Lecture 13 (Parkinson's)

Question 1

resting tremor vs. action tremor

Answer 1

resting:
- tremors when resting
- symptom of idiopathic PD

action:
- less tremors during rest but more tremors when doing something
- symptom of Mn-induced PD

Question 2

IPD vs. Mn-induced PD (causes)

Answer 2

both are types of Parkinson’s

IPD is from an unknown cause

Mn-induced PD is from Manganese

Question 3

IPD symptoms

Answer 3

IPD:
- resting tremors, little to no head titubation
- on-off phenomena, hallucinations, or dystonia (muscle twitching)
- response to L-dopa therapy
- lewy inclusion bodies in substantia nigra

Question 4

traits of PD (TRAP)

Answer 4

tremors

rigidity

akinesia (frozen) or bradykinesia (slowness)

postural instability

Question 5

IPD vs Mn-induced PD (symptoms)

Answer 5

similarities:
- chronic movement disorders (rigidity, bradykinesia, posture instability, different tremors)

differences:
- minor or no resting tremor, mainly action tremor
- not responsive to L-dopa therapy
- Mn has psychiatric symptoms while IPD does not
- IPD has Lewy bodies. Mn does not
- IPD has lesions in substantia nigra. Mn has lesions in globlus pallidus and striatum

possible causes:
- drug-induced
- toxin-induced
- medical conditions

Question 6

Mn-induced PD symptoms

Answer 6

dystonia (cock gait)

micrography from hand tremor (action tremor)

Question 7

describe neuropathology of IPD and why L-dopa works

Answer 7

substantia nigra must signal to striatum through dopamine neurons

in IPD, dopamine neurons die –> no more signaling

L-dopa replaces these dead dopamine neurons

Question 8

why doesn’t L-dopa work for Mn-induced patients?

Answer 8

their dopamine neurons were never dead

rather, Mn damages the globes pallidus (another part of brain in striatum) –> disrupts signals from working dopamine neurons

–> so adding more dopamine will not do anything

Question 9

where is main storage organ of Mn?

Answer 9

liver

skeletal system

Question 10

what is half-life of Mn in body?

Answer 10

36-41 days in blood

8-9 yrs in bone

Question 11

what disease is a disease associated with Mn in liver?

Answer 11

hepatic encephalopathy (loss of brain function when liver doesn’t function well)

MRI scan showed clear Mn signals in brain in patient with cirrhosis

when translated with healthy liver, Mn signals from brain disappeared

Question 12

describe chelation therapy for Mn

Answer 12

chelation therapy with EDTA to remove Mn –> removes Mn from blood

PAS (para-amino-salicylic acid) –> crosses blood brain barrier to draw out Mn. Also has an anti-inflammatory effect