In the case that I’m reviewing, the patient’s main complaint was the dizziness. What struck me as interesting about the case was that the size of infarcts– bilateral cerebellar (assuming PICA distribution from what I’ve been reading, but the case didn’t come with imagining unfortunately)– as compared to the severity of the deficits. As mentioned in the previous post, her list of deficits was long, the dizziness was just her main concern, which is why I focused so heavily on it in treatment. BUT the multiple infarcts were described as “lacunar.”
What does that term, “lacunar,” mean anyway? That’s not a term I learned in school, but see it a lot on the medical literature.
Lacunar– of or relating to a lacuna, according to Miriam-Webster. Ok, not helpful. Moving on.
Lacuna– a blank space or missing part; a small pit, cavity or discontinuity in an anatomical structure.
Lacunar stroke– occlusion of small penetrating arteries in the brain (Wikipedia).
Key word here being “small.” So these infarcts are tiny. Typically, you see a size correlation with stroke symptom severity UNLESS the structure involved is also tiny.
Diagnosis and initial management of cerebellar infarction as originally seen in The Lancet– Neurology
This article we’ve covered mostly as it’s about assessment, BUT it did have an interesting blurb buried in the middle of the article.
“Although deep cerebellar infarcts do occur in patients with [long-standing high blood pressure] without obvious [clots] or [fatty deposits in the large blood vessels], there is no evidence that they result from [fatty deposits] in the small penetrating vessels; therefore the term “lacunar stroke” […] is probably not the preferred term.”
So that leads me to think that perhaps these multiple small infarcts are not so much due to a local problem as the site of the infarct, but perhaps small clots or fatty deposits from elsewhere in the body that happened to get stuck in this particular area.
This case reminds us that individual anatomical differences also play a role in any physiology and therefore, pathophysiology seen. So I suspect that my case was born with small arteries in her cerebellum that lead her to be susceptible to many small infarcts landing in 1 structure that perhaps originated somewhere else in the body. Her history did not involve in vessel disease, but it did include high blood pressure and atrial-fibrillation (a heart rhythm problem). Both of those are known to cause clots. So my hypothesis is entirely probable. Although I do wonder what lead her body to release so many small clots at once. Curious.
The patient’s nystagmus (involuntary eyeball movements) was some of the craziest I have EVER seen. It made me dizzy watching her eyeballs! It didn’t seem to matter what I did, it was just terrible with everything honestly, although did vary in intensity somewhat as mentioned in the assessment previously.
This article states that the area of the cerebellum fed by the PICA artery– the middle back part– would indeed lead to problems with making eyeball adjustments both with observing external motion and with moving yourself, which my case demonstrated.
The final 3 articles I’ll mention serve as a warning when assessing nystagmus. In courses on management of vestibular cases, we are often taught to look at what direction the nystagmus goes– does it go up? down? rotate?– and use that as one hallmark for diagnosis.
This article discusses 2 cases in which a gravity-dependent, direction changing nystagmus– meaning that the motion of the eyeballs changed depending on how the patient was positioned (lying down, sitting, sidelying) in comparison with gravity– was the hallmark sign they presented with to distinguish them from the peripheral vestibular problems that cerebellar strokes often get confused for.
Then comes the warning of the last 2 articles
So basically the direction of the nystagmus may NOT accurately tell us what’s going on. In fact, they may not present with any nystagmus at all. Be careful when using direction of the nystagmus to guide your clinical decision making. I honestly couldn’t see this without Frenzel goggles at the time of this case, so I didn’t look for it, nor document what direction my case’s nystagmus took.