Lesion Axonal Difusa, Contusion y Lesion Del Tallo Encefalico
The NeurologicExam And Lesion LocalizationThe NeurologicExam And Lesion Localization. What is the...
Transcript of The NeurologicExam And Lesion LocalizationThe NeurologicExam And Lesion Localization. What is the...
ErinAkin,DVM,DACVIM(Neurology) BushVeterinaryNeurologyService
WoodstockGAJuly 16,2017
TheNeurologic ExamAnd
LesionLocalization
Whatisthegoaloftheneuroexam?
• Neuroanatomicallylocalizethelesion• Rememberthatitisthelocationofthediseasewithinthenervoussystem(notthedisease)thatdeterminestheclinicalsigns
Brain• Cerebrum(Hemispheres)• Diencephalon(Thalamus)• Mesencephalon(Midbrain)
§ CN– IIIandIV• Metencephalon(Pons)
§ CN– V• Myelencephalon(Medulla)
§ CN– VI-XII• Cerebellum
SpinalCordAnatomy
• SpinalSegments(NotVertebrae)§ C1-C5§ C6-T2§ T3-L3§ L4-S2(3)
• L4-L6(FemoralN.)• L6-S2(3)(SciaticN.)
NeurologicExamination• History/Signalment• MentalStatus• GaitandPosture• PosturalReactions• CranialNerves• SpinalReflexes• SpinalPain• Nociception• Syndrome/Localization• DifferentialDiagnoses
History/Signalment
• Establishtimeline• Reviewpertinentmedicalhistory
• Definechiefcomplaint
Observation
• Lookatthepatient§ LevelofConsciousness
• Alert• Depressed/Obtunded– drowsybutarousablewithmildstimulus
• Stuporous– patientina“sleepstate,”butarousablewithnoxiousstimulus
• Comatose– patientunconscious
GaitAnalysis
• Lameness• Ataxia
§ Spinal/proprioceptiveataxia§ Cerebellarataxia§ Vestibularataxia
• Paresis--weakness• Paralysis/plegia
Posture
• Positionofheadandbodywithrespecttogravity
• Examples:§ Wide-basestance§ Decerebraterigidity§ Decerebellaterigidity§ Opisthotonus§ Schiff-Sherrington
PosturalReactions
• Proprioceptivepositioning(knuckling)• Orthodiseasevs.neurodisease
• Hopping• Hemistandingandhemiwalking
• Wheelbarrow• Extensorposturalthrust
PosturalReactions
Hopping Hemiwalking/Hemistanding
PosturalReactions
Wheelbarrow
ExtensorPosturalThrust
CranialNerves
I. Olfactory*II. OpticIII. OculomotorIV. TrochlearV. TrigeminalVI. AbducentVII. FacialVIII.Vestibulocochlear
IX. GlossopharyngealX. VagusXI. AccessoryXII. Hypoglossal
CranialNerveII:Optic
• MenaceResponse• IItosee,VIItoblink
§ Maybeabsentinpuppiesandkittensyoungerthan12weeks
§ Ipsilateralcerebellarlesion
• Following(cottonball)• ObstacleCourse
CranialNervesIII,IV,andVI:Oculomotor,Trochlear,andAbducent
• Controleyemovements• Lookforstrabismus• Observeeyemovementsaspatientlooksaround
• MoveheadupanddownANDleftandrighttoinducenormalnystagmus
OcularMuscleAnatomy
Neuroanatomy and Clinical Neurology, pg. 142
CranialNerveIII:Oculomotor(PLR)
CranialNerveV:Trigeminal
• Motor§ Symmetryofmasseterandtemporalis
• Sensory§ Ophthalmic—medialcanthus
§ Maxillary—lateralcanthus
§ Mandibular—lowerlip
CranialNerveVII:Facial
• Observeforsymmetry(eyelids,ears,lips)
• Palpebralreflex• Muzzle/lipMovement
• EvaluatetearingwithSchirmerteartest
CranialNerveVIII:Vestibulocochlear
• Auditory§ BAER§ Makeanunexpectednoise
• VestibularSystem§ Centralvs.peripheral§ Headtilt,abnormalnystagmus,ataxia,broad-basedstance,falling,rolling
§ Elicitpositionalnystagmusorstrabismus
CranialNerveVIII:Vestibulocochlear
CranialNervesIXandX:GlossopharyngealandVagus• Consideredtogether• Askclientaboutdysphagia,regurgitation,voicechange,etc.
