A 60-year-old man who worked at a waste management facility developed serious nerve and brain problems after being exposed to mercury. He experienced shaking, muscle stiffness, slurred speech, and memory problems. Doctors discovered he had high levels of mercury in his blood and hair, along with a vitamin B12 deficiency. This case shows that mercury exposure can cause long-term damage similar to Parkinson’s disease. The findings suggest doctors should test for heavy metal poisoning when patients have unexplained nerve and brain symptoms that don’t respond to standard treatments.

The Quick Take

  • What they studied: How mercury exposure from a workplace caused serious nerve and brain damage in one patient, and what doctors learned from treating him
  • Who participated: One 60-year-old man who worked at a waste management and environmental protection facility and was exposed to mercury over several years
  • Key finding: The patient had blood mercury levels of 15.2 μg/L (normal is much lower) and developed Parkinson’s-like symptoms including tremors, stiffness, and slurred speech, along with vitamin B12 deficiency that made the nerve damage worse
  • What it means for you: If you work with chemicals or heavy metals and develop unexplained shaking, muscle stiffness, or speech problems, ask your doctor to test for mercury and other heavy metal poisoning. This is especially important if standard treatments don’t help.

The Research Details

This is a case report, which means doctors documented the medical history and treatment of one patient in detail. The patient worked at a waste management facility where he was exposed to mercury for about 3 years. Over 10 months, he developed increasingly serious symptoms including tremors (shaking), muscle spasms, tingling sensations, irritability, slurred speech, stiffness, sleep problems, and mild memory loss. Doctors performed multiple tests including blood and hair analysis to measure mercury levels, brain imaging (MRI and PET scans), and spine imaging to understand what was happening in his body.

Case reports are important because they describe unusual or serious conditions that doctors might not see often. This case is valuable because it shows how mercury poisoning can cause symptoms that look like Parkinson’s disease but are actually caused by heavy metal exposure. By documenting this case carefully, doctors can learn to recognize similar patterns in other patients and test for mercury poisoning earlier.

This is a single case report, which means it describes one person’s experience rather than comparing many patients. While case reports are less powerful than studies with many participants, they are valuable for identifying new patterns and warning signs. The strength of this case comes from the detailed testing (blood tests, hair analysis, brain imaging) that confirmed high mercury levels and showed the damage to the nervous system.

What the Results Show

The patient had blood mercury levels of 15.2 μg/L, which is significantly elevated (normal levels are typically below 5 μg/L). Hair analysis also showed elevated mercury at 3 μg/g. Beyond mercury, the patient also had high arsenic levels in urine. Laboratory tests revealed the patient had a functional vitamin B12 deficiency, meaning his body couldn’t use the B12 properly even if he had enough of it. Brain imaging showed abnormal glucose metabolism (the brain wasn’t using energy properly) in the temporal and parietal regions. Spine imaging revealed signs of myelopathy, which is damage to the spinal cord. The patient developed Parkinson’s-like symptoms including tremors, muscle rigidity, and slow movement, but unlike typical Parkinson’s disease, he did not respond to levodopa, the standard Parkinson’s medication.

The patient also had vitamin D deficiency, which can contribute to nerve problems. He experienced cognitive decline (memory and thinking problems), emotional instability, insomnia (sleep problems), and dysarthria (difficulty speaking clearly). Physical therapy and speech therapy provided significant benefit. Treatment with N-acetyl cysteine (a compound that helps remove toxins) resulted in moderate improvement of symptoms. The combination of mercury exposure, vitamin B12 deficiency, and spinal cord damage created a condition called subacute combined degeneration, which affects multiple parts of the nervous system.

This case is similar to Minamata disease, a well-known form of mercury poisoning that occurred in Japan when people were exposed to methylmercury in contaminated fish. Minamata disease causes sensory problems, loss of coordination, Parkinson’s-like symptoms, speech difficulties, and vision and hearing loss. This case adds to the medical literature by showing that occupational mercury exposure (from workplace contact) can cause similar serious neurological damage. The case is unique because it shows how mercury can cause therapy-resistant symptoms that don’t respond to standard Parkinson’s treatments.

This is a single case report, so we cannot determine how common this condition is or whether it would happen the same way in other people. The patient had multiple exposures (mercury and arsenic), so it’s unclear which metal caused which symptoms. We don’t know the long-term outcome because this is a case report at one point in time. The patient’s response to treatment may not be typical for others with similar exposure. Additionally, we cannot determine causation definitively from a single case, only that the exposure and symptoms occurred together.

The Bottom Line

If you work with mercury or other heavy metals and develop unexplained nerve or brain symptoms (tremors, stiffness, speech problems, memory issues), ask your doctor to test your blood and urine for heavy metals. This is especially important if standard treatments don’t work. Ensure your workplace has proper safety measures to minimize mercury exposure. If mercury poisoning is confirmed, treatment may include vitamin supplementation (B vitamins, vitamin D, selenium), physical therapy, speech therapy, and medications to manage symptoms. Confidence level: Moderate - based on one detailed case, but supported by historical knowledge of mercury poisoning.

People who work in waste management, environmental protection, mining, dental offices (where mercury was historically used), or other industries with heavy metal exposure should pay attention to this case. Anyone developing unexplained neurological symptoms should consider asking their doctor about heavy metal testing. This is particularly important for people whose symptoms don’t respond to standard treatments. People without occupational exposure to mercury have very low risk of this condition.

In this case, symptoms developed gradually over 10 months after 3 years of exposure. Improvement with treatment occurred over several months. However, the patient continued to have some symptoms even after treatment, suggesting that mercury damage can be partially irreversible. The longer someone is exposed to mercury, the more damage may occur, so early detection and removal from exposure is important.

Want to Apply This Research?

  • If you work with chemicals or heavy metals, track any new neurological symptoms weekly: tremors (rate 1-10), muscle stiffness (1-10), speech clarity (1-10), memory/concentration (1-10), and sleep quality (hours per night). Note any changes and share with your doctor.
  • If you work with mercury or heavy metals: (1) Use all required safety equipment consistently, (2) Wash hands thoroughly before eating or touching your face, (3) Schedule regular health checkups with symptom tracking, (4) Request occupational health screening including heavy metal testing, (5) Report any neurological symptoms to your doctor immediately rather than waiting for them to worsen.
  • Establish a baseline health assessment including blood mercury levels if you work with heavy metals. Schedule follow-up testing annually or if new symptoms develop. Keep a symptom diary noting any tremors, stiffness, speech changes, or cognitive changes. Share this information with both your occupational health provider and primary care doctor to catch problems early.

This case report describes one patient’s experience with mercury poisoning and should not be used for self-diagnosis. Mercury poisoning is rare and requires confirmed testing by a healthcare provider. If you suspect heavy metal exposure, consult with your doctor or occupational health specialist before making any changes to your work or treatment. This information is educational and not a substitute for professional medical advice. Always work with qualified healthcare providers for diagnosis and treatment of neurological symptoms.