Neurology

Question 1

Posterior fossa malformations - Agenesis of cerebellar vermis with cystic enlargement of 4th ventricle (fills the enlarged posterior fossa). Associated with hydrocephalus, spina bifida. -absent cerebellum

Answer 1

Dandy-Walker malformation (midline sagittal MRI shows large cystic 4th ventricle)

Question 2

These cells give physical support, repair, K+ metabolism, removal of excess neurotransmitter, component of blood-brain barrier, glycogen fuel reserve buffer. Reactive gliosis in response to neural injury. Specific marker: GFAP. Derived from neuroectoderm.

Answer 2

Astrocytes

Question 3

These phagocytic scavenger cells of CNS (mesodermal, mononuclear origin). Activated in response to tissue damage. Not readily discernible by Nissl stain. Infected cells fuse to form multi nucleated giant cells in CNS.

Answer 3

Microglia

Question 4

These cells increase their conduction velocity of signals transmitted down axons –> Saltatory conduction of action potential at the nodes of Ranvier, where there are high concentrations of Na+ channels. CNS-oligodendrocytes; PNS-Schwann cells. Wraps and insulates axons: increase space constant and increases conduction velocity.

Answer 4

Myelin

Question 5

Sensory Receptors - Free nerve endings: These fibers are located on the skin, epidermis, and some viscera. Detect pain and temperature. –> Slow, un myelinated fibers.

Answer 5

C Fibers

Question 6

Sensory Receptors - Free nerve endings: These fibers are located on the skin, epidermis, and some viscera. Detect pain and temperature. –> Fast, myelinated fibers.

Answer 6

A sigma

Question 7

Large, myelinated fibers; adapt quickly. Location: Glabrous (hairless) skin. Senses: Dynamic, fine/light touch, position sense.

Answer 7

Meissner corpuscles

Question 8

Large, myelinated fibers; adapt quickly. Location: Deep skin layers, ligaments, joints. Senses: Vibration, Pressure.

Answer 8

Pacinian corpuscles

Question 9

Large, myelinated fibers; adapt slowly. Location: Finger tips, superficial skin. Senses: Pressure, deep static touch (e.g., shapes, edges), position sense.

Answer 9

Merkel disks

Question 10

Dendritic endings with capsule; adapt slowly. Location: Finger tips, joints. Senses: Pressure, slippage of objects along surface of skin, joint angle change.

Answer 10

Ruffini corpuscles

Question 11

Phagocytic scavenger cells of CNS (mesodermal, mononuclear origin). Activated in response to tissue damage. Not readily discernible by Nissl stain. HIV-infected cells fuse to form multinucleated giant cells in CNS.

Answer 11

Microglia

Question 12

Physical support, repair, K+ metabolism, removal of excess neurotransmitter, component of blood-brain barrier, glycogen fuel reserve buffer. Reactive gliosis in response to Euronav injury. Marker: GFAP. Derived from neuroectoderm.

Answer 12

Astrocytes

Question 13

Posterior fossa malformations - significant herniation of cerebellar tonsils and vermis through foramen magnum with aqueductal stenosis and hydrocephalus. Often presents with lumbosacral meningomyelocele, paralysis below the defect.

Answer 13

Chiari II

Question 14

What pathology is being described: elevated CSF pressure (>200mmHg in non obese, and >250mmHg in obese patients)
CT scan: Absence of ventricular dilation, no tumor or mass
Papilledema, and vision loss, headaches - daily worse in mornings, pulsitile, possible nausea/vomiting, and retro ocular pain.

Answer 14

Pseudotumor cerebri

Question 15

Glial cells with a ciliated simple columnar form that line the ventricles and central canal of the spinal cord. Apical surfaces are covered in cilia (which circulate CSF) and microvilli (which help in CSF absorption).

Answer 15

Ependymal cells

Question 16

This system is comprised of the hippocampus, amygdalae, mammillary bodies, anterior thalamic nuclei, cingulate gyrus, and entorhinal cortex. What is being described, and what is its function?

Answer 16

Limbic system - reponsable for feeding, fleeing, fighting, feeling, and sex.

5Fs!

Question 17

Which spinal tract conveys the following information: touch, vibration, and pressure sensation.

Answer 17

Dorsal columns

Includes fasciculus gracilus and fasiculus cuneatus

Question 18

Which spinal tract conveys the following information:

Voluntary motor command from motor cortex to body

Answer 18

Lateral and ventral corticospinal tracts

Question 19

Which spinal tract conveys the following information:

Voluntary motor command from motor cortex to head/neck

Answer 19

Corticobulbar tract

Question 20

Which spinal tract conveys the following information:

Alternate routes for the mediation of voluntary movement

Answer 20

Reticulospinal and rubrospinal tracts

Question 21

Which spinal tract conveys the following information:

Pain and temperature sensation

Answer 21

Lateral spinothalamic tract

Question 22

Which spinal tract conveys the following information:

Important for postural adjustments and head movements

Answer 22

Vestibulospinal tract

Question 23

Which spinal tract conveys the following information:

Proprioceptive information for the cerebellum

Answer 23

Dorsal and ventral spinocerebellar tracts

Question 24

What is Being described:

Scanning speech, intention tremor, and nystagmus

Answer 24

Charcot’s Triad of Multiple Sclerosis

Question 25

What hallmark is being described:
Alternating syndromes - long tract symptoms on one side (i.e. hemiparalysis, motor or sensory) and cranial nerve symptoms on the other

Answer 25

General brain-stem lesion

Question 26

What CNs are found in the:
Midbrain

Answer 26

CN 3 and 4

Question 27

What CNs are found in the:
Medulla

Answer 27

CNs 9, 10, and 12

Question 28

What CNs are found in the:
Pons

Answer 28

CNs 5, 6, 7, and 8

Question 29

What CNs are found in the:
Spinal Cord

Answer 29

CN 11 - Accessory (Spinal Accessory) Nerve

Question 30

Patient presents with bilateral loss of pain and temp sensation, with weakness and atrophy of the hand muscles. What pathology is at hand and the associated disease?

Answer 30

Syringomyelia - Chiari Malformation