• Testwithgagreflex
CranialNerveXI:SpinalAccessory
• Deficitsmayresultinatrophyofthetrapeziusmuscle
CranialNerveXII:Hypoglossal
• Lookforasymmetry,atrophy,movementoftongue
• Innervationtostriatedmusclesofthetongue
Horner’sSyndrome• Miosis• Enophthalmos• Ptosis• Prolapsed3rd eyelid
Horner’sSyndrome• Midbrain• LateralTectotegmentalSpinalTract
• ExitsT1-T3• RamiCommunicans• VagosympatheticTrunk• CranialCervicalGanglion
• OphthalmicbranchofCNV
AnyQuestionsAboutCranialNerves?
SpinalReflexesReflex Nerve Spinal SegmentBiceps Musculocutaneous C6-T1
Triceps/Extensor CarpiRadialis
Radial C7-T2
Flexorwithdrawal(forelimb)
Ulnar,median,musculocutaneous
C6-T2
CranialTibial Peroneal (sciatic) L6-L7
Patellar Femoral L4-L6
Gastrocnemius Sciatic L7-S1
Flexorwithdrawal (pelviclimb)
Sciatic L6-S1
Perineal Pudendal S1-S3
Cutaneous Trunci Lateralthoracic C8-T1
ReflexArc
Veterinary Neuroanatomy, pg. 75
http://vetgrad.com/show10MinuteTopUp.php?type=&Entity=10MinuteTopUps&ID=21
ForelimbReflexes
Biceps Triceps ECR Withdrawal
HindlimbReflexes
CranialTibial Patellar Gastrocnemius Withdrawal
CutaneousTrunci• Afferent
§ Spinal
• Efferent§ LateralThoracic
OtherSpinalReflexes
PerinealS1-S3 Babinski
SpinalPain/Palpation• Palpateentirespine• Cervicalrangeofmotion
§ Dorsal,ventral,leftandrightlateral
• Rectalexam• Canperforminlateralrecumbency
§ Avoidsloadingjoints
NociceptionPROPRIOCEPTION
PARESIS
PARALYSIS
LOSSOFSENSATION
Nociception
• Superficialpain(skin)• Deeppain(bone)
MovingontoLesionLocalization
Remember,LocalizationistheGoal!
• Forebrain(includingdiencephalon)
• Brainstem(midbrain,pons,medulla)
• Cerebellum• Cervicalspinalcord• CTspinalcord• TLspinalcord• LSspinalcord• Neuromuscular
• Don’tforgetaboutmultifocaldisease
NeuroanatomicLocalization• Neurologicsignsarecaudaltolesion• TolocalizethelesionweinterrogatetheCNS
§ Cranialnerves§ Cervicalintumescence
• Tricepsreflex– RadialN.• Bicepsreflex– MusculocutaneousN.• Withdrawalreflex
§ Lumbarintumescence• Patellarreflex– FemoralN.• Cranialtibialreflex– CommonperonealN.• Withdrawalreflex
§ Cutaneoustrunci• DorsalspinalandLateralthoracic(C8-T1)
• Intercapitalligament§ LowincidenceofdiscextrusionsbetweenT2-T11
Forebrain(Hemisphere,Thalamus)Localization• ClinicalSigns
§ Contralateralposturaldeficits§ Contralateraldecreaseinnasalsensation§ Dullness,stupor,coma§ Lossoflearnedbehaviors§ Cognitive
• Thought,Thinking§ Pacing§ Staringoff§ Seizures§ Circling
ObtundedStray
BrainstemLocalization• Mesencephalon(Midbrain),Metencephalon(Pons),Myelencephalon(Medulla),Cerebellum
