Lecture 16

Question 1

What are the characteristics of UMN spinal cord injury and the bladder?

Answer 1

-hypertonicity caudal to lesion
-increased external urethral sphincter tone
-increased resting tone to detrusor

Question 2

Why does bladder dysfunction occur with UMN spinal cord injury?

Answer 2

-loss of higher-level coordination of detrusor/sphincter
-cannot overcome resistance from external urethral sphincter

Question 3

What are the characteristics of LMN spinal cord injury and the bladder?

Answer 3

-hypotonicity of pelvic and pudendal nerves
-decreased external urethral sphincter tone
-decreased detrusor strength

Question 4

Why does bladder dysfunction occur with LMN spinal cord injury?

Answer 4

-inability to contract detrusor
-dribbling due to inability to constrict sphincter

Question 5

What are the characteristics of prazosin?

Answer 5

-sympatholytic drug
-alpha-1 R antagonist
-relaxes internal urethral sphincter
-side effect is hypotension

Question 6

What are the characteristics of bethanechol?

Answer 6

-parasympatholytic drug
-works on detrusor muscle receptors
-contracts detrusor muscle
-side effects include salivation, lacrimation, urination, defecation, diarrhea, and emesis (SLUDDE)

Question 7

What are the characteristics of valium/diazepam?

Answer 7

-skeletal muscle relaxant
-acts on external urethral sphincter
-relaxes external urethral sphincter
-side effects include sedation and hepatic failure

Question 8

What are the clinical signs of horner’s syndrome?

Answer 8

-miosis
-ptosis/drooping of eyelid
-enophthalmos/sunken eyes
-3rd eyelid protrusion/prolapse
-possible loss of vascular tone on affected side (warm skin, sweating)

Question 9

What causes horner’s?

Answer 9

any lesion along the path of the sympathetic innervation of the eye

Question 10

What are the characteristics of dysautonomia?

Answer 10

-Key-Gaskell in dogs and cats
-Grass Sickness in horses
-only disease that selectively affects entire ANS
-SNS and PNS are affected; PNS blockade more pronounced
-loss of both pre- and post-ganglionic cell bodies

Question 11

What causes dysautonomia in horses?

Answer 11

-degeneration of autonomic and enteric nervous system
-strong association with grazing during spring and early summer
-pasture associated factor

Question 12

What is the presentation of dysautonomia in horses?

Answer 12

-typically in young adults; 2 to 7 years old
-per-acute, acute, and chronic forms

Question 13

What are the signs of dysautonomia in dogs and cats?

Answer 13

-bilateral mydriasis and absent PLR
-prolapsed 3rd eyelid
-decreased tear production
-xeromycteria/dry nose
-decreased saliva production
-depression
-anorexia and weight loss
-megaesophagus
-megacolon
-bradycardia
-fecal and urinary incontinence

Question 14

What are the signs of dysautonomia in horses?

Answer 14

-dysfunction of ANS +/- somatic neuronal damage
-anorexia
-dysphagia
-stomach distention
-reflux esophagitis
-intestinal dysmotility
-bilateral rhinitis sicca (chronic)
-poor BCS (chronic)
-tachycardia
-ptosis
-patchy sweating
-muscle fasciculations
-weight loss
-generalized weakness (chronic)

Question 15

What are the characteristics of organophosphates and carbamates?

Answer 15

-used for insect control
-organophosphates cause irreversible inhibition of acetylcholinesterase
-carbmates cause reversible inhibition

Question 16

What are the clinical signs of organophosphate/carbamate toxicity?

Answer 16

-excessive parasympathetic stimulation
-bradycardia
-salivation
-lacrimation
-miosis
-increased bronchial secretions
-urine dribbling
-muscle twitching
-tremors
-anxiety
-restlessness
-seizures

Question 17

How do these pupil diagrams relate to prognosis and disease?

Answer 17

1. normal CN 3 function; good prognosis
2. CN 3 nerve irritation; prognosis guarded
3. CN 3 nucleus - unilateral compression; guarded prognosis
4. CN 3 nuclei - bilateral compression/loss of blood supply; prognosis grave

Question 18

What is the use of the modified glasgow coma scale?

Answer 18

determine prognosis based on motor activity, brainstem reflexes, and level of consciousness