Final answer:
Drooling, a flat affect, and a shuffling gait are symptoms of Parkinson's disease, a neurodegenerative disorder causing loss of dopamine neurons, leading to tremors, muscle rigidity, and other motor and psychological symptoms.
Step-by-step explanation:
Drooling, a flat affect, and a shuffling gait are all signs of Parkinson's disease. This neurodegenerative disease causes the loss of dopamine neurons in the substantia nigra, a crucial area in the brain for regulating movement. Symptoms of Parkinson's disease include tremors, muscle rigidity, slowed movement, and postural instability. These physical symptoms often lead to a distinctive stooped, shuffling walk. Parkinson's disease can also cause psychological symptoms such as dementia and emotional problems.