• Clinicalsigns§ IpsilateralDeficits§ AlteredlevelofConsciousness(ARAS)§ CNNIII-XII§ Ataxia,dysmetria§ Gaitabnormalities§ Vestibular
Handbook of Veterinary Neurology, 5th Ed., pg. 20
BrainstemMUE
VestibularLocalizationPeripheral Central
Headtilt Yes(ipsilateral) Yes(ipsilateral, maybecontralateralwithparadoxicaldisease)
Ataxia Yes Yes
Nystagmus--Horizontal--Rotary--Vertical--Positional
YesYesNo (?)Rarely
YesYesYesYes
PosturalReactionDeficits No Yes(ipsilateral)
Circling Yes(ipsilateral) Yes(eitherdirection)
FacialParalysis Yes(ipsilateral) Nottypically
Horner’sSyndrome Yes(ipsilateral) Nottypically
VestibularDisease
• Fastphaseofnystagmusrunsawayfromthelesion(usually)
• Bilateral—wideheadexcursions• Paradoxical
§ SideofCPdeficits§ Headtiltopposite
VestibularDisease
CerebellarLocalization
• Intentiontremor• Dysmetria(Hypermetria)• Ipsilateralmenacedeficit• NoCPdeficits• Decerebellatepostureifsevere
C1-C5Localization• Cranialnerves
§ +/- IpsilateralHorner’s• Posture
§ Scoliosis§ Torticollis
• Gait§ Tetra/Hemiparesis§ Tetra/Hemiplegia
• Posturalreactions§ Posturaldeficits(normaltodecreased
toabsentx4)• Reflexes
§ Normaltohyper-reflexivex4limbs§ Normaltoincreasedmuscletonex4
limbs• Bladder
§ +/- Normalorlargeandfirm• RespiratoryFailure
§ PhrenicN(C5-C7)
C1-C5Localization
C6-T2(CervicalIntumescence)Localization• Cranialnerves
§ +/- IpsilateralHorner’s• Thoraciclimb
§ Brachialplexusavulsion§ Monoparesis/plegia
• Posture§ Torticollis,nerverootsignature
• Gait§ Tera/Hemiparesis§ Tetra/Hemiplegia
• Posturalreactions§ Posturaldeficits(normaltodecreased
toabsentx4)• Reflexes
§ Normaltohyper-reflexivehindlimbs§ Decreasedtoabsentreflexesforelimbs§ Reducedtoabsentcutaneoustrunci
• Bladder§ +/- NormalorLargeandfirm
C6-T2(CervicalIntumescence)Localization
T3-L3Localization• Thoraciclimbs
§ Normal• Gait(Pelviclimbs)
§ Spastic§ Mono/Paraparesis§ Mono/Paraplegia
• Posturalreactions§ Posturaldeficits(oneorboth
limbs)• Reflexes
§ Normaltohyper-reflexive§ Reducedtoabsentcutaneous
trunci• Bladder
§ +/- NormalorLargeandfirm§ Overflowincontinence§ Increasedurethralsphinctertone
T3-L3Localization
Schiff-Sherrington• Clinicalsigns
§ Severeextensorrigidityofthoraciclimbswithflaccidparalysisofpelviclimbs• Normalmovementofthoraciclimbs• Disinhibitionofextensormotorneurons• InjurytoBorderCells
– GraymatterfromspinalsegmentsL1-L5– SynapseonthoraciclimbextensorLMNsinthecervicalintumescence
• Possibleareflexiainpelviclimbs• Takeaway
§ Schiff-Sherringtonindicatesaseverelesion§ ItisNOTaprognosticindicator!
