Term
| What is the nervous system? |
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Definition
- The major controlling, regulatory, and communicating system in the body.
- The center of all mental activity including thought, learning, and memory.
- Together w/ the endocrine system, the nervous system is responsible for regulating and maintaining homeostasis |
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Term
| What are the general functions of the nervous system? |
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Definition
3 general, overlapping functions
- sensory
- integrative
- motor |
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Term
| What is the Peripheral Nervous System and what are the components of the PNS? |
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Definition
Organs of the PNS are the nerves and ganglia
– PNS is further subdivided into an afferent (sensory) division that transmits impulses from peripheral nervous system and an efferent (motor) division that transmits impulses from the CNS out to the peripheral organs to cause an effect or action.
– PNS subdivided further into somatic nervous system (also called the somatomotor or somatic efferent nervous system, supplies motor impulses to the skeletal muscles. Because these nerves permit conscious control of the skeletal muscles, it is sometimes called the voluntary nervous system) and the autonomic nervous system also called the visceral efferent nervous system, supplies motor impulses to cardiac muscle, to smooth muscle, and to glandular epithelium. It is further subdivided into sympathetic and parasympathetic divisions. Because the autonomic nervous system regulates involuntary or automatic functions, it is called the involuntary nervous system |
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Term
| What are neurons and what are their functions? |
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Definition
- Neurons, or nerve cells, are the basic functional unite of the nervous system
- carry out the functions of the nervous system by conducting nerve impulses.
- They are highly specialized and amitotic. This means that if a neuron is destroyed, it cannot be replaced because neurons do not go through mitosis.
- Functionally, neurons are classified as afferent, efferent, or interneurons (association neurons) according to the direction in which they transmit impulses relative to the central nervous system.
- Afferent, or sensory, neurons carry impulses from peripheral sense receptors to the CNS. They usually have long dendrites and relatively short axons.
- Efferent, or motor, neurons transmit impulses from the CNS to effector organs such as muscles and glands. Efferent neurons usually have short dendrites and long axons.
- Interneurons, or association neurons, are located entirely within the CNS in which they form the connecting link between the afferent and efferent neurons. They have short dendrites and may have either a short or long axon. |
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Term
| What is another name for Sensory neurons and what is their function? |
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Definition
| Afferent, or sensory, neurons carry impulses from peripheral sense receptors to the CNS. They usually have long dendrites and relatively short axons. |
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Term
| What is another name for Motor neurons and what is their function? |
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Definition
| Efferent, or motor, neurons transmit impulses from the CNS to effector organs such as muscles and glands. Efferent neurons usually have short dendrites and long axons |
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Term
| 8. The Sympathetic nervous system, which is part of the Peripheral nervous system, is responsible for _____________or ____________ responses and this system prepares the body for __________ responses |
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Definition
| Flight or flight and prepares the body for quick responses |
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Term
| 1. The Parasympathetic nervous system, which is part of the Peripheral nervous system, is responsible for _________ and __________. This allows the body to ______ ________ and __________ ____________/ |
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Definition
| Rest and digest, allows the body to conserve energy, and control digestion |
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Term
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Definition
| No, they are amitotic – they do not go through mitosis and thus cannot be replaced |
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Term
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Definition
- Many axons are surrounded by a segmented, white, fatty substance called myelin or the myelin sheath.
- Myelinated fibers make up the white matter in the CNS, while cell bodies and unmyelinated fibers make the gray matter.
- The unmyelinated regions between the myelin segments are called the nodes of Ranvier.
- The myelin sheath and the nodes of Ranvier work together to enhance the speed of conduction of nerve impulses along the axon.
- Myelinated axons conduct nerve impulses faster then unmyelinated axons |
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Term
| What are the 2 main functions of the spinal cord? |
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Definition
Serving as a conduction pathway for impulses going to and from the brain. Sensory impulses travel to the brain on ascending tracts in the cord. Motor impulses travel on descending tracts.
Serving as a reflex center. The reflex arc is the functional unit of the nervous system. Reflexes are responses to stimuli that do not require conscious thought and consequently, they occur more quickly than reactions that require thought processes. For example, with the withdrawal reflex, the reflex action withdraws the affected part before you are aware of the pain. Many reflexes are mediated in the spinal cord without going to the higher brain centers. |
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Term
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Definition
can be helpful when trying to determine the cause of a disease when the diagnosis is not straight-forward.
