1. The fundamental pathogenic event in Alzheimer disease is:
Loss of dopaminergic neurons
Deposition of β-amyloid in the brain
Mutation of huntingtin protein
Autoimmune demyelination
Explanation:
Alzheimer disease is driven by abnormal deposition of β-amyloid derived from APP.
2. Insoluble β-amyloid is produced when APP is cleaved by:
α-secretase only
α and γ secretase
β-secretase only
β and γ secretase
Explanation:
β and γ secretase cleavage produces insoluble, fibrillogenic β-amyloid.
3. The APP gene is located on chromosome:
21
19
4
14
Explanation:
The APP gene is located on chromosome 21, explaining early Alzheimer pathology in Down syndrome.
4. Hyperphosphorylation of tau protein leads to formation of:
Lewy bodies
Pick bodies
Neurofibrillary tangles
Amyloid plaques
Explanation:
Hyperphosphorylated tau forms insoluble filaments within neurons called neurofibrillary tangles.
5. Neurofibrillary tangles are:
Extracellular and specific for Alzheimer disease
Intracellular and not specific for Alzheimer disease
Composed of α-synuclein
Seen only in the cortex
Explanation:
Neurofibrillary tangles are intracellular tau filaments and are not specific for AD.
6. Which apolipoprotein allele increases the risk of Alzheimer disease?
Apo E2
Apo E1
Apo E3
Apo E4
Explanation:
Apo E4 increases deposition of fibrillar β-amyloid and raises AD risk.
7. The most prominent gross brain change in Alzheimer disease is:
Cerebral atrophy with widened sulci
Basal ganglia hemorrhage
Brainstem necrosis
White matter plaques
Explanation:
Alzheimer disease causes cortical atrophy with narrowing of gyri and widening of sulci.
8. Ventricular dilatation in Alzheimer disease is best described as:
Obstructive hydrocephalus
Communicating hydrocephalus
Hydrocephalus ex vacuo
Normal pressure hydrocephalus
Explanation:
Ventricular dilatation results from cortical atrophy and is termed hydrocephalus ex vacuo.
9. The second most common cause of dementia after Alzheimer disease is:
Pick disease
Vascular dementia
Lewy body dementia
Huntington disease
Explanation:
Vascular dementia (multi-infarct dementia) is the second most common cause.
10. Grey matter lesions on MRI are characteristic of:
Vascular dementia
Multiple sclerosis
ALS
Parkinson disease
Explanation:
Vascular dementia shows predominant grey matter infarcts.
11. Parkinson disease is caused by degeneration of neurons in the:
Caudate nucleus
Putamen
Globus pallidus
Substantia nigra
Explanation:
Loss of dopaminergic neurons in the substantia nigra causes Parkinson disease.
12. Lewy bodies are composed primarily of:
Tau protein
β-amyloid
α-synuclein
Huntingtin protein
Explanation:
Lewy bodies contain aggregates of α-synuclein.
13. Dementia occurring within 1 year of Parkinson motor symptoms defines:
Alzheimer disease
Lewy body dementia
Pick disease
Vascular dementia
Explanation:
Lewy body dementia is defined by dementia appearing within 1 year of Parkinsonism.
14. Huntington disease is caused by mutation on chromosome:
21
19
14
4
Explanation:
Huntington disease is an autosomal dominant disorder due to CAG repeats on chromosome 4.
15. The hallmark movement disorder of Huntington disease is:
Chorea
Resting tremor
Rigidity
Dystonia
Explanation:
Huntington disease presents with choreiform, dance-like involuntary movements.
16. Atrophy of which structure causes ventricular enlargement in Huntington disease?
Putamen tail
Globus pallidus
Head of caudate nucleus
Thalamus
Explanation:
Caudate nucleus atrophy leads to ex vacuo dilatation of the lateral ventricles.
17. In ALS, which neurons are characteristically spared early?
Anterior horn cells
Cognitive cortical neurons
Upper motor neurons
Brainstem motor nuclei
Explanation:
ALS preserves cognition, memory, and personality until late stages.
18. The most common genetic mutation associated with familial ALS involves:
Tau protein
Presenilin
α-synuclein
Superoxide dismutase (SOD-1)
Explanation:
SOD-1 mutation on chromosome 21 is the most frequent familial ALS mutation.
19. A purely upper motor neuron degenerative disorder is:
Primary lateral sclerosis
ALS
Progressive spinal muscular atrophy
Huntington disease
Explanation:
Primary lateral sclerosis affects corticospinal tracts without LMN involvement.
20. Bulbar involvement in ALS affects cranial nerves:
3, 4, 6
5, 7, 8
9, 10, 11, 12
1, 2, 8
Explanation:
Bulbar ALS involves degeneration of cranial motor nuclei IX–XII.