By Sade Oguntola
IN 2016, Maxwell Omabuwa Chinedu Etoromi, the son of Ms Stella Oduah, a former Minister of Aviation and senator representing Anambra State, was said to have died after suffering a subarachnoid haemorrhage, an uncommon type of stroke caused by bleeding on the surface of the brain. It’s a very serious condition and can be fatal.
In its report, Sahara reporters claimed that doctors at a Turkish hospital in Abuja said Oduah’s son died of a brain haemorrhage some 30 minutes after he was rushed from another hospital.
Rates of subarachnoid haemorrhage have increased in older people and men in recent years and such stroke occurs among black people at a disproportionately higher rate compared to people of other races.
A subarachnoid haemorrhage occurs when bleeding takes place in the space between the brain and the membrane that covers it, typically as a consequence of a burst blood vessel. This kind of stroke may result from an aneurysm rupture, excessive blood pressure, or head injury.
A brain aneurysm is a bulge in a blood vessel caused by a weakness in the blood vessel wall, usually at a point where the vessel branches off.
In a new study, researchers found the incidence of subarachnoid haemorrhage was greater among black people with an average of 15 cases per 100,000 people compared to non-Hispanic white people with an average of 10 cases. The researchers only looked at those that were not caused by trauma.
Incidence increased among black people by 1.8 per cent a year while rates for Hispanic, Asian and non-Hispanic white people did not change over time.
Researchers found that over the 10-year study, the average incidence of this type of stroke for all participants was 11 cases per 100,000 people. Rates were higher in women with 13 cases per 100,000 people, and lower in men with 10 cases.
Incidence also increased with age. For middle-aged men, the average was four cases per 100,000 people while for men 65 and older, the average was 22 cases. Incidence increased over time, by 0.7% on average per year overall, with most of the increase in middle-aged men at 1.1%, older men at 2.3% and older women at 0.7%, while the incidence in young women declined by 0.7%.
A limitation of the study was researchers’ inability to differentiate between strokes caused by aneurysms and those not caused by aneurysms, which would have provided further insight.
Professor Mayowa Owolabi, a stroke expert at the University College Hospital (UCH), Ibadan said that evidence indicates that today Africa could have up to 2–3-fold greater rates of stroke incidence and higher stroke prevalence than Western Europe and the USA. Moreover, many Africans have a stroke within the fourth to sixth decades of life, with serious implications for the individual, their family and society.
He listed the three major types of stroke in Africa as ischemic stroke, intracerebral haemorrhage strokes and subarachnoid haemorrhage.
“In Africa, ischemic stroke also called dry stroke, which occurs when a blood vessel supplying blood to the brain is obstructed accounts for 60 -70 per cent of all cases of stroke. Intracerebral haemorrhage strokes result from bleeding occurring inside the brain and account for about 30 to 40 per cent of stroke cases while subarachnoid haemorrhages are the case in about 5 to 10 percent of all stroke cases,” he added.
However, an ischemic stroke can also occur as a result of a subarachnoid haemorrhage. More than half of all patients who have had a severe subarachnoid haemorrhage will develop an ischemic stroke within the first two weeks after their brain bleeds.
Professor Owolabi, however, said that one of the greatest drivers of stroke in Africa is hypertension although with subarachnoid hemorrhage there is also an underlying problem in the blood vessel which is called an aneurysm. Smoking and excessive alcohol are also important risk factors for subarachnoid hemorrhage.
Studies have found that Indigenous Africans and Afro-Americans are twice more likely to develop a stroke compared to Europeans with the same level of blood pressure. Also, Africans are more sedentary and so at a higher risk of developing stroke.
The brain aneurysm, he said, occurs in some individuals born with a weakness in the blood vessel that carries blood into the brain (artery) and in other people with health conditions such as high blood pressure, infections like syphilis or related to other inherited diseases that may result in weaker than normal blood vessel walls.
As blood passes through the weakened vessel, the pressure causes a small area to bulge outwards like a balloon. Occasionally, this bulge can burst (rupture), causing bleeding around the brain.
Nonetheless, if the aneurysm is there and it does not burst, it cannot be said to be the cause of a stroke.
According to him, “One of the major reasons why an aneurysm ruptures is if there is hypertension. Hypertension is becoming a lot more common because of what we call epidemiological transition, sedentary lifestyle, obesity, dietary problems and so on.
“People are developing hypertension at a younger age and many times, they are not aware of it and that then leads to the rupture of the aneurysm if it was there and more commonly in blacks.
“Globally, Africans are highly susceptible to hypertension and the prevalence of hypertension is highest in Africa according to the World Health Organization recording. Also, its control rate is the lowest. Only 10 percent of hypertension is controlled in Africans and 90 per cent is either not diagnosed, not on treatment but not controlled and that is a huge problem.”
In addition, physical exertion and emotional stress may also increase the risk of aneurysm rupture.
For the study, researchers reviewed state hospitalization databases for New York and Florida and identified 39,475 people hospitalized for non-traumatic subarachnoid haemorrhage between 2007 and 2017. Using Census data, they then calculated the annual rates of this type of stroke in those states and compared those rates over time for men, women, various age ranges, races and ethnicities.
When looking at race and ethnicity, researchers found incidence was greater in black people with an average of 15 cases per 100,000 people compared to non-Hispanic white people with an average of 10 cases.
Incidence increased in black people by 1.8 per year while rates for Hispanic, Asian and non-Hispanic white people did not change over time.
However, Professor Owolabi said that to prevent subarachnoid haemorrhage, individuals eat a healthy diet, including lots of fruits and leafy green vegetables, not too much salt and meat as well as be physically active or take at least 7,000 steps a day.
Also, it is important to maintain a healthy body mass index of 25kg/m2, avoid unhealthy foods and from the age of 30 years start to check blood pressure regularly and when found to be high be on treatment for life.
To prevent subarachnoid haemorrhage, he said that those with a family history of someone that had subarachnoid haemorrhage also need to check their blood pressure more frequently for blood pressure and if possible have a brain scan to see whether they have any aneurysm.
The size of the aneurysm can be monitored over time and it can be treated by clipping it. Also, it is important to prevent head injury.
Previous studies have found Black people develop high blood pressure at younger age and are more likely to have uncontrolled high blood pressure than non-Hispanic white people, so expanding efforts to control blood pressure may help reduce rates.
The causes also likely extend to socioeconomic factors including structural racism. Tackling racial disparities will require multifaceted interventions targeted at stroke risk factors and socioeconomic inequity.
From a public health perspective, these results are troubling and indicate the need to be more aggressive with the primary prevention of high blood pressure. Failure to reverse the trend could be devastating.
Subarachnoid haemorrhage is more deadly and more likely to cause loss of life and long-term disability than other types of stroke.