D - Degenerative / Developmental
A - Allergic / Auto-immune / Anatomical
M - Metabolic
N - Neoplastic, Neurologic, Nutritional
I - Infectious, Idiopathic, Immune-mediated, Inflammatory
T - Traumatic, Toxic
V - Vascular |
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Term
| What does signalment include? Why is this important |
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Definition
- The signalment includes the species, breed, age, sex and color. While many conditions affect all animals, certain diseases are unique to some species and even to certain breeds of that species. Wobbler's disease is most common in the horse and dog. Moreover, in dogs, it is most often recognized in young Great Danes and older Doberman Pinchers. One would not think of feline leukemia, if treating a dog.
- The age of the animal can also be important. Younger animals are more prone to congenital problems, infections and toxicities. Older animals are more likely to have degenerative, metabolic, infectious and neoplastic diseases.
- The sex and color of the patient can alter the differential list as well. Hypocalcemia is more common in females around the time parturition. Mammary neoplasia is more common in females, while prostatic disease is most common in male dogs. Blue-eyed, white cats are often congenitally deaf |
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Term
| 2. Why is it important to know about the diet, medical and surgical history, and medications of an animal suffering from a neurological disease? |
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Definition
- can all be important in developing the differential diagnosis. If the diet is improper, nutritional or secondary metabolic diseases may develop.
- Animals who lack exercise may hasten the development of degenerative diseases.
- Having access to other animals and potential trauma from living outside may increase the risk of infectious or traumatic disease.
- Seizures secondary to canine distemper generally occur after the patient has recovered from the original infection.
- Lack of preventative medication (such as heartworm prevention) may lead to neurologic symptoms secondary to developing the disease.
- On the other hand, certain medications may allow manifestation of a previously sub-clinical problem. For example, certain heartworm preventatives can lower the seizure threshold. Treatment with aminoglycoside antibiotics can lead to disorders of cranial nerve VIII. Occurrence of the disease process following pesticide application or the availability of such pesticides may help determine the nature of intoxication. |
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Term
| What is meant by Mechanisms of Disease? |
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Definition
The
basic mechanisms of neurologic disease are congenital, inflammatory, metabolic, toxic, nutritional, traumatic, vascular,
degenerative, neoplastic and idiopathic. |
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Term
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Definition
| unconscious and unresponsive to repeated noxious stimuli |
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Term
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Definition
| – semiconscious, responsible only to noxious stimuli, demented, w/ unconscious vocalization |
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Term
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Definition
| disoriented, irritable, fearful, capable of responding to the environment but that response may be inappropriate |
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Term
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Definition
| – lethargic, despondent but capable of responding to the environment in a normal manner |
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Term
| Describe the care of animals with acute SC injury. |
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Definition
- should be handled carefully with minimal manipulation so as to avoid further cord injury from any unstable vertebrae.
- Traumatized animals should be placed in lateral recumbency upon admission and maintained in this posture during clinical/neurological examination and radiographic procedures.
- Struggling animals can be restrained and immobilized by being firmly taped to a rigid backboard [79].
- Animals should be immediately evaluated for airway obstruction, shock, visible hemorrhage or limb fractures.
- Clinical signs typically are acute in onset, usually nonprogressive, and either stable or improve with time. In rare cases in which clinical signs are progressive, continued bleeding and/or excessive bony movement at the site of injury should be suspected. Clinical syndromes seen with spinal fractures and luxations are cervical, cervicothoracic, thoracolumbar or lumbosacral [80]. Localization of the lesion in such cases usually can be determined with the animal in lateral recumbency. |
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Term
| Describe the medical treatment of animals with SC trauma. |
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Definition
- Prompt medical treatment is mandatory. Methylprednisolone succinate (MPS) presently remains the drug of choice in people with acute spinal cord injury due to its neuroprotective effects against the physiological cascade associated with the secondary spinal injury events [88-92]. These beneficial effects occur when MPS is given within 8 hours of injury. Clinical studies in humans suggest that spinal cord damage may be exacerbated if MPS treatment is initiated more than 8 hours after injury [93,94].
