Dr. Darin Madson - CNS Disease diagnostics

• 1. CNS Disease in the Nursery 2013 Allen D. Leman Swine ConferenceCNS Disease Diagnostics Darin Madson [email protected] Diagnostic Laboratory Iowa State University

2. Points of Understanding Central nervous system (CNS) disease Can have many different presentations Disease is not always Strep Clinical observation first step Potential location of insult Sample submission DifferentialsVeterinary Diagnostic Laboratory Iowa State University 3. CNS Clinical Disease Cerebrum Behavior Voluntary movement Consciousness CerebellumMultiple locations can be affected at the same time Coordinated movement Balance and posture Spinal Cord Similar to cerebellum Muscle rigidity or flaccidity Veterinary Diagnostic Laboratory Iowa State University 4. TermDefinition / CommentLikely originHyperaesthesiaIncreased response to stimuliBrain cerebrumSpastic, spasticity PaddlingIncreased muscle tone, usually episodic Walking motion while in lateral recumbency Lack of coordinated intentional movementBrain - cerebrum; spinal cordIncoordinationBrain - cerebrum, brain stem Brain - cerebrum, cerebellum; spinal cord; or muscleAtaxia, abnormal Failure of muscular coordination; gait incoordinated ambulationBrain - Cerebellum, brain stem; spinal cordTremorsInvoluntary rhythmic muscle contraction; shaking; quakingBrain - Cerebrum, spinal cord, peripheral nerves, muscle, cold, pain, fearFlaccid or flaccidity ParalysisDecreased muscle toneSpinal cordComplete loss of sensation and motor function; plegiaSpinal cordParesisPartial loss of sensation or function; Spinal cord weakness No sphincter response; unable to pass Spinal cord feces or urineAnal tone Proprioceptive deficitsImproper positioning of feet and legs, knucklingPeripheral nerves; spinal cord Veterinary Diagnostic Laboratory Iowa State University 5. Disease or AgentPaddling Sudden Fever DeathTremors / SeizuresIncoordinate or weaknessEdema disease (hemolytic E. coli)YesYesNoNoYes + edemaBacterial septicemia or meningitisYesYesYesNoNoVirus (PRV, rabies, Teschovirus, HEV, etc.)NoNoYesYesYesAcute hypocalcemiaNoYesNoYesYesWater deprivation / Na+YesNoNoYesYes: dog-sitElectrical shockNoYesNoNoYes: paralysisVariesVariesNoVariesVariesVariety of toxicitiesVeterinary Diagnostic Laboratory Iowa State University 6. Bacterial Meningitis Most common cause of CNS disease Strep suis or H. parasuis 1 differentials Any bacteria bacteremia or septicemia = meningitis A. suis, Salmonella choleraesuis, A. pyo Clinical Signs: Elevated Temperature Stiff gait Tremors Incoordination Paddling Convulsions Nystagmus May be accompanied by arthritisVeterinary Diagnostic Laboratory Iowa State University 7. Bacterial Meningitis Gross lesions: White colored (milky) exudate in the meningesMicroscopic Lesions: Suppurative meningeal exudate. Veterinary Diagnostic Laboratory Iowa State University 8. Brainstem/Spinal cordOccipital condylesPartially skinned head ready for brain removalPicture courtesy of Dr. Pat HalburVeterinary Diagnostic Laboratory Iowa State University 9. Picture courtesy of Dr. Pat HalburVeterinary Diagnostic Laboratory Iowa State University 10. Use a swab to tease out the brain to expose the meninges for culturePicture courtesy of Dr. Pat HalburNotes: Swabs are great, but need histopathology for confirmation! Bag fresh brain separately!!!!Veterinary Diagnostic Laboratory Iowa State University 11. Viral CNS Disease In USFAD Porcine Enterovirus CSF CNS signs rare ASF CNS signs rare LPMV/BEP paramyxovirus blue eye Teschen, Talfan, others PRRSV Rabies Eastern Equine Encephalitis Hemagglutinating encephalomyelitis Vomiting & Wasting Disease Encephalomyocarditis virus Pseudorabies/Aujeskys disease clinical syndromes resemble PRV Japanese Encephalitis Nipah (Porcine Respiratory & Encephalitis Syndrome = PRES)Veterinary Diagnostic Laboratory Iowa State University 12. Viral CNS Disease Clinical Signs: Fever Depression Ataxia Nystagmus Convulsions Opisthotonus Coma Gross Lesions: Typically none Enteroviruses impacts the spinal cord to a greater degree than brain Veterinary Diagnostic Laboratory Iowa State University 13. Porcine enterovirusEnterovirusSapelovirusTeschovirusVeterinary Diagnostic Laboratory Iowa State University 14. Veterinary Diagnostic Laboratory Iowa State University 15. Spinal cordVeterinary Diagnostic Laboratory Iowa State University 16. 