Madisyn joins us on Untold: The Stories of Cook Children’s to tell us about the seemingly minor incident led to her paralysis, the challenges she faced, and the unwavering spirit that carried her as she walked out of Cook Children’s Medical Center three months later. You’ll hear how her faith, positivity and care at Cook Children's played a crucial role in her remarkable journey.

This episode is a testament to the power of the human spirit and the extraordinary things that can happen when hope prevails. Listen to the podcast on Apple Podcasts, Spotify or watch on YouTube. 

Sickle cell disease (SCD) can cause damage to blood vessels in the brain, putting children as young as age 2 at risk for stroke.

That’s why patients with certain types of SCD need preventive screenings called transcranial doppler ultrasound. The ultrasound measures how fast blood is flowing in the brain’s arteries, an indicator of stroke risk.   

SCD is a genetic disorder that causes red blood cells to be sticky, stiff and sickled – shaped like crescent moons, in other words. Sickled cells don’t move easily in the blood vessels, which causes pain and possibly anemia or stroke. Sickle cell disease affects people of African, Central and South American, Middle Eastern, Asian, Indian and Mediterranean descent. An estimated 1 in 365 Black newborns have SCD, a lifelong condition.

September is National Sickle Cell Awareness Month, a time to highlight the tools to treat children and teens with the disorder. Cook Children’s serves about 400 patients with SCD. About 5-10% of that population have the genes that make stroke more likely. They need ultrasound screenings at least once a year from age 2-16.

“The main patients that we are concerned about with stroke are the patients who have hemoglobin SS and sickle beta-zero thalassemia, which are severe types of SCD,” said Cassandra Wallace, RN, BSN in the Hematology and Oncology Center at Cook Children’s. “Those patients typically have a higher percentage of sickled cells and more damage done to the blood vessels in the brain. That’s what causes the changes to the blood flow and puts then a higher risk for stroke.”

Hematologist Clarissa Johnson, M.D. heads up the Sickle Cell Program at Cook Children’s, which includes testing, diagnosis, treatment and research. Ultrasound screening is one component of the program.   

Dr. Johnson said the ultrasound screenings allow the medical team to intervene before a stroke happens. Depending on the results of the ultrasound, the medical team might order further tests, adjust the patient’s medication, or start the patient on monthly blood transfusions. If the blood flow is normal, the ultrasound will be repeated in a year.

Screening for Stroke

Most SCD patients at Cook Children’s get their screenings done at the Dodson Specialty Clinics building. It’s a painless process that typically takes about 30 minutes.

Technicians target specific blood vessels on both sides of the patient’s head to measure the rate of blood flow. If inflammation has caused the vessels to narrow, the blood flows faster.

Dr. Johnson says ultrasound results fall into three categories:

• Normal
• Conditional yellow zone (slightly high rate)
• Elevated red zone (high rate)

Depending on what the ultrasound finds, follow-up care might include getting an MRI, starting on a medication, or adjusting the dose. Another treatment option is monthly blood cell transfusions to lower the percentage of sickled cells. 

Wallace said Cook Children’s keeps track of when SCD patients are due for their next ultrasound as part of their ongoing checkups. What’s the outcome? Better management of stroke risk.

“The changes that occur in the brains of sickle cell patients are not visible,” Wallace said. “We do the screening to pick up on minute changes that we may not otherwise see had we not done the transcranial doppler.”

Know the Signs

Another component of SCD care at Cook Children’s is educating patient families about the warning signs of stroke. A stroke occurs whenever the blood supply to the brain is disrupted, causing a loss of oxygen. It can happen at any age. The damage can be permanent.   

Sometimes a stroke happens “silently” and can only be detected later by MRI. Silent strokes occur in as many as 39% of children with SCD before they turn 18, according to the American Stroke Association. Silent strokes can cause learning difficulties and other cognition problems.

Overt strokes, meanwhile, cause slurred speech, facial droop, weakness in the arms and legs, difficulty walking and confusion. If your child has these symptoms, call 911.

“We try to push the parents to know that ‘Time is Brain.’ We want them to remember that it’s very important that they seek treatment right away to save as much brain tissue as we can,” Wallace said.

To spot the signs of stroke, remember the acronym BE FAST:

Balance - Is there a sudden loss of balance or coordination?

Eyes - Is there blurred or lost vision?

Face - Is one side of the face drooping or numb?