- A similar regimen for MPS (i.e., IV bolus of 30 mg/kg followed by 5.4 mg/kg/hour for 24 hours) [95] has been proposed for spinal cord injury in dogs. Bagley suggests an empirical modification [96]: an initial bolus of 30 mg/kg IV followed by additional doses of 15 mg/kg IV of MPS given at 2 and 6 hours after the initial dose.
- In cats, the recommended regimen for MPS is 30 mg/kg as an initial intravenous bolus, followed by 15 mg/kg at 2 and 6 hours, and continues with an intravenous infusion of 2.5 mg/kg/hour for 42 hours (see review by Olby [73]).
- The use of dexamethasone for treating animals with acute spinal cord trauma is no longer recommended due to doubts about its efficacy and because of its detrimental side effects [23,73].
- In patients with fractures and luxations, medical management is usually combined with prompt surgical intervention such as decompression of the spinal cord, vertebral reduction, and internal stabilization (e.g., use of Steinman pins and polymethylmethacrylate or coated polypropylene) [42,96,106,107,117]. The choice of stabilization technique is contingent on the location in the spinal column, size of the patient, and the surgeon's experience [106,117]. Acute surgical intervention is also required in cases with neurological deterioration associated with spinal cord compression from bone and disk fragments, hematoma, or unreduced subluxation [9]. |
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Term
| signs of progressive neurological deterioration in order of presentation are: |
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Definition
More heavily myelinated fibers show earliest dysfunction; thus, signs of progressive neurological deterioration in order of presentation are [2]:
a. loss of proprioception,
b. motor dysfunction such as paresis and paralysis, and
c. sensory disturbances including hypesthesia, hyperesthesia, and anesthesia.
Neurological recovery occurs in reverse order; however, proprioceptive loss may be permanent. |
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Term
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Definition
any sudden and uncontrolled movement of the animal's body caused by abnormal
brain activity.
- Seizures may be very severe and affect all of the body, or quite mild, affecting only a portion of the pet.
- The pet may or may not seem conscious or responsive, and may urinate or have a bowel movement. |
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Term
| Differentiate between partial seizures and generalized seizures. |
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Definition
Generalized seizures
- Tonic-clonic (may be Grand Mal or Mild):
- In the grand mal seizure, the tonic phase occurs as the animal falls, loses consciousness, and extends its limbs rigidly. Respiration also stops (apnea). This phase usually lasts 10-30 seconds before the clonic phase begins.
- Clonic movements include paddling of the limbs and/or chewing. Other signs that appear during the tonic or clonic phase are dilation of the pupils, salivation, urination, and defecation. The mild seizure involves little or no paddling or extension of limbs, and usually no loss of consciousness.
- Generalized seizures are usually associated with primary epilepsy.
Partial seizures
- Movements are restricted to one area of the body, such as muscle jerking, movement of one limb, turning the head or bending the trunk to one side, or facial twitches.
- A partial seizure can progress to (and be mistaken for) a generalized tonic-clonic seizure, but the difference can be established by noting whether or not a seizure starts with one specific area of the body.
- Partial seizures are usually associated with secondary epilepsy. |
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Term
| Define the term status epilepticus |
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Definition
- Status can occur as one continuous seizure lasting 30 minutes or more, or a series of multiple seizures in a short time with no periods of normal consciousness.
- It can be difficult to tell status epilepticus from frequent cluster seizures; but both are considered life-threatening emergencies.
- Most status patients usually suffer from generalized tonic-clonic seizures. Though status epilepticus can occur with either primary or secondary epilepsy, it may also suddenly arise in dogs with no previous history of seizures (traumatic brain injury, toxins, or disease). |
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Term
| Why is status epilepticus an emergency? |
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Definition
o When excessive and abnormal electrical impulses occur in the brain this causes seizure activity. The muscles of the body contract and relax continuously. This muscle activity creates a lot of heat which can lead to hyperthermia. When hyperthermia occurs for an extended period of time, this can cause body proteins to denature and all the organ systems of the body begin to fail.
o When a group of neurons in the brain begin to fire excessively and abnormally in an uncoordinated effort, this affects neighboring neurons, which begin firing. This can then affect additional neurons which affect more neurons. This is called “kindling”. An analogy for this is the spread of a forest fire. The more neurons (trees) that are affected, the harder the seizure (forest fire) is to control |
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Term
| List the 3 phases of seizures and what occurs in each. (Some references may list 4 phases) |
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Definition
- the aura or prodrome - a recognizable change in the pet's behavior that alerts the owner to an impending seizure. Most commonly, the pet that has an aura will act upset and anxious. He may seek attention from his owner or withdraw and hide. This aura may represent a focal beginning of the seizure and thus indicate a focal seizure, but we commonly see it in generalized seizures as well.