1. Remove all the viscera 2. Barnes Dehorner works well to remove the vertebral column Spinal cordVeterinary Diagnostic LaboratoryPicture courtesy of Dr. Pat HalburIowa State University 17. The entire spinal cord can be exposed within a few minutes time with a sharp Barnes DehornerVeterinary Diagnostic LaboratoryPicture courtesy of Dr. Pat HalburIowa State University 18. Use a forceps and scissors to clip peripheral nerves and remove the spinal cord from the vertebral column Picture courtesy of Dr. Pat HalburVeterinary Diagnostic Laboratory Iowa State University 19. Edema Disease - Pathogenesis E. coli (usually hemolytic) attachment (K88, F18) proliferates shiga-like toxin (Stx2e) systemic capillary permeability Edema Disease Clinical Signs: Sudden death Staggering gait Tremors Incoordination Paddling Eyelid edemaE. coli may cause: 1. Diarrhea 2. Edema Disease 3. Edema Disease with Diarrhea Veterinary Diagnostic Laboratory Iowa State University 20. Gastric Wall EdemaEdema Disease Gross Lesions: Eyelid EdemaMesocolonic EdemaVeterinary Diagnostic Laboratory Iowa State University 21. Edema Disease Diagnostics Microscopic lesions: Brain: Cerebrovascular lesions Intestine: E. coli colonization Culture Results: High to heavy growth of hemolytic E. coli from intestine At the time of submission will not always recover Genotyping: Attachment (F18 or K88) Positive for the StX2e gene Veterinary Diagnostic Laboratory Iowa State University 22. Salt Toxicosis/Water Deprivation May be isolated to particular pens. Biggest pigs are often affected Bully their way in for the longest drink when water is restored! Clinical signs: Blind Seizures Opisthotonus PaddlingVeterinary Diagnostic Laboratory Iowa State University 23. Salt Toxicosis/Water Deprivation May observe Cerebellar Herniation through foramen magnumVeterinary Diagnostic Laboratory Iowa State University 24. Salt toxicosis/Water deprivation Diagnostics Histopathology: Brain: perivascular cuffs dominated by eosinophils Cerebrocortical neuronal necrosis Laboratory Tests: Elevated brain sodium levels.Veterinary Diagnostic Laboratory Iowa State University 25. Selenium Toxicosis Typically occurs following feed mixing errors Clinical signs: Typically have multiple animals affected Diffuse alopecia Coronary band necrosis Hind limb paresis/paralysis (or paralysis of all 4 limbs) Mentally alert continue to eat and drink Histopathology:Widening of spinal cord Brachial intumescence C6 to T1 Lumbar intumescence L4-S2 Spinal Cord poliomyelomalacia Ventral horns of the cervical and lumbar intumescences. Veterinary Diagnostic Laboratory Iowa State University 26. Poliomyelomalacia Selenium Toxicosis Veterinary Diagnostic Laboratory Iowa State University 27. Not So Common CNS DifferentialsVeterinary Diagnostic Laboratory Iowa State University 28. Pyogranulomatous inflammationSpinal cord Veterinary Diagnostic Spinal cord compression = Likely vaccine inducedLaboratory Iowa State University 29. Porcine CNS Disease Meningeal swab Prior to brain removal Brain fresh and fixed Spinal cord Several pieces Fresh and fixed Ileum Fresh and fixed Serum Other tissues Liver, lung, tonsil, etc Veterinary Diagnostic LaboratoryDont forget to save feed if possibleIowa State University 30. Take Home Points 1. Neurologic assessment Try to localize the issue2. Differentials are vast Meningitis is most common Dont forget viral, nutritional, or toxin mediated3. Sample submission Arriving to the correct etiology is based upon testing the appropriate tissue or sample and combing these with the clinical findings. Veterinary Diagnostic Laboratory Iowa State University 31. Questions?? LocationCerebrumClinical signs Altered mention, decreased awareness Loss of consciousness Loss of voluntary movement (nystagmus) Seizures TremorsCerebellumAtaxia Proprioceptive deficits IncoordinationSpinal CordAtaxia Proprioceptive deficits, knuckling Incoordination Rigidity Flaccidity Veterinary Diagnostic Laboratory Iowa State University