Final answer:
Lead pipe and cogwheel rigidity are indicative of Parkinson's disease, a neurological condition that leads to the stiffening of muscles in a uniform or intermittent manner.
Step-by-step explanation:
Lead pipe or cogwheel rigidity should make you think of the diagnosis of Parkinson's disease. These terms describe the type of muscle stiffness seen in this condition. Lead pipe rigidity is a uniform increase in muscle tone during passive movement of a limb. Cogwheel rigidity is a combination of lead pipe rigidity and tremor, which gives the feeling of intermittent resistance, like a cogwheel or ratchet. Parkinson’s disease is a neurodegenerative disorder that affects predominantly dopamine-producing neurons in a specific area of the brain called the substantia nigra.
Symptoms generally develop slowly over years, and besides rigidity, include tremor, bradykinesia (slowness of movement), and postural instability. The cause of Parkinson's is unknown, and although there is presently no cure, treatment options vary and include medications and surgery. Therapy, support groups, and specific lifestyle changes can also be beneficial.