Arm - Is there weakness, numbness or loss of movement in the arms, legs or one side of the body?

Speech - Is speech slurred?

Time - If you or someone you know is experiencing any of these symptoms, call 911 immediately.

The most important thing to know is that strokes happen in children. If something is different or off about your child, seek emergency care.

Related Stories:

Teen Survives Life-Threatening Sickle Cell Crisis 

Fighting The Stigmas: Meet Daylen, the Sickle Cell Warrior

New Therapy for Battling Sickle Cell Disease Gives Hope to Younger Patients

Sometimes a mother’s intuition can be the difference between life and death. That was true for 7-year-old Ismael Aguilera whose episodes of debilitating headaches turned out to be a life-threatening condition. Ismael’s mom, Karla, questioned the doctor every time she was told he had migraines.

“I knew it was not normal for him to be feeling like that every few weeks,” Karla said.

Ismael went through eight months of episodes including unsteady walking, vomiting, dizziness, sweating, slurred speech and blurry vision. A couple of trips to the local Emergency Department also left Karla and her husband Isack with more questions than answers. Last July, Ismael had another episode, but this time one side of his face drooped down and one side of his body tingled. They once again rushed Ismael to the Emergency Department and pushed for answers. 

Worsening Condition

Ismael’s condition worsened as his mental status rapidly declined and he experienced weakness on his left side. Doctors in their local Emergency Department contacted Cook Children’s and the Teddy Bear Transport team acted fast. Once in the Intensive Care Unit at Cook Children’s, the team intubated Ismael and quickly began testing which revealed he was in a dire situation. Karla remembers hearing the doctors tell her the severity and urgency of Ismael’s condition, but she was in shock and not able to process everything.

“Even though I couldn’t think through it all, I had this feeling that he was going to be fine, and he would leave the hospital walking,” Karla said. “My faith in God got me through.”

They told her that during these episodes he was having smaller strokes but this one was in a different area affecting the basilar artery which can be fatal if not treated immediately. The area included the brainstem which coordinates breathing and maintains alertness. Only an extremely skilled physician can treat this successfully. 

Right Place, Right Team, Right Time

Marcela Torres, M.D., Cook Children’s Hematology and Oncology - Stroke and Thrombosis Program co-director, began treating Ismael with blood thinners to prevent more strokes. She had to strike a delicate balance with the medications – not enough could cause more strokes but too much could cause him to bleed into the vital area of his brain. 

“It is very possible he only had a matter of hours before we would not have been able to save him,” Dr. Torres said. “I remember watching the images of Ismael’s MRI in real time and texting Dr. Gerstle because I knew we needed him right away.”

Ronald Gerstle, M.D., pediatric interventional radiologist at Cook Children’s Medical Center, performed a thrombectomy which came with many risks but was the only chance at saving Ismael’s life. He very carefully removed the clot through a tiny catheter that went from Ismael’s leg to his brain.

“It takes an experienced stroke center with all the resources to perform these procedures in kids this young and in a timely manner so we can save their brains,” said Richard Roberts, M.D., pediatric neurosurgeon at Cook Children’s Jane and John Justin Neurosciences Center.

After the procedure, the team anxiously waited for Ismael to show signs of progress.

“There was a chance Ismael wouldn’t wake up after the procedure,” said Rachelle Herring, M.D., one of Cook Children’s pediatric stroke neurologists who treated Ismael in the ICU. “We were all surprised and thankful to watch him slowly wake up and then talk, move and regain function.”

A Miracle in the Making

After five days, Ismael was extubated. Drs. Herring and Torres checked on him frequently to monitor his neurologic status and assess his level of recovery. Ismael continued to improve at a faster pace than anyone expected. He spent one month in rehab learning to walk and eat again – all while wearing a cervical collar since the doctors suspected his strokes were caused by bow hunter’s syndrome. With this condition, turning the neck compresses the artery and causes strokes.

Two months later, Dr. Gerstle performed an angiogram to confirm the diagnosis. Sure enough, every time he turned Ismael’s neck during the procedure, it began to compress the artery.

Road to Recovery

In January, Dr. Roberts performed a rare procedure fusing Ismael’s head and neck to prevent further strokes. Dr. Roberts placed screws in the cervical vertebrae and a head plate on the base of his skull – operating in an area that was one millimeter away from the artery running through Ismael’s neck.

