03 - Brain and Cranial Nerve Disorders

Question 1

(brainstem lesions)

1. ascending white matter tract injury causes what?
2. descending UMN injury causes what?

Answer 1

1. ipsilateral conscious proprioceptive deficits
2. tetraparesis or paralysis

Question 2

(cerebellar lesions)

1. cause what?

Answer 2

1. incoordination, intention tremor of head, menace response absent ipsilaterally

(mental status is usually normal)

Question 3

(forebrain lesions)

Question 4

manifestation of systemic metabolic alterations

1. signs are usually diffuse, with alteration of mental status
2. seizures may also be seen

Question 5

(neoplasia)

1. most common primary tumors in dog?
2. most common primary tumor in the feline?

Answer 5

1. meningioma and glioma
2. meningioma

Question 6

Question 7

(treatment)

1. what used to treat edema and meningioma?
2. what is used in those with increased intracranial pressure?
3. what is indicated if seizures are present?
4. surgery may be possible, depending on location
5. radiation consistently prolongs survival

Answer 7

1. corticosteroids
2. mannitol
3. phenobarb

Question 8

(inflammatory brain diseases)

what are the meninges?

Answer 8

the membranes that envelop the brain and spinal cord of the central nervous system

Question 9

what is meningoencephalitis?

Answer 9

inflammation of the brain and meninges

Question 10

(infectious meningoencephalitis)

1. more common in cats or dogs?
2. many agents can cause this
3. dx = min database, radiographs, ophthalmological eval

Answer 10

1. cats

Question 11

(idiopathic inflammatory brain disorders)

1. more common in dogs or cats?

Answer 11

1. dogs

Question 12

(idiopathic inflammatory brain disorders)

(Granulomatous meningoencephalomyelitis (GME))

1. immunde mediated condition with perivascular accumulations of what?
2. usually affects what dogs?
3. dx?
4. what may cause remission?

Answer 12

1. lymphocytes, plasma cells, and histiocytic cells
2. small and toy breed dogs between 1 and 8 years
3. by exclusion
4. prednisone

Question 13

(idiopathic inflammatory brain disorders)

(necrotizing encephalitis)

1. similar to GME and may have an immune mediated component. multifocal, necrotic, cavitating lesions are commonly seen

Question 14

(vascular diseases)

(vascular encephaolopathies)

1. typically affect older animals. ishcemia or infarction occurs as a result of thrombosis of a blood vessel secondary to an underlying condition
2. Cx are usually asymmetrical and cause what brain signs?

Answer 14

2. forebrain dz and vestibular dz

Question 15

(vascular diseases)

(feline ischemic encephalopathy)

1. caused by a cerebral infarction of what artery?
2. Cx?
3. anticonvulsant therapy may be needed

Answer 15

1. the middle cerebral artery
2. cerebral dysfx

Question 16

(brain trauma)

1. trauma can cause an increase in intracranial pressure leading to what 3 things?
2. how does elevating the head help?

Answer 16

1. bradycardia, hypertension, and pulmonary edema
2. help maintain cerebral blood flow and enhance CSF resorption

Question 17

(brain trauma)

(treatment)

1. what may be beneficial if there is brain edema?
2. what fluids should be used in those with hypovolemic shock and head trauma?
3. use what to control seizures?

Answer 17

1. mannitol and furosemide
2. hypertonic saline with hetastarch
3. diazepam

Question 18

(metabolic brain encephalopathies)

1. what brain region is most commonly affected?

Answer 18

1. cerebrum (altered behavior, dementia, seizures)

Question 19

(thiamine deficiency)

1. from improper diets (esp all fish diets)

cats or dogs more affected?

2. Cx?
3. tx?

Answer 19

1. cats
2. wt loss, ataxia, coma, blindness, seizures
3. parenteral thiamine

Question 20

(neurotoxins)

(lead poisoning)

1. cx?
2. RBC look how?
3. treat with what?

Answer 20

1. vomiting, diarrhea, behaviors changes, seizures, blindness
2. basophilic stippling
3. chelating drug (D-penicillamine)

Question 21

(neurotoxins)

(metaldehyde)

1. produces severe metabolic acidosis
2. seizures, tremors, depression

Question 22

(neurotoxins)

(methlxanthines - caffeine, theobromine)

1. Cx?
2. tx?

Answer 22

1. tachycardia, cardiac arrythmias, vomiting, PU/PD, cyanosis, seizures, ataxia, coma
2. activated charcoal, promote diuresis, treat cardiac arrythmias and seizures

Question 23

(neurotoxins)

(organophosphate and carbamate poisoning)

1. acetylcholinesterase is inhibited -> so acetylcholine is not broken down at muscarinic and nicotinic sites of the somatic and autonomic and somatic nervous systems
2. Cx: salivation, vomiting, diarrhea, miosis, bradycardia, musc tremors, weakness, ex intol, hyperactivity, seizures
3. dx based on history and clinical signs
4. tx?

Answer 23

4. induce vomiting if ingestion in previous 2 hours, anticonvulsants, atrophine, IV fulids

Question 24

(neurotoxins)

(ivermectin toxicity)

1. usually can’t enter BBB, defect in pump allows in what breeds?
2. Cx?
3. tx?

Answer 24

1. sheepdogs and some collies

(single oral dose can be toxic if defect is present)

2. ataxia, musc tremors, tetraparesis, coma
3. supportive: prog good but can take weeks

Question 25

(neurotoxins)

(metronidazole)

1. it can cause if given for how long?

Answer 25

1. greater than 7 days

Question 26

(neurotoxins)

(bromethalin poisoning)

1. present in rodenticides and uncouples phoshporylation -> hyperexcitability, seziures, etc