Congenital and Other Risk Factors in Cerebral Aneurysm Pathology

 Introduction 

Although less than 10% of people in the United States will have a cerebral aneurysm (CA)—either an unruptured or ruptured—the malady still seriously affects nearly 30,000 Americans each year (Nahed et al., 2007). A dangerous ballooning of a brain blood vessel (often where the vessel bifurcates in the brain), cerebral aneurysms tend to affect more women than men and more people over the ages of 50 to 60, although it is prevalent in all age groups (Etminan et al., 2015).

Considered by many to be a quiet killer (Sundt, 2019), the occurrence of cerebral aneurysms can be mysterious, with a variety of risk factors and anatomical features acting as catalysts for their development and potentially dangerous consequences. Treatment of an aneurysm depends upon its classification (secular, fusiform, mycotic), with the victims’ prognosis being historically mixed (Hokari et al., 2013; Olafsson et al., 1997). Overall, cerebral aneurysms are both complex in anatomical formation and complex in medical diagnosis and treatment. Decades of research have narrowed down the causes and risks for cerebral aneurysms into three main camps: congenital in origin, developmental in origin, and volitional or behavioral in origin (Schiffer et al., 2002; Sadasivan et al., 2013; Weir et al., 1998).

Many people are born with structural problems of their arteries and/or blood vessels that have a propensity to develop into an aneurysm later on in life (Woodhall et al., 1952). Thus, an aneurysm can develop over a person’s lifespan, contigent upon the natural breakdown of body tissues, detrimental effects of various diseases, and the reduction of arterial plasticity over the years. Finally, many people embrace risky lifestyles that can increase one’s chances of developing an aneurysm such as heavy drinking, excessive smoking, unhealthy over-eating, and wanton drug abuse.

With the aforementioned in mind, this paper will provide an in-depth discussion of the etiology of cerebral aneurysms, specifically concerning how the three different etiological branches of aneurysms (congenital, developmental, volitional) stem from and/or affect cerebral anatomy and function.

Origins of Aneurysms

Congenital Genesis

As mentioned earlier, cerebral aneurysms can be congenital in origin. Many victims of cerebral aneurysm are born with diseases and syndromes that affect the brain’s vascular structure and functionality (Olubajo et al., 2020). Complicating diagnosis and treatment, pediatric aneurysms are rare, diverse, simingly spontaneous, and dissimilar in many ways to adult aneurysms (Requejo et al., 2010). As Albornoz et al. (2006) point out, “Our finding in this large series that more than 20% of TAAs occur with familial clustering . . . This statistic certainly under-estimates the true prevalence of aneurysm disease in kindred, however, because many family members may harbor unknown aneurysms” (p. 1404).

Most people are aware of more of the serious congenital defects such as cleft lip, club foot, Down syndrome, muscular dystrophy, spina bifida, anencephaly, and and so on. Beyond these are more hidden congenital cerebral disorders such as phenylketonuria (PKU), neural tube closure defects, corpus callosum anomalies, or other structural and vascular weaknesses—all of which that can lead to brain aneurysms. Victims of cerebral aneurysm are often born with serious anatomical malformations (Regalado et al., 2011). These include a weakened endothelial layer, or people may suffer from neural tube closure issues, cephalocoele, and other disorders that can lead to localized swelling of intracranial arteries that can become aneuryistic (Zhou et al., 2018).

Inherited Genesis

Although anyone can be stricken with a cerebral aneurysm, several medical studies have shown that familiar patterns of past aneurysms increases the likelihood of a first-degree relative suffering the same fate (Juvela et al., 2001). In other words, if a parent or grandparent has had aneurysm issues, it is very likely that their children will, too (Mackey et al., 2013). This is due to the natural transmission of genes and chromosomes from parent to child (Requejo et al., 2010), with many people in danger of developing inherited anatomical weaknesses (Albornoz et al., 2006). For instance, familial aneurysms are one of the biggest risk factors for close relations themselves developing intracranial berry aneurysms later on in life (Hitchcock et al., 2017).

