Parkinsonism Overview

<p>Substantia nigra pars compacta (C)</p> Signup and view all the answers

<p>Extrapyramidal motor disorder (D)</p> Signup and view all the answers

<p>Wilson’s disease (A)</p> Signup and view all the answers

<p>Depletes dopamine levels (C)</p> Signup and view all the answers

<p>Loss of ability to move (C)</p> Signup and view all the answers

<p>It exerts an inhibitory influence on these structures. (D)</p> Signup and view all the answers

<p>Tremors and rigidity. (B)</p> Signup and view all the answers

<p>Prolactin. (B)</p> Signup and view all the answers

<p>By utilizing active transport in the small intestine. (C)</p> Signup and view all the answers

<p>Hair loss. (D)</p> Signup and view all the answers

<p>Less levodopa is available for absorption. (C)</p> Signup and view all the answers

<p>Amount of glucose consumption. (C)</p> Signup and view all the answers

<p>Gradual tolerance development. (B)</p> Signup and view all the answers

<p>Enhance levodopa activity (D)</p> Signup and view all the answers

<p>Acute fatal hepatitis (D)</p> Signup and view all the answers

<p>200 mg with each dose (D)</p> Signup and view all the answers

<p>Diarrhoea (C)</p> Signup and view all the answers

<p>Decrease its elimination (D)</p> Signup and view all the answers

<p>Rasagiline is taken once daily (D)</p> Signup and view all the answers

<p>Entacapone (A)</p> Signup and view all the answers

<p>Associated with acute rhabdomyolysis (B)</p> Signup and view all the answers

<p>Pramipexole (B)</p> Signup and view all the answers

<p>0.4–0.8 g (A)</p> Signup and view all the answers

<p>Pramipexole and ropinirole (C)</p> Signup and view all the answers

<p>1–2 weeks (D)</p> Signup and view all the answers

<p>75–100 mg of carbidopa with 100–200 mg of levodopa (A)</p> Signup and view all the answers

<p>Pramipexole (D)</p> Signup and view all the answers

<p>Madopar (D)</p> Signup and view all the answers

<p>Fewer than those treated with bromocriptine (B)</p> Signup and view all the answers

<p>100 mg BD (D)</p> Signup and view all the answers

<p>Livedo reticularis (D)</p> Signup and view all the answers

<p>3–6 years (B)</p> Signup and view all the answers

<p>Confusion (A)</p> Signup and view all the answers

<p>Prolong its therapeutic effect (A)</p> Signup and view all the answers

<p>Antihistamines (B)</p> Signup and view all the answers

<p>Reducing unbalanced cholinergic activity (C)</p> Signup and view all the answers

<p>Yes, but there is no proof yet (B)</p> Signup and view all the answers

<p>10–25% (B)</p> Signup and view all the answers

<p>Tremor (B)</p> Signup and view all the answers

<p>Urinary retention (B)</p> Signup and view all the answers

<p>Selegiline (A)</p> Signup and view all the answers

<p>In younger patients with early/mild disease (A)</p> Signup and view all the answers

<p>Similar to atropine (D)</p> Signup and view all the answers

<p>Ropinirole (A)</p> Signup and view all the answers

<p>Dyskinesias are related to dose and duration (C)</p> Signup and view all the answers

A neurodegenerative disorder characterized by symptoms like rigidity, tremors, and slow movement, often affecting older individuals.

The degeneration of neurons in the substantia nigra pars compacta and the nigrostriatal tract, which is the most consistent lesion found in Parkinson's Disease.

The neurotransmitter dopamine is depleted in Parkinson's Disease, leading to the characteristic symptoms.

A drug that provides relief from the symptoms of Parkinson's Disease.

Reserpine depletes dopamine in the brain, leading to symptoms similar to Parkinson's Disease.

Levodopa, a precursor to dopamine, can be used to treat Parkinson's Disease, as it can cross the blood-brain barrier and be converted into dopamine.

Drug-induced Parkinsonism can occur as a side effect of some medications, such as antipsychotics and antiemetics.

Excess glutamate can damage neurons through 'excitotoxicity', leading to neuronal death.

Pramipexole has a stronger affinity for dopamine receptors (D3) compared to levodopa. This means it can bind more effectively to these receptors, potentially leading to a more pronounced effect.

Pramipexole, ropinirole, and bromocriptine are all dopamine agonists used in Parkinson's disease treatment. While bromocriptine has a longer history, pramipexole and ropinirole are often preferred due to better tolerability and fewer gastrointestinal side effects.

Levodopa is a precursor to dopamine, which is deficient in Parkinson's. It is commonly used in combination with carbidopa or benserazide to reduce side effects and improve efficacy.

The usual daily maintenance dose of levodopa ranges from 0.4 to 0.8 grams, combined with carbidopa or benserazide in specific doses. The dosage and preparation are tailored to individual patients' needs, and doses are increased gradually.

Dopamine agonists can be used in advanced Parkinson's disease. This is because they can stimulate dopamine receptors even when dopamine levels are low.

Dopamine agonists are increasingly used as initial treatment for early Parkinson's disease. They often provide symptom relief that is comparable to levodopa.

Studies have shown that patients treated with ropinirole may require less supplemental levodopa compared to those on bromocriptine.

