SAM Nero

Localization of the nero system

• Intracranial

  • Forebrain, brainstem, cerebellum

• Spinal cord

  • C1-5, C6-T2, T3-L3, L4-S1

• PNS

  • Somatic nerve, muscle, NMJ, autonomic nerve,

• Enteric nerve

Mentation/behavior

• Brainstem dx:

  • LOA, dull, coma

  • Use ascending reticular activating system (ARAS)

    • level of awareness

• Foerbrain dx:

  • Confusion, disorientation, loss of learned behaviour, compulsive behaviours

Gait

• slowly, strait, turns, fatigue, free, joint flexion or extension

• Plegia: absent gait generation

• Paresis: weakness, min gait generation

  • LMN: maintains tone, short strided

  • UMN: gait generation, slower protraction and longer stride, ataxia

    • Ataxia: without order, long stride and has unpredictable foot placement

• Cerebellar: hypermetric, head tilt/listing/falling, Slow nystagmus (<60 per min), sm circles, rolling

• Cerebrum: Lg circles, contralateral sign, precept issues, side step

  • forebrain dosnt’t influence gait

Posture

• Postural Reactions: test 2x, support, do all limbs

  • Paw position, hopping, bracing

• Muscle tone: symmetry

  • focal loss in 8d from nerve dx

  • Cranial tibial from L7-S1 disk/stenosis

• Decerebrate: head up, legs strait down

• Decerebellate: downward dog posture

• Schiff Sherrington: extended front limbs

  • T3-L3

Reflex testing

• Done standing or lateral

• Pelvic Limb: patellar, cranial tibial, calcaneal or gastrocnemius, and withdrawal

• Thoracic Limb: biceps, extensor carpi, triceps and withdrawal

• Cutaneous trunci

  • key for localization

• Perineal

Withdrawal in reflex testing

• LMN stimuli to withdrawal limb

  • continued emotional rxn post stimuli = deep pain

• Squeeze toes and watch

  • Which joints flex? Is it complete? does the animal kick?

  • Crossed extensor in lateral = UMN

LMN signs

• Weakness, decreased tone, decreased reflexes

  • withdrawal

• Short stride, proprioceptive deficit

• Slow to rise/slow to sit, dribble urine or drop stool

  • L7S

UMN Signs

• Descending Tract Failure

  • Weakness, Increased reflex, long stride, Increased tone

• Ascending Tract Failure

  • Proprioceptive ataxia, Postural deficit

Peripheral neuropathy/myopathy

• LMN signs

  • Short stride, weakness, good proprioception

  • Frequently normal cranial nerves??

• Systemic signs

  • WBC, temperature, malaise

Cranial Nerves

• CN II: menace, tracking, obstacle course, PLR

• CN III: PLR, head movement, Strabismus

• CN IV: head movement, Strabismus

• CN V: facial sensation/tone

• CN VI: head movement, Strabismus

• CN VII: facial sensation/tone

• CN VIII: head movement, Strabismus

• CN IX: gag reflex, resp sounds, tounge

• CN X: gag reflex, resp sounds, tounge

• CN XI: gag reflex, resp sounds, tounge

• CN XII: gag reflex, resp sounds, tounge

Mence response

• CN II

• dev @ 12-16w

• Forebrain dx

  • Contralateral to the lesion

  • opp if its cerebellar (rare)

  • Abnormal PLR and menace = Rostral to the diencephalon

  • Normal PLR but abnormal menace: Caudal to the diencephalon

Horner’s Syndrome

• MOA: Long pathway within the CNS and periphery

  • Brain, cervical, thoracic, and middle ear disease

    • Consider both CNS and systemic diseases

    • can be partial or complete

• CS: Miosis, Ptosis, Nictitans protrusion, Enophthalmos, Sweating (horse)

• DDX: parasympathetic dx

  • 2 cat an 5 dog branches

    • weird pupils (D in cats)

Retention/Storage of urine

• Pontine storage to hypogastric nerve (T10-11) detrusor and trigone

• Pudendal nerve to external urethral and anal sphincter

• Voluntary control regulated by the forebrain

• Cerebellar inhibition of urination

Dysfunction in different parts of the brain

• Forebrain

  • Seizures, near normal gait, compulsive behaviours, inappropriate urination

  • Lg circles to lesion, contralateral sensory deficits

• Brainstem

  • Altered gait, altered LOA, proprioception

• Cerebellum

  • Intention tremor, postural reaction issues,

    hypermetric gait, wide stance, normal strength

• Vestibular

  • Central: gait and proprioceptive issues

  • Peripheral: normal tone, proprioception, nystagmus opp lesion, head tilt, rolling to lesion

Disfunction in different parts of the spine

• C1-5: Long stride and ataxia, proprioceptive deficits, weakness, increased tone and reflexes to all four limbs

• C6-T2: Short stride, decreased reflexes, withdrawal changes and tone in front, long stride with ataxia, increased tone and reflexes in hind, proprioceptive deficits, in all four

• T3-L3: Normal front, long stride with ataxia in hind, proprioceptive deficits, altered tone, and reflexes, cutaneous trunci changes, bladder control.

