Call to Schedule Free Consultation at Over 80 Centers Worldwide!

(844) GET-STEM

Stem Cell Therapy for Newborns After Stroke: What the PASSION Study Found

Written by Dr. David Greene, MD, PhD, MBA on May 16, 2026

Table of Contents

A neonatal stroke—specifically a perinatal arterial ischemic stroke—is a life-altering event that occurs in approximately 1 in 2,500 live births. These strokes often result in long-term neurological challenges, including cerebral palsy (CP), epilepsy, and significant cognitive or motor delays.

Current standard care focuses on supportive therapy, but it does little to repair the damaged neural tissue. However, the PASSION study (Perinatal Arterial Stroke treated with Stromal cells Intranasal) has introduced a promising regenerative approach using mesenchymal stem cells.

What is the PASSION Study?

The PASSION study was an open-label clinical trial conducted in the Netherlands. Researchers followed 10 neonates who had recently suffered an arterial stroke. Each infant received a single intranasal dose of 50 million mesenchymal stem cells.

The researchers chose the intranasal route because it allows cells to bypass the blood-brain barrier via the olfactory and trigeminal nerve pathways, delivering the treatment directly to the central nervous system without the need for invasive surgery. This represents a significant shift in how stem cell therapy works for acute neurological injuries.

Clinical Outcomes and Findings

Over a two-year follow-up period, a multidisciplinary team—including neurologists, pediatricians, and physical therapists—evaluated the infants across several domains to determine if stroke patients can recover more effectively with regenerative intervention.

1. Prevention of Cerebral Palsy and Epilepsy

Historically, approximately 65% of children who suffer a perinatal stroke go on to receive a clinical diagnosis of cerebral palsy. In the PASSION study, only 20% (2 out of 10) developed CP. Furthermore, while epilepsy is a common secondary complication of neonatal brain injury, zero infants in the study group developed the condition.

2. Preservation of Brain Tissue

Serial MRI scans were used to track the progression of the brain injury. Compared to a historical control group receiving standard care, the infants treated with MSCs showed significantly less brain tissue loss. This suggests that the stem cells may exert a neuroprotective effect, potentially “rescuing” at-risk neurons in the penumbra. This data is vital for those researching stem cell therapy for stroke recovery.

3. Motor and Cognitive Development

While the small sample size (10 infants) meant the results did not reach the threshold of formal “statistical significance” required for broad clinical adoption, the objective data showed marked improvements in:

  • Fine and gross motor function.
  • Visual field integrity.
  • Speech and language acquisition.
  • Cognitive processing.

Safety and Tolerability

One of the most critical findings of the study was the safety of the procedure. The infants tolerated the intranasal administration exceptionally well. No serious adverse events or safety concerns were identified during the two-year observation window, reinforcing the advantages of mesenchymal stem cells in regenerative medicine.

This high safety profile aligns with the broader application of regenerative medicine. For instance, R3 Stem Cell has overseen over 28,000 procedures globally over the last decade, maintaining a rigorous focus on patient safety and what to expect during stem cell therapy.

Comparison: Standard Care vs. MSC Therapy

Outcome Measure

Standard Care (Historical)

PASSION Study (MSC Treated)

Cerebral Palsy Risk

~65%

20%

Epilepsy Development

Common complication

0%

Tissue Loss

Significant permanent loss

Reduced tissue loss via MRI

Delivery Method

Supportive/Rehabilitative

Non-invasive Intranasal

The Future of Regenerative Neurology

The PASSION study serves as a “proof of concept” that regenerative therapies are not only safe for the most vulnerable patients but may also fundamentally change the trajectory of recovery after a brain injury. This research joins a growing body of evidence exploring stem cell therapy for cerebrovascular accidents and other complex neurological conditions.

Exploring Regenerative Options

Regenerative medicine is rapidly evolving, offering new possibilities for neurological and musculoskeletal conditions alike. At R3 Stem Cell, we are committed to providing access to these advanced therapies, including umbilical cord stem cell therapy, through our global network of 80 centers.

If you are researching treatment options for a loved one, it is essential to choose the right stem cell clinic and consult with specialists who understand the latest developments in the field.

Contact R3 Stem Cell today:

  • Phone: +1 844-GET-STEM
  • Email: info@r3stemcell.com
  • Locations: 80 centers across 8 countries.

Contact Us

Why Dr. Hector is "Passionate" About the Word "Natural"

Consent alone is not sufficient. Donor mothers also undergo comprehensive medical screening, which typically includes:

What Does the Bioethics Community Say?