Narrowing it down even more, both Ehlers-Danlos syndrome and Marfan syndrome (noticeable at birth) can negatively affect the vascular environment of the brain (Rubinstein, & Cohen, 1964). Vascular Ehlers-Danlos syndrome, because of its genetically-fostered arterial fragility, can lead to serious intracranial problems such as carotico-cavernous fistulae and aneurysms in the Circle of Willis (Olubajo et al., 2020). Although rare, Marfan syndrome can affect connective tissues in the brain and/or spinal column, leading to hemorrhages or aneurysms (Wityk et al., 2002). Inherited genetic orders such as these can dramatically impact the social, psychology, and physical life of its sufferers.

Therefore, due to the early onset incidence rate associated with familial aneurysms, close relatives (first-order) should be screened as soon as possible (Albornoz et al., 2006). Furthermore, it is important to consider the options in determining if an aneurysm exists, and then to formulize steps in preventing an aneurysm from developing. Finally, it is imperative to determine which treatment(s) can and should be utilized if a cerebral aneurysm is diagnosed (Bacigaluppi et al., 2014; Tanweer et al., 2014).

Developmental Genesis

Not all cerebral aneurysms are genetic or inherited. Some cerebral aneurysms are developmental in origin (Sadasivan et al., 2013). That is, the cerebral aneurysms are caused from physical impairments experienced as people’s bodies grow and change through their life stages.

Pathologically (and depending upon the type of disease or disorder), degeneration can occur in crucial anatomical regions of the brain at a cellular or vascular level (Frosen et al., 2012). Weakened cellular walls can become prone to aneurysm ruptures (Frosen et al., 2012). Sharp arterial angles and underdeveloped vascular bifurcations in the brain can create a risky region for the development of aneurysms (Bor et al., 2008). As Sadasivan et al. note (2013), “The consequences of aneurysmal hemorrhage are dire, carrying a mortality rate of about 50% and a morbidity rate among survivors of about 50%” ( p. 1347).

Aneurysms are also connected to other diseases such as diabetes and polycystic kidney disease (Krex et al., 2001; Matsumura et al., 1985), but even some functionally healthy bodily states can act as an impetus for cerebral aneurysms. Paradoxically, lowered serum cholesterol has been associated with intracranial hemorrhaging in the eldery Japanese in Hawaii and Japan (Yano et al., 1989). Thus, the potential for developing a cerebral hemmorhage has a lot to do with which disease a person is stricken and with the overall condition of his or her changing anatomical systems.

Complicating medical matters even more (and adding to the mystery of cerebral dysfunction), aneurysms can occur anywhere in the body and for a number of reasons. For instance, intracranial hemorrhages are more about stress than the site (Kondo et al., 1997). Cerebral aneurysms also share characteristics with other types of aneurysms in the body (Tanweer et al., 2014); yet, traumatic aneurysms are rare and are more likely to be situated on extradural vessles rather than intracerebral arteries (Benoit & Wortzman, 1973).

Generally speaking, the degradation of the body’s vascular environment can put any person at risk for aneurysms as well. Vascular tone, diminishment of elasticity, and thinning of vasculature can escalate the development of aneurysms (Valencia et al., 2008). The development of blood disorders or structural dilapitation can also lead to the formation of aneurysms (Sadasivan et al., 2013). Hypertension (especially in association with smoking and drinking) is strongly correlated with the formation of aneurysms (Krex et al., 2001).

Behavioral Genesis

Not all aneurysms stem from genetic or developmental causes. Some cerebral aneurysms are volitional or behavioral in origin (Sadasivanet al., 2013). Succinctly, people’s choices and actions can directly lead to the formation of cerebral aneurysms. As Pozzi et al. (2008) state, “The spreading misuse of cocaine, amphetamines, and ecstasy among young people had modified the list of the traditional etiological factors for hemorrhagic stroke” (p. 269).