• L4-S1: Normal front, short stride in hind, flopping of the distal limb, altered withdrawal, decreased reflexes and tone, slow to rise/sit, tail drop, incountenance

Seizure-like Episodes

• Cataplexy, narcolepsy, REM sleep disorder

• Vestibular episodes

• Panic attack

• Episodes of neuromuscular disease or encephalitis

• Myoclonus

• Syncope

• Cervical muscle spasm

• Head bobbing & breed associated muscle disorders

Seizure terms

• Seizure: a sudden attack or convulsion

• Status epilepticus: a persistent seizure >5 min, lowers lifespan

• Cluster seizures: >1 in 24hrs, lowers lifespan

• Non-convulsant seizure: sensorium only, lowers lifespan, common w/ clusters, ECG req

• Refractory seizure: multi tx fail

  • Super-refractory: ER tx fail

Seizure causes

• NT changes: High excitatory NT or Low inhibitory NT

• Young (<1y): infectious, anomalous, metabolic, trauma, toxin

• 1-5y: idiopathic

• >5y: neoplasia, infarct, inflam, metabolic, infection

Refractory seizure cases

• MOA:

  • multi tx fail

  • Aussie, colie, Italian Spinoni

• Tx:

  • Be aggressive >2 anticonvulsants

  • Rescue and emerg plan

  • Set expectations

  • 6m monitoring & CBC

General treatment of seizure cases

• Goal: <1seziure every 3m

• Establish:

  • emerg, monitoring, tracking plan

  • maintenance, post episode tx

• Consider:

  • Who, what, where, when, why?

  • Postictal phase behaviour (recovery)

  • takes 5 ½ lifes to reach steady state w/ meds

Phenobarbital

• Use: anticonvulsant

• MOA: Ca/Na channel, Gaba

• Monitor:

  • Liver, Bone Marrow, Skin, Endocrine toxic

  • BW 2w after changes then 6m

  • high metab of T4 and P450

• Loading: 16-30 mg over 24hrs in 1-6 doses

Keppra

• Use: anticonvulsant

  • DEA not req

• MOA: Ca channel, NT release

• Loading: 60-100mg/kg IV

Potassium Bromide

• Use: anticonvulsant

  • not in cats: pneumonia

• MOA:

  • Membrane stabilization/hyperpolarization

  • 24hrs ½ life

• Monitor: Pancreatitis, Esophagitis

  • 3m after changes then yearly

  • high Cl

• Loading: 400-600mg/kg over 5d

  • 1/2 dose q12 to avoid nausea

Zonisamide

• Use: anticonvulsant

• MOA: Na channel

• Monitor: idiosyncratic/acidosis

Emergency and rescue plan

• Home

  • Repeat maintenance meds 1-3x

  • New med w/ short half life for 1-3d

  • Diazepam/midazolam: IN 80% or rectal 60%

• ER/Clinic

  • Hospitalization after >3 till 24hrs clear

  • Supportive care

  • Load meds or new meds

  • Diagnostics, MRI, EEG

Benzo

• AKA: Diazepam/Midazolam

• Use: active seizures

• MOA: Gaba

  • Action of 15-30min

  • Tolerance 1-2w

Ketamine

• Use: Refractory Status Epilepticus

  • no rxn w/ benzos

• MOA: NMDA

• Steps:

  • see EEG w/ active seizure

  • give w/ Propofol to stop movement

super-refractory epilepsy treatment

• Meds:

  • Ketamine-Dexdomitor

  • Propofol to stop movement

• Other:

  • Induce hypothermia (36.7-37.7)

• Indications:

  • no rxn to benzos

  • continues seizure

Stages of Feline seizures

• Prodromal: behavior/personality change

• Aura: sensory type change/anticipation

• Ictus: seizure phase

• Post-ictal: persistent deficits min-days

  • High ALP/ALT, ataxia, aggression, disoriented, vison loss

Feline seizure causes

• Neoplasia: meningioma #1

  • cats see changes in behaviour

  • dogs have seizures

• FIP: ventriculitis & diffuse inctercranial/spinal signs, high protien fluid

• Ischemic encephalopathy: Parasite migration through the brain, variable forebrain signs, sneezing

