Clinical Aspects for Exam #1

Question 1

What causes Shingles (herpes zoster) pain? Where is it felt?

Answer 1

Inflammation of DRG —> acute root pain.
It is felt in the dermatome supplied by the affected nerve root.
#50

Question 2

What clinical disorders are associated with deficient neuroectoderm (mesoderm) induction (2)?

Answer 2

Spina bifida, Dandy-Walker syndrome.

L2a #43

Question 3

Describe an ependymoma

Answer 3

Tumor in the 4th ventricle or spinal cord —> From ependymal cells.
L1c #78

Question 4

What deficits result from cavitation of the spinal cord?

Answer 4

At the level of cavitation –BILATERAL loss of pain and temperature sensation AT THE LEVEL of cavitation.
Due to bilateral decussation, both sides are injured, and only at the level of injury.
L4 #70

Question 5

Describe the pathology of Alzheimer’s disease.

Answer 5

Degeneration of cholinergic terminals.
-Shrinks the individuals brains due to plaques that kill neurons (neurons with tangles).
L1c #49

Question 6

Occlusion of which vessel will damage the VPL nucleus? Result?

Answer 6

Thalamogeniculate arteries —> Occlusion = CONTRALATERAL SENSORY DEFICITS.
L4 #34

Question 7

Describe the two types of hydrocephalus, their causes, and presentation.

Answer 7

1.) Communicating: Results from blockage within the subarachnoid space, i.e. movement of CSF from subarachnoid space into venous system is obstructed. All parts of ventricles and subarachnoid spaces are unobstructed. Presents as increased intracranial and subarachnoid pressure.
Causes: Defective/absent arachnoid villi or granulations.

2.) Non-communicating: Results from an obstruction within the ventricles and causes increased pressure in parts of the ventricular system (but NOT the subarachnoid space).
Causes: Congenital aqueductal stenosis or blockage of some sort.
L3a #66, p.30 BRS, p.93 text

Question 8

What pathology/symptoms defines ALS?

Answer 8

Syndrome of combined lesions in anterior horns and lateral pyramidal tract = Flaccid paralysis of upper limbs (wrist/hands). Spastic paralysis of lower trunk and limbs.
L3b #83

Question 9

What is Brown-Sequard Syndrome? What are the symptoms (4)?

Answer 9

Hemisection of spinal cord.
1.) Posterior column: Ipsilateral sensory loss (fine touch, vibration, proprioception).
2.) ALS: Contralateral sensory loss (pain, temp., crude touch).
3.) Corticospinal tract: Ipsilateral spastic paralysis.
4.) Anterior horn neurons: Ipsilateral flaccid paralysis at the level of the lesion.
L3b, #77

Question 10

What is the result of damage to the main (1˚) somatosensory cortex? Accessory (2˚)?

Answer 10

1˚: Loss of contralateral tactile perception.
2˚: Loss of contralateral texture/shape discrimination.
L4 #35

Question 11

Describe cauda equina syndrome –Cause and symptoms; sensory (2) and motor (1).

Answer 11

Compression of cauda equina (L2 to Co), intervertebral disc prolapse –predominantly on one side.
Symptoms: Sensory –Saddle back anesthesia, pain and altered sensation.
Motor –Asymmetric weakness of lower limb.
L3b #80

Question 12

Damage to the PSCT will result in what?

Answer 12

Deficit to NON-CONSCIOUS proprioception on the ipsilateral side.
L4 #42

Question 13

Define (1) Hyperalgesia, and (2) Allodynia.

Answer 13

1.) Hyperalgesia: Receptor sensitization; refers to a stimulus that is normally mildly uncomfortable but for some reason becomes extremely painful (e.g. slap on sunburned skin).
-1˚ = Affected area, 2˚ = Surrounding area.
2.) Allodynia: Refers to normally innocuous stimulus that suddenly becomes painful.
L4 #56

Question 14

Define lissencephaly. Give three clinical manifestations, along with a possible cause.

Answer 14

Defects in migration within brain parenchyma. Results in (1) Smooth surface, i.e. poor/absent gyration (only principal fissures), (2) Thicker cortex (piling up of post-migratory neurons), and (3) inverted lamination. Can assume a “double-cortex appearance
-Often results from REELIN DEFICIENCY
L2a #14, p.77 text

Question 15

Describe a medulloblastoma

Answer 15

Common in children –From primitive cells in cerebellum: Neuronal/glial/embryonal cells.
L1c #79

Question 16

A lesion of which arteries will cause contralateral sensory deficits via the PCML?

Answer 16

Anterior cerebral artery (ACA), and Thalamogeniculate artery.
L4 #34, p.233 text

Question 17

A vascular lesion at which artery at T6 will affect the gracile and cuneate fasciculae? Result?

Answer 17

Posterior spinal artery = Vascular lesion at T6 = Inhibits transmission of discriminative touch and vibration on the ipsilateral side at T6 and BELOW.
L4 #26

Question 18

Describe a Schwannoma/Neurofibroma

Answer 18

Usually found in close association with CN VIII (vestibulocochlear n.) —> Difficult to separate from axon.
L1c #81

Question 19

What is the most common type of brain cancer? What is the marker?

