Question

A)What are the structural and/or functional changes that happen to the nervous system in this disorder (Parkinson's disease)? (around 250 words)

B) How do these changes lead to the symptoms observed? (around 250 words)

Looking for detailed answers within the word limit or slightly over. Please answer the questions as 2 responses: answer for A and then the answer for B. If you are not willing to do this, then don't comment.  Many Thanks!

Answer 1

Parkinson disease is a slowly progressive degenerative disease of nervous system associated with destruction of brain cells, which produce dopamine.

Parkinson disease occurs due to lack of dopamine caused by damage of basal ganglia.

It is mostly due to the destruction of substantia nigra and the nigrostriatal pathway, which has dopaminergic fibers. Damage of basal ganglia usually occurs because of the following causes example Viral infection of brain like encephalitis ,Cerebral arteriosclerosisi, njury to basal gangliai drug-induced parkinsonism and idiopathic parkinsonism.

Mechanism of symptoms -

Body movement is controlled by a complex chain of decisions involving inter-connected ganglia. Striatum with the substantia nigra to send impulses back and forth from the spinal cord to the brain. The basal ganglia and cerebellum are responsible for smooth movement.
When dopamine receptors in the striatum are not adequately stimulated, parts of the basal ganglia are either under- or over-stimulated. In particular, the subthalamic nucleus becomes overactive and acts as a brake on the globus pallidus interna causing shutdown of motion and rigidity. When the GPi is overstimulated, it has an over-inhibitory effect on the thalamus, which in turn decreases thalamus output and causes tremo

Symptoms include

1. Resting tremor - In Parkinson disease, the tremor occurs during rest. But it disappears while doing any work. So, it is called static tremor or resting tremor.

2. Slowness of movement --Over the time, movements start slowing down (brady-kinesia) and it takes a long time even to perform a simple task.

3. Rigidity (Lead pipe rigidity)

4. Maskike facies i.e. No facial expression

5. Festinant gait --- The patient walks quickly in short steps by bending forward as if he is going to catch up the center of gravity.

6. Emotional disturbance and depression