L8- Neurodegenerative Disease, PD

Question 1

PD classic triad

Answer 1

• muscle rigidity
• tremor
• dyskinesia / akinesia

Question 2

PD is mostly a (familial/sporadic) disorder that is caused by the loss of (2). The familial form usually involve a (3) genetic change.

Answer 2

1- sporadic (exact pathogenesis is unknown)

2- dopaminergic neurons in Substantia Nigra pars compacta (medial)

3- mutation in α-synuclein gene –> autosomal dominant PD

Question 3

list some other common diseases that can exhibit Parkinsonism

Answer 3

• dopaminergic antagonists (antipsychotics)
• Lewy body dementia
• multiple system atrophy

Question 4

describe the 3 main changes seen in the brain during PD pathogenesis

Answer 4

Note- exact pathogenesis is unknown

• accumulation of protein
• mitochondrial abnormalities
• neuronal loss in SNc

Question 5

describe the gross appearance of PD

Answer 5

pallor (loss of black pigmentation) and atrophy of Substantia Nigra

Question 6

describe the microscopic appearance of PD

Answer 6

• loss of pigmented neurons + gliosis
• Lewy Bodies in remaining neurons in SNc: single/multiple, cytoplasmic, eosinophilic (pink) inclusions + filaments of α-synuclein
• Lewy Neurites: dystrophic neurons w/ α-synuclein

Question 7

describe the course of PD disease progression

Answer 7

• ~10-15 yrs

- most common cause of death: aspirational pneumonia OR trauma from falls (postural instability)

Question 8

list the many clinical features of PD

Answer 8

• asymptomatic pill rolling tremor
• bradykinesia: gait changes = shuffling, postural instability
• Cogwheel rigidity: alternating patterns of resistance with passive movements
• Masked facies, hypokinetic dysarthria , micrographia, sleep disorder
• dementia (fluctuating course) and hallucinations

Question 9

define Lewy body dementia

Answer 9

• similar motor symptoms to PD: rigidity, tremor, bradykinesia/akinesia
• if dementia develops (usually w/ hallucinations) w/in 1yr of motor Sxs = Lewy Body dementia