Brainstem Morphology - 4/25 Stephens Flashcards
Lesions of the MLF result in what?
Characteristics?
Internuclear Ophthalmoplegia
Abnormal horizontal gaze in direction opposite side of the lesion
Unilateral lesions of the MLF result in impairment of what muscle?
What condition?
Loss of adduction - middle rectus m. Of the ipsilateral eye
Nystagmus of the AB-ducting eye
Where do most corticobulbar fibers descend from?
Course through what?
Decussate Where?
Innervate what?
Head region of Precentral gyrus
Genu of internal capsule and cerebral peduncles
Lower pons bw CN 5 and 6 (uncrossed at and above CN 5)
Somatic motor nuclei
Lesions of the CBT above the decussation may result in what?
Contralateral CN palsy -> supranuclear facial palsy
Supranuclear Facial palsy has what clinical manifestations?
Paralysis of the contralateral lower quadrant of the face (facial droop, cannot smile)
Upper quadrant of face unaffected
Trochlear nerve brainstem level?
Midbrain
Glossopharyngeal nerve brainstem level?
Medulla Oblongata
Facial nerve brainstem level?
Pontomedullary Sulcus
Vagus nerve brainstem level?
Medulla Oblongata
Optic nerve brainstem level?
Diencephalon
Trigeminal nerve brainstem level?
Pons
Hypoglossal nerve brainstem level?
Medulla Oblongata
Abducens nerve brainstem level?
Pontomedullary Sulcus
Oculomotor nerve brainstem level?
Midbrain
Vestibulocochlear nerve brainstem level?
Pontomedullary Sulcus
Spinal Accessory nerve brainstem level?
Medulla Oblongata
Lesion of what CN causes external strabismus?
Oculomotor nerve
Paralysis of muscles of mastication is due to lesion of what nerve?
CN 5
Internal strabismus due to what CN lesion?
Abducens (6)
Lesion of the Nucleus Ambiguus results in what symptoms?
What special symptom?
Dysarthria, dysphagia, hoarseness
Deviation of uvula away from affected nucleus
Lesion of Hypoglossal nucleus has what symptoms?
What special symptom?
Ipsilateral paralysis and atrophy of the intrinsic muscles of the tongue
Tongue deviates towards side of lesion
What is the critical link in conjugate movements of the eyes that connects the Oculomotor nucleus with the Abducens nerve?
MLF (Medial Longitudinal Fasciculus)
Olfactory nerve brainstem level?
Telencephalon
What structures are located in the spinal cord?
Spinal nerves
LSTT
FG, FC
LCST
What does the MLF convey?
Vestibular influences to CN 3, 4, and 6