Rare Brain Disease Linked to Ancient Surgical Practice Raises Concerns
A 43-year-old New Zealand man has been diagnosed with iatrogenic cerebral amyloid angiopathy (iCAA), a very rare and incurable brain disease, believed to be the first identified case in the country. The condition stems from a dural graft – a membrane used to repair the brain – received as a baby in the early 1980s. This case highlights a growing awareness of iCAA and its potential link to medical procedures performed decades ago.
What is iatrogenic Cerebral Amyloid Angiopathy (iCAA)?
iCAA is caused by the transmission of misfolded amyloid-beta proteins into brain tissue through human-derived grafts. These proteins then “seed” the development of cerebral amyloid angiopathy (CAA), a progressive cerebrovascular disorder that can lead to brain bleeding and cognitive decline. CAA is strongly associated with Alzheimer’s disease and typically affects older individuals, making this case particularly unusual due to the patient’s age.
The History of Cadaveric Dural Grafts
The patient received a lyophilised (freeze-dried) cadaveric dura mater graft to repair a scalp defect. Cadaveric dura mater was commonly used in neurosurgery for dural repair worldwide, including New Zealand, in the 1980s. However, its use was discontinued when it was linked to Creutzfeldt-Jakob disease (CJD), another neurodegenerative condition caused by misfolded proteins. The World Health Organisation advised against using these grafts in 1997.
A Growing Global Concern
While CJD prompted the initial halt to the use of cadaveric dura mater, the link to iCAA is a more recent discovery. Cases have been identified internationally, including a case in the UK where two siblings have been diagnosed with the disease. Currently, 52 confirmed cases are listed on the international iCAA register.
Why is iCAA Now Emerging?
The long delay between exposure (the graft) and the onset of symptoms is a key factor. Symptoms, including increased seizure frequency, cognitive decline and behavioural changes, can take decades to manifest. This means cases are only now beginning to surface in individuals who received these grafts in the past.
What Does This Mean for New Zealand?
Doctors in New Zealand are now considering the possibility of more undiagnosed cases. No registry of patients who received cadaveric dural grafts was kept, making it difficult to determine the extent of exposure. The Dunedin Hospital neurology team, who reported this case, emphasize the importance of considering iCAA in younger patients with relevant imaging findings and a history of dural graft use. Reviewing old case notes may be necessary to uncover potential exposures.
Understanding Cerebral Amyloid Angiopathy (CAA)
CAA is a condition where amyloid protein builds up in the walls of blood vessels in the brain. This weakens the vessels, increasing the risk of bleeding. While often associated with aging and Alzheimer’s disease, iCAA demonstrates that it can also be triggered by external factors, such as contaminated medical materials.
FAQ
- What are the symptoms of iCAA? Symptoms can include seizures, cognitive decline, and behavioral changes.
- Is iCAA treatable? Currently, there is no cure for iCAA. Treatment focuses on managing symptoms and reducing the risk of bleeding.
- How is iCAA diagnosed? Diagnosis typically involves MRI scans and, in some cases, brain biopsies.
- Who is at risk of iCAA? Individuals who received cadaveric dural grafts, particularly in the 1980s, are at potential risk.
Pro Tip: If you or a family member received a dural graft in the 1980s, discuss your medical history with your doctor, especially if you are experiencing neurological symptoms.
This case serves as a crucial reminder of the long-term consequences of medical practices and the importance of ongoing vigilance in patient care. Further research is needed to understand the full scope of iCAA and develop potential treatments.
Did you know? The transmission of misfolded proteins is not unique to iCAA and CJD. Similar mechanisms are being investigated in other neurodegenerative diseases.
To learn more about neurological conditions and ongoing research, explore articles on brain health and disease prevention. Share your thoughts and experiences in the comments below.
