PEOPLE“The man who smiles in the face of

trouble…

Has found someone to blame it on.”

Anatomy

forebrain is responsible for "thinking," behavior, and final integration of sensory information

Brain: Neoplasia

Enlarging mass in brain; causes compression of healthy tissue or replacement with cancerous tissue

• Primary:____________,______________, choroid plexus papilloma, pituitary adenoma or adenocarcinoma (____________), and others.

• Secondary (metastasis): hemangiosarcoma, mammary carcinoma and melanoma

• Dogs most common meningiomas and gliomas

• Sagittal MRI of the brain of an 8 year old female German Shepherd dog.

• Seizure • Well encapsulated mass in the olfactory bulb

and frontal cortex of the brain • Meningioma (histopathology)• TX: surgical removal of the tumor followed by

radiation• PX: Good not touching brain (unlike gliomas:

radiation therapy)

Hemangiosarcoma

Brain: Neoplasia• Forebrain

– Behavior• ______________, loss

of learned behavior– Seizures: acute onset, 5-6

yrs old– Pacing and circling

(Vestibular signs)– Ipsilateral vision: bump– E.g. Glioma’s and new

treatments• ___________________

breeds: such as the Boxer, the Boston terrier, and the French and English bulldog

Brain - Neoplasia

• The Brainstem

– ___________ function (the ability to walk, CV and resp function), consciousness and balance

– 1st signs: loss of balance (vestibular signs) and paresis of one side of the body

– Dysphagia, change in voice and inability to move the eyes

– Progresses into paralysis, coma and death.

• Vestibular signs:

• Head __________________

• Leaning and falling to the side of the head tilt

• Drunken gait with loss of balance (ataxia)

• ________________ to the side of the head tilt

• nystagmus

• Anorexia and vomiting

• Strabismus

• Kasey, a 10-year-old female Golden retriever

• trigeminal nerve root tumor• sensation to the face and

motor function to the muscles of mastication

• 15 months

Brain - Neoplasia

• The Cerebellum - coordination of movements and interacts closely with the vestibular system to control ____________ and posture. – Uncoordinated gait characterized by dramatic goosestepping

(___________________)

– Intention tremors: Head tremors that are worst when the animal is intent on something (i.e., food) but disappear when the animal is relaxed Swaying of the trunk

– Wide based stance

– Sometimes there can be vestibular signs such as a head tilt

– The animal's strength remains ____________________

Brain: Neoplasia

• Dx– Systematic screening for tumors in other organs– CBC, chem panel– Radiographs: _______________– CSF tap to assess increased cerebral spinal

pressure– Ophthalmic exam may indicate optic nerve

edema– Computed tomography (CT) scanning or

magnetic resonance imaging (MRI) to locate tumor

CT or MRI

• MRI

– shows the brain in ________________ than CT

– the test of choice when assessing for brain tumors

– more expensive test and less widely available

– CT images (more artifacts for brainstem/ cerebellum): meningiomas, choroid plexus papillomas

– MRI:______________, brainstem or cerebellar disease or Boston Terrier.

Brain: Neoplasia• Rx— surgical removal, radiation therapy,

chemotherapy, and palliative treatment of the symptoms

– Surgical removal of superficial single lesions

• Tumors of the brainstem pose problems

• Forebrain: you can resect certain parts of the forebrain without long-term effects.

• _________________ tend to be located on the surface of the brain and are therefore the best candidates for surgical removal.

• Gliomas are more difficult to remove because they lie deep within the substance of the brain.

MRI of a 6 year female old Boxeroligodendroglioma

Brain: Neoplasia

– Radiation therapy

– Chemotherapy; efficacy varies with tumor

type (lymphomas respond well; other less so)

– Palliative: Anti-seizure medication (Phenobarbital PO 2-3 times/day), Corticosteroids—prednisone

• Client info– The more severe the signs, the worse the outcome

– The larger the tumor, the worse the outcome

– _________________________ tumors (tumors of the forebrain) have a better prognosis than infratentorial tumors (tumors of the brainstem and cerebellum)

– Radiation therapy does prolong lifespan in most cases

– Meningiomas have a better outcome than tumors that lie within the brain (e.g. gliomas)

