Chapter 54 - Neurocranium and brain

Question 1

What are the important causes of morbidity and mortality in horses related to neurologic disorders?

Answer 1

Brain, spinal cord, and nerve disorders

Question 2

What is a crucial cause of death in horses due to neurologic disorders?

Answer 2

Traumatic Brain Injury (TBI)

Question 3

What type of injury is most common as a result of horses running into fixed objects or being kicked by another horse?

Answer 3

Frontal injury to the head

Question 4

What is indicated by the presence of spinal fluid in the ear canal in horses?

Answer 4

Temporal bone fracture

Question 5

Which breed was most represented in a retrospective study of horses with TBI?

Answer 5

Thoroughbreds

Question 6

What is the most common cause of TBI in horses?

Answer 6

Skull fractures due to trauma

Question 7

What are common neurologic signs observed in horses with TBI?

Answer 7

Ataxia, altered mentation, vestibular deficits

Question 8

What risk factors are associated with nonsurvival in horses with TBI?

Answer 8

Persistent recumbency and fracture of the basilar bones

Question 9

What was a significant finding regarding PCV levels on admission in a study of horses with TBI?

Answer 9

Lower PCV in surviving horses

Question 10

What percentage of horses discharged after TBI were observed to have persistent neurologic deficits?

Answer 10

19%

Question 11

What injuries result from trauma to the poll in young horses?

Answer 11

Basilar skull fractures

Question 11

What brain region is affected when a horse with TBI shows seizures and cortical blindness?

Answer 11

Cerebrothalamic region

Question 11

How many horses returned to their previous physical activity after being discharged with TBI?

Answer 11

29% of discharged horses

Question 11

What is the outcome of massive bleeding from injury to the basilar artery in horses?

Answer 11

Bleeding into the guttural pouch and out the nares

Question 12

Which clinical sign is associated with cerebellar injury in horses with TBI?

Answer 12

Hypermetria

Question 13

What percentage of horses with TBI were discharged alive in one study?

Answer 13

C) 62%

Question 14

What are the common brainstem signs observed in horses with severe TBI?

Answer 14

Altered state of consciousness, multiple cranial nerve dysfunctions

Question 15

What does primary traumatic brain injury (TBI) in horses comprise?

Answer 15

Direct physical injury to the brain such as compression, deformation, displacement

Question 16

What is concussion in horses classified as in terms of TBI?

Answer 16

A primary injury that is not severe and involves transient loss of consciousness

Question 17

What does secondary brain injury in horses include?

Answer 17

A series of events like excitotoxicity, ischemia, inflammation, and neuronal cell death

Question 18

Which disorders contribute to secondary brain injury in horses?

Answer 18

A combination of intracranial and extracranial disorders

Question 19

What is the impact of increased intracranial pressure (ICP) on cerebral perfusion pressure (CPP) and cerebral blood flow (CBF)?

Answer 19

Increased ICP decreases CPP and CBF

Question 20

What are key parameters to evaluate the neurologic status of a horse with TBI

Answer 20

Brain function, brainstem reflexes, and spinal cord function

Question 21

How are severe spinal cord injuries indicated in horses with TBI?

Answer 21

Absence of voluntary motor function

Question 22

what imaging techniques are used for neuroimaging of the equine head in cases of TBI?

Answer 22

CT and MRI

Question 23

What does the presence of air in the brain, ventricles, or vertebral canal indicate in horses with TBI? A) Infection B) Inflammation C) Presence of fracture D) Neurological recovery

Answer 23

Presence of fracture

Question 24

What can result from a laceration, the most severe primary brain injury in horses? A) Mild confusion B) Slight headache C) Intracranial hemorrhage D) Temporary dizziness

Answer 24

C) Intracranial hemorrhage

Question 25

What is a significant effect of hypotension on the brain following TBI?

Answer 25

Increased cerebral blood flow and intracranial pressure

Question 26

What is the role of astrocytes in the brain following TBI?

Answer 26

They clear the extracellular space of glutamate

Question 27

What happens to astrocytes in response to a massive release of excitatory neurotransmitters post TBI?

Answer 27

they swell up, resulting in glial swelling

Question 28

What are the consequences of altered respiratory patterns in patients with severe TBI? A) It has no impact on brain function B) It leads to consistent cerebral blood flow C) It can impact cerebral blood flow, volume, and intracranial pressure D) It results in immediate recovery of brain function

Answer 28

C) It can impact cerebral blood flow, volume, and intracranial pressure

Question 29

What does the absence of pain perception indicate in horses with TBI?

