Andrew Phelps

30 October 2020

Stroke and Aphasia

I work in the ER as a phlebotomist, and we have many patients a day who’s reason for the visit is, “Altered mental status” or the board says, “ams,” for short. The causes of each of their changes in mental status are extremely variable. It could be a symptom of sepsis, injury, stroke, genetic disease, or several other things that hopefully the doctors getting the big bucks can figure out. It’s wild how so many different things can affect the brain in different ways. 

A few times a day I’ll hear the call overhead, “Code stroke one” and I’ll hurry and run to the hallway with a few other staff while they bring back a patient who recently began displaying stroke symptoms. I will do my part of throwing an IV in their arm and snagging some blood samples before we send them off to get a scan of their brain to make sure there’s no hemorrhage. 

Since I’ve been working here I’ve always been intrigued by this process and intrigued by the ams and stroke patients. There’s many ways that injuries to the brain manifest themselves in the rest of the body, and many ways that things affecting the body also affect the brain. Being myself so intrigued, and being given an opportunity to research the brain and drugs that treat it, I decided to dig into strokes, complications, and treatment and how they affect the brain and beyond.

There are two main types of strokes: ischemic and hemorrhagic. In an ischemic stroke, something has blocked a blood vessel in the brain, leading the downstream cells to suffer from lack of perfusion of nutrients and death. In a hemorrhagic stroke, a blood vessel in the brain will burst and bleed into the brain tissue. Both of these damage the brain and cause similar symptoms, however the acute treatment will differ. This is why when we bring the patient back, after the physician conducts a physical exam and I insert an IV and collect blood samples, we send the patient to CT to look for a brain bleed or ischemic damage. 

If a patient presents with an ischemic stroke, there is IV medication to treat it. Tissue plasminogen activator (tPA) dissolves the blood clot that is causing the stroke and restores blood flow to the ischemic tissue. While not a complete reversal of the effects, this reduces damage and improves the prognosis for recovery. However, a patient is only a candidate for tPA treatment within 4.5 hours or so of onset of stroke symptoms. Of course, anticoagulant treatment is not viable to use in the case of a hemorrhagic stroke as was the case with an elderly patient who recently came in with severe stroke symptoms and imaging showed he had a brain bleed. In such cases, medication to relieve intracranial pressure and blood pressure are favored.

The many complications and ways a stroke affects the patient and their recovery is where it starts to get real juicy. While there are many, many complications that require attention, I would like to focus on post stroke aphasia, including types, therapy, and drug treatment. I am lucky to have a friend who is a speech and language pathologist and has experience with these patients. I was able to ask her questions to help guide my research.

Poststroke aphasia, the impairment of the patient’s ability to express and comprehend language due to brain damage, is present in 21-38% of acute stroke patients (Berthier, 2005). There are different types of aphasia and some classic syndromes depending on the area of the brain that is damaged. Wernicke's aphasia, damage to the part of the brain responsible for comprehension of speech, is also referred to as fluent aphasia or receptive aphasia. On one recent occasion I was trying to explain some things to a kind, confused elderly woman, she kept repeating, “I can hear that you're talking but I can’t understand what you’re saying.” In Wernicke’s/fluent/receptive aphasia, production of speech is not impaired, but the patient’s understanding is. My friend who works with these patients described them as being able to talk all the day long, yet their response is, well, less than 100% correlated with whatever question you’ve just asked them. 

Another common aphasia is Broca’s aphasia. Broca’s area is the region of the brain in the dominant side of the patient’s frontal lobe and has functions linked to language processing and speech production. A stroke in this area impairs the patient’s ability to express speech. While they may know what they want to say, they can’t form the words and sentences to express it. I can’t imagine how frustrating either of these syndromes would be. One afternoon I was collecting blood samples from a patient who’d had a stroke earlier that day. It took several minutes of struggled communication between us for me to understand what he was asking me for. 

