Intracranial Aneurysm

Introduction:?

Intracranial Aneurysm develops when a localized dilation or ballooning of the blood vessel form may be as a result of pressure in the vessel or other external influences. There are different types of aneurysms, they include;?

1. Saccular Aneurysm?

2. Fusiform Aneurysm?

3. Microaneurysms?

4. Subarachnoid Hemorrhage?

5. Microaneurysm?

Treatments?

● Surgical Clipping?

● Endovascular Coiling?

Thesis?

Can signs of aneurysm be overlooked in a woman who is undergoing post-menopause and do gender inequality quantify this ??

Modified* : Signs of Aneurysmal subarachnoid hemorrhage (SAH) can be overlooked in women (Possibly input an age range) undergoing post menopause because of estrogen deficiency.

Theory?

Genetic conditions associated with connective tissue disease may also be associated with the development of Aneurysms. Specific genes are also associated with intracranial aneurysm. Health disparities can play a role in diagnosing an aneurysm, especially if the patient is a female above the age of 40. Could aneurysms be more prevalent in women above the age of 40 than men due to social and environmental stressors that come with their gender and how does that lean into the?

Background/ Abstract?

Intracranial aneurysm is disorder that weakens the wall of the cerebral arteries or vein there are still many factors that have not been found in regards to how this aneurysms are formed because for the most part it is the causations or end results that the physician sees. Most times it is only the solutions that are researched not what created the aneurysm. The thickness and solidity of the skull proves to be a disadvantage in this peculiar type of disease and only diagnostic imaging would provide the slightest clue to even know there is somethings to be cautious of, even diagnostic professionals who find aneurysms could be living with aneurysms themselves and not know it. Like balloons floating around a pile of sharp pins, these aneurysms wait for years and most cases decades before they prove to be dangerous There are four different types of aneurysms;?

1. Saccular Aneurysm: Also known as a berry aneurysm, it appears as a round outpouching and is the most common form of cerebral aneurysm. When larger than 25 mm the maximal dimension they are called great cerebral aneurysms, they develop as a result of chronic hypertension and appear most commonly in the basal ganglia and other areas like the thalamus, pons and cerebellum which have small penetrating vessels.?Berry aneurysms can be imagined in a variety of methods with Computed Tomography(C.T) angiography, Magnetic Resonance(M.R.I) angiography and digital subtraction (Catheter) angiography in general the Catheter is considered the gold standard. In C.T, the appearance is well-defined round, slightly hyperactive lesion with calcification present; in most cases there is a bright uniform enhancement. For MRI, if it is a T1 the aneurysm appears as flow void or may show heterogeneous signals intensity but in T2,(W. Philip, J.Easton, 2001), the aneurysm is typically hyperintense as a laminated thrombus may show a hyperintense rim. Management of small aneurysms is controversial less than 7mm in maximal diameter aneurysms are statistically unlikely to rupture however in numerous patients with small ruptures develop to subarachnoid hemorrhage, the consequences are devastating.?

2. Fusiform Aneurysm: Fusion dolichoectatic aneurysm represents a hardening of a segment of an artery around the entire blood vessel, rather than just arising from a side of an artery's wall. They can rupture but usually they do not and are most common in the vertebrobasilar circulation, they can be accidental or asymptomatic very often this aneurysms are discovered during check-ups for unrelated symptoms,(A.Yeung, P.Howard, 2010). Fusiform aneurysms can be presented as nonspecific headache without hemorrhage or other signs such as transient ischemic attack or worst subarachnoid hemorrhage?

3. Microaneurysms: Also known as charcot-bouchard aneurysm, typically occur in small blood vessels (less than 300 micrometer in diameter), most often the lenticulostriate are minute aneurysms which develop as a result of chronic hypertension and appear most commonly in the basal ganglia and other areas of the brain. Many times they are confused with saccular aneurysms found in larger intracranial vessels in subarachnoid space and a rupture of charcot-Bouchard aneurysms is the most common cause of intracerebral hemorrhage and is commonly seen in patient on anticoagulation.?Patients will present depending on the region and size of the hemorrhage. Putraum hemorrhage usually presents with ipsilateral deviation of the eyes due to descending capsular pathways from the frontal eye field. Thalamic hemorrhage on the other hand often presents with downward deviation of eye and lack of pupillary response to light and lastly pontine hemorrhage usually causes coma due to disruption of the reticular activating system (unless small) and quadriparesis due to disruption of the coctiticspiral tract. Chronic hypertension causes lipohyalinosis of small arterioles so that there is a defect in the muscular coat and only a thin intimal layer with some surrounding gliosis. All this makes the charcot-bouchard aneurysm prone to rupture, with the inability to control bleeding by vasomotor spasms.?

4. Subarachnoid Hemorrhage: Subarachnoid hemorrhage, a medical emergency, is usually from a bulging blood vessel that bursts in the brain (aneurysm). It may lead to permanent brain damage or death if not treated promptly. Subarachnoid hemorrhage is one of the types of extra-axial intracranial hemorrhage and denotes the presence of blood within the subarachnoid space. Patients tend to be older than middle age, typically less than 60 years old(B.Saveland. H.Brandt, 1985) subarachnoid hemorrhage accounts for 5% of stroke and 5% of stroke deaths.