As one of the significant factors, smoking increases the risk of developing an aneurysm (Chalouhi et al., 2012).Moreover, cigarette smosing is correlated with a high percentage of subarachnoid hemorrhages in the brain (Chalouhi et al., 2012). Not surprisingly, consistent, heavy smoking is strongly associated with cerebral aneurysms (Adamson et al., 1994). Somewhat tragically, although many cigarette labels warn about the dangers of smoking leading to strokes (and clogged arteries), not many labels warn about how smoking promotes the growth of intracranial aneurysms (Juvela et al., 2001).

Another dangerous pastime, drug use can be damaging to the brain’s vascular health and increases one’s risk of developing an aneurysm (Mcevoy et al., 2000). Drugs like cocaine and methamphetamines create a host of hemorrhagic disorders in the brain (Pozzi et al., 2008). Although most drugs are physically harmful regardless of introduction method, intravenous drug use is correlated with a rare but serious risk of intracranial aneurysms (Ares et al., 2018). Even popularly-considered “safe” and “legal” drugs like marijuana still carry dangerous risks because of their effects on the heart and cerebral vasoconstriction (Auger et al., 2020).

A persistent artifact in all cultures, historically, alcohol has long been correlated with the development of cerebral aneurysms (Stampfer et al., 1988). Social drinking patterns (casual, acute, chronic) are integral to possibly cultivating or preventing the development of cerebral aneurysms (Teunissen et al., 1996). Smoking and alcohol could be confounders, since people often do them simultaneously in relaxation or celebration. Speaking again of conflicting physical factors, for women, moderate alchol drinking increases the risk of subarachnoid hemorrhaging but decreases the risk of coronary heart disease and stroke (Stampfer et al., 1988).

Conclusion 

Due to the complex etiology of aneurysms, it is important to know the various congenital, developmental, and volitional forces at work in the human brain and how they may lead to the development of cerebral aneurysms. The causes of cerebral aneurysms can be still somewhat indeterminate; however, there are scientifically acknowledged risks that can lead to their formation and avoidance. These include genetic and congenital factors, normal life development health issues, and poor personal choices such as smoking, alcohol, and drug use. All of these issues can influence the vascular environment of the brain, leading to intracranial aneurysms.

Beyond the physical or health factors concerning cerebral aneurysms, there are key implications for those who embrace the Christian worldview. Regarding the mortal risks associated with cerebral aneurysms, although God does not rejoice when his children suffer physically, the reality of the Fall (when Adam and Eve rebelled and brought sin into this world) carries with it the natural consequence of death. With explicit purpose, the Bible mentions that it is not good that man should live forever in this fragile state (Gen 3:21–23, New International Version). Yet, the Bible also indicates that God does not ultimately want to doom humanity to afflictions such as cerebral aneurysms.

Fortunately, any physical maladies leading up to death that people experience on earth will be rectified and their bodies restored when His followers join God after the Great Judgment (2 Cor 5:1–10, New International Version Bible). In the meantime, human beings are admonished to live good, healthy lives and to depend upon the fruits of God’s wisdom in the Bible (and in the counsel that He gives to the world, in many ways). As God is truth, scientific truths can be embraced and utilized to serve and help others through their suffering. In fact, there is a biblical mandate that people are to love one another (John 13:34, New International Version Bible) and bear each other’s burdens (Galatians 6:2, New International Version Bible).

Therefore, neuropsychological assessments are more than reasonable and beneficial—as long as they do not require Christian professionals to recant their faith or to repent to the inferior, as spelled out in the Old and New Testaments. Within moral limits, medical methods used to treat cerebral aneurysm (that do not come at the cost of another person’s life or through worshipping anyone or thing besides God) are allowed and endorsed in the Bible. Supporting this, one need only look to the Gospel of Luke, the book of Acts, and other writings of the church fathers to learn about this ancient physician who was regularly spoken of and favorably.

Of course, any healing that goes on right now is only temporary, and human beings still must contend with medical maladies like cerebral aneurysms, but soon the Great Physician will heal and comfort all people eternally—another reality evidenced by the miraculous healings of Jesus Christ during His ministry on earth (John 6:2, New International Standard Bible).

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