the hand. In other words, the entire upper extremity is dedicated to help the hand function. So back to our question: What is the analog for the AFO and assist device for the upper extremity? Put another way, which rehab devices can a survivor use to help them immediately grasp and release? There are really only three possibilities: electrical stimulation, an outrigger orthotic that uses bands or springs to passively open the hand, or a wearable robot.
Few clinicians use outrigger orthotics and few use electrical stimulation to make the hand functionally grasp and release. Even fewer have used anything like a robot on the hand. So when someone claims the leg comes back before the arm, they’re really reflecting the fact that the leg mends functionally through the assistance of devices designed to help the survivor walk. Meanwhile, the hand is usually left to its own devices.
You Have Another Arm
There’s an old joke about injuring the arm: “I don’t worry about it. I have another one.” You can live a pretty productive life with one arm. But try walking with one leg. Because walking is such an important element of day-to-day functioning, recovering functionality in the leg is the central priority for recovering from a stroke. The arm, though, can be left to do little to nothing for the remainder of the survivor’s life.
The lack of use of the arm leads to many detrimental physiological processes that work against recovery, including muscle atrophy, continued spasticity, and soft tissue shortening (contracture). However, that’s not even the worst of it. The lack of attention paid to arm recovery after a stroke taps into the brain’s “use it or lose it” quality. If the arm is not being used, the part of the brain dedicated to the arm shrinks. In fact, it shrinks a lot and very quickly. This process is known as “learned nonuse.”
No One Cares About The Toes
If you were to be honest about the “what comes back first” question, you would focus on the toes. Typically, the last things that come back after stroke are the most distal parts of the body, which are the fingers and the toes. Most clinicians believe these distal parts come back last because of an old canard in rehab that says “Return of recovery is proximal to distal.” However, recent research has proven this to be incorrect.
It is true that because the movement of fingers and toes is the most complex, it typically takes the longest for the brain to corral. So if you wanted to prove the “arm comes back before the leg,” you’d have to make finger and toe extension your outcome measure, and nobody ever measures toe extension post-stroke. Why? Because toe extension is mostly used during dorsiflexion, and is seen an unnecessary because of the AFO.
So What Does Come Back First?
While no one knows definitively, it is still widely accepted that the upper extremity comes back earlier. This conclusion originated in a study conducted by Thomas Twitchell in the 1950s and has been questioned little since. It may be high time to rethink.
It is true that functionally, for the reasons outlined about, the leg comes back sooner. But if true neurological control over the limbs were the benchmark, a new framework may emerge in which the relative return is a toss-up. Recovery from stroke is notoriously variable.
If the leg comes back first functionally, and function is what everyone for managed care prioritizes, the leg does, indeed, recover first. But what if recovery and not function was the goal? (They are different after all.)
The arm suffers from a “bigotry of lowered expectations.” It’s almost as if the collusion of managed care requires that if a limb cannot be tied or wrapped or cajoled or have some orthotic on it to make it immediately functional, it is disregarded to the “learned nonuse” trash heap.
There is, however, a bit of good news: researchers from around the world agree that increased intensity improves outcomes. It may not be that the arm comes back after the leg. The arm’s stunted recovery may actually be a result of rehab focused on prioritizing function over recovery. Like the leg, the arm needs focused attention in order to recover to the highest level.