Neuro Exam 3: Lecture 10

Front 1

Where is the myelencephalon?

Back 1

Medulla

Front 2

Where is the metencephalon?

Back 2

Pons

Front 3

Where is the mesencephalon?

Back 3

Midbrain

Front 4

From which view can you see the cranial nerves?

Back 4

Ventral

Front 5

What is the olfactory bulb?

Back 5

Synapse for second order neuron for cranial nerve I.

Front 6

The cerebral aqueduct is associated with what brainstem level?

Back 6

Midbrain

Front 7

The 4th ventricle is associated with what brainstem level?

Back 7

Pons

Front 8

The Foramen of Magendie is associated with what brainstem level?

Back 8

Medulla

Front 9

What cranial nerves are seen exiting and contain nuclei within ventral medulla?

Back 9

CN IX, CN X, CN XI, CN XII

Front 10

What cranial nerves are present at pontomedullary junction?

Back 10

CN VI (protopathic info), CN VII, CN VIII

Front 11

The anteriolateral sulcus is the exit for what cranial nerve?

Back 11

XII (Hypoglossal)

Front 12

What differentiates between the closed medulla and the open medulla?

Back 12

In the closed (caudal) medulla, there is not 4th ventricle. The sulcus limitans opens and the 4th ventricle begins, which defines the open (rostral) medulla.

Front 13

What is the function of the sulcus limitans in the medulla?

Back 13

Organizes nuclear groups and pathways into sensory (alar) & motor (basal) areas.

Front 14

What dorsal surface features are available in the caudal medulla?

Back 14

-gracile & cuneate tubercles (posterior median sulcus)

-tuberculum cinereum (over spinal tract of V)

Front 15

What dorsal surface features are available in the rostral medulla?

Back 15

(know that the sulcus limitans shifts)

-obex

-floor of 4th ventricle (region of posterior median sulcus)

Front 16

Describe the level of the closed (caudal) medulla.

Back 16

Level of spinomedullary junction to obex. Made up of 2 parts:

-level of pyramidal decussation (spinomedullary junction)

-level of caudal medulla (sensory decussation)

Front 17

Describe the open (rostral) level of the medulla.

Back 17

Level of obex to the pontomedullary junction (rostral medulla).

Front 18

Describe the nuclear groups and pathways at the sensory decussation.

Back 18

-Tuberculum cinereum (nucleus/tract of CN V)

-Gracile and Cuneate Tubercles (respective fasciculi and nuclei)

-Internal Arcuate Fibers

-Accessory/Lateral Cuneate Nucleus (cuneocerebellar)

-Nucleus Ambigous; Solitary Tract (CN IX, X, XI related to parasympathetic)

-Emerging Inferior Olivary Nucleus

-Ventral/Anterior & Anterolateral (pyramids & corticospinal)

Front 19

Where are you in the medulla if the central canal is beginning to rise up and the sensory and motor nuclei/tracts are shifting?

Back 19

Level of obex

Front 20

What are the surface features of the open medulla at the mid-olivary level?

Back 20

-Olive (pre & post-olivary sulcus)

-Restiform body (ICP)

-Vagal & Hypoglossal trigone

-Inferior Olivary Nuclear Complex

-Vestibular Nuclear Complex & Cochlear Nuclei

-Nucleus Ambiguous

-Raphe nuclei (role in inhibition of pain transmission in posterior horn of sc)

-Pontomedullary junction (disappearing olivary nucleus & shifting of medial lemniscus)

Front 21

What are the raphe nuclei?

Back 21

Moderate sized cluster of nuclei found in brainstem that release serotonin. They comprise the medial portion of the reticular formation and are the most medial part of the brainstem.

Front 22

In what section of the medulla does the sulcus limitans open and the vagal and hypoglossal trigones shift medially?

Back 22

Rostral medulla

Front 23

Which SC pathways travel up the through the brainstem?

