NCS Neurologic Pathophysiology 1 — Questions and Answers
Question 1: Which neurotransmitter imbalance is primarily implicated in the pathophysiology of schizophrenia?
- Excessive serotonin
- Deficient dopamine
- Excessive dopamine (Correct answer)
- Deficient norepinephrine
Correct answer: Excessive dopamine
The dopamine hypothesis of schizophrenia posits that the positive symptoms of the disorder, such as hallucinations and delusions, are primarily associated with excessive dopamine activity in certain brain regions. Antipsychotic medications, the cornerstone of treatment, primarily work by blocking dopamine D2 receptors. While other neurotransmitters are involved, dopamine dysregulation remains a central focus in understanding and treating schizophrenia.
Question 2: In Huntington's disease, which of the following is the primary genetic mutation responsible for the condition?
- Mutation in the HTT gene causing CAG repeat expansion (Correct answer)
- Mutation in the APP gene causing amyloid-beta deposition
- Mutation in the PSEN1 gene causing tau hyperphosphorylation
- Mutation in the SOD1 gene causing oxidative stress
Correct answer: Mutation in the HTT gene causing CAG repeat expansion
Huntington's disease is an inherited neurodegenerative disorder caused by a dominant mutation in the HTT gene (Huntingtin gene). This specific mutation involves an abnormal expansion of a CAG trinucleotide repeat sequence within the gene. The increased number of CAG repeats leads to the production of an abnormally long and toxic huntingtin protein, which damages neurons, particularly in the basal ganglia, leading to the characteristic symptoms of the disease.
Question 3: Which type of stroke is caused by the rupture of a blood vessel in the brain?
- Ischemic stroke
- Hemorrhagic stroke (Correct answer)
- Transient ischemic attack (TIA)
- Subdural hematoma
Correct answer: Hemorrhagic stroke
A hemorrhagic stroke occurs when a blood vessel in the brain ruptures, causing bleeding into the surrounding brain tissue. This bleeding directly damages brain cells and increases intracranial pressure, leading to neurological deficits. In contrast, an ischemic stroke is caused by a blockage of blood flow, and a transient ischemic attack (TIA) is a temporary blockage with no permanent damage.
Question 4: In multiple sclerosis (MS), which of the following is the primary pathophysiological process?
- Cortical neuron apoptosis
- Demyelination of the central nervous system (Correct answer)
- Autoimmune destruction of peripheral nerves
- Excessive dopamine release in the basal ganglia
Correct answer: Demyelination of the central nervous system
Multiple Sclerosis (MS) is an autoimmune disease characterized by the immune system attacking the myelin sheath, which insulates nerve fibers in the central nervous system (brain, spinal cord, and optic nerves). This demyelination disrupts the efficient transmission of nerve impulses, leading to a wide range of neurological symptoms. It is the primary pathophysiological process that defines MS.
Question 5: Which neurodegenerative disease is primarily associated with the accumulation of amyloid-beta plaques and tau tangles in the brain?
- Multiple Sclerosis
- Alzheimer's Disease (Correct answer)
- Amyotrophic Lateral Sclerosis
- Huntington’s Disease
Correct answer: Alzheimer's Disease
Alzheimer's Disease is primarily associated with the accumulation of two distinct pathological hallmarks in the brain: amyloid-beta plaques and neurofibrillary tangles. Amyloid-beta plaques are extracellular deposits of amyloid-beta protein, while neurofibrillary tangles are intracellular aggregates of hyperphosphorylated tau protein. These abnormal protein deposits disrupt neuronal function and lead to widespread neuronal death, particularly in areas critical for memory and cognition.
NCS Neurologic Pathophysiology 1
Which neurotransmitter imbalance is primarily implicated in the pathophysiology of schizophrenia?