Final answer:
Lennox-Gastaut syndrome presents with early symptoms like temperature instability, apnea, and bradycardia, while late onset includes seizures and hemiparesis among others.
Step-by-step explanation:
Lennox-Gastaut syndrome typically presents with a variety of symptoms that can be classified into early onset and late-onset categories. Early onset symptoms may include temperature instability, apnea (cessation of breathing), bradycardia (slow heart rate), hypotension, difficulty feeding, irritability, and limpness. During sleep, affected infants may also exhibit significant lethargy, being notably difficult to wake up. Late-onset symptoms of the syndrome are more likely to encompass seizures, a bulging fontanel (soft spot), stiff neck, hemiparesis (weakness on one side of the body), and opisthotonos (a condition where the body is rigid with an arched back and the head thrown backward).