- the seizure (ictus)
- post-seizure (post-ictal) behavior - Following the seizure, the pet may lay motionless for a period of time. Eventually they get back on their feet. He may bounce back and be perfectly normal afterwards, but more typically there is a period of post-ictal behavior. Often the pet appears blind and disoriented during this post-ictal phase. He may pace or run about the house, bumping into things as he goes. Sometimes they are excessively hungry and will devour any food available. Rarely, a dog may behave aggressively during this period, especially if they are restrained. While such aggressive behavior is rare, it is important to recognize the possibility, especially if the dog is large and there are children in the household. Usually this post-ictal behavior begins to resolve within a few hours after the seizure and the dog gets back to normal. |
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Term
| 1. What drugs used to help manage seizures? Which drugs are used to help prevent seizures from occurring (ie, antiepileptic drugs), and which are used to stop seizures. |
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Definition
Anti Epilepsy Drugs: (AEDs)
• Phenobarbital.
• Potassium & Sodium Bromide.
• Home Treatment with Diazepam for Cluster Seizures in Dogs: -W.B.Thomas DVM. MS, Dipl. ACVIM (Neurology)
• The Other AEDs - Maureen Setter, Sandie Snider & Dr WB Thomas DVM
• Carbamazepine
• Primidone
• Phenytoin
• Valproic Acid
• Felbamate,
• Gabapentin
• Keppra
• Chlorazepate
• Zonisamide
• New anticonvulsant drugs show promise in dogs, cats: Article by Johnny D. Hoskins, DVM, PhD, Dipl. ACVIM
Diazepam is used to stop seizures |
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Term
| What are the most common causes of seizures in dogs: |
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Definition
- 0-6 months of age? - animals less than one year of age typically have seizures due to a birth defect such as hydrocephalus (water on the brain) or a liver defect called a portosystemic shunt (among others).
- 6 months to 5 years of age? - typically suffer from epilepsy
- Over 5 years of age - often have another medical condition causing the seizures such as
a brain tumor, stroke or low blood sugar. |
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Term
| What is included in a diagnostic workup for seizures? |
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Definition
| CBC/Chem/T4, pre and post prandial bile acids. EKG, films (chest/abdo) |
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Term
| How should anti-seizure medications be stopped? |
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Definition
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Term
| What would you advise owners do at home once their pet begins to seizure? |
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Definition
Protect the pet from injuring herself during or after the seizure. Keep her from falling from
a height and especially keep away from water.
- Remove other pets from the area as some pets become aggressive after a seizure.
- Protect yourself from being bitten.
- Record the time the seizure begins and ends, and if it started with a certain body part (such
as twitching of an eye).
- If the seizure or convulsion lasts over 3 minutes, cool the pet with cool (not cold) water on
the ears, belly and feet, and seek veterinary attention at once.
- If your pet has two or more seizures in a 24-hour period, seek veterinary attention.
- If your pet has one seizure that is less than 3 minutes and seems to recover completely,
contact your veterinarian’s office for further instructions. A visit may or may not be
recommended based on your pet’s medical history.
- If the pet loses consciousness and is not breathing, begin CPCR, formerly called CPR.
Special instructions for toy breeds and diabetic pets on insulin: If your pet is a toy breed, such as
a Yorkshire terrier or Maltese, or a diabetic, the seizure may be due to hypoglycemia (low blood
sugar). If the pet is able to stand, is not vomiting and acts normally, offer a small meal. If the pet
is non-responsive, vomiting or actively seizing, rub some honey or pancake syrup on the gums -
take care not to get bitten - and proceed immediately to your veterinarian or local emergency
center. Prolonged low blood sugar can cause irreversible brain injury. |
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Term
| What are the symptoms of Thoraco-lumbar disc disease? |
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Definition
- neurological deficits
- pain usually less dramatic than that associated with cervical disc disease.
