Disorders of Movement

Question 1

Huntington’s Disease

Answer 1

Huntington’s Disease: inherited degenerative disease due to autosomal dominant gene and has a combination of psychiatric, cognitive and motor symptoms.

1. offspring of affected are 50% chance and diagnosed when between ages 30-50.
2. emotional and cognitive symptoms appear first (depression, apathy, anxiety, antisocial, forgetful).
3. Then motor symptoms include fidgeting/clumsiness, followed by facial grimaces and piano-playing movements of the fingers, which are the earliest signs of chorea (jerky, involuntary movements of the extremities)
4. Chorea: worsens and causes a dance-like gate, athetosis (slow, writhing movements) become prominant.
5. Cognitive impariments gradually progress to deficits in planning, problem-solving, and decision making and eventually to dementia.
6. *linked to loss of GABA-secreting neurons and glutamate excitotoxicity in the basal ganglia especially in the caudate nucleus, putamen, and globus pallidus. *

Question 2

Parkinson’s Disease

Answer 2

Parkinson’s Disease: progressive degeneration of dopamine-containing cells in the substantia nigra, which affects other areas of the brain that connect with cells in certain areas in the thalamus and frontal lobes.

1. Linked to exposure to herbicides, pesticides, and other toxins over long periods of time.
2. Positive Symptoms: tremor at rest (pill-rolling between thumb and forefinger), muscle rigidity (mask like facial expression), and akathisia (cruel restlessness).
3. Negative Symptoms: postural distrubances, speech difficulties, bradykinesia (slowed movements) and akinesia (reduced or no spontaneous movement.
4. Depression: in 20% depression precedes motor signs, and up to 50% have prominent symptoms of depression at some time during the illness.
   
   1. fact that some people develop depression as an initial symptom indicates that it is endogenous to the disease rather than just a reaction to it. Cool!
5. TREATMENT: motor symptoms iniatially alleviated by L-dopa (dopamine agonist). But this diminishes over time. alternative include injecting cells into the basal ganglia.