Since then, Ismael has continued to recover well without any vascular events. In April, he was cleared to remove the cervical collar and continues to follow up with Dr. Roberts and Fernando Acosta Jr., M.D., Stroke and Thrombosis Program co-director.

“He now has an excellent prognosis with a low risk of more strokes,” Dr. Herring said. “His recovery has been miraculous considering where the major stroke was located. We are all so amazed.”

‘Thank God They Knew What to do’

“We needed to be at Cook Children’s all along,” Karla said. “Everyone from child life specialist Madi Mayfield who Ismael called his best friend to nurse Tyler Adair who went out of his way to make him happy with special handshakes and talking about his favorite things to the amazing doctors who got Ismael to where he is today. Thank God they knew what to do.”

Because of the fusion, Ismael will not be able to participate in impact sports or jump on trampolines or bounce houses. This could pose a significant risk of extension or hyperextension of the neck and potentially break the hardware or his bone putting Ismael at risk for strokes again.

But other than that, Karla says he is back to being a normal kid who loves animals, riding horses, playing outside and watching the Steelers play football.

“Ismael has such a caring heart,” Karla said. “I really think God put him on this journey to help others. He has a purpose here.”

To spot the signs of stroke, remember the acronym BE FAST:

Balance - Is there a sudden loss of balance or coordination?

Eyes - Is there blurred or lost vision?

Face - Is one side of the face drooping or numb?

Arm - Is there weakness, numbness or loss of movement in the arms, legs or one side of the body?

Speech - Is speech slurred?

Time - If you or someone you know is experiencing any of these symptoms, call 911 immediately.

The most important thing to know is that strokes happen in children. If something is different or off about your child, seek emergency care.

March 28, 2022, was coming to a close like any other ordinary day for the Chavez-Llanas family. Salvador and Laura Chavez-Llanas were upstairs bathing their youngest of three sons while their older two were playing video games downstairs. In a moment, their peaceful evening turned to chaos.

A cry for help rang out from downstairs. It came from Salvador and Laura’s middle son. Laura rushed to check on him, only to find her oldest, 8-year-old Santiago, on the floor. He was conscious but drooling, and unable to stand up or move the right side of his body. His speech was slurred, and one side of his face drooped.

Laura yelled for her husband’s help. He called 911, and an ambulance arrived within minutes to carry Santiago to the emergency room at Cook Children’s Medical Center. That’s where Laura met Rachelle Herring, M.D., a pediatric neurologist.

“Santiago was pretty severely impaired at that point,” Dr. Herring explained. “He had a dense hemiplegia, which means he really could not move the right side of his body at all. He had very slurred speech but, fortunately, he was alert and understood everything that was going on.”

Santiago quickly underwent imaging tests of his brain. They confirmed he was having an ischemic stroke. This type of stroke occurs when a blood clot blocks the flow of blood in a vessel in the brain, cutting off oxygen and disrupting the function controlled by that part of the brain.

“We were just playing our Nintendo Switch and that's when my controller fell," Santiago said. "I started reaching for it, but then I felt like I was getting weak in my right side so I tried even harder to get it and then I fell down.”

Santi, as his mother calls him, has always been a healthy, active boy who loves playing basketball, swimming and riding bikes with his family. Never did his parents imagine their son would be one of the 5 in 100,000 kids each year ages 1 to 18 to have an ischemic stroke. It’s more common in newborns, occurring in 1 in 2,500 full-term infants during their first month of life.

“It was pretty shocking,” Laura said. “Your world as you know it just disappears. It’s so hard.”

Time was of the essence. With stroke, recovery is directly related to how quickly treatment can be administered. But stroke in children is so rare that the drug considered the gold standard treatment for adults has not been studied enough in kids to be approved for use in pediatric cases.

The medication, called tissue plasminogen activator, or tPA, breaks up blood clots. It’s administered through an IV with the goal of dissolving the clot within the vessel and restoring as much blood flow as possible. To be most effective in reversing damage, it must be administered within 4 ½ hours of the onset of stroke.

Although it’s considered off-label to use tPA to treat children, some hospitals administer the drug to pediatric patients after carefully weighing the risks and benefits.

“That’s what we did in the case of Santiago,” Dr. Herring said. “He came in very quickly after the stroke and I reached out to Dr. Marcela Torres, our hematologist who specializes in blood clots, about giving tPA. We’re basing our decision on the adult data that when the patient comes in within 4 ½ hours of an ischemic stroke, we think tPA can help restore the blood flow to the affected area of their brain."