• Stroke: renal, endocrinopathies, hypertension, systemic disease

• Idiopathic: bimodal, normal neuro exam, 9-12y cats

Seizures maintenance in cats

• Leviteracitam, Zonisamide, Phenobarbital, Topomax

• NO KBr: pneumonia

Treating disk disease

• NSAIDS: better QOL score & recovery

• Sx: best tx, timeline does not impact has recovery or success

• Acupuncture: faster recovery

• Physical therapy: better recovery

• Glucocorticoids: contradicted

• Methylprednisolone: no benefit, reduces bld flow & PMN’s

• Cage rest: no benefit

Evaluating disk disease prognosis

• Moderate reoccurrence for rx and low for sx

• Higher grade worse rx prognosis, sx indicated

• Thoracolumbar

  • Paraplegia/deep pain negative: poor rx, moderate sx

  • Paraplegia/deep pain positive: moderate rx, good sx

  • Non-ambulatory paraparesis: moderate rx, good sx

  • Ambulatory paraparesis: moderate rx, good sx

  • Paraspinal hyperasthesia: good rx, good sx

• Cervical

  • Grade I-III: moderate rx, good sx

  • Grade IV-V: low sx, moderate sx

Testing for disk disease

• Deep pain negative: eval w/ MRI

• Evalute breed, focality, progressiveness

  • ??????Myomalasia: diaphragm innervation issues, risk w/ acute

    • C6-7 keep u from heaven, C5-4 keeps you from the door (diaphragm)

• DDX: Fibrocartilagenous emboli, Acute non-compressive nucleus pulposus extrusion, cancer, metabolic dx, malformations

Hydrocephalus

• MOA: Active distention of ventricular system obstruction flow

  • breed mesencephalic stenosis, acquired

• CS: High ICP, white matter pressure, cortical atrophy, dome head, altered behavior, seizures, stupid, ataxia, circling, blindness

• ID:

  • Congenital: MRI, CT, US

  • Acquired: MRI, CSF

• Tx: Long term pred & Omeprazole, ventriculoperitoneal shunt sx, ventriculostomy sx

Atlanto-occipital or axial junction malformations

• MOA:

  • AO: overlap, concussive, medulla compression

  • AA luxation: cranial/cervical spine concussion

• CS: paresis, plegia, vestibular signs

• ID: CT, MRI, C2 rads (AA)

• Tx: sx stabalization, braces (1” rolled gauze “dough nuts” in emerg)

  • Avoid ventroflexion

Caudal occipital junction malformations

• MOA: overcrowding of fossa, poor fluid dynamics, herniation, cerebellum/medulla compression

• CS: hyperesthesia, phantom scratching, ataxia, vestibular signs, paresis, vocalization, face rubbing, seizures

• ID: CT, MRI

• Tx: Long term, NSAID, Steroid, gabapentin/lyrica, omeprazole, sx w/ short term success but reoccurs

Vertebral malformation

• MOA: segment failure or trama

  • transition, butterfly, block, wedge, hypoplasia (pugs/frenchies), hemivertebra

  • Scoliosis, lordosis, kyphosis: brachiocephalic breeds

  • young T3-L3 myelopathy or old w/ multi disk injuries

• CS: paraspinal discomfort, paresis, plegia, incontinence, ataxia

  • UMN signs

• ID: MRI, rads

• Tx: NSAID, gabapentin, sx stabilization

  • gliosis/atrophy of spinal cord = guarded the prognosis,

Arachnoid diverticula

• MOA: ?

  • Dilation of the arachnid space in caudal cervical/thoracolumbar spine

  • Brachycephalic, Rotty

• Tx: decompressive/stabilizing sx

Localizing spinal cord/myelopathies based on CS

• C1-2

  • UMN: all limbs and bladder

• C6-T2:

  • UMN: hind limb and bladder

  • LMN: front limb

• T3-L3

  • UMN: hind limb and bladder

• L4-S1:

  • LMN: hind limb and bladder

Steroid responsive meningitis arteritis

• MOA: 6m-2y Beagle, Berner, Boxer

• CS: low head, stiff

• ID: Febrile 103-105, neutrophilia, high IGA, CSF

• Tx: Steroids, cyclosporine

Discospondylitis

• MOA: Infection of the disk/endplate

  • lg dogs

• CS: Pain, empyema/disk extrusion

• ID: difficult, rad, MRI, CRP, culture, urine analysis

• Tx: C&S antibiotics (6-12m), analgesic, euth w/ brucella

Infection/empyema of the spine

• MOA: Grass awn from resp into L4 @ diaphragm

• CS: Cough, pain

• Tx: Sx, long term antibiotics

Tetanus

• MOA: 1-3w post wound or sx

  • Travels retrograde to block interneuron

• CS: rhesus sardonus, extensor rigidity, light/sound hypersensitivity, saw horse stance, lock jaw