Answer 29

Severe spinal cord injury with poor prognosis

Question 30

What conditions increase morbidity and mortality in humans with TBI and are presumed to be similar in horses?

Answer 30

Hypotension and hypoxemia

Question 31

Why should CSF sampling be avoided in patients with severe TBI?

Answer 31

High risk of cerebral or cerebellar herniation

Question 32

What effect does head position have on intracranial pressure (ICP) in patients with brain injury?

Answer 32

Elevated head position reduces ICP

Question 33

What should be considered in the supportive care of a recumbent horse with TBI?

Answer 33

Hydration, nutrition, urination, defecation, and bedding

Question 34

Why should ketamine and acepromazine be used cautiously in patients with TBI?

Answer 34

They can increase cerebral metabolic demands and ICP

Question 35

What has been the observed effect of corticosteroids in humans with TBI?

Answer 35

Increase in risk of death, severe disabilities, infection, and gastrointestinal bleeding

Question 36

What is the role of hyperosmolar therapy in the treatment of TBI in horses?

Answer 36

To decrease intracranial pressure and cerebral edema

Question 37

What are the benefits of hypertonic saline solution (HSS) in managing TBI? A) It increases intracranial volume B) It decreases intracranial volume and ICPC) It improves renal function D) It enhances muscle recovery

Answer 37

B) It decreases intracranial volume and ICP

Question 37

What is the recommended plasma osmolality level when administering hyperosmolar solutions for TBI? A) Below 320 mOsm/L B) Above 350 mOsm/L C) Between 150-200 mOsm/L D) Between 400-450 mOsm/L

Answer 37

A) Below 320 mOsm/L

Question 38

What risks are associated with mannitol therapy in horses with TBI? A) Acute renal failure and electrolyte disturbances B) Increased blood pressure C) Decreased heart rate D) Skin irritation

Answer 38

A) Acute renal failure and electrolyte disturbances

Question 39

How can prophylactic hypothermia benefit patients with TBI? A) By reducing cerebral metabolic rate and ICP B) By increasing cerebral oxygenation C) By improving digestive function D) By enhancing physical activity

Answer 39

A) By reducing cerebral metabolic rate and ICP

Question 39

What is the purpose of antioxidant treatment in TBI cases? A) To increase blood flow B) To reduce oxidative stress C) To enhance bone healing D) To improve coat conditio

Answer 39

B) To reduce oxidative stress

Question 40

What is the approach for seizure management in horses with TBI? A) Use of anticonvulsants like benzodiazepines and phenobarbital B) Physical therapy C) Avoiding any medication D) Immediate surgery

Answer 40

A) Use of anticonvulsants like benzodiazepines and phenobarbital

Question 41

What therapeutic approach is rarely performed in horses but commonly used in human ICU units for TBI? A) Decompression craniectomy B) Physical exercise C) Homeopathic treatment D) Dietary changes

Answer 41

A) Decompression craniectomy

Question 42

What bones form the cranial cavity in horses?

Answer 42

Frontal, parietal, interparietal, basioccipital, basisphenoid, presphenoid, and temporal bones

Question 43

How are fractures of the bones surrounding the brain in horses classified?

Answer 43

by the degree of fragment displacement and damage to underlying tissues

Question 43

What type of cranial fractures in horses do not penetrate the underlying dura mater? A) Type I B) Type II C) Type III D) Type IV

Answer 43

A)Type I Type I cranial fractures are displaced but do not penetrate the underlying dura mater. Type II fractures only disrupt the dura mater, while Type III fractures lacerate the dura mater as well as the brain parenchyma.

Question 43

Why are surgical approaches to the base of the horse's skull considered experimental? A) Due to the procedure being technically easy and low risk B) Because it is a new method not yet fully researched C) The procedure is technically difficult, provides limited access, and carries a high risk D) It is a commonly performed procedure with a high success rate

Answer 43

C) The procedure is technically difficult, provides limited access, and carries a high risk

Question 44

What surgical interventions might be considered for horses with traumatic brain injury? A) To manage increased intracranial pressure or to evacuate intracranial hematomas B) Cosmetic surgeries only C) Routine spaying and neutering procedures D) Procedures unrelated to the brain or skull