The Basal Ganglia Flashcards
These pallidal efferents go to:
A. Thalamus.
B. Putamen.
C. Red nucleus.
D. A and B.
E. A, B, and C.
Thalamus
Besides the thalamus (arrow), the globus pallidus also projects to the subthalamus.
Thalamic lesions are used to alleviate Parkinson’s disease in cases that are refractory to L-dopa. What thalamic nucleus is the stereotaxic target for the neurosurgeons? This brain is from a patient who had a left electrolytic thalamotomy and a right chemopallidectomy 10 years before death that resulted in considerable improvement.
A. Centromedian.
B. Ventral posterior.
C. Lateral dorsal.
D. Ventral lateral.
E. Pulvinar.
Ventral lateral.
Ventral lateral nucleus and ventral anterior nucleus project to premotor and supplementary motor regions which in turn project to precentral gyrus.
The majority of hypertensive hemorrhages occur in the basal ganglia. Rupture of branches of which artery are most common?
A. Middle cerebral.
B. Lenticulostriate or lateral striate.
C. Anterior cerebral.
D. Anterior communicating.
E. Posterior communicating.
Lenticulostriate or lateral striate
The lateral or lenticulostriate arteries are small branches that arise at right angles from the middle cerebral artery. They are under high pressure and rupture, typically into the region of the extreme or external capsule, anterior limb of the internal capsule or striatum.
Hemiballismus on the left side is usually due to a vascular accident affecting the:
A. Left subthalamic nucleus.
B. Right subthalamic nucleus.
C. Right striatum.
D. Left striatum.
Right subthalamic nucleus
The right subthalamus has reciprocal inhibitory connections with the right globus pallidus. Since right basal ganglia influence the right cortical motor areas through the thalamus, the release of normal inhibitory control, ``release of function’’, would be manifest by flailing movements on the left side of the body.
The prominent caudate and putamen seen in this axial or horizontal MRI section are separated by the:
A. Anterior limb of the internal capsule.
B. Genu of the internal capsule.
C. Posterior limb of the internal capsule.
D. All limbs of the internal capsule.
Anterior limb of the internal capsule.
In the anterior region the large striatum is divided into caudate and putamen by the prominent anterior limb.
This is a picture is of the brain of a patient with Huntington’s Disease. Microscopically you would see:
A. Loss of melanin filled cells in the striatum.
B. Loss of cells in the caudate and putamen.
C. Degenerating axons from the substantia nigra.
D. All of the above.
Loss of cells in the caudate and putamen.
Huntington’s disease is characterized by a loss of the medium sized cells in the caudate and putamen. Cell loss also occurs in the cerebral cortex. This is an autosomal dominant disease appearing in the 30s or 40s with abnormal jerking movements and mental deterioration.
The basal ganglia exert their effects on motor behavior through the:
A. Rubrospinal tract.
B. Vestibulospinal tract.
C. Reticulospinal tract.
D. Corticospinal tract.
E. All of the above.
Corticospinal tract.
Both the basal ganglia and cerebellum exert their influence on the spinal cord through the corticospinal tract. Connections through VL of the thalamus to premotor, supplementary motor and precentral gyrus are important modifiers of corticospinal tract activity.
A patient with a resting tremor in the right hand is killed in a traffic accident and is autopsied. The neuropathology report states there is a loss of cells in:
A. The right substantia nigra.
B. The left substantia nigra.
C. The right globus pallidus.
D. The left globus pallidus.
The left substantia nigra.
The left basal ganglia and substantia nigra influence the right side of the body. This gentleman’s Parkinson’s disease began on his right. Normally, the tremor soon becomes bilateral.
Pallidothalamic axons cross the
A. Anterior limb of the internal capsule.
B. Genu of the internal capsule.
C. Posterior limb of the internal capsule.
Posterior limb of the internal capsule
associate in your mind the three structures see here: thalamus, posterior limb, and globus pallidus. The point of this question is to stress the relationship.
