What is the difference between a stroke and a brain aneurysm?
A stroke occurs when an artery in the brain becomes blocked or ruptures, disrupting blood flow and causing brain cells to die. On the other hand, a brain aneurysm is a bulge or ballooning in a blood vessel in the brain, often caused by damage to the artery.
What Are The Symptoms of Stroke?
In a stroke, we observe a sudden numbness or weakness of the face, arm or leg. Usually, this is present on one side of the body.
Numbness of the body parts is often accompanied by a sudden and severe headache with no known cause [1, 2]. In addition, patients experiencing stroke might also have problems with understanding speech or confusion [1, 2, 3].
Further, early signs of stroke might be vision problems, loss of balance or dizziness. Such problems include sudden trouble walking or seeing in one or both eyes or eye gaze impairment [1, 2, 3, 4, 5].
The symptoms of stroke may vary based on the affected part of the brain. For example, in the case of basal ganglia stroke, the symptoms may include various movement disorders, such as hemiballism , dystonia or akinesia.
Brain Aneurysm Symptoms
A brain aneurysm is a bulge in a brain vessel which can press on the nerves and therefore cause disruptions.
However, brain aneurysms do not cause any symptoms until they become large. When the symptoms occur, they vary depending on the location and size of the aneurysm.
For instance, we can see visual problems such as dropped eyelids, double vision, dilated pupils or even pain behind the eye as a consequence of the brain aneurysm pressing on nerves in the brain [6, 7, 8].
Apart from visual problems, one can experience similar to stroke numbness or weakness on one side of the body, headaches, difficulties with speaking and lack of balance [6, 7, 8]
Causes: Stroke vs Aneurysm
Stroke and aneurysm are both complex conditions with multiple causes. While some causes are unique to each condition, others overlap, possibly indicating a shared pathophysiology.
Stroke Causes
The most common cause of stroke is atherosclerosis a buildup of plaque in the arteries) of the cerebral vasculature or cardioembolism (when the heart pumps unwanted materials into the blood circulation) [9] leading to ischemic strokes or acute ischemic strokes. Ischemic strokes account for almost 90% of all strokes [10, 2, 9].
Hypertension, or high blood pressure, is a contributor to stroke and is considered a significant risk factor for stroke [11, 12, 13]. Hypertension contributes to both types of stroke, the aforementioned ischemic stroke but also hemorrhagic stroke (a less common type of stroke).
In addition to hypertension problems with smoking, alcohol high cholesterol or diabetes and obesity can also contribute to ischemic stroke [11, 12].
Although a lot of progress in understanding the causes of strokes has been made, around 30% of strokes occur without any of these risk factors present [14].
In rare cases, strokes can be caused by conditions such as iron deficiency anaemia [14], and certain genetic factors have also been implicated in the aetiology of ischemic stroke [15, 16].
Aneurysm Causes
The exact cause of aneurysm is often unclear. However, several factors have been identified which contribute to the development of aneurysm.
Arterial damage and high blood pressure are one of the main causes of aneurysms. Arterial damage can be caused by blockages made of fatty deposits which lead to the heart pumping “harder” than necessary to push blood through the fatty buildup. This added stress due to increased pressure can then damage the arteries [17]. On the other hand, high blood pressure can enlarge or weaken blood vessels leading to the development of aneurysm [17, 18].
Atherosclerotic disease, a form of plaque buildup in the arteries, can also lead to an aneurysm. The plaque, composed of cholesterol, fat, and other substances, damages the arteries and prevents blood from flowing freely [17].
Apart from these, certain genetic conditions and abnormalities of blood vessels have been identified to contribute to the formation of aneurysms.
Certain genetic conditions and abnormalities of blood vessels can also contribute to the formation of aneurysms. In particular, mutations in genes encoding extracellular matrix protein or Marfan’s syndrome ( a polycystic kidney disease) and neurofibromatosis (a genetic disorder that causes tumours to form on nerve tissue) have been associated with an increased risk of the aneurysm[19].
