Neuro - Anat & Phys (Spinal Cord Lesions)

Question 1

Draw the spinal cord areas affected in Poliomyelitis and spinal muscular atrophy (Werdnig-Hoffmann disease).

Answer 1

See p. 467 in First Aid 2014 for associated visual

Question 2

What kind of lesions are associated with Werdnig-Hoffmann disease, and what causes them? What is another characteristic of this disease?

Answer 2

LMN lesions only, due to destruction of anterior horns; Flaccid paralysis

Question 3

What is the disease name for spinal muscular atrophy?

Answer 3

Werdnig-Hoffmann disease

Question 4

Draw the spinal cord areas affected in Multiple sclerosis.

Answer 4

See p. 467 in First Aid 2014 for associated visual

Question 5

What characterizes the spinal cord lesions associated with multiple sclerosis, and what causes them?

Answer 5

Due to demyelination; Mostly white matter of cervical region; Random and asymmetric lesions, due to demyelination

Question 6

What are 3 symptoms associated with Multiple sclerosis?

Answer 6

(1) Scanning speech (2) Intention tremor (3) Nystagmus

Question 7

Draw the spinal cord areas affected in Amyotrophic lateral sclerosis.

Answer 7

See p. 467 in First Aid 2014 for associated visual

Question 8

What are the deficits that are present versus absent in Amyotrophic lateral sclerosis?

Answer 8

Combined UMN and LMN deficits with no sensory, cognitive, or oculomotor deficits; both UMN and LMN signs

Question 9

What can cause Amyotrophic lateral sclerosis?

Answer 9

Can be caused by defect in superoxide dismutase I.

Question 10

How does Amyotrophic lateral sclerosis commonly present? What is its most serious complication?

Answer 10

Commonly presents as fasciculations with eventual atrophy and weakness of hands; fatal.

Question 11

What is the treatment for Amyotrophic lateral sclerosis, and how does it work?

Answer 11

Riluzole treatment modestly increases survival by decreasing presynaptic glutamate release; Think: “for LOU gehrig disease, give riLOUzole.”

Question 12

What is Amyotrophic lateral sclerosis commonly known as? What is a well-known patient with this disease?

Answer 12

Commonly known as Lou Gehrig disease; Stephen Hawking is a well-known patient who highlights the lack of cognitive deficit

Question 13

Draw the spinal cord areas affected in Complete occlusion of anterior spinal artery.

Answer 13

See p. 467 in First Aid 2014 for associated visual

Question 14

What parts of the spinal cord are spared with the complete occlusion of anterior spinal artery?

Answer 14

Spares dorsal columns and Lissauer tract

Question 15

What is a watershed area relevant to ASA territory, and why?

Answer 15

Upper thoracic ASA territory is a watershed area, as artery of Adamkiewicz supplies ASA below ~T8.

Question 16

Draw the spinal cord areas affected in Tabes dorsalis.

Answer 16

See p. 467 in First Aid 2014 for associated visual

Question 17

What condition causes Tabes dorsalis? What is its pathogenesis and its associated deficits?

Answer 17

Caused by tertiary syphilis. Results from degeneration (demyelination) of dorsal columns and roots –> impaired sensation and proprioception and progressive sensory ataxia (inability to sense or feel the legs –> poor coordination).

Question 18

What are 3 (non-spinal cord lesion) signs/symptoms associated with Tabes dorsalis (and tertiary syphilis)?

Answer 18

Associated with Charcot joints, shooting pain, Argyll Robertson pupils (small bilateral pupils that further constrict to accommodation and convergence, not to light).

Question 19

What 2 signs will be present on exam of patient with Tabes dorsalis?

Answer 19

Exam will demonstrate absence of DTRs and (+) Romberg.

Question 20

Draw the spinal cord areas affected in Syringomyelia.

Answer 20

See p. 467 in First Aid 2014 for associated visual

Question 21

What causes Syringomyelia, and what deficits result?

Answer 21

Syrinx expands and damages anterior white commissure of spinothalamic tract (2nd-order neurons) –> bilateral loss of pain and temperature sensation (usually C8-T1)

Question 22

With what condition is Syringomyelia seen?

Answer 22

Seen with Chiari I malformation

Question 23

What is a concern regarding the extent of Syringomyelia?

Answer 23

Can expand and affect other tracts

Question 24

Draw the spinal cord areas affected in Vitamin B12 or Vitamin E deficiency.

Answer 24

See p. 467 in First Aid 2014 for associated visual

Question 25

What is the name of the collection of deficits/lesions associated with Vitamin B12 deficiency? What are those deficits/lesions?

Answer 25

Subacute combined degeneration - demyelination of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts

Question 26

What symptoms are associated with Vitamin B12 or Vitamin E deficiency, and why?

Answer 26

Ataxic gait, paresthesia, impaired position and vibration sense; Subacute combined degeneration - demyelination of dorsal columns, lateral corticospinal tracts, and spinocerebellar tracts

Question 27

What causes poliomyelitis? Explain the pathogenesis and resulting lesion(s).

Answer 27

Caused by poliovirus (fecal-oral transmission). Replicates in the oropharynx and small intestine before spreading via the bloodstream to the CNS. Infection causes destruction of cells in anterior horn of spinal cord (LMN death).

