Brainstem Clinical Application Flashcards
Which tracts connect the spinal cord with the contralateral cerebrum?
The vertical tracts:
- Lateral corticospinal (CST) - Dorsal column/medial lemniscus (DCML) - Spinothalamic (STT)
Lesions of lateral corticospinal and dorsal column tracts in the brainstem usually cause ____lateral signs. Why?
contralateral, because these tracts cross the midline in the inferior medulla
Where is the only location where a brainstem lesion would cause ipsilateral corticospinal or DCML signs?
The corticospinal tract or dorsal column nuclei in the inferior medulla
Where does the corticobrainstem tract convey motor signals from and to?
From the cerebral cortex to cranial nerve nuclei in the brainstem
Upper motor neuron lesions are associated with muscle _____tonia.
hypertonia
Lower motor neuron lesions are associated with ___tonia
hypotonia
What does a complete motor neuron lesion of the facial nerve results in?
Flaccid paralysis of muscle in the ipsilateral face
What does a unilateral UMN lesion interrupt?
Voluntary control of contralateral facial muscles in the lower half of the face
Why are muscles in the upper half of the face spared in an UMN lesion?
Because the right and left cerebral cortices have bilateral projections to lower motor neurons innervating the muscle of the forehead and surrounding the eye
Are people with UMN lesions that prevent voluntary control of the contralateral lower face able to laugh and cry normally?
Yes, because the pathway involved in emotional vocalization is separate from the corticobraintem tract for the same activity
What does a lesion in the brainstem cause?
a mix of ipsilateral and contralateral signs
What does a lesion in the vestibular nuclei in the brainstem cause?
- vertigo
- nausea
- vomiting
- nystagmus
- tilted head position
- balance problems
What does a lesion on the lateral cuneate nucleus and inferior cerebellar peduncle cause?
ataxia
What does a lesion in the afferents to the solitary nucleus cause?
loss of taste from the ipsilateral anterior tongue
What does a lesion in the spinal tract and nucleus of the trigeminal nerve cause?
loss of pain and temperature sensation from the ipsilateral face
