Recovery depends on neuroplasticity? Yeah...not entirely.

There's this idea among many clinicians and survivors that when it comes to recovery it's all about neuroplasticity. Certainly, my book as well as many of my articles support this concept. But it's not 100% true. Some of recovery comes from stuff other than neuroplasticity.

To explain this, let's nail down two things:
1. What neuroplasticity is
2. When neuroplasticity is important

What is neuroplasticity?
Neuroplasticity – the simplest definition: Changing the structure and/or function of neurons in the brain. Actually, this is not entirely true. Neuroplasticity can happen anywhere in the nervous system. Even peripheral nerves can change in terms of structure and function. This is why, when it comes to stroke, researchers often talk about "cortical plasticity." They are being very specific about where the plasticity is happening: in the cortex of the brain. 

The cortex is where all the neuron cell bodies are, and therefore where all the neuroplastic action is.

So very specifically the definition of neuroplasticity as a relates to stroke is this: Changing the structure and or function of neurons in the cortex of the brain.

Okay. We have neuroplasticity nailed down. Now let me nailed down when neuroplasticity is important after stroke.

When is neuroplasticity important?
The first thing to do is figure out when neuroplasticity is not that important. The cortex of the brain is constantly rewiring in all of us -- all of the time. But it is only robust enough to make a difference in a stroke survivor once they are chronic. The chronic phase is generally defined as "after the first three months after stroke." But probably a better way to define it is: the point after the plateau. So once a survivor has plateaued from then to the end of their life they are considered chronic.

During the chronic phase neuroplasticity is vitally important to recovery. It is only through forging new pathways a chronic stroke survivor learn to move better.

So neuroplasticity is vital to recovery during the chronic phase. And make no mistake: for most very successful stroke survivors who recover a lot the recovery done during the chronic phase is represents a huge part of their recovery.

However, most recovery, for most survivors happens during the subacute phase (from 7 days to 3 months, average). But during the subacute phase neuroplasticity, by and large, is not the predominant driver of recovery.

So what is the primary driver during the subacute phase?

To put it simply, recovery during the subacute phase has to do with "using the penumbra."

The penumbra is the portion of the brain that surrounds the area that was killed by the stroke. NOT using the whole penumbra is the essence of learned nonuse.

The 2 minute survivor exam that tells you a ton

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I've been involved in a lot of trials that have involved brain scanning. (example)

But I've never been a big fan of using brain scans to try to predict the deficit. In school we were taught to look at the artery that was blocked. The artery that was blocked leading to the brain or in the brain was supposed to give you some indication about what deficits were.

I would suggest this is where neurology and physiatry on one hand-- and neuroscience on the other-- kind of disagree. The neurologist and phsyiatrist say that this info (brain scan and/or artery blocked) helps determine the deficit, and even the chance of recovery.

But neuroscientists would suggest that, because the brain wiring is "random access" (that any part of the brain may be wired to any other part of the brain), looking at a brain scan maybe grossly predictive, but really tells you not much at all.

In all my seminars I suggest that the thing to do is to examine the patient in a very limited way.

Here's suggestions that will give you global insight into the potential for recovery:

1. Can they move their hand? First, let's define "hand movement." I would suggest that hand movement is any movement from the wrist to fingers, in any direction. The easiest movement for most survivors is closing (fist) the hand. The problem is that many strokes survivors think that they can't close their hand. If they think they can't, do this: 

• Bend (technically: Flex) the wrist. This will allow you to open the fingers. 
• Put the elbow in more than 90° of extension (more straight than a"shake hands" position) 
• With your fingers inside the palm ask the survivor to try to touch their chin. 
• This will force the flexor synergy into play, and if they are able, the fingers will flex and you'll feel the pressure on your fingers. Voilà: they have hand movement! From that you can determine potential for recovery of the hand. (Hint: there is potential).

2. Brush both forearms lightly with your fingertips. Ask the survivor if they feel the same, and if not, how they feel different. If they do feel different, this suggests that sensation has been hit. Try to get them to give you a percentage ("My bad arm feels about 25% of my my good arm feels"). There is a general association between tactile (brushing your fingertips) and proprioception (feeling where that limb is in space). And proprioception has huge implications for recovery.

3. Vision: Can they follow the tip of a pen with their head held straight in front of them all the way towards their affected side? If they tend not to follow things on the affected side, this suggests a hemi field cut and possibly "unilateral neglect" – an inability to attend to the affected side.

4. Speech: can they speak; do they understand what's being said?

5. Are they walking, how well, how fast are they walking?

There-- now you have global insight into that stroke survivor. Isn't that more important than knowing that an occlusion of the inferolateral arterial group infarcted the posterolateral thalamus?

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