Doctors reported a case of a 43-year-old man who had multiple strokes and nerve damage caused by dangerously high levels of a substance called homocysteine in his blood. The high levels came from several problems working together: vitamin B12 deficiency from drug use, not enough folate replacement, poor nutrition, and a genetic mutation that affects how his body processes these vitamins. This case shows why doctors need to look at all possible causes when patients have unusual health problems, not just focus on the most obvious ones.

The Quick Take

  • What they studied: Why did one patient have multiple strokes and nerve damage, and what caused the dangerous buildup of homocysteine in his blood?
  • Who participated: One 43-year-old man with chronic myeloid leukemia (a type of blood cancer) who experienced progressive nerve damage and recurrent strokes
  • Key finding: The patient had extremely high homocysteine levels caused by a combination of vitamin B12 deficiency, insufficient folate supplementation, poor nutrition, and a genetic variation that makes it harder for his body to process these vitamins
  • What it means for you: If you or someone you know has had multiple strokes or nerve problems, doctors should check for high homocysteine levels and vitamin deficiencies, especially if there’s no obvious cause. This case reminds us that health problems often have multiple causes working together.

The Research Details

This is a case report, which means doctors documented the medical story of one patient in detail. The 43-year-old man came to the hospital with progressive nerve damage (neuropathy) in his legs and feet, which got worse over time. Later, he suffered an ischemic stroke, which happens when blood flow to the brain is blocked. Doctors ran blood tests and genetic tests to figure out what was causing these problems. They discovered his homocysteine levels were dangerously high—much higher than normal. Homocysteine is a natural substance in the blood, but too much of it can damage blood vessels and nerves.

The doctors traced the high homocysteine back to several causes happening at the same time. The patient had been using nitrous oxide (laughing gas) for a long time, which damages the body’s ability to use vitamin B12. He was also taking folate supplements without B12, which doesn’t work well together. Additionally, he wasn’t eating well enough to get proper nutrition. Finally, genetic testing showed he had a specific genetic mutation (MTHFR 677C>T) that makes it harder for his body to process these important vitamins.

This case is important because it shows how multiple problems can pile up and cause serious health issues. The doctors had to look at everything—his medical history, his habits, his diet, his medications, and his genes—to understand what was happening.

This research approach matters because it teaches doctors to think broadly when patients have unusual or complicated health problems. Instead of stopping at the first explanation, doctors should ask: ‘What else could be causing this? Are there multiple things working together?’ This thorough approach can catch serious problems that might otherwise be missed.

This is a single case report, which means it describes one patient’s experience. Case reports are useful for teaching doctors about unusual situations, but they can’t prove that something works for everyone. The strength of this report is that the doctors did very thorough testing and found clear evidence of what was wrong. However, because it’s just one person, we can’t say these findings apply to everyone with similar symptoms. The doctors were careful to explain all the different factors involved, which makes the report more reliable.

What the Results Show

The patient had extremely high homocysteine levels in his blood—much higher than what’s considered safe. Normal homocysteine levels are usually below 15 micromoles per liter, but this patient’s levels were severely elevated. Blood tests also showed he had very low vitamin B12 levels. When doctors gave him B12 supplements, his B12 levels improved, but he still had more strokes. This was surprising because B12 supplementation should have helped prevent them.

Further investigation revealed the patient had a genetic mutation called MTHFR 677C>T in both copies of the gene (homozygous). This genetic variation affects how the body processes folate and B12, making it harder to break down homocysteine. The combination of this genetic factor, plus the vitamin deficiencies, plus the damage from nitrous oxide use, created a perfect storm that led to the strokes and nerve damage.

The nerve damage (neuropathy) the patient experienced was progressive, meaning it got worse over time. He had weakness and numbness in his legs and feet. The strokes were ischemic, meaning blood clots blocked blood flow to his brain. Even after starting B12 treatment, he had recurrent strokes, showing that fixing just one problem wasn’t enough.

