l-A. Progressive supranuclear palsy is associated with Parkinson disease. It is characterized by paresis of downgaze; later, paresis of upgaze occurs. Pseudobulbar palsy, which is always present, results from multiple hemispheric lesions that destroy upper motor neurons (UMNs) bilaterally; it leads to a loss of cells in the globus pallidus, periaqueductal gray, red nucleus, sub-stantia nigra, and dentate nucleus. Usually, the cerebral and cerebellar cortices are not affected. Neurofibrillary tangles are found in surviving neurons.
2. Which thalamic nucleus projects to the striatum? (A) Centromedian nucleus (B) Mediodorsal nucleus (C) Ventral lateral nucleus (D) Ventral anterior nucleus (E) Ventral posterolateral nucleus
2-A. The striatum (caudate nucleus and putamen) receives thalamic input from the centromedian nucleus, the largest of the intralaminar nuclei.
3. The globus pallidus projects to the thalamus via the (A) fasciculus retroflexus (B) stria medullaris (C) ansa lenticularis (D) ansa peduncularis (E) stria terminalis
3-C. The globus pallidus projects to the thalamus via the lenticular and thalamic fasciculi and via the ansa lenticularis. The ansa peduncularis (part of the inferior thalamic peduncle) interconnects the amygdaloid nucleus and the hypothalamus. It also interconnects the orbitofrontal cortex and the thalamus (mediodorsal nucleus). The fasciculus retroflexus (habenulointerpeduncular tract) interconnects the habenular nucleus and the interpeduncular nucleus. The stria medullaris (thalami) interconnects the septal area (nuclei) and the habenular nuclei. The stria terminalis projects from the amygdaloid complex to the septal area and the hypothalamus.
4-B. Huntington chorea, inherited as an autosomal dominant trait, is associated with severe degeneration of the striatum and cell loss in the cerebral cortex. Striatal cell loss results in widening of the frontal horn of the lateral ventricle; this is called hydrocephalus ex vacuo. A DNA marker linked to Huntington chorea is located on chromosome 4.
5-B. Wilson disease (hepatolenticular degeneration) is a familial metabolic disease transmitted as an autosomal recessive trait. Low serum ceruloplasmin, or low serum copper, and increased urinary copper excretion usually corroborate the diagnosis. In the early course of the disease, liver biopsy shows a high copper content. The corneal Kayser-Fleisher ring is pathognomonic of this disease. A gene locus has been found on chromosome 13.
6. The basal ganglia include all of the following structures EXCEPT the (A) globus pallidus (B) caudate nucleus (C) putamen (D) lentiform nucleus (E) subthalamic nucleus
6-E. The basal ganglia include the caudate nucleus, putamen, and globus pallidus. The putamen and globus pallidus together are called the lentiform (lenticular) nucleus. The subthalamic nucleus, a diencephalic nucleus, is not a basal ganglion but is a component of the striatal system. From an embryologic standpoint, the amygdaloid nucleus (archistriatum) and the claustrum are basal ganglia, because they are derived from the telencephalic corpus striatum.
7-E. The corpus striatum includes the caudate nucleus, the putamen, and the globus pallidus. The enigmatic claustrum is found between the external capsule and the extreme capsule.
8-C. Dopamine-containing neurons (cell bodies) are found in the pars compacta of the substantia nigra in the ventral tegmental area of the midbrain. The predominant cell type in the putamen is the medium-sized gamma-aminobutyric acid (GABA)-ergic spiny neuron.
9-A. Glutamatergic neurons have not been identified in the globus pallidus; they have been located in the subthalamic nucleus and thalamus.
12. The striatum receives major input from all of the following nuclei EXCEPT the (A) substantia nigra (B) centromedian nucleus (C) motor cortex (D) sensory cortex (E) subthalamic nucleus
12-E. The striatum (caudate nucleus and putamen) receives major input from three sources; the neocortex, including the motor and sensory cortices; the thalamus (centromedian nucleus); and the substantia nigra (pars compacta). The subthalamic nucleus has important reciprocal connections with the globus pallidus; it does not project to the striatum.
10-B. Dopaminergic neurons of the substantia nigra project via the nigrostriatal pathway to the striatum (caudate nucleus and putamen). Dopamine released in the striatum is thought to regulate the production of neuropeptides and peptide mRNA within the resident striatal neurons. The subthalamic nucleus receives gamma-aminobutyric acid (GABA)-ergic input from the lateral (external) segment of the globus pallidus. The subthalamic nucleus projects excitatory glutamatergic input to both segments of the globus pallidus.
11-C. The substantia nigra receives gamma-aminobutyric acid (GABA)-ergic input from the caudate nucleus and putamen. It projects dopaminergic fibers to the caudate nucleus and putamen. It projects GABA-ergic fibers to the ventral lateral and ventral anterior thalamic nuclei.
14. Is the overall most common cause of chorea (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
14-F. Sydenham chorea (St. Vitus dance) is the most common cause of chorea overall. It is usually found in girls as a sequela to rheumatic fever. Magnetic resonance imaging (MM) studies show an increased signal in the head of the caudate nucleus with T2-weighted images. Quantitative MM reveals an increase in the size of the caudate nucleus, putamen, and globus pallidus. In Huntington disease, there is massive loss of neurons in the caudatoputamen.
16. A corneal Kayser-Fleischer ring is pathognomonic for this dyskinesia (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
16-B. Hepatolenticular degeneration, Wilson disease, is an autosomal recessive disorder due to a defect in the metabolism of copper. The Kayser-Fleisher ring is a green band of pigmentation found around the limbus in Descement membrane; it is a pathognomonic of Wilson disease.
17. Results from a lesion of the subthalamic nucleus (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
17-C. Hemiballism results from a contralateral lesion (usually vascular) of the subthalamic nucleus. It is characterized by violent flinging (ballistic) movements of one or both extremities.
13-A. The globus pallidus, the major effector nucleus of the striatal system, projects to the ventral anterior, ventral lateral, and centromedian thalamic nuclei. It receives input from the stria-turn (the caudate nucleus and putamen). The globus pallidus also has reciprocal connections with the subthalamic nucleus. The motor cortex does not project to the globus pallidus.
19. Can be traced to a single gene defect on chromosome 4 (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
19-D. Huntington disease has its gene locus on chromosome 4 (gene location 4pl6.3)
20. Has its gene locus on chromosome 13 (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
20-B. In Wilson disease the abnormal gene has been assigned to the esterase D locus on chromosome 13.
15. Results from a loss of dopaminergic neurons in the pars compacta of the substantia nigra (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
15-E. Parkinson disease results from a loss of dopaminergic neurons in the pars compacta of the substantia nigra.
18. Is characterized by repetitive choreic movements affecting the face, limbs, and trunk, which results from treatment with an tipsychotic drugs (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
18-G. Tardive dyskinesia is a syndrome characterized by repetitive choreic movements affecting the face and trunk, which results from treatment with antipsychotic drugs (e.g., phenothiazines, butyrophenones, or metoclopramide).
21. Is characterized by cortical atrophy and loss of neurons in the head of the caudate nucleus (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
21-D. Huntington disease is characterized by cortical atrophy and loss of neurons in the head of the caudate nucleus, which results in hydrocephalus ex vacuo.
22. Central nervous system (CNS) lesions are characterized by necrosis and cavitation of the putamen (A) Chorea gravidarum (B) Hepatolenticular degeneration (C) Hemiballism (D) Huntington disease (E) Parkinson disease (F) Sydenham chorea (G) Tardive dyskinesia
22-B. Wilson disease is characterized by necrosis and cavitation of the putamen.