Epilepsy

• Signs of seizure– short aura (stare into distance,

seek comfort/protection from

someone, vocalize)

– seizure lasts_________________ ; may consist of total body muscle twitching with extended arms and legs and arching of neck dorsally (opisthotonus)

– dog will be disoriented/blind for a few minutes

– may be a single event (no veterinary intervention needed) or followed shortly by other seizures (__________________; requires veterinary intervention)

– may be incited by certain events

– normal at other times

Click for video

• http://www.thepetcenter.com/gen/epilepsy.html

Epilepsy• Dx

– CBC, chem panel—r/o metabolic diseases causing seizures• ________________________________• hypocalcemia• hepatic encephalopathy (failure to detox blood)

– Shunt– Cirrhosis

• Pb poisoning– Radiographs—r/o head trauma or __________________– CT scan or MRI—r/o space-occupying lesion in brain

• Rx—directed at cause if one can be found– treat if >1 every mo or two (Rx will not completely stop seizures)– Phenobarbital is _________________________

Status Epilepticus• Signs—prolonged, uninterrupted seizures (>5-10

minutes)• Rx

– Diazepam (2-10 mg to effect); can be repeated over several minutes

• Phenobarbital - – Time to steady state blood levels: 10-14 days– Side effects: sedation, ataxia, PU/PD/PP,

hepatotoxicity, blood _______________________ (Rare)

– Establish an open airway– IV cath with IV fluids to keep an open vein– Monitor blood Ca and glucose; treat is needed– Monitor body temp; if elevated, treat appropriately– If cerebral edema is suspected, treat with _____________(IV)– Phenobarbital—IV or IM

Status Epilepticus

• Client info—– Epilepsy is an __________________ disease

– Even with treatment, animal may still seize; • goal is to reduce frequency and intensity of seizures

– Spaying/neutering will remove any hormonal influence on seizures

– Medications will probably be required for life

– Most animals that seize can live a normal life

– If seizure free for 6-9 mo, may reduced or discontinued Rx

LIFE“Life is the art of drawing without an

eraser.”

-John w. Gardner

Spinal Cord

• Function– Nerve fibers carry signals

between brain - rest of body

• Anatomy– Like brain, protected by

hard covering – _______________

Intervertebral disk (cushion):• between vertebral body

• increases range of motion

• prevents vertebrae rubbing

Spinal Cord: Anatomy

Like brain, spinal cord enclosed in hard coveringIVDD problem in both humans and canineAnatomical differences—cervical same; lumbar—human bears weight, canine doesn’tAttached rib (thorax) helps stabilize the IV joint; worse at T-L junction (dogs)

Degenerative Disc Disease: Humans

Degeneration of disk occurs with ageDries out, shrinks (we get shorter as we age)

IV Disk Disease: AnatomyNormal spinal column and disk Prolapsed disk

nucleus fibrosus

1/3 thickness

Intervertebral Disk Disease

• Etiology– IVD dries out with age →_____________, less

compliant

– ↑Pressure from jumping

– Occurs most commonly in_____________, caudal thoracic, and lumbar vertebrae

– Most __________________ spinal cord disorder in companion animals

Intervertebral Disk Disease

• Hansen TYPE I: ________________ herniates upward; narrowest part of annulus fibrosus– TYPE I: Most common in chondrodystrophic

(“faulty development of cartilage”) breeds• ______________________ , shih tzus, Lhasa apsos,

beagles, basset hounds (poodles also affected)

• Acute onset

• Can occur at any age, but generally younger dogs

Intervertebral Disk disease

• Hansen TYPE 2: dorsal protrusion of the annulus into the _____________________– Common in older dogs and nonchondrodystrophic

breeds• Occurs over a longer period of time

• Clinical signs may be less severe

• Generally ________________ dogs

Intervertebral Disk Disease• Signs:

– Pain

– Paresis/paralysis; nerve function is lost in this order:• _____________________—largest fibers; most susceptible to

pressure; signs are ataxia

• ____________ fibers—next smallest fibers; signs are weakness/paresis

• Cutaneous sensory fibers—small; require a lot of pressure to disrupt function; decreased panniculus reflex

• _______________ fibers—smallest fibers; require the most pressure to disrupt; loss is associated with poor prognosis

• Severity of clinical signs depends on:• Speed at which disk material is deposited

• Degree of compression

• Duration of compression

IVDD – Paralysis of rear legs

Cervical IVDD

Loss of Deep Pain

IVDD Dx: Spine X-Rays

Normal horse’s head consistent IV space

Subluxation L2-3(old lesion)

IV Disk Disease: Myelogram: Definitive diagnosis

Which disk space?

