B. The lateral medulla
The patient has lateral medullary syndrome. The long tracts affected in this syndrome are the spinothalmic tract and the descending hypothalmic fibers. The cranial nerves that may be affected by the lesion and localize the lesion to the lateral medulla are the vestibular or the cochlear nuclei, the glossopharyngeal nerve, and the vagus nerve. The spinal tract and spinal nucleus of the trigeminal nerve may be lesioned in lateral medullary syndrome.
C. The caudal pons
The patient has a form of medial pontine syndrome that has affected the corticospinal tract, the exiting fibers of the abducens nerve, and the facial nerve.
The answer is E. The patent has medial midbrain syndrome. Medial midbrain syndrome results in a lesion of the corticospinal and corticobulbar tracts and the oculomotor nerve.
F. A cranial nerve or cranial nerves outside of the brainstem
The answer is C. The patient has medial medullar syndrome, with 2 long tract signs (the medial lemniscus and the corticospinal tract), combined with a lesion of the hypoglossal nerve that localizes the lesion to the media medulla.
A. Posterior inferior cerebellar artery
The patient has lateral medullary syndrome. A lesion of descending hypothalmic fibers results in Horner’s syndrome with mitosis, ptosis, and anhidrosis ipsilateral to the lesion. Spinothalmic tract lesions result in a loss of pain and temperature sensations in the limbs and body contralateral to the lesion. The cranial nerves that may be affected by the lesion and localize the lesion to the lateral medulla are the vestibular or the cochlear nuclei, the glossopharyngeal nerve, and the vagus nerve.
E. Deep (thalmoperforating branches of a posterior cerebral artery)
The patient has medial midbrain syndrome. Medial midbrain syndrome result in a lesion of the corticospinal and corticobulbar tracts and the oculomotor nerve. A lesion of the corticobulbar fibers results in a contralateral lower face weakness.
8. A patient has numbness of the face and scalp on the right, burns the anterior part of the tongue but cannot feel the stimulus, and has weakness in chewing on the right. When the left cornea is stimulated both eyes blink, but when the right cornea is stim- ulated neither eye blinks. Localize the probable lesion site. A. Trigeminal nerve B. Spinal nucleus of V C. Principal sensory nucleus of V D. Ventral trigeminal tract E. Mesencephalic nucleus of V
A. Trigeminal nerve
C. Nucleus ambiguus
The answer is D. The analgesia and thermal anesthesia most likely resulted from a lesion of the spinal tract of V because the patient’s loss is limited to pain and temperature on the side of the lesion.
The answer is D. The horizontal nystagmus will have a quick component to the right; the fast phase of a vestibular evoked nystagmus is away from the side of the lesion (the left). In this patient, the uvula may deviate to the right. Sensation of touch will not be altered in the anterior two third of the tongue. the pupil on the left will be constricted (Horner’s syndrome) compared with the pupil on the right. Retrograde changes might be evident in neurons in the dorsal horns of the spinal cord on the right (left spinothalmic tract).
The answer is A. Hair cell degeneration at the base of the cochlea is the most common cause of presbycusis, a sensorineural hearing loss in the elderly. All other choices indicate a conductive hearing loss.
13. A complete destructive lesion of the facial nerve just as it emerges from the brainstem will result in retrograde chromatolysis in which of the following nuclei? A. Nucleus ambiguus B. Inferior salivatory nucleus C. Superior salivatory nucleus D. Ventral cochlear nucleus E. Solitary nucleus
The answer is C. The superior salivatory nucleus contains the cell bodies of preganglionic parasympathetic neurons with axons in the facial nerve. There would be an anterograde degeneration in the solitary nucleus; no other choices contributes fibers to the facial nerve.
D. Altered sensation in the skin of the forehead
D. A nystagmus with a quick component to the left
The answer is C. All other structures are found in either the pons or midbrain.
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 17. Internal strabismus
F. Abducens nucleus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 18. Tongue deviates upon protrusion
O. Hypoglossal nucleus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 19. Uvula deviates during swallowing
L. Nucleus ambigus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 20. Decreased output of parotid gland
C. Inferior salivatory nucleus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 21. Ptosis and constricted pupil
Q. Descending hypothalmic fibers
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 22. Diplopia and ptosis
Oculomotor nucleus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 23. Hoarseness
L. nucleus ambiguus
MATCHING PROBLEMS Questions 17–42: Clinical features match Choose from A–U the one most closely associated with the clinical deficit. Choices (each choice may be used once, more than once, or not at all): A. Facial motor nucleus B. Solitary nucleus C. Inferior salivatory nucleus D. Motor nucleus of V E. Edinger-Westphal nucleus F. Abducens nucleus G. Trochlear nucleus H. Spinal nucleus of V I. Mesencephalic nucleus of V J. Dorsal motor nucleus of X K. Superior salivatory nucleus L. Nucleus ambiguus M. Principal sensory nucleus of V N. Oculomotor nucleus O. Hypoglossal nucleus P. Trigeminal ganglion Q. Descending hypothalamic fibers R. Corticospinal fibers S. Corticobulbar fibers T. Anterolateral system U. Medial lemniscus 24. Loss of motor limb of blink reflex
A. Facial motor nucleus