1. A person has a tumor in the posterior fossa, on the dorsal surface of the cerebellum. Which of the following statements best describes the location of the tumor?

A. Between the cerebellum and the occipital lobe
B. Between the cerebellum and medulla
C. Between the cerebellum and temporal lobe
D. Between the cerebellum and tentorium

Comment: The tentorium separates the cerebellum from the overlying occipital and temporal lobes. Because of this, the tumor does not contact either lobe.

2. From lateral to medial, the anterior and posterior lobes of the cerebellar cortex connect with the deep nuclei in the following order:

A. dentate, interposed, fastigial
B. fastigial, interposed, dentate
C. dentate, fastigial, vestibular
D. fastigial, interposed, dentate, vestibular

3. Which of the following is the principal synaptic target of Purkinje neurons of the nodulus?

A. Dentate nuclei
B. Interposed nuclei
C. Fastigial nuclei
D. Vestibular nuclei

4. A person had a unilateral cerebellar stroke. Which of the following best explains the laterality of ataxia (ie, side of body on which ataxia presents) during reaching?

A. Contralateral, because cerebellar output is ipsilateral and the descending motor pathways decussate
B. Ipsilateral, because cerebellar output decussates and the descending pathways decussate
C. Bilateral, because the cerebellar output is bilateral
D. Bilateral, because the cerebellar output is ipsilateral and the descending pathways are bilateral

Comment: Limb motor signs are classically ipsilateral to cerebellar lesions. This is because the circuit is double crossed—once as the output of the cerebellum, and the second as the decussation of the motor pathway. The principal input paths to the cerebellum, the dorsal and cuneocerebellar tracts, are ipsilateral.

5. Which of the following circuits traces the connection, via the cerebellum, from the right posterior parietal cortex to the spinal cord?

A. Triple crossed: right posterior parietal cortex → right pons → left cerebellum → right thalamus → right motor cortex → left spinal cord
B. Double crossed: right posterior parietal cortex → right pons → right cerebellum → left thalamus → left motor cortex → right spinal cord
C. Triple crossed: right posterior parietal cortex → left pons → right cerebellum → right thalamus → right motor cortex → left spinal cord
D. Double crossed: right posterior parietal cortex → left pons → left cerebellum → left thalamus → left motor cortex → right spinal cord

Comment: Routing information through the pontine nuclei adds one additional decussation to the cerebellar control circuit. Since the double crossing of the cerebellar output results in ipsilateral control, we see that the cortico-pontocerebellar circuit restores the typical decussated control by the cortex.

6. The principal output nuclei of the vestibulocerebellum are

A. dentate nuclei
B. interposed nuclei
C. fastigial nuclei
D. vestibular nuclei

7. It is discovered at autopsy that a person with Friedreich ataxia, a progressive degenerative spinocerebellar disorder, had extensive degeneration of Clarke’s nucleus. This produced degeneration of which of the following pathways?

A. Cuneocerebellar tract
B. Dorsal spinocerebellar tract
C. Ventral spinocerebellar tract
D. Spinothalamic tract

8. A person has olivopontocerebellar atrophy, with extensive degeneration of the inferior olivary nucleus and the pontine nuclei, as well as parts of the cerebellum. Which of the following sets of connections is likely to be lost in this person?

A. Between mossy fibers and Purkinje neurons
B. Between mossy fibers and granule neurons; between climbing fibers and Purkinje neurons
C. Between climbing fibers and basket neurons; between mossy fibers and Purkinje neurons
D. Between climbing fibers and granule neurons

Comment: This condition would primarily produce loss of climbing fibers from the inferior olivary nucleus and mossy fibers from the pontine nuclei. Climbing fibers synapse on Purkinje cells, not granule cells. Mossy fibers synapse on granule cells, not Purkinje or basket cells.

9. Lesion of the interposed nuclei would impair?

A. Distal limb control by interrupting cerebellar connections to rubrospinal neurons
B. Proximal limb control by interrupting connections to the rubro-olivary neurons
C. The functions of mossy fibers from the cerebellum to the red nucleus
D. The functions of climbing fibers from the cerebellum to the red nucleus

Comment: The magnocellular division of the red nucleus is the recipient of cerebellar output from the interposed nuclei; rubrospinal neurons, which contribute to distal limb control, originate from this division. Mossy and climbing fibers are inputs to the cerebellum.

10. The cerebellum is thought to be a site of dysfunction in several neuropsychiatric diseases, such as schizophrenia and autism. Which of the following statements best describes how information from frontal and temporal lobe areas involved in cognition and emotion can be influenced by cerebellar processing?

A. Frontotemporal association areas must transmit information first to premotor and motor areas, which project to the pontine nuclei and then the cerebellum.
B. Frontotemporal association areas must transmit information first to the posterior parietal association cortex, which projects to the pontine nuclei and then the cerebellum.
C. Frontotemporal association areas transmit information directly to the pontine nuclei and then the cerebellum.
D. Frontotemporal association areas project directly to the cerebellar cortex as mossy fibers.

Comment: Virtually all cortical regions—motor, premotor, and association areas—project to the pontine nuclei, which provide mossy fiber inputs to the cerebellar cortex (more the cortex than the dentate nucleus). This provides both a route for cortical areas important in cognition and emotion to influence movement, via the cerebellum, as well as contributing to the nonmotor functions of the cerebellum.