Stroke Education

I really need to be working. I am chronically behind at work. Some of it is due to the amount of time I've been out due to the stroke and its aftermath. Much more of it is due to the seasonal nature of our business. But anyway, there's no way I'm going to be able to concentrate on my job until after the kids are in bed anyway, so I thought I'd share with you a little of the knowledge I've accumulated in the last month.

J.J.'s stroke occurred in the middle cerebral arterty (MCA) in the left hemisphere of his brain. The MCA is essentially a branch of the carotid and is the main blood supply for the frontal lobe. Left MCA strokes are the most common type of stroke, with incidence of about 80 per 100,000 people per year.

Although we still don't know for sure, the theory is that J.J.'s stroke was an ischemic stroke. This means that an obstruction (a blood clot, embolus or similar) travelled to the MCA and created a blockage. This type of stroke has about a 70-85% survival rate during the acute phase, which is defined as the first 30 days. Ischemic strokes are the way to go in this case; the other classification of stroke is hemorrhagic (where the blood vessel leaks blood into the brain), which has only about a 20% survival rate in the acute phase.

The risk of MCA stroke increases with age. Most MCA strokes occur in individuals in their 70s and 80s. Of the strokes that occur in younger patients (defined as those under age 46), most are hemorrhagic. About 20% of strokes in patients under the age of 45 are defined as having unknown origin, which is what I assume J.J.'s will end up classified as. So we do have company, although it's not a typical case.

Okay, so now that we have that out of the way, let's look at the area where J.J.'s stroke occured. In most (about 95%) right handed individuals, the brain's speech and language functions are housed primarily in the left hemisphere. The main speech centers are Broca's area (a small area lying between the frontal and parietal lobes) and Wernicke's area (which lies further back in the parietal lobe, also taking up some real estate in the temporal and occipital lobes). Broca's area is responsible for expressive language, the ability to formulate speech. This is the aphasia I refer to (although in J.J.'s case, it would technically be known as dysphasia. The prefix a- indicates the absence of something, which is not true for J.J. He can speak, it's just not as he normally would. The prefix dys- indicates trouble performing the task). It also plays a role in reading comprehension and written expression. From J.J.'s deficits, we know that his stroke dramatically impacted Broca's area. Wernicke's area is responsible for language comprehension. Since J.J. has very little trouble understanding what is said to him, it is likely that this area of his brain was not impacted by the stroke.

Okay, so what are other classic impacts of a left MCA stroke?
-Apraxia, which is the inability to perform previously learned movements without physical damage to the structures responsible. The term apraxia is often qualified to denote the part of the body impacted. You may recall that J.J. originally was diagnosed with apraxia of speech, which meant that he had trouble getting his lips and tongue to move in ways to create speech. Over 90% of patients with Broca's aphasia have this problem at some point. This issue seems to be almost completely resolved.

-Extinction and/or neglect, where objects placed on one side of the patient's visual field are ignored. In left MCA strokes, the neglect should occur on the right side. J.J. has been diagnosed as having some slight right neglect, but I challenge this diagnosis given the fact that the man IS BLIND IN HIS RIGHT EYE. I don't notice any significant changes from his pre-stroke function in this area.

-Right side physical weakness. Specifically in left MCA strokes, the hand and arm are often impacted more severely than the right leg and foot, which are partially spared. J.J. has had the right side weakness, although it seems to be mostly resolved. In his case, though, his deficits were actually worst in his lower body. Just J.J. bucking conformity. Again.

-Difficulty swallowing. This actually never was a problem for J.J., but the possibility of it being a problem is what kept him NPO for a couple of days.

-Numbness or sensation changes. Again, this never was a problem in J.J.'s case.

-Diminished attention span. This actually is a slight problem for J.J., although he's always been slightly to the ADHD end of the spectrum. It's getting much better as time goes on, though. I actually think this, rather than the damage to Broca's area, is responsible for some of his reading comprehension problems.

-Difficulty creating new memories. Haven't noticed any gaps in J.J.'s memory, other than perhaps the night of the stroke.

-Motor planning problems, especially with walking. Again, not a problem for J.J.

-Peripheral vision loss. This is why we saw the specialized optometrist. J.J. did not lose any peripheral vision and actually has a better visual field than most people with two functioning eyes.

-In some rare cases, patients experience a syndrome called facial agnosia, which leads to difficulty identifying familiar objects, particularly faces. Thankfully, not J.J.

So there you have it. By looking at the symptoms J.J. does and does not have, we can narrow down the area of damage in his brain to a very small sliver of the posterior left frontal and the anterior left parietal lobes. And indeed, this is what the CT scan confirmed.

The good news is that as a 33 year old man, J.J.'s brain has a large amount of plasticity, which is the ability to shunt functionality away from the damaged areas and into other areas of the brain. This is what's happening every day with him and why he's making such progress. It's not a linear process, though, which is frustrating to him. And sometimes the deficits make very little sense; for instance, J.J. has a big problem with the word "pineapple". Can't say it on his own, doesn't respond to cuing, takes several tries to repeat it after me when I say it. So the neural connection to wherever he's stored pineapple in his brain appears to be still under construction. Luckily, I doubt this will keep him from leading a full and productive life.

Now I must go do some INHP work. But I hope this has shed some light on what's going on in J.J.'s head. I actually think it's fascinating, although I kinda wish I wasn't in the middle of a case study...