In Japanese, the word “Moyamoya” means “puff of smoke,” but the disease it represents is a rare and progressive cerebrovascular disorder caused by blocked arteries at the base of the cranium. Moyamoya also describes the look of the tangle of tiny vessels formed to compensate for the blockage.
The first case of Moyamoya, which primarily affects children but can also occur in adults, was found in Japan in the 1960s and is still prevalent in the East Asian island nation.
Patients of this disease, even though rare, can be found now in other countries around the world. Its incidence rate, however, is higher in Asian countries than in Europe or North America.
Even though the disease is quite unknown in Bangladesh, there are quite a number of patients who have been treated successfully at the National Institute of Neurosciences and Hospital (NINSH) in Dhaka’s Agargaon.
Until now, 30 patients have undergone bypass surgeries in NINSH while only one of them has died. This 98% success rate, however, is much higher than in the other countries, say doctors at NINSH and experts.
The first known Moyamoya patient in Bangladesh was diagnosed at Bangabandhu Sheikh Mujib Medical University hospital in Dhaka in 2012. The case was mentioned in a report published in the Journal of Bangladesh College of Physicians and Surgeons the same year.
However, NINSH had its first Moyamoya patient in 2014 when seven-year-old Mohona Aktar from Kushtia was brought in.
In the initial stage, the child was frequently suffering from sudden muscular weakness, one of the first symptoms of the disease. She used to feel better after resting for a while, her family said. But two weeks later, she suffered temporary paralysis on one side of her body.
Her family had taken her to several state-run hospitals in Kushtia, one of which later referred her to NINSH where she underwent brain surgeries twice in the next two years. Although her condition has improved now, Mohona undergoes monthly checkups.
The second patient with Moyamoya disease who came in at NINSH one year later was another child named Jannatul Ferdousi Nupur, 9, from Bogra.
Her father Jahidur Rahman told the Dhaka Tribune: “Three years ago, one day, Nupur had fallen suddenly on the school grounds and couldn’t speak. Since then, this started happening to her from time to time. She was also having constant severe headaches.”
Nupur was also treated initially at different local hospitals, doctors at one of which had told her parents about Moyamoya’s possibility. They also referred them to NINSH.
Jahidur said: “Doctors had said Nupur will have to undergo brain surgeries. In the last two years, doctors operated on her head twice. Nupur is better now. She has also resumed school.”
Dr Sudipto Kumar Mukherjee, the assistant professor at NINSH’s Department of Pediatric Neurosurgery, told the Dhaka Tribune: “In Nupur's case, the disease was hereditary. Later we found out that her mother was suffering from Moyamoya too.
“With every patient, we always check first whether he/she has anyone in the family who has the disease. This disease is mostly seen in six to 14-year-old children, but we have also treated a one-year-old child.”
Moyamoya and its symptoms
Moyamoya is a rare idiopathic vaso-occlusive disease characterised by progressive irreversible occlusion, or blockage, of main blood vessels to the brain as they enter into the skull. The blockage tends to cause strokes or seizures.
Apart from muscular weakness, in children the first symptoms include stroke, or recurrent transient ischemic attacks (commonly referred to as “mini-strokes”), or paralysis affecting one side of the body, or seizures, according to National Institute of Neurological Disorders and Stroke (NINDS) at Maryland in the US.
It says adults can also experience these symptoms which happen from blocked arteries, but more often suffer a hemorrhagic stroke due to bleeding into the brain from the abnormal vessels.
Individuals with this disorder may have disturbed consciousness, problems with speaking and understanding speech, sensory and cognitive impairments, involuntary movements, and vision problems.
NINDS says about one in 10 individuals with Moyamoya has a close relative who is also affected; in these cases researchers think that this disease is the result of inherited genetic abnormalities.
NINSH’s Dr Sudipto Kumar said: “When the blood vessel becomes slightly narrowed, it disrupts the blood flow in the brain. As the demand for blood in the brain increases, the vessels fail to circulate enough blood during any kind of movement, eating or crying.
“As a result, the muscular weakness on any side of the body occurs. This is called Transient Hemiparesis or temporary paralysis.”
How patients pick up Moyamoya
About 10% of the Moyamoya cases are hereditary, while some cases result from specific genetic mutations. This disease can also be either congenital or acquired.
Patients with Down syndrome, sickle cell anaemia, congenital heart disease, fibro muscular dysplasia, or head trauma can develop Moyamoya symptoms too. Although about a third of those affected are male, it is more common in women.
Many women have said that their children, who generally are suffering from Moyamoya, do not want to go to school and insist on staying or returning home from halfway because of the headache and disorientation they feel, which many think are excuses to avoid school.
In the rural areas in Bangladesh, villagers try to treat such problems through superstitions. Even local doctors, who have not heard of Moyamoya disease, feel confused under the circumstances, experts have said.
According to NINSH, 70% of the 30 patients who underwent surgeries there in the last three years were girls. Most children were between six and 14 years.
Nine-year-old Faisal Rahman had fallen sick with Moyamoya in October last year. Doctors conducted two surgeries on his head.
His father Mahfuz Rahman told the Dhaka Tribune: “Faisal is sort of okay now, but the doctor has said that there is another block in his brain. He will undergo another operation after six months. He is still under constant supervision of the doctors.”
Dr Md Aminul Hasanat, assistant professor of anaesthesiology at NINSH, said: “If I put it more simply, the pain generally starts when blood fails to flow freely to the brain through the vessels.
That could happen due to flow voids in the area of circle of Willis and in the basal ganglia, which looks like “something hazy just like a puff of cigarette smoke drifting in the air.”
Dr Hasanat also said: “An important factor in these surgeries is anaesthesia as the patients are in severe pain most of the time. When NINSH began treatment of Moyamoya, I used to do it alone. But now we have nine doctors who can take care of that part during a surgery.”
Emphasising the usual symptoms, experts said that children with Moyamoya disease may feel severe headache and even lose consciousness when they do something with extra energy, like running, playing any sorts of sports or in the case of babies, crying, which creates pressure on the brain. They may also lose their ability to speak while enduring pain.
Even after successful operations, patients can have problems, said doctors at NINSH. “We maintain communication with them over phone and have them undergo monthly checkups when they leave the hospital after surgeries.”
Three years ago, the Dhaka hospital was unable to treat patients of Moyamoya disease let alone conduct surgeries. The hospital then sent Dr Sudipto Kumar Mukherjee to South Korea for higher studies on the disease with the sole aim to treat Moyamoya patients here.
The government, in an admirable initiative, is also bearing all costs of the surgeries that are happening at NINSH every now and then. People from Bangladesh used to go to India and spend at least Tk30 lakhs on such operations and treatment three years ago.
According to NINDS of the US, there are several types of surgery that can restore blood flow to the brain by opening narrowed vessels or by bypassing blocked arteries.
It says children usually respond better to this surgery than adults, but the majority of patients suffer no further strokes or related problems after surgery.
Without the surgery, most Moyamoya patients will experience mental decline and multiple strokes because of the progressive narrowing of arteries, says NINDS. Without treatment, this disease can be fatal as the result of intracerebral haemorrhage (bleeding within the brain).