The patient’s chronic myeloid leukemia (blood cancer) may have contributed to his overall health problems and nutritional status. His history of nitrous oxide use was a major factor—this drug specifically damages the ability to use B12 properly. The fact that he was taking folate without B12 is also important: folate and B12 work together, and taking one without the other can cause problems. His poor nutrition overall meant his body wasn’t getting enough of the vitamins it needed to stay healthy.

High homocysteine levels are known to increase stroke risk and can cause nerve damage, but having both problems at the same time is unusual. Previous research has shown that vitamin B12 deficiency and folate deficiency can each cause high homocysteine, and that genetic variations like MTHFR can affect how well the body processes these vitamins. However, this case is notable because it shows how all these factors—genetic, nutritional, and behavioral—came together in one person. It reinforces what doctors already know but sometimes forget: that serious health problems usually have multiple causes, not just one.

This is a report about one person, so we can’t say these findings apply to everyone. We don’t know if other people with similar genetic mutations and vitamin deficiencies would have the same problems. The patient had several unusual factors (nitrous oxide use, blood cancer, genetic mutation) that might not be common in other people. We also don’t know what would have happened if doctors had caught and treated these problems earlier. Finally, this case report doesn’t tell us how common this combination of problems is or how many people might be at risk.

The Bottom Line

If you have had multiple strokes or progressive nerve damage without a clear cause, ask your doctor to check your homocysteine level and your B12 and folate levels. If you use nitrous oxide recreationally, stop—it can cause serious vitamin deficiencies and nerve damage. If you’re taking folate supplements, make sure you’re also getting enough B12. Eat a balanced diet with foods rich in B vitamins (meat, fish, eggs, dairy, leafy greens). If you have a family history of strokes or nerve problems, talk to your doctor about whether you should be screened for homocysteine levels and genetic factors. These recommendations are based on this one case and existing medical knowledge, so discuss them with your healthcare provider.

People who have had multiple strokes or progressive nerve damage should pay attention to this case. People who use nitrous oxide should be especially concerned. Anyone with a family history of strokes, nerve damage, or blood clotting problems might want to discuss homocysteine screening with their doctor. People with vitamin B12 deficiency or those taking folate supplements should make sure they’re also getting adequate B12. However, this case doesn’t mean everyone with high homocysteine will have strokes—many people manage this condition successfully with proper treatment.

If high homocysteine is the cause of health problems, it usually takes weeks to months of proper supplementation to see improvement in symptoms. However, preventing future strokes requires ongoing management, which could take months to years to show full benefit. Nerve damage recovery is often slower than other improvements and may take many months or longer. The key is catching and treating these problems early, before serious damage occurs.

Want to Apply This Research?

  • Track your B12 and folate intake daily (through food or supplements), your homocysteine levels at doctor visits, and any symptoms of nerve damage like numbness, tingling, or weakness in your legs and feet. Note any unusual substances you use that might affect vitamin absorption.
  • Set daily reminders to take B12 and folate supplements together if your doctor recommends them. Log your meals to ensure you’re eating enough B-vitamin-rich foods. If you use nitrous oxide, use the app to track your progress in reducing or eliminating this habit, and set goals for healthier choices.
  • Schedule regular blood tests to monitor homocysteine, B12, and folate levels every 3-6 months as recommended by your doctor. Keep a symptom diary noting any new numbness, tingling, weakness, or other nerve-related symptoms. Track medication adherence and supplement intake. Share this information with your healthcare provider at each visit to ensure your treatment plan is working.

This case report describes one patient’s experience and should not be used to diagnose or treat yourself or others. High homocysteine levels and vitamin deficiencies are serious medical conditions that require professional diagnosis and treatment. If you have experienced strokes, nerve damage, or other neurological symptoms, consult with a qualified healthcare provider immediately. Do not start, stop, or change any supplements or medications without talking to your doctor first. This information is educational and not a substitute for medical advice. If you use nitrous oxide or other substances that might affect your health, discuss this with your healthcare provider confidentially.