Patients typically present a thunderclap headache, usually the worst headache of their lives, it is often associated with photophobia and meningism. In a substantial number of patients (almost half) it is associated with collapse and loss of consciousness even in those patients who subsequently regain consciousness and have a good grade. (C.Borkhataria et al 2017) Focal neurological deficits often present either the same time as a headache or soon thereafter and 5 groups are present for grading the patients on their clinical presentation, using the Hunt and Hess grading system.?There are three distinct patterns of subarachnoid hemorrhage and several treatments and prognosis complications: suprasellar cristen with diffuse peripheral extension,(JD.Nafziger et al 1965) perimesencephalic and basal cistern and isolated cerebral convexity. Aetiology includes; trauma, cocaine use, enous infections, cerebral vasculitis and many more, risk factors include family history, connective tissue, female gender, African race and japanese or finnish descent.?

Although MRI is thought to be more sensitive to the presence of subarachnoid blood than CT, as well as having great sensitivity to the wide range of causative lesions, logistics and limited access means that in the vast majority of cases a CT if the brain is obtained as the first investigation (S.Worthy, A.Gholkar, 1996). The diagnosis is suspended with a hyperattenuating material seen filling the subarachnoid space. Most commonly this is apparent around the circle of willis, on account of the majority of aneurysms occurring in this region or in the sylvian fissure. Small amounts of blood can sometimes be appreciated pooling in the interpeduncular fossa appearing as a small hyperdense triangle or within the occipital horns of the lateral ventricles.

Subarachnoid hemorrhages are grouped into four categories according to the amount of blood by the fischer scale. This scale has been updated to the modified fisher scale which correlates the risk of vasospasms more accurately. MRI is sensitive to subarachnoid blood and is able to visualize it well in the first 12 hours typically as a hyperintensity in the subarachnoid space on FLAIR (VE.Torres, DO.Wiebers, 1992), this angiography and venography are able to detect a causative aneurysm or another source of bleeding but the problem is poor availability compared to CT, longer scan times and great difficulty transferring and looking after patients who often are unstable and intubated.?

Importance of the disease, prevalence?

The prevalence varies on the size of aneurysm, posterior circulation has a higher risk of rupture, they are small aneurysms , large aneurysms (25mm) and super giant aneurysms( 50mm). 1% to 5% of the world suffers from this disease, 4 0ut of 7 people who suffer aneurysms end up with disabilities, the ratio of women to men is 3:2. Catheter ablation is less invasive but it destroys the blood vessels and causes bleeding.?

Symptoms of disease, diagnosis?

Before ruptures individuals usually feel; severe headache, nausea, vision?impairment, vomiting and loss of consciousness. (P.Greebe, D.Hassan, A.Algra 1995)Some individuals do not show any symptoms which makes diagnosis difficult

Figure 1: Prevalence of aneurism per age group from five autopsy studies and five angiographic studies.?

The risk of rupture of aneurysms depended more on the characteristics of the aneurysm than on those of the patient. Women and patients at higher age tended to have an increased risk of rupture, but the 95% confidence intervals were wide, (J.Gijn et al 1996). Symptomatic aneurysms, posterior circulation aneurysms, and large (>10 mm) aneurysms had a higher risk of rupture. Additional aneurysms also had a higher risk of rupture than accidentally found asymptomatic aneurysms, but this difference was not statistically significant. Data provided in the publications were insufficient for a multivariate analysis to assess whether these factors are independent prognosticators.?

Disease progression?

If an aneurism begins to leak (ruptures) the onset usually presents a thunder-clapping headache and depending on the size, a focal neurological deficit, (D.Moher, P.Fortin, T.Klassen, K.Linde, 1996). Unfortunately genetics associations comes into effect mostly when the patient is 60 years or older, many people have aneurysms that would not present a problem throughout their life, but because of neurodegeneration other diseases may come into effect and be the cause

Figure 2: Bar graph?demonstrating frequency of?subarachnoid hemorrhage?in patients with vertebral?artery aneurysms by?different locations?

For the risk of rupture, the?type of aneurysm is an important factor. Incidentally found aneurysms tend to have a lower risk of rupture than aneurysms found additional to a ruptured aneurysm, (MM.Cohen et al 1955). Symptomatic aneurysms, aneurysms larger than 10 mm, and basilar artery aneurysms were all found to have a markedly increased risk of rupture. Because symptomatic aneurysms are often large, size and being symptomatic may not be independent risk factors, but unfortunately the data provided in the publications did not allow us to assess the interdependence of these factors.?

