What disease is characterized by a powerful neurotoxin released by Clostridium tetani, causing muscle spasms?

The disease characterized by a powerful neurotoxin released by Clostridium tetani, causing muscle spasms, is indeed tetanus. This condition occurs when the bacteria enter the body through wounds or injuries and produce a toxin that affects the nervous system. The neurotoxin interferes with the normal function of motor neurons, leading to sustained muscle contractions and spasms known as "lockjaw," where the muscles of the jaw tighten, but it can also affect other muscles in the body.

Understanding the impact of the toxin in tetanus is crucial; it prevents the normal inhibition of muscle contractions, resulting in painful spasms that can be dangerous and potentially life-threatening if not treated promptly. This starkly contrasts the other diseases mentioned, which do not share the same mechanism or effects related to muscle spasms caused by a neurotoxin.