Answer 19

Astrocytoma: Glioblastoma multiforme —> Grade IV variety.
Marker: GFAP
L1c #77

Question 20

Explain how viral meningitis is caused and what viruses (4)?

Answer 20

Vector often latent in nasal mucosa and accesses meninges through bloodstream at places where barrier is weak, e.g. CHOROID PLEXUS.
Herpes simplex, varicella zoster (chicken pox/shingles), mumps, HIV
L3a #32

Question 21

Give definition and list symptoms (3) of posterior column syndrome.

Answer 21

1.) Loss of posterior column sensation (fine touch, proprioception, vibration).
2.) Positive Romberg.
3.) Common in Tabes dorsalis (Syphilis).
L3b, #79

Question 22

What clinical disorders are associated with deficient (1) cell proliferation, (2) cell migration (two), and (3) apoptosis?

Answer 22

1.) Microencephaly
2.) Lissencephaly and heterotopias
3.) Altered nuclear size.
L2a #43

Question 23

What artery supplies the dorsal columns (gracile and cuneate fasciculi)? What is the result of a lesion of this artery at T6?

Answer 23

Posterior spinal artery (PSA).
Lesion at T6 = Loss of discriminative touch and vibration on ipsilateral side at T6 and below.
L4 #26, p.231 text

Question 24

Describe meningitis and the symptoms (6, including classic triad).

Answer 24

Acute inflammation of the meninges.
Classic triad: Nuchal rigidity, sudden high fever, altered mental status.
Other symptoms: Phono- and photophobia, petechiae.
L3a #30

Question 25

Describe that pathology of myasthenia gravis.

Answer 25

Auto-antibodies bind to ACh receptors at the NMJ and block them, thus impairing muscle contraction.
L1c #47

Question 26

Regarding complete transections of the spinal cord, what happens if it occurs at the following locations?

1. ) Above C3
2. ) Above C5
3. ) Below T1

Answer 26

Loss of sensations and movement below the lesion
1.) Paralysis of breathing; quadriplegia.
2.) Quadriplegia
3.) Paraplegia, urinary and fecal incontinence.
#76

Question 27

What are the effects of poliomyelitis?

Answer 27

Flaccid paralysis at the level of the lesion.

L3b #82

Question 28

Describe metastatic neural tumors

Answer 28

Multiple tumors at the junction between white and gray matter; all subsequent lesions resemble the 1˚ lesion, histologically.
L1c #82

Question 29

Describe the etiology (2) and symptoms (4) of Dandy-Walker syndrome. Associated conditions (3)?

Answer 29

Dandy-Walker malformation consists of cystic dilation/malformation of the fourth ventricle (open to the world), and partial or complete absence of cerebellar vermis.
-Clinical manifestations include macrocephaly (increased intracranial pressure), ataxia, poor coordination, jerky eye movements.
-Associated with absence of corpus callosum, spina bifida, and/or hydrocephalus.
L2a #36, p.75 text

Question 30

What artery supplies the medial lemniscus? Lesion?

Answer 30

Anterior spinal artery (ASA); arises from vertebral arteries.
Lesion = Sensory (touch) deficits from level of occlusion and below on CONTRALATERAL side.
L4 #27, p.231 text

Question 31

Damage to the anterior gray will cause contralateral sensation deficits (due to ML) at which CNS levels?

Answer 31

Caudal medulla and above.

L4 #30

Question 32

If there is a lesion in the L4-L5 IV disc (e.g. protrusion), which nerve gets compressed?

Answer 32

L5 *Always the one below the lesion*
#49

Question 33

Describe the pathology of of Parkinson’s disorder.

Answer 33

Degeneration of dopaminergic neurons of the brainstem. 
-Much less dopamine released from neuron = movement disorders. 
#50

Question 34

What blood findings determines bacterial meningitis (6)?

What types of bacteria (3)?

Answer 34

1-3.) Higher CSF WBC, neutrophils, and protein.
4.) Lower CSF glucose.
5-6.) Higher CRP and WBC.
Streptococcus, E.coli, influenza type B
L3a #32

Question 35

What deficits result from hemisection of the spinal cord (two lateralities, each with own deficits, and one specific type of deficit).

Answer 35

1.) Ipsilateral loss of discriminative touch, vibratory sensation, two-point discrimination, and proprioception at the level of lesion and below.
2.) Contralateral loss of pain, temperature, and crude touch sensation at the level of lesion and below.
3.) Flaccid paralysis ipsilateral to lesion at the level of lesion and below.
L4 #69

Question 36

Which cells are targeted in HIV encephalopathy?

Answer 36

Microglia

Question 37

Describe deafferentiation pain. Cause(s), symptoms, and treatment(s).

Answer 37

Increased sensitivity and disinhibition of central disconnected neurons.
-Caused by complete or partial interruption of afferent nerve impulses.
-Symptoms are spontaneous or inappropriate pain in the region of denervation.
-Treated with (a) Radiofrequency coagulation of dorsal root entry zone, or (b) Cordotomy.
#41

Question 38

Where on the PCML must an injury occur in order to cause ipsilateral deficits? Contralateral?