Back 23

-DC-ML

-DSCT, Cuneocerebellar

-ALS

-CST

-RS (rubrospinal starts in midbrain and goes down)

-Corticobulbar

Front 24

What pathway is this describing?

-1st order neuron: motor cortex fibers travel in the internal capsule through the cerebral peduncle, pons, and pyramids
-90% of fibers cross in pyramidal decussation
-2nd order neuron synapses in ventral horn
-gamma or alpha motor neuron output to skeletal muscles

Back 24

Corticobulbar Tract (bilateral innervation except 2 CN's)

Front 25

Which lateral group of subcortical pathways originates in the red nucleus in the midbrain, faciliates flexion & inhibits extension in UE, and corrects ongoing motor activites?

Back 25

Rubrospinal tract

Front 26

Which lateral group of subcortical pathways is located in the raphe nuclei throughout the brainstem and is important in the pain feedback loop?

Back 26

Raphespinal tract

Front 27

What are the ascending tracts of the medulla?

Back 27

-DC-ML (light touch, vibration)

-DSCT (unconscious proprioception)

-ALS (pain & temp)

Front 28

What are the descending pathways of the medulla?

Back 28

Important Ones:
-Corticospinal

-Rubrospinal

Less Important One's:
-Raphespinal

-Reticulospinal & Lateral Vestibulospinal

Front 29

Where is acoustic neuroma found, and what CN's does it affect?

Back 29

It is found at the cerebellopontine angle (spinal fluid filled space between the cerebellum and pons) and it is a tumor of CN VIII with secondary effects on CN VII. Patient presents with ringing in the ear.

Front 30

Describe the vasculature to the closed medulla at the sensory decussation.

Back 30

-Posterior spinal artery

-Vertebral artery

-Anterior spinal artery

Front 31

Describe the vasculature to the open medulla at the mid-olivary level.

Back 31

-Posterior spinal artery
-PICA
-Vertebral artery
-Anterior spinal artery

Front 32

Name the syndrome:

-occlusion of PICA and vertebral artery
-contralateral loss of P & T (ALS)
-ipsilateral loss of face P & T (spinal tract and nucleus of V)
-vertigo and nystagmus (vestibular nucleus)
-loss of taste on ipsilateral 1/2 of tongue (solitary tract & nucleus)
-hoarseness and difficulty swallowing (nucleus ambiguous and CN IX, X)
-Horner's syndrome
-Ataxia (spino/cuneocerebellar tracts)

Back 32

Lateral Medullary Syndrome (Wallenberg Syndrome)

Front 33

Name the syndrome:

-occlusion of vertebral artery and anterior spinal artery
-ipsilateral impaired tongue movements (CN XII)
-paralysis of ipsilateral aspect of tongue
-deviation upon protrusion to side of ipsilateral lesion
-contralateral fine touch (DCML)
-contralateral paresis (CST)
-contralateral ataxia DCML)

Back 33

Medial Medullary Syndrome

Front 34

What occurs in medullary compression of the lateral reticular nucleus?

Back 34

-loss of control of HR and respiration

-sudden onset of central apnea (diaphragm and chest muscles stop working)

-cerebellar ataxia, dyarthria (poor articulation), and dysphasia (impairment of language ability) of abrupt onset

Front 35

Which fibers exit the brainstem in the medulla?

Back 35

DSCT & CCT

Front 36

Atrophy, flaccidity, paralysis, and areflexia are indicative of what type of motor neuron injury to the CST?

Back 36

Lower motor neuron injury

Front 37

Hyperreflexia (increases deep tendon reflexes), spasticity, paresis, and Babinski's sign are indicative of what type of motor neuron CST injury?

Back 37

Upper motor neuron injury

Front 38

What is a rhizotomy?

Back 38

Surgery to treat spasticity in which rootlets are stimulated before cutting off dorsal roots. Cutting too much dorsal root causes areflexia = BAD.