• Tx: antibiotics, clean, antitoxin, high mortality

Degenerative Myelopathy

• MOA: Progressive degeneration SOD 1 mutation

  • GSD, Boxer, Corgi (still RARE

• CS: Non painful, Ataxia

• ID: genetic screening (purple top MSU/OFA)

  • neg, carrier, affected

• Tx: fucked, PT, 6-18m till euth

Trigeminal neuritis

• CS: Drop jaw/bilateral

• Tx: assist feed, 6w to fix

Polyradiculoneuritis

• AKA: Coonhound paralysis

• MOA: Rapid porgression

• CS: LMN signs w/ intact sensation, Rapid atrophy 8d, normal cranial nerves

• Tx: 4-6w recovery, can relapse, spontaneous

Laryngeal paralysis

• MOA: Vibration of larynx causes

  • think horses

• CS: Roaring, heat/exercise intolerance

• Tx: Tie-back

Nerve sheath tumor

• MOA: Trigeminal, brachial plexus, pelvic plexus

• CS: focal rapid atrophy, progressive

• ID: palpate, US

• DDX: mononeuropathy

Endocrinopathies

• CS: Classic Cushing’s signs, stiff stilted gait

• Tx: Do not recover motor function

Immune myopathies

• MOA: location dependent, Immune attack on musle/NMJ

  • Masticatory muscle embryo distinct

• CS: swelling, pain, progresses atrophy, fibrosis

  • ocular myositis: eye bulge

  • Junctionopathy: aspiration

• ID: AB titer, biopsy, eosinophils, high CK/CPK/AST

  • Poly myositis is tricky

• Tx: Immune suppress (steroids)

Myasthenia Gravis

• MOA: acquired or congenital, thymoma

• CS: Exercise intolerance, fatiguable palpebral, megaesophagus, regurge, sits

• Tx: Tensilon, pyridostigmine, mass remvoal sx

Dealing with Head trauma

• ID:

  • Breathing patterns, Postures, Diaphragm, forebrain CS

  • Brainstem evaluation: LOA, UMN function, reflexes

    • Score of 1-6 for each, total >8 = 50% survival @ 48hrs

    • Cushing’s reflex: high ICP, low CBF, high CO2

      • life threatening

• Tx: replace fluids, NSAIDS, fentanyl, benzodiazepines, ketamine, dexmetatomidine, propofol, anticonvulsant medications

  • Short acting reversible drugs

High ICP

• MOA: Cushing’s reflex

  • high ICP, low CBF, slow HR, high CO2

  • life threatening brainstem issue

• CS: Slow HR (<60), high BP (>150), brain stem CS

• Tx: incline to 30^o, lower metab (barbiturate/sedation), anticonvulsants (Keppra/phenobarbital), electrolytes (Mannitol/hypertonic saline)

Hyperosmolars

• Mannitol: sugar, osmotic diuretic, decrease CSF production, draws extracellular fluid into vessels, rheologic/improve cerebral blood flow

• Hypertonic saline: Salt, osmotic diuretic, draws extracellular fluid into vessels, improved cerebral blood flow, less diuretic effect

• Can dehydrate a patient if used alone

• Contradictions: not for intracranial hemorrhage

Meningoencephalitis

• MOA: inflam of brain/meninges

  • Sm dogs: pug, korkie, Maltese

• CS: rapid progression (3-7d), status epileptics, blindness

• DDX: peripheral vestibular disease

Caudal Fossa

• MOA: immune CNS dx

  • bacti, fungi, viral, parasites

  • forebrain/brain stem issue

• CS: balance loss, side stepping, peripheral vestibular dx

• ID: MRI, CSF, Myringotomy

Peripheral vestibular dx

• Nystagmus greater than 60bpm

• Head tilt

• Falling/rolling

• Normal proprioception, mentation

• Cranial nerve 7 dysfunction

Myringotomy

• Otoscope/endoscope w/ tom cat catheter

• Puncture TM

• Culture material beyond TM

Otitis

• ID: Culture canal or myringotomy

• Tx:

  • Antibiotic/fungal, topical if tympanum is intact

  • Media/interna will require long tx

  • Sx

Meningitis

• ID: MRI, CSF

• Tx: Immune suppress (steroids, cyclosporine), chemotherapeutics

  • long tx