Dr. Herring explained the risks of using the powerful drug to Santiago’s mom.

“At that point, I couldn’t say no,” Laura said. “Because I want to have my kid with me.”

It was the right call. Not long after receiving the drug Santiago’s symptoms began to resolve, and he was transferred from the ER to the pediatric ICU for monitoring. Because tPA is a blood thinner, patients are at risk of bleeding and must be watched closely. The stroke team also wanted to keep an eye on his neurological status and run tests to determine the cause of the stroke. 

Images of Santiago’s brain showed inflammation of the blood vessels consistent with a condition called cerebral vasculitis.

“We don't know exactly what caused the vasculitis,” Dr. Herring said. “It could have been triggered by some type of prior infection. The body's immune system goes a little haywire and can cause irritation to the blood vessels in the brain.”

Santiago spent two weeks in the hospital, all the while making a remarkable recovery. By the time he was discharged he had only a mild facial droop and had regained all of his movement. He’s on medications to reduce inflammation in his blood vessels, as well as blood thinner to prevent more strokes, and will undergo more imaging tests in the future to make sure his vessels return to normal.

In the meantime, Santiago is enjoying being back home with his family and back to school part time.

Looking back, Laura recalls a few things her son told her that may have signaled something was wrong. A few days before the stroke, Santiago complained of not feeling well. He said he felt like he was going to pass out at school. When questioned in detail by his mother, the only word he could find to describe how he felt was “weird.” Now, Laura wants parents to know to listen to their kids and know the signs and symptoms of stroke.

“Look at your kids,” she said. “Look at how they're behaving, and if they tell you something hurts, pay attention to every single different thing.”

To spot the signs of stroke, remember the acronym BE FAST:

Balance - Is there a sudden loss of balance or coordination?

Eyes - Is there blurred or lost vision?

Face - Is one side of the face drooping or numb?

Arm - Is there weakness, numbness or loss of movement in the arms, legs or one side of the body?

Speech - Is speech slurred?

Time - If you or someone you know is experiencing any of these symptoms, call 911 immediately.

“The most important thing to know is that stroke happens in children,” Dr. Herring said. “If something is different or off about your kid, do not discount it. It could be something serious. Seek emergency care because even if they're not a candidate for tPA, sometimes they're a candidate for other therapies. The sooner we're able to see that patient and try to figure out what's causing the stroke, the better off their prognosis is going to be.”

Lori Lopez hoped to hear that her grandson, Mathew Westerman, was doing better and made some progress in his treatment for blood clots caused by a rare coagulation disorder. But she got more than she ever expected from the physicians overseeing her grandson’s care – Marcela Torres, M.D., a hematologist/oncologist and medical director of the Stroke and Thrombosis Program at Cook Children’s, and from Fernando Acosta Jr., M.D., a neurologist and associate medical director of the program.

“Dr. Acosta said, ‘They are gone. All the blood clots are gone,’” Lopez said. “I couldn’t believe it. I asked him to repeat it. I thought I didn’t hear him correctly. It was great. Dr. Torres told us he would no longer have to receive blood thinners, or injections, the infusions, the medication for seizures … it was a miracle. Honestly, it was a miracle to go in and hear this kind of news. I was like, ‘Oh my God. I didn’t know how to contain myself. I had so much joy and happiness with this news. It was the best news I had ever received.”

It was amazing how far Mathew, who was 1 when he became sick and is now 31 months old, had come. In October 2016, Mathew came down with a slew of health issues – two ear infections, strep throat, mono, pneumonia, asthma. He couldn’t seem to get well.

He was eating and drinking very little, causing dehydration and iron deficiency anemia. One morning, Lopez and Mathew’s mother, Catherine Arreola, noticed the little boy’s arms and feet twitching. He was having a seizure. They rushed him to the emergency room in San Angelo.

From there, Mathew was transported to Cook Children’s where he was diagnosed with thrombosis of the sinus veins of the brain. This is a type of stroke that occurs when a blood clot forms in the brain’s venous sinuses which prevent blood from being able to drain out of the brain. Brain damage can occur from the increased pressure and blood can leak out into the already damage tissue (known as a hemorrhagic stroke). This means that, unfortunately, Matthew had all three types of strokes: sinus vein thrombosis, ischemic and hemorrhagic.

