Hello and welcome to HCM,

In order to understand the etiology/ cause of these abnormal motor behaviors, certain questions, certain tests and investigations are needed to come close to the etiology and diagnosis. They are:
1. The duration of onset of symptoms- from birth or later on in life, if later at what age the symptoms developed
2. Are the motor abnormalities localized to upper limb or lower limb. Are they symmetrical or asymmetrical?
3. On examination, are the limb muscles wated/ flaccid?
4. Is the tone of muscles maintained?
5. Whether muscle twitching present or not?
6. Babsinki sign positive or negative?
7. Is there any association with visceral involvement- bowel involvement, bladder involvement, pharangeal involvement (swallowing reflex).
8. Is there any history of exposure to any drug, nuclear fall outs, some local food item, etc as the symptoms are present in a large group of people residing in the same area.

The above mentioned points will help to know the cause, pattern and prognosis of the disease process.

Thanks and take care
Dr Shailja P Wahal

Sir,

The key question I like to ask is:
The decrease in dopamine levels comes before or after neuronal degeneration of the substantia nigra?

Why this question
The primary symptoms of Parkinson's Disease stem from the deterioration of the part of the brain that controls motor functioning. This region is the substantia nigra which is found deep within the brain stem and contains neuronomelanin, pigment cells, which synapse to cells of the striatum. The striatum is responsible for balance, control of movements, and walking. Dopamine, produced in the substantia nigra, passes messages between the striatum and the substantia nigra. When the cells of the substantia nigra deteriorate, as in the case of Parkinson's, there is a corresponding decrease in the amount of dopamine produced between these cells. The decreased levels of dopamine cause the neurons of the striatum to fire uncontrollably, preventing the patient to be able to direct motor function.

Dopamine receptors, induction of dopamine production, and blocking the breakdown of dopamine is yet to answer

Thank you