Parkinson's Disease .

"Parkinson's diesease  also know as idiopathic ,hypokinetic rigid syndrome .

"It is a progressive neurodegenerative disorder , which result from degeneration of dopaminergic neurons in the Substantia niagra ,characterized by tremor,rigidity,and akinesha.

The dieses is named after the English doctor JAMES PARKINSONS , who published the first detailed in Essay on Shaking Palsy in 1817.

◆ Etiology 

Damage of dopaminergic neurons, the Etiology of Parkinsons disease is still unclear , most cases are hypothesized to be due to combination of genetic and environmental factor .

Currently known genetic causes of Parkinsons disease account for approximately 10% of cases

◆1) Environmental Cause

Environmental risk factor commonly associated with the development of Parkinsons disease include use of pesticide , living in rular environment , consumption of well water , exposure of herbicide and proximity to industrial plants or quarries .

◆2) Genetic Factor 

Concordance in generally identically monozygotic twins will be greater than in dizygotic twins, who share only 50% of gene . Early Parkinsons disease twin studies generally found low and similar concordance rates for monozygotic and dizygotic twins pair.

However genetic factor in parkinsons disease appear to be very important when the disease being at or before age 50 years . In a study of 193 twins , overall concordance For monozygotic and dizygotic twins pairs was similar but in 16 pairs of twins in whom Parkinsons disease was diagnosed at or before age 50 years , all 4 monozygotic pairs, but only 2 pair of 12 Dizygotic , were concordant.

◆ Pathophysiology :

The neurological diagnosis of Parkinsons disease,as the specificity and sensiti6 of its characteristic finding have not been clearly established. However , the following are 2 Major neuropathologic finding in parkinsons disease .

● loss of pigmented dopaminergic neurons of the Substantia niagra compacta .

●The presence of lewy  bodies and lewy neurites.

The loss of dopaminergic neurons occurs most prominently in the ventral lateral Substantia niagra approximately 60-80% of dopaminergic neurons are lost before the motor signs of Parkinsons disease emerge.

◆Symptoms

1】It is first symptoms appear in PD . Tremor can be seen in the hand nd head of the affected person . Because this person can not held anything properly in his hand 

E.g  He can not pick the glass of water

2】 Rigidity : Affect persons muscle becomes rigid that in frozen joints stopped posture , Flexed knees and elbows.

3】 Akinesia :- this is a lack or difficulty in initiating voluntary muscle movement and in advance stage characterized by the "Frozen muscle" , resulting in mask like face , difficulty with Daily activity such as writing ,shaving using knife and fork and opening of buttons , slowed chewing and swallowing .

◆Treatment :- 

Anti Parkinsons Drug .

1) Levodopa for dopamine replacer .

2) carbidopa , Benserazude for dopa decarboxylase inhibitor 

3) Selegeline for MAO-B inhibitor 

4) Amantodine for Dopaminergic facilator.