Voltage-gated sodium channels are proteins found throughout the body, however the most influential of these are found in neurons. Because the gate is permanently open and cannot close, there is not an action potential gradient to utilize and signals cannot be received by nerves. This lack of signaling is what causes paralysis of muscles, cardiac failure, and respiratory failure which eventually leads to death.
Voltage-gated sodium channels are ubiquitous proteins, but those in neurons have the most profound effect. The permanent openness of the gate prevents a signal gradient from forming, hindering nerve communication. This disruption results in muscle paralysis, heart failure, and respiratory failure, culminating in mortality.