IV Disk Disease: MyelogramIV Disk Disease: Myelogram

Which disk space?

Cervical IVDD

Myelogram: Disk herniation at C2-3 (narrowed IV space, narrowed spinal canal)

IVDD• Rx TYPE I, acute onset

• Medical Rx is recommended for animals, with deep pain intact, with or w/o neuro deficit– High levels of corticosteroids is CONTROVERSIAL

• Strict _________________—2 wk minimum (easy when dog hurts; not so easy after steroids/other pain medications take effect)

• Nursing care– Soft padded cage– Urinary cath or express bladder several times/day

• Surgery is recommended for– repeat offenders– No voluntary motor function– loss of deep pain (needs to be done QUICKLY!)– worsening neuro signs (_____________________)

Laminectomy

IVDD: Possible sequela

IVDD

IVDD - rehabilitation

http://www.youtube.com/watch?v=7AkNVDc4lig&feature=related

IVDD – Alternative/Optional Treatment

• __________________ (muscle relaxant)15-20 mg/kg q 8hr

• High-dose Methylprednisolone sodium succinate (CONTROVERSIAL!) and should be given within 8 hours– Although there is proven benefit in humans, results have not

been proven in dogs• Low dose prednisone – various regimens• NSAIDS

– Carprofen, deracoxib, etodolac• Gastroprotectants• Acupuncture

Veterinary Acupuncture

• http://www.youtube.com/watch?v=Z-JjZPnk_Mw&feature=related

• http://www.youtube.com/watch?v=vJIJDUQyOmw&feature=fvw

IVDD

• Client info• Do not let susceptible breeds get _________________

• Encourage animals to keep spine parallel to ground– No jumping on/off couch

– No begging on hind legs

– No stair climbing

• Loss of deep pain >24 h has ________________ prognosis

• If surgery is done soon enough, there is a good Px of recovery

• Almost half of animals treated medically will have recurrence

• Extensive home care is required for medical and surgical patients

• Severe damage to spinal cord is not reparable

Atlantoaxial Joint

Atlanto-Axial Joint

Atlantoaxial Instability (Subluxation)

• Signs– ________________ and miniature breeds (<1 yr)

– Reluctance to be patted on head

– Neck pain

– May have ____________________ (weakness in all 4 limbs) or tetraplegia (paralysis in all 4 legs)

– Sudden death due to respiratory paralysis

• Diagnosis—– Radiographs: lateral x-ray of neck in slight ventroflexion

• avoid further spinal cord damage with positioning

Atlantoaxial Instability (Subluxation)

CT scan:dens is marked by *

Normal toy breed dog Toy breed dog with atlantoaxial subluxation

X-rays of same dogs; note separation of C1 and C2 when dog’s neck is flexed in B

Narrowed spinal canal

Atlantoaxial Instability (Subluxation)

• Treatment—– Medical

• splint neck in extension with cage _________________ x 6 weeks

• treat like other spinal cord trauma– Surgical (if unresponsive to medical Rx)

• stabilize/decompress• attach dorsal process of axis to arch of atlas• fuse atlas and axis joint with pins and bone graft• ________________________ to relieve spinal cord compression

• Client info—– prognosis is fair to good for animals with mild signs– animals should not be used for breeding; may be

hereditary

Atlantoaxial Instability: Surgical Correction

Stabilization using screws and bone cement

Stabilization using trans-articularscrews

References

• Alleice Summers, Common Diseases of Companion Animals

• http://cvm.ncsu.edu/vhc/tc/clinical_services/neuro/brain_tumor.html