Table 4 The parasite and host mechanisms possibly involved in loa-associated encephalopathy

PARASITE RELATED MECHANISMS

Massive movement and death of parasite clumps in vessels → embolic blockage → local vascular inflammation and subsequent tissue damage in sensitive tissues (similarities to malaria)

Reactions against dying adult worms or wandering larvae?

Due to two or more parasite species being present

PATIENT RELATED MECHANISMS

PATHOLOGICAL

Effects of alcohol (co-administration and/or chronic changes)

Effects of food (co-administration)

Gut disease (increasing uptake)

Altered processing (liver damage)

Other co-existent infections or disease processes

CNS Toxicity (overdose)

Allergic drug sensitivity (rare)

GENETIC

Blood Brain Barrier Alterations

Mdr1 mutation – homozygous

Human equivalent to dogs, mice, knockout mice and cattle

Polymorphism to inflammation

Pro- versus anti-inflammatory cytokine expression

Genetic predisposition to microfilariaemia