Simplify the following text for a Grade 9 native English-speaking person.
Original: , a reference to the body tremors that are a classic symptom of the disease ; it is also known among the Fore as the laughing sickness due to the pathologic bursts of laughter people would display when afflicted with the disease .
Simplified: The Kuru disease is also known as the laughing sickness due to the pathologic bursts of laughter that the patient displays .