Parkinson’s disease

Mohd. Akmal b. Rosli (060)

Nur Hanisah bt. Zainoren (062)

Overview

Causes

Features

Treatments

• Parkinson's disease is a degenerative neurologic disease.

• Degenerative = declining in quality

(Thus, the disease increases in severity over time)

• Neurologic = the nervous system.

• described by James Parkinson

• Parkinson’s Disease results from the degeneration of dopaminergic nigrostriataltract

• With age, there is progressive loss of dopamine and dopamine receptors in the basal ganglia (caudate nucleus and putamen)

Primary or idiopathic

(cause is not exactly known)

Cerebral arteriosclerosis

Use of drugs such as

phenothiazinewhich

blocks the D2 dopamine receptors

Features

Hypokineticmovements

(decreased bodily movement)

Hyperkinetic movements

(decreased bodily movement)

Hypokinetic movements

• Difficulty in initiating movements and decreased spontaneous movements

AKINESIA

• Slowness of movements

BRADYKINESIA

• Examples of associated movements: -Swinging of arms during walking -Facial expressions during speaking

DECREASED ASSOCIATED MOVEMENTS

Grossly diminished in Parkinsonism

EXPRESSIONLESS FACE/MASK FACE

• Dopamine is secreted in the caudate nucleus and putamen.

• It act as inhibitory transmitter

– In which destruction of dopaminergic neuron in substansia nigra happen in Parkinson’s disease.

• This cause the caudate nucleus and the putamen to be overly active

Hyperkinetic feature

• It also cause continuous output of excitatory signal to the corticospinal motor control system which lead to rigidity.

• Lead pipe

• increase in muscle tone causing a sustained resistance to passive movement throughout the whole range of motion

• Cogwheel

• It is a combination of lead pipe and tremor

• jerky resistance to passive movement as muscles tense and relax

Rigidity

• Involuntary tremor

• It is due to the high feedback gain after the loss of inhibition lead to tremor of Parkinson’s disease.

• This happen during all walking hours.

Tremor

• Administration of L-dopa

– It’s a drug that can cross blood brain barrier

– This will be converted in the brain into dopamine

– Restored the balance between inhibiton and excitation of caudate nucleus and putamen

Treatments

• This drug inhibit monoamine oxidase which is an enzyme that destroy dopamine.

• It will make dopamine remain longer in the basal ganglia.

• Adminstration of L-dopa and L-deprenyl will provide better treatment than just one drug alone.

Treament with L-deprenyl

• This dopamine secreting cells is retrived from the brain of aborted fetuses.

• It is transplanted into the caudate nucleus and putamen.

• However this only lasted for few months

Treament by transplant of fetal dopamine cells

• Parkinson’s disease is cause by the loss of function of substansia nigra to produce dopamine.

Conclusion

• Textbook of Physiology, Volume 2, Prof. A.K. Jain

• Textbook of Medical Physiology, Prof GK Pal

• http://www.umm.edu/parkinsons/facts.htm