I want to have a little thread here about cerebellar stroke, and everything I have gleaned so far from having had one, and current research into the matter. I hope that my information is accurate or at least in the right ball park. I will edit this thread if anything needs to be amended or added as time goes on. Obviously, this thread may only be of interest to cerebellar stroke survivors.
As we know, every stroke is different because the damage will be dispersed disparately, and our brains all have been shaped according to our own development. However, there will be some commonalities in how the symptoms post-stroke affect us. In the same way that each one of us will respond subjectively to being struck by a bramble, depending on many variable factors concerning the bramble strike, but the wound will most likely still be the same.
The cerebellum houses 80% of the brain pan’s neurones, when we have a stroke, professionals deems that we lose 1.9 million neurones a minute. The cerebellum is referred to as the “little brain”. A cerebellar stroke is rare, accounting for 2-3% of all strokes, but it also has nearly twice the mortality and morbidity rate compared to a regular cerebrum stroke. We are very lucky to be alive. Post-cerebellar stroke is so little understood that it has a name all to itself, “cerebellar stroke syndrome”. In my view, the cerebellum is a sort of survival filter for the cerebrum, it makes sure we don’t knock things over, or say the wrong thing, or get ahead of ourselves. Excuse the pun. I have heard many medical professionals say that if you could choose your stroke, a cerebellar stroke would be the one to choose. I disagree.
The cerebellum remains an under-explored part of the “entire brain”. It has always had the reputation as the motor-function part of the network, but recently it has been discovered that it also manages some language and emotional functions little understood. It is the survival mechanism to the higher part of our cerebral system. That means it operates most of our primitive functions, but over time has adopted some more complex functions as well.
If you have a cerebellar stroke, the main problem is going to be the cerebrum-to-cerebellar communication loop. The big brain is working fine, but when it sends a message down to the damaged cerebellum, the message gets scrambled, and what gets passed on to the vestibular and central nervous system is lost in translation. This also relates to the oculomotor reflex function, so even if your occipital lobe is trying to see something for what it is, the cerebellum can’t quite pass that information on to the eyes. In turn, there may also be oculomotor reflex dysfunction because of this disruption to the cerebral-cerebellum loop. This equates to our cognitive visual-spatial awareness. It’s a precision function that when disrupted causes giddiness, blurriness, double-vision, nystagmus, stereopsis, and a whole host of other distortions that make just looking around, taxing on the old grey matter.
Another large concern will be the body’s vestibular system, which is the internal balancing function that keeps us steady. This disruption is part of the vestibular-oculomotor function that attempts to place us where we should be in a physical space. It is difficult to use physiotherapy in order to rectify this because every positioning of the body and every surrounding environment is always going to be slightly different, this adds more stimulus to the brain and more calculations need to be managed in order to function in a calibrated way. If I walk out into my garden, and walk across the grass twenty-times, each of those times are going to be different. It may be the same walk but the lighting will change, my thoughts will change, my movement will change, the wind will change, movement outside will change, my focus will change … all of this is a new challenge for the brain despite it being the same walk.
Another cognitive disablement of cerebellar stroke may be the working memory. Memory we use to function everyday. Survival memory. It’s more than just walking into a room and wondering why you went in there. This affects many people, and shouldn’t be attributed to stroke. Working memory is retaining information short-term. It’s tabla rasa, not just getting distracted, as we all do, even with an undamaged brain. This, I am to suspect, is why multi-tasking is difficult but it is also key to exercising that memory function. Exercising the memory with sequences is a good way to encourage the brain to be able to multi-task again without straining itself.
Language. cerebellar stroke can affect language use. Particularly the parsing of sentences, the syntax if you like. recent research has narrowed aspects of it down to agrammatism, which is using incorrect inflections in a sentence. I suffered from this acutely during the first year of the stroke. I would use the wrong tense frequently, and have to go back and correct my sentences. Now, I seem to muddle up"on/in" a lot. I do this in speech and in writing. Fortunately, care for solecism is less these days, so I notice others doing it more than me.
Emotions. Cerebellar stroke can lead to blunted emotional response, inappropriate behaviour and disinhibition. All the things we ought not to do if we want to survive. Once again, a survival mechanism that has been cross-wired, making for social responsibility challenging. I have a reduced impulse control and disinhibition of saying what I think. It has led me into some murky waters, but those closest to me are aware of this. I have actually had to turn on my inner monologue and tell myself not to say something lest it be taken the wrong way.
A little bit to start physio. Physio with cerebellar stroke is difficult. It’s important, I think, to always exercise in a controlled environment, as well as going out and doing everyday things. The reason for this is because the brain uses preconceived experience to function using the least amount of energy so that it can save its reserves for the unexpected. If we just carried on with life as usual, our damaged brain doesn’t have the facility to rely on these preconceived experiences because that function has been disrupted. So, the brain will be firing on all cylinders, and thus we get fatigued, but also it can’t implement repair effectively. So, a controlled environment allows the brain to achieve what it needs to achieve without being strained. Then, we can go out an it will be better prepared for the everyday. Conceivably, cerebellar stroke symptoms can repair through everyday life, but it may take longer and be more exhausting than if balanced with contained exercises.