- The dog may show kyphosis and reluctance to run or jump, and discomfort when picked up or when palpated in the thoracolumbar region.
- Pain alone may be misinterpreted as being of abdominal origin. |
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Term
| What are the symptoms of Cervical disc disease? |
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Definition
- predominant clinical sign is severe neck pain which may be acute or chronic
- neurological deficits not as common as in thoraco-lumbar disc dz |
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Term
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Definition
| Survey radiographs may give a tentative diagnosis of thoracolumbar disc disease but should never be used as the sole means of confirming the diagnosis when decompressive surgery is planned. Disc space narrowing and radio-opacity of the intervertebral foramen are the most common findings. However, be aware that the thoracic intervertebral disc spaces are normally more narrow than the lumbar disc spaces. In cats, disc disease may occur in the lower lumbar region (L5/L6 and L6/L7) and calcified disc material may be seen in the spinal canal. Myelography is required for confirmation of diagnosis (Figure 5). In case the cervical myelogram stops cranial to the disc lesion because of spinal cord swelling (especially in acute cases) lumbar myelography (injection of contrast medium between L4/L5) may be performed. Lateral and ventral radiographs should be taken. Oblique views are usually required to identify whether the compressive lesion is situated more on the left or the right side which determines the side for the hemilaminectomy. In institutions where CT or MRI is available these techniques replace myelography (see cervical disc disease). |
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Term
| What breeds are at higher risks of disc disease? |
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Definition
- chondrodystrophic breeds (e.g., Dachshund) Hansen Type I mainly
- Nonchondrodystrophic breeds (e.g., German shepherd) are less frequently affected. Hansen Type II mainly
- Small breeds, particularly those with chondrodystrophic characteristics, are commonly affected, but it can occur in any dog. Dachshunds, Beagles, Poodles, Spaniels, Shih Tzus, Pekingese, and Chihuahuas are most often affected.
- Most small dogs are older than 2 years with a mean of 6-7 years. Disc disease is rare in dogs less than one year. There is no sex predilection. |
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Term
| Which disc areas more commonly herniated? |
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Definition
Thoracolumbar
- Over 50% of all thoracolumbar disc lesions occur at the T12/T13 and T13/L1 disc and over 75% occur between T11/T12 and L1/L2.
- Lumbosacral disc disease, a cauda equina disease at L6/L7 or L7/S1, occurs frequently in large breed dogs (e.g., Shepherd dogs) and is associated with Hansen type II disc disease, vertebral instability and spinal stenosis and the complex is called degenerative lumbosacral stenosis
Cervical
- Most occurrences are Hansen Type I extrusions, Hansen type II protrusions do occur, generally in larger breed of dogs such as the Dobermann.
- The C2/C3 disc is most frequently affected, with the incidence decreasing caudally.
- The C6/C7 disc is rarely affected, with the exception of Dobermans and other large breeds as part of CCSM.