Dose adjustments for optimal results with pramipexole and ropinirole can be achieved relatively quickly (1-2 weeks). Bromocriptine, on the other hand, may take several months to find the right dose.

In Parkinson's disease, degeneration of neurons in the substantia nigra pars compacta (SN-PC) reduces dopamine (DA) levels in the striatum, leading to an imbalance between DA and acetylcholine (ACh). This imbalance results in the cardinal motor symptoms of Parkinson's: hypokinesia (slowness of movement), rigidity (muscle stiffness), and tremor (involuntary shaking).

The basal ganglia play a crucial role in regulating movement by modulating the output of the motor cortex to skeletal muscles. It ensures smooth and controlled movements by reducing basal tone (muscle stiffness) and fine-tuning motor commands.

Levodopa is rapidly absorbed from the small intestines using the active transport system for aromatic amino acids. Its bioavailability is affected by gastric emptying time and the presence of other amino acids in food, both of which can reduce the amount of levodopa that reaches the brain.

Levodopa undergoes significant 'first-pass' metabolism in the gut wall and liver, meaning a large portion of it is broken down before reaching the bloodstream. This reduces its bioavailability and necessitates higher doses of levodopa to achieve therapeutic levels in the brain.

Nausea and vomiting are common side effects of levodopa therapy, often experienced by most patients at the initiation of treatment. Tolerance usually develops over time, allowing for gradual dose increases.

Levodopa is a precursor of dopamine that can cross the blood-brain barrier and be converted into dopamine by the enzyme dopa decarboxylase. This action replenishes dopamine levels in the brain, improving motor function in Parkinson's disease patients.

Dopamine, in addition to its role in the brain, acts as an endocrine hormone. In the pituitary gland, it inhibits prolactin release and stimulates growth hormone (GH) release. However, in Parkinson's disease patients, increased GH levels are not observed despite a decrease in prolactin.

The striatum is a brain region involved in movement control. It receives input from the substantia nigra pars compacta (SN-PC), which releases dopamine. Dopaminergic action in the striatum exerts an inhibitory influence on the substantia nigra pars reticulata (SN-PR) and globus pallidus internus (GP-I) via two pathways.

A medication used to treat Parkinson's disease, it is a selective inhibitor of type B monoamine oxidase (MAO-B). It helps improve symptoms by increasing dopamine levels.

Selegiline is not recommended for use by patients with a history of seizures because it could increase the risk of having a seizure.

Selegiline can interact with certain medications, such as pethidine, tricyclic antidepressants, and selective serotonin reuptake inhibitors (SSRIs), potentially leading to adverse effects.

It is used to treat Parkinson's disease, specifically to reduce the breakdown of dopamine in the brain.

Rasagiline is a MAO-B inhibitor, similar to Selegiline but it's five times more potent, longer acting, and doesn't metabolize to amphetamine.

It is used to treat Parkinson's disease, specifically to reduce the breakdown of dopamine in the brain.

Entacapone and Tolcapone are COMT inhibitors used in Parkinson's disease. Entacapone is commonly used as it is considered safer than Tolcapone.

Adding a COMT inhibitor to levodopa treatment can worsen side effects like nausea, vomiting, and dyskinesia. Adjusting the levodopa dose can help minimize these side effects.

Entacapone and tolcapone enhance and prolong the therapeutic effect of levodopa-carbidopa in advanced and fluctuating Parkinson's Disease.

They act by reducing the unbalanced cholinergic activity in the striatum of parkinsonian patients.

These are drugs having a higher central : peripheral anticholinergic action ratio than atropine, but the pharmacological profile is similar to it.

A characteristic side effect due to local release of CAs resulting in postcapillary vasoconstriction is livedo reticularis (bluish discoloration) and edema of ankles.

None of the above drugs alter the basic pathology of PD—the disease continues to progress. Drugs only provide symptomatic relief and give most patients an additional 3–6 years of happier and productive life.

Considering that oxidative metabolism of DA generates free radicals which may rather hasten degeneration of nigrostriatal neurones, it has been argued that levodopa therapy might accelerate progression of PD.

There is little to choose clinically among these drugs, though individual preferences vary.

Side effects are accentuated when it is combined with anticholinergics.

All anticholinergics can improve Parkinsonian symptoms but they are less effective than Levodopa. They can be used alone in mild cases or combined with Levodopa to reduce the dosage.

Anticholinergics are the only effective treatment for drug-induced Parkinsonism, which is caused by medications like phenothiazines.

Anticholinergics have side effects like memory impairment, confusion, blurry vision, and urinary retention, especially in the elderly.

Trihexyphenidyl is the most commonly used anticholinergic drug for Parkinson's Disease treatment.

Newer dopamine agonists like ropinirole and pramipexole are increasingly used for early Parkinson's, especially in younger patients, due to their fewer motor complications compared to Levodopa.

When Parkinson's progresses, levodopa combined with a decarboxylase inhibitor is the standard therapy, replacing Levodopa use alone.

Combining selegiline with levodopa can help overcome the "wearing off" effect, which is the loss of effectiveness of levodopa over time.

Levodopa therapy might cause dyskinesias, abnormal involuntary movements, which increase with higher doses and longer duration of treatment.