While knowing the type of aphasia in a patient can be helpful, it does not always influence prognosis and applied therapy. The type of aphasia also commonly changes during therapy. The caregivers such as my friend, rather than working according to type of aphasia, always target and work according to whatever is the patient’s deficit. The patient’s prognosis for recovery depends almost solely on the severity of the stroke, and slightly on the location/type of aphasia. Previous intelligence of the patient may also help recovery and, of course, socioeconomic status influences access to resources and therefore prognosis. 

Interestingly, it has been shown that the brain is able to adapt pretty well to slow destruction of Broca’s area, keeping speech functional, likely shifting the function to a nearby part of the brain (Plaza et al., 2009). However, acute stroke gives the brain no time to dodge. Though, full recovery is possible even for patients with severe aphasia.

Recovery from stroke is possible due to the brain’s plasticity. The brain can rewire itself following an injury, making new connections. The healthy part of the brain can acquire the functions of the injured part, allowing the patient to relearn the skills they had lost. This brain plasticity allows for a high degree of spontaneous recovery, and our treatment methods are directed at modifying and boosting this process (Hara, 2015). 

Speech and language therapy (SLT) is a ubiquitous treatment, though it is not proven to be extremely effective. Researchers have been looking into drugs to be used as treatment, usually in conjunction with SLT. The results are… alright. They’re mixed. Some work better than others, yet none are demonstrated by large-scale studies to be valid. Most drugs being tested theoretically help the brain plasticity used to recover.

The most widely investigated and commonly used are dopaminergic drugs, levodopa or bromocriptine, a dopamine agonist. The treatment is most effective in patients with transcortical motor aphasia, adynamic aphasia, and mild to moderate Broca’s aphasia, but no effect in cases of severe Broca’s aphasia. The benefits are attributed to enhanced dopaminergic tone in the mesocortical pathway. The drugs increase neurotransmitter levels, stimulating widespread cerebral activity and enhancing effects of behavioural treatment. This is most helpful while the brain is most plastic in the 6-12  months following the stroke. In trials, the drug is ineffective without concurrent SLT also being applied. However, some randomized studies show the drugs to help, and some don’t. It seems that the common thing with stroke treatment, from onset to a year out, is that nothing works perfectly but we’re sure going to try our best.

1. Berthier ML. Poststroke aphasia : epidemiology, pathophysiology and treatment. Drugs Aging. 2005;22(2):163-82. doi: 10.2165/00002512-200522020-00006. PMID: 15733022.

2. National Aphasia Association. (2019, October 30). Wernicke's (Receptive) Aphasia. Retrieved October 31, 2020, from https://www.aphasia.org/aphasia-resources/wernickes-aphasia/

3. Plaza M, Gatignol P, Leroy M, Duffau H. Speaking without Broca's area after tumor resection. Neurocase. 2009 Aug;15(4):294-310. doi: 10.1080/13554790902729473. Epub 2009 Mar 9. PMID: 19274574.

4. Mayo Clinic. (2020, August 08). Stroke - diagnosis and treatment. Retrieved October 31, 2020, from https://www.mayoclinic.org/diseases-conditions/stroke/diagnosis-treatment/drc-20350119?mc_id=google

5. Toronto Stroke Networks. (2016). Neuroplasticity. Retrieved October 31, 2020, from http://strokerecovery.guide/neuroplasticity

6. Berthier ML, Pulvermüller F, Dávila G, Casares NG, Gutiérrez A. Drug therapy of post-stroke aphasia: a review of current evidence. Neuropsychol Rev. 2011 Sep;21(3):302-17. doi: 10.1007/s11065-011-9177-7. Epub 2011 Aug 16. PMID: 21845354.

7. Gill, S. K., & Leff, A. P. (2012). Dopaminergic therapy in aphasia. Aphasiology, 28(2), 155–170. https://doi.org/10.1080/02687038.2013.802286

8. Hara Y. Brain plasticity and rehabilitation in stroke patients. J Nippon Med Sch. 2015;82(1):4-13. doi: 10.1272/jnms.82.4. PMID: 25797869.