Neuroanatomy and Clinical Neurology pg. 249
Myelomalacia
L4-S3Localization• Thoraciclimbs
§ Normal• Gait(Pelviclimbs)
§ Shortstrided§ Mono/Paraparesis§ Mono/Paraplegia§ Plantigrade
• Posturalreactions§ Posturaldeficits(oneorbothlimbs)
• Reflexes§ Decreasedtoabsentreflexes
• Tail§ Normal,Paresis,Plegia§ Lossofperinealreflexandsensation
• Bladder§ Flaccidbladder§ Lossofurethralsphinctertone§ Incontinence§ Internalurethralsphincterintact
AnatomyoftheBladder• Hypogastric
§ SympatheticL1-L4• α-adrenergictotheurethra(increasetone)• β-adrenergictothebladder(relaxdetrusor)
• Pelvic§ ParasympatheticS1-S3
• Contractionofdetrusor§ Afferenttosympathetic
• Pudendal§ S1-S3§ Somatic
BSAVA Neurologia, pg. 312
Neuroanatomy and Clinical Neurology, pg. 184
TreatmentsforMicturitionDisorders• Stimulatedetrusorcontraction
§ Bethanechol• Viacholinergic• 1.25-25mgperdayTID
• Decreaseurethraltone§ Diazepam
• Skeletalmusclerelaxant• 2-10mgTID
§ Phenoxybenzamine• α-adrenergicantagonist• 0.25-0.5mg/kgSID-BID
§ Prazosin• α1-adrenergicantagonist• 1mg/15kgSID-BID
NeuromuscularLocalization• Shortchoppygaitx4limbs,
fatiguesandthencollapse• Weak(crouched,trembling)• Normalproprioceptionx4limbs• Notataxic• Non-painfulonspinalpalpation• Diminishedtoabsentreflexes• Denervationatrophy• Perceivespain,unableto
withdraw• Fatiguingpalpebral• Regurgitation
NeuromuscularLocalization
DifferentialDiagnoses• D—degenerative• A—anomalous
(congenital)• M—metabolic• N—neoplastic,
nutritional• I—infectious,
inflammatory,idiopathic
• T—trauma,toxin• V—vascular
World’sSmallestTakeHomePoints• Takingathoroughhistoryisalwaysimportant,butitiscriticalwhendealingwitha
neurologicpatient.• Knowwhatisnormal!• Thethreegoalsoftheneurologicexaminationareto1)determineifthepatient
hasaneurologicproblem,2)localizethelesion,and3)generateashortlistofdifferentialdiagnoses.
• Usefultoolsfortheneuroexaminclude:aquietroom,anexperiencedassistant,non-slipsurface(i.e.yogamatorother),reflexhammer,hemostats,cottonballs,penlight,lens,etc.
• Thereareeightbasicareastowhichalesionmaybelocalized:forebrain(includingdiencephalon),brainstem(midbrain,pons,medulla),cerebellum,cervicalspinalcord,cervicothoracicspinalcord,thoracolumbarspinalcord,lumbosacralspinalcord,andneuromuscular.Rememberthatitisthelocationofthediseasewithinthenervoussystem(notthedisease)thatdeterminestheclinicalsigns.
• PleasecallDr.AkinorDr.Nearyaboutanyquestionsorcasesyoumayhave.Weareeagertohelp!
References• Chrisman,C.,C.Mariani,S.Platt,andR.Clemmons.2003.Neurologicalexaminationtechniquesand
lesionlocalization.InNeurologyforthesmallanimalpractitioner,15–40.Jackson:TentonNewsMedia.
• deLahuntaA,GlassE.VeterinaryNeurologyandClinicalNeurology.Elsevier:Philadelphia,3rd ed.pgs248-250,2009.
• Glass,E.N.,andM.Kent.2002.Theclinicalexaminationofneuromusculardisease.VeterinaryClinicsofNorthAmerica:SmallAnimalPractice32(1):1–29.
• LorenzeMD,KornegayJN.Handbookofveterinaryneurology.Elsevier:Philadelphia,5th ed,pgs49-89,2009.
• Oliver,J.E.,M.D.Lorenz,andJ.N.Kornegay.1997.Neurologichistoryandexamination.InHandbookofveterinaryneurology,3rded.,3–46.Philadelphia:W.B.Saunders.
• Platt,S.R.,andN.J.Olby,eds.2004.BSAVAmanualofcanineandfelineneurology,3rded.Gloucester,UK:BSAVA,1–23.
• SharpNJH,WheelerSJ.Smallanimalspinaldisorders:Diagnosisandsurgery.Elsevier:Philadelphia,2nd ed,pgs11-17.2004.
• http://www.vetmed.wsu.edu/cliented/anatomy/nervous.aspx• http://www.aisti.info/en/neurology/neurological_examination.html• http://www.neuroanatomy.wisc.edu/SClinic/Weakness/Weakness.htm• http://www.vetmed.wsu.edu/cliented/anatomy/nervous.aspx
Anyquestions?