Similarly to the risk factors contributing to stroke, smoking, and obesity increase the risk of aneurysm [17, 18]. In addition to these, a diet high in fats and cholesterol does so as well.
Interestingly, males are more likely to have aneurysms than females and so do people over 65 [17].
Treatment: Stroke vs Aneurysm
Stroke and aneurysm are both serious medical conditions that require immediate attention. The treatment for each condition varies depending on the type, severity of the condition and time elapsed since the onset of symptoms.
Stroke Treatments
The treatment of stroke involves a variety of methods, including:
Thrombolytic Therapy
Thrombolytic therapy involves the use of tissue plasminogen activator (tPA) to restore cerebral blood flow in the acute phase of ischemic stroke. However, this treatment sometimes causes hemorrhagic transformation and has a narrow therapeutic window, typically within 3 hours of stroke onset [20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30].
Stem Cell Therapy
Stem cell therapy is used to repair disrupted neuronal networks with newly born neurons in the chronic phase of ischemic stroke [20].
Drug Therapy
Drug therapy includes the use of antiplatelet and anticoagulant medications to prevent future strokes. These medications reduce the likelihood of blood clot formation. Examples include aspirin, clopidogrel (Plavix), warfarin (Coumadin), and dabigatran (Pradaxa) [27, 31].
Carotid Endarterectomy
Carotid endarterectomy is a surgical procedure. In this procedure, the patient gets plaque buildup in the carotid artery (a major cause of stroke) removed. This serves as a prevention procedure [26, 27].
Neuroprotective Agents
Neuroprotective agents are still in ongoing clinical trials. Precisely in Phase II and III clinical trials. These agents aim to protect brain tissue against ischemia and might provide future prevention against strokes [32].
Non-Pharmaceutical Therapies
Non-pharmaceutical therapies for stroke include rehabilitation exercises, hypothermia, ischemic/hypoxic conditioning, acupuncture, medical gases, transcranial laser therapy, and mechanical endovascular recanalization devices [33].
Drug Repurposing
Drug repurposing is a novel approach to broaden treatment options for stroke. It involved using available drugs which are not intentionally stroke treatment drugs to treat symptoms of stroke or prevent stroke based on their safety and efficacy [22].
Restorative Therapy
Restorative therapy targets the repair processes after a stroke. This includes drugs, growth factors, monoclonal antibodies, activity-related therapies including telerehabilitation, and devices related to brain stimulation or robotics [34].
Aneurysm Treatments
The treatment of aneurysms has evolved significantly over the past few decades. Currently, there is a wide range of available treatment ranging from surgical to non-surgical methods.
Surgical Treatments
- Endovascular Coiling
This is currently the gold standard for aneurysm treatment. However, recurrence is observed in over 20% of cases [35].
- Clipping
This is another treatment option for cerebral aneurysms [36].
- Endovascular Stent Graft
This minimally invasive procedure is used to repair and reinforce damaged blood vessels, reducing the chance of infection, scarring, and other problems [17].
- Use of Hydrogel
A novel hydrogel composed of polymeric alginate, a novel ion-releasing glass, and glucono-delta-lactone has been developed to treat aneurysms [35].
Non-Surgical Treatments
- Medications
These aim to prevent the aneurysm from getting larger or bursting. Medications that may be used for aortic aneurysms include beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and statins [37].
- Lifestyle Changes
As mentioned above, smoking, a high-fat or high-cholesterol diet and obesity are major risk factors for aneurysm development. Therefore, quitting smoking, focusing on a heart-healthy diet, getting regular physical activity, and reducing stress might be a good idea as a prevention strategy [37].
In addition to these, new technologies and techniques are being developed and tested, such as stent-assisted coiling, flow-diverting devices, and Onyx embolic agents [38]. However, the choice of treatment depends on the location and type of aneurysm, and the patient's overall health condition.