1) Parkinson’s Parkinson’s is caused by a Loss of Dopaminergic Neurons within the substantia nigra. This essentially eliminates the “go” signal, preventing the initiation of movement. The classic symptoms of Parkinson’s stems from bradykinesia (difficulty initiating movement). This will manifest itself in slowmovements in general and even cognitive slowing. Logo for the classic cog-wheel rigidity, a resting pill-rolling tremor, and gait disturbances / postural instability (the little muscles that keep you straight up don’t correct for position, so these patients are high risk for falls). The patient will have difficulty with the get-up-and-go test, and will walk with shuffling steps. A board buzz word is a mask-like expressionless face.
The diagnosis is clinical. While brain imaging might be attempted to rule out something else (CT for a bleed, MRI for stroke), said imaging is not needed. The test might throw at you an MRI of the substantia nigra showing degeneration, but that is NOT needed for the diagnosis in life. Treatment is about the go signal. The go signal is dopamine. The stop signal is Acetylcholine. The fo cus of therapy is supplying the go signal. Dopamine Agonists agonists are the mainstay of therapy for young, functional people (70 OR Non functional
2) Intention Tremor = Cerebellar Dysfunction A tremor that’s absent at rest and gets worse the closer to the target the finger gets. This is also called an intention tremor because it arises as the patient attempts (intends) to do something. Since there’s a physical lesion (stroke, atrophy) of the cerebellum there’s no therapy. 3) Huntington’s Huntington’s is an autosomal dominant genetic disease caused by trinucleotide repeats. The more repeats a person has, the earlier the disease sets in. Most people begin to exhibit symptoms near middle age (30-60). It also exhibits anticipation: occurring earlier and earlier in subsequent generations as the number of trinucleotide repeats expands. Chorea is purposeless ballistic movements . The prognosis is terrible as it leads to dementia, psychosis, and often death by suicide. There’s no treatme nt.