- The C7/T1 disc herniates occasionally. |
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Term
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Definition
| Survey radiographs may give a tentative diagnosis of thoracolumbar disc disease but should never be used as the sole means of confirming the diagnosis when decompressive surgery is planned. Disc space narrowing and radio-opacity of the intervertebral foramen are the most common findings. However, be aware that the thoracic intervertebral disc spaces are normally more narrow than the lumbar disc spaces. In cats, disc disease may occur in the lower lumbar region (L5/L6 and L6/L7) and calcified disc material may be seen in the spinal canal. Myelography is required for confirmation of diagnosis (Figure 5). In case the cervical myelogram stops cranial to the disc lesion because of spinal cord swelling (especially in acute cases) lumbar myelography (injection of contrast medium between L4/L5) may be performed. Lateral and ventral radiographs should be taken. Oblique views are usually required to identify whether the compressive lesion is situated more on the left or the right side which determines the side for the hemilaminectomy. In institutions where CT or MRI is available these techniques replace myelography (see cervical disc disease). |
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Term
| List recommended medical treatment including physical therapy. |
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Definition
Nonsurgical
- cage rest (2 – 4 weeks)
- anti-inflammatory meds (NSAIDS or corticosteroids)
- PT
- progression of cervical pain or lack of response to non-sx tx in 1 – 2 wks indicates tx failure
- recurrence of clinical signs after nonsurgical tx in 40% of pts
Surgical (Cervical(
- ventral fenestration or ventral decompression
- rarely dorsal laminectomy
Surgical (thoracolumbar)
- Dorsal right-sided or left-sided hemilaminectomy is most common
- Urinary retention is the most common post-op problem in thoracolumbar disc dz |
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Term
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Definition
| Loss of the ability to coordinate muscular movement. |
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Term
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Definition
| the ability to sense the position and location and orientation and movement of the body and its parts |
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Term
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Definition
| closing of the eyelids in response to the touching of the skin |
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Term
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Definition
| weightbearing on the dorsal surface of a flexed foot or paw; often a sign of deficit in normal proprioception that would reflexly cause a repositioning to the normal position. |
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Term
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Definition
| a condition that involves an abnormal increase in sensitivity to stimuli of the sense |
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Term
| Define “primary” brain tumors |
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Definition
| A mass in the brain arising from the cells of the brain and its lining |
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Term
| Define “secondary” brain tumors |
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Definition
| A mass in the brain arising elsewhere and spreading to the brain |
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Term
| A mass in the brain arising elsewhere and spreading to the brain |
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Definition
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Term
| What cells do meningiomas arise from? |
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Definition
- Arise from the arachnoid mater of the meninges (the membranes that line the brain) not the cells of the brain itself.
- As such they are not strictly brain tumors but tend to be grouped with them because they arise w/in the cranial cavity and compress or invade the brain |
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Term
| Give 3 examples of secondary tumors that may form in the brain. |
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Definition
- hemangiosarcoma
- mammary carcinoma
- melanoma |
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Term
| 10. List how brain and spinal cord tumors are diagnosed. |
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Definition
Complete physical and neurological examination to identify any other health problems and to localize the neurological signs to a particular area of the brain
2. Routine blood work to rule out a systemic problem and assess the anesthetic risk
3. Thoracic radiographs to check there is no evidence of spread (metastasis) of cancer to the lungs (a common site of metastasis)
4. CT or MRI of the brain. This has to be done under general anesthesia. As a general rule, MRI shows the brain in more detail than CT and is the test of choice when assessing for brain tumors. However, it is a more expensive test and less widely available. CT images will identify most meningiomas and choroid plexus papillomas but can fail to identify gliomas. CT images also have a lot of artifact when trying to assess the brainstem and cerebellum. We therefore strongly recommend an MRI if the animal has signs of brainstem or cerebellar disease, or if it is a breed of dog that is predisposed to gliomas, such as the Boston Terrier.
5. Tumor type can be suspected from the appearance of the mass on CT or MRI, but can only be definitively identified by taking a sample of the tumor, either at surgery or by biopsy. Indeed, masses caused by infections (for example abscesses or fungal granulomas) can look like brain tumors on brain images (figure 8). It is therefore vital that a sample of the tumor is taken and examined with a microscope to identify the cell types involved. Not only will this identify the tumor type, but it will also grade the malignancy of the tumor. Many neurologists, particularly those working in university teaching hospitals, routinely perform CT guided biopsies of tumors. |
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Term
| What is the prognosis for brain tumors? Why? |
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Definition
| They may be treated, not cured, sx depends on where located |
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Term
| What are clinical signs of tumors of the Cerebellum? |
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Definition
The cerebellum controls coordination of movements and interacts closely with the vestibular system to control balance and posture. Signs of cerebellar disease include:
- Uncoordinated gait characterized by dramatic goosestepping (hypermetria)
- Head tremors that are worst when the animal is intent on something (i.e., food) but disappear when the animal is relaxed (intention tremors)
- Swaying of the trunk
- Wide based stance
- Sometimes there can be vestibular signs such as a head tilt
- The animal's strength remains normal |
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Term
| Can plain radiographs be used to diagnose brain tumors? Why? |
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Definition
| No, tumors are soft tissue and cannot be used to definitely dx tumors by radiography |
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