When I started The Stroke Blog in 2014, I had a few ideas of what readers might be seeking. In fact, I kept a running list of topics that I thought patients would find informative. I am now humbled to admit that cerebellar stroke was not on that original list. I had diagnosed and treated hundreds of cerebellar strokes at that point, and had noticed that a number of these patients had complaints that extended well beyond balance and coordination difficulties, but I had not considered writing a blog post devoted entirely to cerebellar stroke. When I heard a segment on NPR in 2015 about a man who was born without a cerebellum, I thought: Okay, I haven’t blogged about cerebellar stroke yet. I’ll put it out there. The result was “Cerebellar stroke – it’s about more than coordination and balance.”
Over the months that ensued, the response was much more robust than I had anticipated. For the past year and a half, without question, this is the post that receives the most daily traffic. It is the post that has received the largest volume of comments from readers. For the past few weeks, I have been reflecting on why this is the case, and I have a few ideas.
First, cerebellar strokes are largely “invisible” in the aftermath they create, meaning they can leave a patient feeling miserable or limited (or both), but this may not be evident to those around them. Because of this, cerebellar stroke patients may be expected to perform at their pre-stroke levels when this is either challenging or impossible for them. Next, many of them are told by healthcare providers when they experience word-finding difficulty, emotional problems, difficulties with concentration, or other symptoms not strictly related to coordination and balance that these parts of their “new normal” do not stem from cerebellar injury (but they actually can). Additionally, cerebellar strokes can be very difficult to diagnose, and are often misdiagnosed initially as benign paroxysmal peripheral vertigo (BPPV), Meniere’s disease, or migraine.
In an effort to keep the dialogue about cerebellar stroke going, I believe that if we as healthcare providers who are likely to encounter patients with this diagnosis can adhere to the following items, care will be substantially enhanced:
- Order the appropriate radiological imaging study. A head CT scan’s sensitivity in revealing evidence of an ischemic process (lack of oxygen-rich blood flow) in the cerebellum is extremely low during the first 24 hours. A brain MRI is a much more sensitive radiological study for identifying early stroke, but even this study isn’t 100% sensitive. Additionally, if a stroke has not occurred yet, but blood flow to the cerebellum is severely restricted because of narrowing in one of the arteries upon which it depends, a CT-angiogram or MR-angiogram would be the appropriate noninvasive radiological study to obtain, because a regular brain MRI is unlikely to declare the existence of the underlying problem.
- You don’t know if you don’t look. Many a patient with cerebellar stroke has initially been thought to have vertigo of a benign etiology based solely on clinical suspicion. Patients with cerebellar strokes can look exactly like patients with benign forms of vertigo. Medical students are taught to perform the Dix-Hallpike maneuver (the patient sits upright and then is abruptly reclined with his or her head hanging off of the back of the bed with the head turned and eyes staring far to the side – for more information click here), and that with this technique they can distinguish between vertigo originating from the inner ear and “central” vertigo (such as from a cerebellar injury). The truth is, if a cerebellar stroke patient is abruptly tilted backwards, vertigo, nausea, and nystagmus (jittery eye movements) can arise, just as they can if there is a problem in the inner ear. A normal Dix-Hallpike maneuver is not helpful in making a diagnosis, and a “positive” one can still be either a cerebellar stroke or more benign vertigo.
- Cerebellar strokes can quickly become life-threatening. The cerebellum sits in a very tight spot just below the back of the brain in an area referred to as the posterior fossa. Very large cerebellar strokes may not seem that severe clinically, but when the cerebellum starts swelling, brainstem compression and death can occur quickly. However, correctly diagnosing a cerebellar stroke and recognizing signs of neurological worsening saves lives. A suboccipital craniectomy is a surgical procedure in which a portion of the skull overlaying the cerebellum is removed, allowing the cerebellum room to swell without putting as much pressure on adjacent brainstem structures. Suboccipital craniectomies are recommended by the American Heart Association/American Stroke Association when patients with cerebellar stroke show signs of neurological deterioration and there is evidence of cerebellar swelling.
- The aftermath of cerebellar stroke is not limited to balance and coordination difficulties in some patients. I elaborated on this statement in the earlier referenced post, which can be found by clicking here.
- Cerebellar stroke recovery is all over the map. Some patients do fabulously well in recovering from cerebellar strokes – it’s all like a bad dream, and they know it happened, but they don’t experience noticeable aftermath from it. Others may have lingering, refractory vertigo. Some have severe migraines, or language difficulties, or swallowing problems. There is no one-size-fits-all formula to cerebellar stroke, so it’s important to keep an open mind when these patients approach us for help.