Onchocerciasis-associated epilepsy: an update and future perspectives

Area of Science:

• Neglected tropical diseases
• Neurology
• Public health

Background:

• Onchocerciasis-associated epilepsy (OAE) is a significant public health issue in regions with high Onchocerca volvulus transmission.
• Childhood epilepsy risk correlates with Onchocerca volvulus microfilarial (mf) load.
• Historically, microfilariae were found in cerebrospinal fluid (CSF), but recent studies show no detection in CSF or brain tissue post-seizure onset.

Purpose of the Study:

• To explore the potential mechanism of OAE development.
• To highlight the importance of including OAE in disease burden estimations for increased resource allocation.

Main Methods:

• Review of existing literature on OAE and Onchocerca volvulus.
• Analysis of historical and recent findings regarding microfilariae detection in biological samples.
• Hypothesizing the role of blood-brain barrier permeability in OAE pathogenesis.

Main Results:

• Microfilariae were previously detected in CSF, but not in recent samples from patients years after seizure onset.
• A hypothesis suggests microfilariae may enter the brain during fever-induced blood-brain barrier permeability.
• The death of microfilariae within the brain could trigger an inflammatory response leading to seizures.

Conclusions:

• OAE pathogenesis may involve microfilariae crossing the blood-brain barrier and causing inflammation.
• Integrating OAE into onchocerciasis disease burden assessments is crucial for mobilizing resources.
• Increased resources are needed for onchocerciasis elimination and care for OAE patients and their families.