Localizing Lesions

djk35024's version from 2011-05-06 04:01


Question Answer
What sensory nucleus is associated with CN5?Principal sensory nucleus in the mid pons
What nucleus is underneath the substantia gelatinosa in the spinal cord?Proper sensory nucleus
What are the 4 parasympathetic nuclei of the CNs?3 (oculomotor) - Edinger-Westphal; 7 (facial) - submandibular and sublingual glands; 9 (glossopharyngeal) - parotid gland; 10 (vagus) - lots of heart and GI stuff
Are all CN UMN ipsilateral or contralateral to the LMN they innervate?Usually contralateral, but 5, 7 and 12 are exceptions (maybe 10); 11 is exception, 3 and 6 have contralateral projections
Are all CN LMN contralateral or ipsilteral to the muscles they innervate?Always ipsilateral
What are the receptors for DC-ML pathway?Meissner's corpuscles, etc.
What are the receptors for the ALS?Free nerve endings, etc.
What 2 major descending tracts fire extensors?Medial tracts - reticulospinal and vestibulospinal (ipsilateral)
What 3 major descending tracts fire flexors?Lateral tracts - spinothalamic, rubrospinal, reticulospinal (spinothalamic and reticulospinal are contralateral)
What is the difference between fasciculations and fibrillations?Fasciculations can been seen under the skin while fibrillations can't be seen and an EMG needs to be run to see if they are happening
What are 4 signs of UMN lesion?Aka spastic paralysis -- increased tone, hyperreflexia, disuse atrophy, abnormal reflexes (clonus, babinski)
What are 4 signs of a LMN lesion?Aka flaccid paralysis -- decreased done, hyporeflexia, neurogenic atrophy, fasciculations/fibrillations
What fibers innervate the LMNs of motor cranial nerves?Corticobulbar tract
Is CN 11 ipsilateral, contralateral or bilateral?Ipsilateral UMN and LMN
Is facial nerve innervation ipsilateral, contralateral or bilateral?Bilateral and equal in upper; contralateral in lower
What CNs are bilateral with contralateral predominance?5 and 12
What CN is bilateral with equal predominance?Upper 7
What would a lesion in the UMN of 5 and 12 cause?Paresis of contralateral side
What would a lesion in the UMN of upper 7 cause?Nothing physical
What would a lesion in the UMN of lower 7 cause?Paralysis of contralateral side
Using the tongue as an example, how would an UMN lesion and LMN lesion affect protrusion of the tongue? What CN is affected?Affects CN12; UMN - tongue would deviate to side contralateral to lesion; LMN - tongue would deviate towards side of lesion
Using the jaw as an example, how would an UMN and LMN lesion affect opening of the jaw? What CN is affected?Affects CN5; UMN - move contralateral to site of lesion; LMN - move towards site of lesion
What muscle protrudes the tongue?Genioglossus
How would an UMN and LMN lesion affect muscles of facial expression? What CN is affected?Affects CN7; UMN - contralateral lower face paralysis; LMN - entire ipsilateral side of face is paralyzed
How big are the spinal trigeminal nuclei?Huge - extend from midbrain to medulla
What information comes into the solitary nucleus?Gustatory, chemoreception and baroreception
What would a lesion to the anterior pons hit?Corticospinal and corticobulbar tracts
What would a lesion to the posterior pons hit?DC-ML, ALS and VTT
How would an UMN and LMN lesion affect lifting of the uvula? What nerve is involved?Affects CN10; UMN - no change; LMN - away from lesion
What information does the VTT carry?Touch, pain and temp (from spinal tract of 5)
What information does the DTT carry?Touch only (not pain or temp)
What artery supplies the medial closed medulla?Anterior spinal
What artery supplies the medio-lateral part of the closed medulla?Vertebral artery
What artery supplies the posterior part of the closed medulla?Posterior spinal
What arteries supply the open medulla?Medial - anterior spinal; mediolateral - vertebral; posterio - posterior inferior cerebellum
What arteries supply the pons and midbrain?Medial - basilar; lateral - basilar; posterior - superior cerebellar
What is alternating hemiplasia and what is the cause of it?Syndrome with ipsilateral and contralateral paralysis in different parts of the body due to a single lesion in the BRAINSTEM
What are the effects of alternating hemiplegia?Due to a single lesion in the brainstem; affects pyramidal tract so contralateral spastic paralysis (tract hasn't crossed over yet - UMN); since cranial nerves 3, 6, and 12 are close to the pyramidal tract they can be affected too but are LMN so see ipsilateral defects
What is alternating hemianalgesia and what is the cause of it?Loss of pain/temp sensation on contralateral body and ipsilateral face due to infarct of posterior inferior cerebellar artery
How does alternating hemianalgesia work and why?Vascular lesion of PICA; open medulla and pons supplied by PICA so if blood supply is lost then ALS and VTT, which run through there, are going to be affected = contralateral loss of bodily pain/temp sensation and ipsilateral pain/temp loss of face
What is Horner's syndrome and why does it come about?Lesions in brainstem or cervical spine disrupt sympathetic innervation to the head; results in 4 symptoms: 1. miosis (unopposed parasympathetic constriction), 2. ptosis, 3. anhydrosis (no sweat), 4. vasodilation

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