Dr. Torres recognized Mathew’s symptoms as soon as she saw him and placed him on blood thinners. Mathew also needed plasma injections to help treat his rare coagulation disorder and balance the blood thinners. Mathew's coagulation disease causes him to have bleeding and clotting complications at the same time. Dr. Torres had to find the balance to not tip the scales on either side. The treatment of anticoagulant blood thinner injections and plasma injections worked and Mathew is doing incredibly well today, completely off all medication.

“I was shocked,” Lopez said. “I didn’t know children could have strokes.”

This is a common misconception. The National Stroke Association says stroke happens in about 1 in 4,000 live births and the risk of stroke from birth through age 18 is almost 13 in 100,000 children per year.

The Cook Children's Comprehensive Stroke and Thrombosis Program, one of 16 such centers in the U.S., is led by Dr. Torres and Acosta with additional support from neurosurgery, neuro-radiology, neuropsychology, a dedicated nurse practitioner, nurse, social worker and Child Life specialist. The team is committed to the early recognition, treatment and prevention of pediatric stroke through research, innovation and education. As members of the International Pediatric Stroke Society, the Cook Children's team works with a network of other pediatric hospitals to improve stroke care worldwide.

And yet, unless it happens to your child, most of us never think of children having a stroke.

Strokes in adults are often brought on by lifestyle choices such as high cholesterol, a history of smoking, too much alcohol and obesity. For children, strokes are usually caused by heart birth defects, infections such as meningitis and encephalitis, brain blood vessel abnormalities trauma and blood disorders such as sickle cell disease

“The difference with children and adults in stroke recovery, is that some children with stroke may have a greater capacity for recovery compared to adults; however, this is not the case for all children,” Dr. Acosta said. “Therefore, a comprehensive stroke program similar to that at Cook Children’s Medical Center, is focused on all aspects of stroke care including acute treatment and post stroke recovery. With the help of physical, occupational and speech therapy, childhood stroke survivors may show surprising recovery in lost function. Ongoing assessment of a child’s learning ability with recommendations for school are particularly important to a child’s success.”

“A problem with pediatric strokes, in contrast to those in adults, is that in pediatric strokes, the causes and circumstances are incredibly diverse,” said Dr. Torres. “and they are also widely different within the pediatric age groups. The potential causes of stroke vary radically from a neonatal stroke to the stroke that affects a teenager/young adult.” The team of physicians from the Stroke and Thrombosis Program at Cook Children’s Medical Center work together to give these children up to date therapy and care.

And yet, unless it happens to your child, most of us never think of children having a stroke.

“Unfortunately pediatric strokes have been ignored for a long time as a true entity,” said Fernando Acosta Jr., M.D., associate director of Cook Children’s Pediatric Neurorehabilitation and Movement Disorder Program. “This has changed over the last few years. The awareness is increasing.”

Strokes in adults are often brought on by behavior such as cholesterol, high cholesterol, a history of smoking, too much alcohol and obesity. For children, strokes are usually caused by birth defects, infections such as meningitis and encephalitis, trauma and blood disorders such as sickle cell disease.

“A problem with pediatric strokes, in contrast to those in adults, is that in pediatric strokes, the causes and circumstances are incredible diverse,” said Marcela Torres, M.D. medical director of Hematology at Cook Children’s. “For example, the physicians at Cook Children’s Stroke Clinic see children from 0 to 18 years. Additionally, the potential causes of stroke vary radically from a neonatal stroke to the stroke in a teenager/young adult.

Related Disabilities

Stroke-related disabilities is another area where childhood and adult stroke survivors can differ.

While strokes in children can be devastating, the good news is children often have a better ability to heal because of the greater plasticity or flexibility of the child’s nervous system and brain. A child’s brain is still developing, therefore it may have a greater ability to repair itself. With the help of physical and speech therapy, most childhood stroke survivors recover the use of their arms, legs and speech.

Symptoms of a stroke

The most effective stroke treatments must be given within the first three hours after stroke symptoms start. By recognizing signs of stroke in children and acting fast, you can help medical professionals lessen a stroke’s damage to the child’s brain. Use the following tool to help you think F.A.S.T.:

For more information:

Approximately six in 100,000 children are affected by stroke. Here in the U.S., it is a leading cause of death among children. Nearly 60 percent of childhood strokes occur in boys. Because the causes and symptoms are so different, treating stroke in children requires specialized training, such as what they will receive at the Cook Children's Stroke and Thrombosis Program.