Answer 38

Ipsilateral: Posterior columns, gracile/cuneate nuclei, internal arcuate fibers –Damage may be physical or vascular.
Contralateral: At and above the medial lemniscus –Damage may be physical or vascular.
L4 #37

Question 39

What clinical disorders are associated with failure of the neuropore to close (2)

Answer 39

1.) Rachischisis – Spina bifida.
2.) Anencephaly
L2a #43

Question 40

Describe the etiology, symptoms, and radiologic presentation of the four hematoma types.

Answer 40

1.) Epidural: Bleeding of middle meningeal or anterior ethmoidal arteries into potential space between periosteal and meningeal layers of dura.
-Lucidity followed by unconsciousness.
-Lenticular hematoma.
2.) Subdural: Venous blood from bridging veins between meningeal dura and arachnoid mater.
-Gradual headache and confusion.
-Slowly developing, crescent-shaped hematoma.
3.) Subarachnoid hemorrhage: Bleeding into subarachnoid space from ruptured aneurysm).
-Thunderclap headache, vomiting, confusion, possibly seizures.
-Increased intracranial pressure, herniation, pupillary dilation, oculomotor symptoms.
-WHICH VESSEL????
Check CSF for blood
4.) Intracerebral hemorrhage: Bleeding into brain parenchyma (HTN, tumor, ruptured aneurysm, or head injury).
-Clinical expression depends on which part of the brain is impacted.
L3a #25-28

Question 41

What is syringomyelia? Symptoms (2)?

Answer 41

Cavitations of the central regions of the spinal cord, which frequently damages the anterior white commissure.
Symptoms: (1) Bilateral loss of pain and temperature at the level of the lesion. (2) Weakness of the corresponding limbs; due to anterior horn damage (usually at the cervical levels, thus, upper limb weakness).
L3b #78, p.137 text

Question 42

What is central cord syndrome? Cause? Symptoms (3 tracts involved)?

Answer 42

Acute occlusion of ASA in the cervical region; caused by hyperextension injury of the neck.
-Anterior horn: Flaccid paralysis at the level of the lesion.
-CS tract: Bilateral spastic paralysis (more upper limb) below the level of the lesion.
-ALS: Bilateral loss of pain and temperature.
Bladder dysfunction; recovery after 5 days
#69

Question 43

Describe the four common CNS herniations.

Answer 43

1.) Subfalcine: Common; headache, contralateral leg weakness.
2.) Transtentorial: Oculomotor (CN III) paresis (= ipsilateral dilated pupil, abnormal EOMs), contralateral hemiparesion.
3.) Tonsillar: Obtundation (less than full alertness).
4.) Pressure groove: Herniation below tentorium.
L3a #13-14

Question 44

Describe a meningioma.

Answer 44

Benign tumor from the meninges —> Origin = Arachnoid cells of villi.
L1c #80

Question 45

Describe a heterotopia and three different manifestations.

Answer 45

Disruption of migration of immature neurons from the ventricular surface, causing mature neurons to take up residence in the intermediate zones.
-May occur because ventricular zone cells never began migration in an orderly way (heterotopia within lumen, i.e. below ventricular zone).
-May occur because migration never stopped properly (heterotopia above marginal zone).
-May also occur on the leptomeninges (pia and arachnoid, #13).
L2a #12, p.77 text

Question 46

Where must an anterolateral cordotomy be done?

Answer 46

In front of denticulate ligament, up to the ventral rootlets. 
*1-2 levels ABOVE uppermost dermatome of pain (because the fibers jump up 1-2 levels before crossing). Therefore, there is CONTRALATERAL analgesia 1-2 levels below the cordotomy*
#58

Question 47

Occlusion of what artery causes deficits in the ALS? Laterality?

Answer 47

Occlusion of the anterior spinal artery (ASA) (CONFIRM THIS!!!) cause deficits on the CONTRALATERAL SIDE, due to almost instantaneous fiber crossing upon entering the spinal cord.
L4 #66

Question 48

Describe conus medullaris syndrome –Cause(s) and symptoms (3).

Answer 48

Compression of conus medullaris (S3 to Co) due to tumor or injury.
Symptoms: Bilateral –Urinary/fecal incontinence (sacral PSNS nucleus), perianogenital sensory loss, minimal weakness in lower limb.

Question 49

Describe the pathology of Lambert-Eaton syndrome.

Answer 49

Antibody against calcium channel in presynaptic terminal.
-Initially Ca2+ channels are blocked, but later they become available.
-Myasthenia-like disease.
L1c #48

Question 50

Differentiate between axonal retrotransport of rabies via direct binding of rabies, and binding of rabies-containing vesicle (i.e what it binds and how it is carried).

Answer 50

1.) Direct binding of rabies PHOSPHOPROTEIN —> Nucleocapsid carried.
2.) Binding of vesicle containing rabies GLYCOPROTEIN —> Virion carried.
L1a #36