Neurodegenerative Disorders Overview

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Questions and Answers

What is a primary characteristic of Alzheimer's disease?

Increase in synaptic connections in the hippocampus

Decrease in extracellular amyloid plaques

Loss of cholinergic neurons in the hippocampus (correct)

Development of myelinated fibers in the cortex

Which of the following features are characteristic of Alzheimer's disease?

Presence of oligodendrocytes

Increased proliferation of brain cells

Intraneuronal neurofibrillary tangles (correct)

Localized gain of neurons

How does the incidence of neurodegenerative disorders generally change with age?

Only affects those under the age of 40

Remains constant throughout life

Increases exponentially after age 65 (correct)

Decreases significantly after age 65

What is a common challenge in treating neurodegenerative disorders?

Effective drug delivery to the CNS Signup and view all the answers

Which of the following statements about Alzheimer's disease is true?

Cognitive impairment has a gradual onset Signup and view all the answers

What type of protein aggregates are associated with Alzheimer's disease?

Amyloid beta-fibrils Signup and view all the answers

Which of the following descriptions is accurate regarding the cognitive impact of Alzheimer's disease?

Short-term memory impairment typically occurs first Signup and view all the answers

What is a prominent effect of neurodegenerative disorders on quality of life?

Profound effect on overall quality of life Signup and view all the answers

Which of the following cholinesterase inhibitors is known for dose-limiting side effects?

Tacrine Signup and view all the answers

What effect do cholinesterase inhibitors have on the progression of Alzheimer's disease?

No effect on disease progression Signup and view all the answers

Which treatment is specifically associated with reducing clinical deterioration in moderate-to-severe Alzheimer's disease?

NMDA receptor antagonist memantine Signup and view all the answers

What is the primary characteristic of Huntington's Disease?

Inherited disorder causing progressive brain degeneration Signup and view all the answers

What role do antihypertensives play in the context of acute ischemic stroke?

They manage elevated blood pressure in the first 24–48 hours. Signup and view all the answers

Which of the following medications is used to treat psychological symptoms associated with Huntington's Disease?

Antipsychotic drugs Signup and view all the answers

What is the primary treatment focus for ischaemic strokes?

Cautious management of blood pressure and prevention Signup and view all the answers

Which statement about recombinant tissue plasminogen activator (tPA) is incorrect?

It can be used for both ischemic and hemorrhagic strokes. Signup and view all the answers

Which neurological feature is commonly associated with the onset of Huntington's Disease?

Chorea or involuntary movements Signup and view all the answers

What is the effect of increased body temperature during acute ischemic stroke?

Associated with poor neurological outcomes Signup and view all the answers

Which of the following is NOT a characteristic of Huntington's Disease?

Complete cure is available Signup and view all the answers

What is the first-line treatment approach for depression in Huntington's Disease patients?

Standard antidepressant drugs Signup and view all the answers

Which of the following statements best describes the action of memantine in Alzheimer's disease treatment?

It blocks NMDA receptors in a use-dependent manner. Signup and view all the answers

Which of the following is primarily a side effect concern when using cholinesterase inhibitors?

Nausea and gastrointestinal distress Signup and view all the answers

Study Notes

Neurodegenerative Disorders (NDs)

Neurodegenerative disorders are conditions involving progressive cell loss in the brain and spinal cord.
Symptoms vary depending on the affected region and rate of change.
Causes are unknown for most.
Common NDs include Parkinson's Disease, Alzheimer's Disease, and Huntington's Disease.
NDs significantly impact quality of life.
Neurological disorders, including those listed above, affect over 1.5 billion globally.
Incidence increases exponentially after age 65.
Current treatment strategies for NDs are limited, and CNS drug delivery presents a significant challenge.

Alzheimer's Disease (AD)

AD involves brain shrinkage and neuron loss, primarily in the hippocampus and basal forebrain.
Loss of cholinergic neurons is linked to cognitive deficits and short-term memory loss.
Two key microscopic features:
- Extracellular amyloid plaques: amorphous deposits of β-amyloid protein (aβ).
- Intraneuronal neurofibrillary tangles: filaments of phosphorylated tau protein.
Both are protein aggregates resulting from protein misfolding, also present in normal brains (though fewer).
AD causes gradual but relentless cognitive decline.
Short-term memory impairment is often the first sign.
Long-term memory retrieval usually remains intact for a longer period.

Treatment of Alzheimer's Disease

Treatment attempts to enhance brain cholinergic function.
Cholinergic precursors (choline chloride, lecithin) have limited effects.
Acetylcholinesterase inhibitors are effective.
Currently approved drugs are cholinesterase inhibitors and memantine.

Cholinesterase Inhibitors

Four approved inhibitors: Tacrine, Donepezil, Rivastigmine, and Galantamine.
Tacrine is a potent central inhibitor, but side effects limit its use.
Other inhibitors (Donepezil, Rivastigmine, Galantamine) produce mild cognitive improvements but don't alter disease progression.
Memantine, an NMDA glutamate-receptor antagonist, reduces clinical deterioration in moderate-to-severe AD.

Huntington's Disease (HD)

HD is an autosomal dominant, inherited neurodegenerative disorder.
It causes progressive brain degeneration starting in adulthood.
Leads to rapid decline and death.
Characterized by gradual onset motor incoordination and cognitive decline in midlife.
Symptoms include:
- Chorea (brief, jerky movements)
- Personality changes
- Fine motor incoordination, rapid eye movement impairment, and/or bradykinesia/dystonia
- Motor deterioration to include dysarthria, dysphagia, and balance impairment.
Neuronal loss is prominent in the striatum (caudate/putamen).

Treatment of Huntington's Disease

Treatment is symptomatic; no current treatment slows progression.
Medication is used to manage various symptoms:
- Antidepressants for depression
- Antipsychotics for paranoia, delusions, and psychosis (especially clozapine, quetiapine or carbamazepine for predominantly rigid symptoms)
- Dopamine-depleting agents (tetrabenazine, reserpine) for severe chorea
- Sedatives or anxiolytics (benzodiazepines) for chorea worsened by anxiety
- Anticonvulsants (clonazepam, valproic acid) for myoclonus and seizures.

Ischemic Brain Damage (Stroke)

Stroke is a common cause of death and disability (after heart disease and cancer).
Ischemic strokes (85%) are caused by thrombosis.
Haemorrhagic strokes (15%) result from artery rupture.
Recombinant tissue plasminogen activator (tPA) is the only approved stroke treatment.
tPA dissolves thrombi when administered intravenously within ~3 hours of the event, should not be given for hemorrhagic strokes.
Stroke management focuses on prevention (blood pressure control, aspirin, atherosclerosis prevention).

Stroke Supportive Care Medications

Oxygenation: Maintain adequate tissue oxygenation to prevent hypoxia.
Antihypertensives: Manage elevated blood pressure.
Antipyretics: Manage fever.
Insulin: Normalise high blood sugar.

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Description

This quiz covers essential information about neurodegenerative disorders (NDs), including their impact, symptoms, and common types such as Alzheimer's Disease and Parkinson's Disease. It also explores the challenges of treatment and the demographic factors associated with NDs.