Neuro Flashcards
Fine touch
Vibration
Proprioception
Dorsal column
Medial lemniscus pathway
Dorsal column - Medial lemniscus decussates?
Medulla
Where does medial lemniscus relay in the thalamus?
Ventral posterolateral nucleus (body sensation)
Pain
Temperature
Spinothalamic Tract
Where does spinothalamic tract decussate?
Anterior white commissure
Do CN decussate?
No
Motor
Lateral corticospinal tract
Where does the lateral corticospinal tract decussate?
caudal medulla
Red nucleus
Rostral Midbrain
CN III
Rostral Midbrain
CN IV
Caudal Midbrain
Damaged in patients with Parkinson’s
Substantia nigra
Superior colliculus
Rostral Midbrain
Inferior colliculus
Caudal Midbrain
Medial Pons
MLF / medial lemniscus / Abducens (CN VI) nucleus / Corticospinal tract
Blood supply of Medial Pons
Paramedian & Median branches of the Basilar a.
Blood supply of Lateral Pons
Anterior Inferior Cerebral a.
AICA
Lateral Pons
Lateral spinothalamic tract / Facial (CN VII) nucleus / Vestibular (CNVIII) nucleus / Spinal Trigeminal (CN V) nucleus & tract
CN V, VI, VII, VIII
Pons
How to tell if you’re in Medulla?
Inferior olivary nucleus / Medullary pyramids
Medial Medulla
Medullary pyramids / medial lemniscus / Hypoglossal (CN XII) nucleus
Blood supply to Medial Medulla
Anterior spinal a.
Blood supply to Lateral Medulla
Posterior Inferior Cerebellar a.
PICA
Lateral Medulla
Lateral spinothalamic tract / Spinal trigeminal (CN V) tract & nucleus / Inferior cerebellar peduncle / vesticular (CN VIII) nuclei / Nucleus ambiguus (CN IX, X)
Swallowing and speech
Nucleus Ambiguus (CN IX, X)
CN X (vagus) contributors
Nucleus ambiguus / Dorsal motor nucleus / Nucleus of solitary tract
Dorsal motor nucleus
Parasympathetic to GI tract, Heart, Lungs
*** NOT MOTOR!!
Where are the sympathetic nervous system?
Spinal cord Horner sydrome (ptosis, miosis, anhidrosis)
Hallmark sign of brainstem lesion?
ALTERNATING SYNDROME:
long tract symptoms on one side (hemiparalysis) and CN symptoms on the other
The Rule of Fours
- 4 medial/midline structures, beginning with M
- 4 side/lateral structures, beginning with S
- 4 CNs originate in the pons, 4 below the pons, 4 above the pons
- 4 motor CN nuclei in the MIDLINE are those that divide evenly into 12 (except CN I and CN II)
Weakness of contralateral arm and leg. Deficit?
Motor pathway - (medial) corticospinal tract
Loss of vibration / proprioception / fine touch (contralateral arm/leg). Deficit?
Medial Lemniscus
Ispsilateral internuclear ophthalmoplegia. Deficit?
Medial Longitudinal Fasciculus (MLF)
Ipsilateral arm and leg ataxia. Deficit?
Spinocerebellar tract
Alteration of pain/temperature in contralateral arm and leg. Deficit?
Spinothalamic tract
Ipsilateral alteration of pain/temperature on face. Deficit?
Sensory nucleus of CN V
Ipsilateral Horner syndrome
Sympathetic pathway
Hoarse voice and difficulty swallowing
Loss of pain and temp in right arm and leg
Ataxia in left arm
Uvula deviates to the right
Left Lateral Medulla
“Wallenberg syndrome”
Spinothalamic
Spinal Trigeminal nucleus
Nucleus ambiguus
Sympathetic tract
Vestibular nucleus
- vertigo / nystagmus / n/v
Inferior Cerebellar peduncle
PICA
Weakness in right arm and leg
Numbness in right arm and leg
Decrease vibration and proprioception on right
Tongue deviates to the left
Left Medial Medulla
“Medial Medullary syndrome”
Anterior Spinal Artery
Left facial droop
Loss of pain and temp on left face
Loss of pain and temp in right arm and leg
Left Lateral Inferior Pons
“Lateral Inferior Pontine Syndrome”
Inability to abduct or adduct right eye
Nystagmus in the left eye when looking left
Left arm and leg weakness
Loss of fine touch, vibration, and proprioception in the left arm and leg
Right Medial Pons
“Medial Pontine Syndrome”
Multiple Sclerosis
Medial Pontine strokes
Risk for?
INO (lesion of MLF)
Can only move eyes
Locked-in-Syndrome
- basilar artery stroke
- rapid hyponatremia correction (CPM)
dysphagia , dysphonia, dysarthria (corticobulbar tract damage)
contralateral spastic hemiparesis (corticospinal tract damage)
CN III palsy –> ipsilateral ptosis, pupillary dilation, and lateral strabismus (eye looks down and out
Weber Syndrome
ANTERIOR MIDBRAIN infarction resulting from occlussion of paramedian branches of posterior cerebral artery
