Table 1.
Neuro-epidemiology and clinical electrophysiology of Konzo.
| Explorations | Abnormalities |
|---|---|
| Epidemiology (putative causal factors) | Heavy and chronic dietary reliance on insufficiently processed bitter (toxic) cassava |
| Neurology | Spastic para/tetraparesis. |
| Pseudobulbar signs and optic neuropathy | |
| Motor evoked potentials (MEP) | Frequent inability to elicit MEPa. When present, central motor conduction time is often increasedb |
| Peripheral nerve conduction studies | Normal motor and sensory nerve conduction. Increased amplitude of F-waves |
| Somatosensory evoked potentials (SEP) | Cortical responses following tibial stimulation frequently absent. If present, the latency is prolonged. Median SEP often normal |
| Visual evoked potentials (VEP) | Frequent delay and decreased amplitude of P100 |
| Electroencephalography (EEG) | Frequent generalized slowing of background activity and non-specific paroxysmal activities |
a
Consistent with reduction of the upper motor neuron pool.
b
Consistent with loss of pyramidal conductivity from spinal tract (axonal) damage.