Question 28

Where does poliovirus replicate, and how does it spread?

Answer 28

Replicates in the oropharynx and small intestine before spreading via the bloodstream to the CNS.

Question 29

What are the 2 major categories of symptoms associated with Poliomyelitis? List specific symptoms under each category.

Answer 29

(1) LMN lesion signs - weakness, hypotonia, flaccid paralysis, fasciculations, hyporeflexia, and muscle atrophy (2) Signs of infection - malaise, headache, fever, nausea, etc.

Question 30

What are CSF findings associated with Poliomyelitis?

Answer 30

CSF with increased WBCs and slight increase of protein (with no change in CSF glucose).

Question 31

From where in the body of a patient with poliomyelitis can the poliovirus be recovered?

Answer 31

Virus recovered from stool or throat

Question 32

What is another name for Spinal muscular atrophy? What is its pathogenesis?

Answer 32

Werdnig-Hoffman disease; Congenital degeneration of anterior horns of spinal cord –> LMN lesion

Question 33

What is the presentation of Spinal muscular atrophy (Werdnig-Hoffmann disease)?

Answer 33

“Floppy baby” with marked hypotonia and tongue fasciculations.

Question 34

What is the median age of death for infantile type of Spinal muscular atrophy (Werdnig-Hoffman disease)?

Answer 34

Infantile type has median age of death of 7 months.

Question 35

What is the mode of inheritance for Spinal muscular atrophy (Werdnig-Hoffman disease)?

Answer 35

Autosomal recessive inheritance

Question 36

What is the genetic defect in Friedreich ataxia and its immediate consequence?

Answer 36

Autosomal recessive trinucleotide repeat disorder (GAA) on chromosome 9 in gene that encodes frataxin (iron binding protein). Leads to impairment in mitochondrial functioning.

Question 37

What are the neurologic deficits associated with Friedreich ataxia?

Answer 37

Degeneration of multiple spinal cord tracts –> muscle weakness and loss of DTRs, vibratory sense, and proprioception.

Question 38

What are 7 symptoms associated with Friedreich ataxia? Which is a cause of death?

Answer 38

(1) Staggering gait (2) Frequent falling (3) Nystagmus (4) Dysarthria (5) Pes cavus (6) Hammer toes (7) Hypertrophic cardiomyopathy (cause of death); Think: “Friedreich is Fratastic (frataxin): he’s your favorite frat brother, always stumbling, staggering, and falling, but has a big heart.”

Question 39

How does Friedreich ataxia present?

Answer 39

Presents in childhood with kyphoscoliosis

Question 40

What causes Brown-Sequard syndrome?

Answer 40

Hemisection of spinal cord

Question 41

What are 5 neurological findings in Brown-Sequard syndrome? Explain the lesion that causes each finding.

Answer 41

Findings: (1) Ipsilateral UMN signs below the level of the lesion (due to corticospinal tract damage) (2) IIspilateral loss of tactile, vibration, proprioception sense below the level of the lesion (due to dorsal column damage) (3) Contralateral pain and temperature loss below the level of the lesion (due to spinothalamic tract damage) (4) Ipsilateral loss of all sensation at the level of the lesion (5) Ipsilateral LMN signs (e.g., flaccid paralysis) at the elvel of the lesion

Question 42

What may a Brown-Sequard patient present with if their lesion occurs above T1, and why?

Answer 42

If lesion occurs above T1, patient may present with Horner syndrome due to damage of oculosympathetic pathway

Question 43

What causes Horner syndrome, and what 3 major findings characterize it?

Answer 43

Sympathectomy of face: (1) Ptosis (slight drooping of eyelid: superior tarsal muscle) (2) Anhidrosis (absence of sweating) and flushing (rubor) of affected side of face (3) Miosis (pupil constriction); Think: “PAM is horny (Horner)” and/or “Ptosis, anhidrosis, and miosis (rhyming).”

Question 44

With what level of spinal cord lesion(s) is Horner syndrome associated? Give 3 examples of such lesions.

Answer 44

Associated with lesion of spinal cord above T1 (e.g., Pancoast tumor, Brown-Sequard syndrome [cord hemisection], late-stage syringomyelia).

Question 45

Explain the route of the oculosympathetic pathway. What lesion(s) along this pathway can cause Horner syndrome?

Answer 45

The 3-neuron oculosympathetic pathway (1) projects from the hypothalamus to the intermediolateral column of the spinal cord, then (2) to the superior cervical (sympathetic) ganglion, and (3) finally to the pupil, the smooth muscle of the eyelids, and the sweat glands of the forehead and face. Interruption of any of these pathways results in Horner syndrome.

Question 46

Draw the oculosympathetic pathway, including and labeling the following: (1) External carotid artery (2) First neuron (3) Hypothalamus (4) Internal carotid artery (5) Ophthalmic division of trigeminal nerve (6) Long ciliary nerve (7) Second neuron (8) Spinal cord (9) Synapse is in lateral horn (10) Superior cervical ganglion (11) To sweat glands of forehead (12) To smooth muscle of eyelid (13) To pupillary dilator (14) To sweat glands of face (15) Third neuron.

Answer 46

See p. 469 in First Aid 2014 for visual in middle of page