Data on prevalence and risk of rupture vary considerably according to study design, study population, and aneurysm characteristics. If all available evidence with inherent overestimation and underestimation is taken together, for adults without risk factors for subarachnoid hemorrhage, aneurysms are found in approximately 2%, (D.D’Spouza, CY.Lee SH.Park, 2015). The vast majority of these aneurysms are small (=10 mm) and have an annual risk of rupture of approximately 0.7%. After the initial assessment for eligibility, two authors independently extracted the following data for studies on prevalence: total number of patients; number of patients with aneurysms; age and sex of all patients and of patients with aneurysms; and site and size of the aneurysms found. The indications for angiography were categorized into the following groups: family history of SAH, ADPKD, atherosclerosis (carotid artery disease or ischemic heart disease), suspected pituitary adenoma, brain tumor, and other, (W. Pryse-Phillips et al 2003). The ages of the patients were grouped into decades; the sites of the aneurysms were grouped into one of four locations:(P.Gates et al 2010), (1) Internal Carotid Artery, (2) Anterior Communicating Arteries or anterior cerebral and pericallosal artery, (3) Middle Cerebral Artery, and (4) vertebrobasilar arteries. The sizes of the aneurysms were categorized into categories of 5-mm increases, and the size was also dichotomized into 10 mm or larger. For follow-up studies in patients with unruptured aneurysms, we recorded the total number of patients, the period of follow-up, and the number of patients with SAH, (C.Oppenheim, V.Domigo, 2005). When possible, we stratified data according to age and sex of the patients and to site and size of the aneurysms, (GJ.Rinkel, J.Gijn, 2001).?

Figure 3: Bar graph demonstrating frequency of subarachnoid hemorrhage in patients with vertebral artery aneurysms by aneurysmal size

Treatments?

The two major treatments are surgical clipping and endovascular coiling (Table 1), and the results so far have seen a huge amount of success but not until the discovery of various medical imaging Technique Physicians could not really see through the skull, (SK.Baik, CH.Sohn, 2005). Aneurysms can be diagnosed radiologically using?magnetic resonance and CT angiography?

● Which imaging techniques could be used?

T1 weighted magnetic resonance imaging has been shown to be?more specific than CT due to the size the aneurysm might present?and the use of high-resolution CT angiography combined with the use of digital subtraction angiography with dynamic rotational views provides the best possible visualization of the flow pattern and characteristics of any intracranial aneurysm?

What are the advantages and disadvantages of each technique (including cost and availability).

MRI is not only slow but at the same time extremely expensive and in most cases many of the patients are rushed to the Emergency Department and that time span is not available (CP.Marder, V.Narla, 2014). CT on the other hand is fast and inexpensive but it is not specific and again if the imaging is done in a hurry, there is that possibility of overlooking important details during a ruptured aneurysm.

What clinical questions need to be answered??

In most cases the question is how big, how big the aneurysm has become and if it can begin of cause cognitive malfunctions. Could genetic conditions associated with connective tissue disease be associated with the development of Aneurysms, (C.Helms, WE.Brant, 2012) and since we know specific genes are also associated with intracranial aneurysm how can that be avoided??

What information does imaging provide??

Imaging provides the size and location of an aneurysm; imaging gives the medical professional options either to begin treatment if diagnosed early or avoid doing anything if it would cause a cognitive impairment to the patient.?

How do the results impact treatment options??

An aneurism in the cerebellum would definitely cause locomotive disorder and if the size that gone out of proportion imaging helps to provide that outlook.Depending on the location again, if the aneurism would affect their personality especially for a younger patient this result would impact the treatment options, (P.Berlit et al 2010).?

How useful is imaging??

Especially in the cases of aneurysm, imaging helps like a G.P.S in spotting the location in the brain and because in the past the skull had to be opened, survival declined. Imaging today has helped most importantly to see through the skull and the survival has increased.

What is the sensitivity and specificity??

Time is a very sensitive and specific aspect intracranial aneurysm unfortunately not everyone go for brain check-up, brain check-up in the sense that like the regular yearly check-up not many people ask for a CT scan or an MRI scan and by the time the aneurysm is ruptured, (L.Lorier, A. Penna, 1996), the chaos becomes so overwhelming first to the individual then the medical professionals who are?

Figure 4. A magnetic resonance imaging scanner?

Conclusions?

A family member of mine suffered a stroke due to an aneurism and was paralyzed before she even arrived at the hospital, of course it was disheartening, her medical history showed that she had high blood pressure as well as hypertension and though she lived an active life this case was as a result of skipping her medication for just a day the irony was that she was a medical professional who worked at a state of the art hospital and never thought of a an MRI or CT scan to detect any signs or symptoms, (A.Algra, B.Sonesson, 1997). A healthy diet and constant check-up can help with preventing aneurysms 1/50 people have aneurysms and it is indeed a ticking time bomb inside the head and early diagnosis would definitely help, like trying to diffuse anything, finding the location on time is always the first step and that is where imaging continues to play that role.?

The information that this paper is portraying is not to scare the mass, but to educate and bring awareness to this serious silent killer that really has existed for a long time without detection. Though some people are genetically born with high blood pressure in today's society especially with osteopathic medicine, a healthy/stress free lifestyle and a conscious effort to go for yearly medical checkups can all be preventive measures for a safe life on earth, (EFM.Wijdicks, CM.Duyn. D.Hasan, 1995). It is a relief to know that a lot of research is going into stem cells and how they can be used to regenerate either through neurogenesis for autoimmune diseases or advancement on radiation therapy is specifically eliminating cancer cells or abnormal growth.

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