Neurological Emergencies Flashcards
What are some neurologic emergencies?
Mentation changes, seizures, traumatic brain injury, tetanus and Botulism and Toxins
What are the types of mentation changes and what part of the brain do they effect?
Obtunded (Decreased response to stimuli and consciousness) - forebrain or brainstem
Stuporous (Dulled) - Brainstem
Comatose (prolonged loss consciousness) - Brainstem
What is the ARAS (Ascending Reticular Activating System) Responsible for?
Wake and dreaming states (effects consciousness)
What are some causes of mentation cahnge?
Toxins, Metabolic, Cardiovascular, neurologic, hydrocephalus, inflammation (abscess, MUE, neoplasia, Trauma, Vascular
What is your clinical approach to mentation change?
Hx: rule out trauma, toxin or metabolic, signalment (hypoglycemia puppy), previous diagnosis
Ex: systemic hypothermia, pulse, pale, neuro
Min Database: CBC, Biochem (hypernatremia)
How do you confirm diagnosis of a stroke?
MRI or CT, CSF analysis
What are the 2 types of stroke?
Ischaemic or Haemorrhagic
What are some underlying causes of stroke?
Cushings (too much cortisol), Hypothyroidism, Hyperthyroidism, PLN, Liver Disease, Idiopathic, Hypertension, Neoplasia, Heart Disease
Toxin, vWD, Haemophilia, Neoplasia, Thrombocytopenia, Liver Disease, HYpertension
What is your triage treatment for Mentation Change?
Correct patient temp, correct metabolic derangements, treat toxin if indicated, Hypo/hypertension treatment, look for signs increased intracranial pressure
Hypothermic warm up
What do you do if you think the animal has gotten into a toxin that is causeing the neurological signs?
Decontaminate, treat if possible (call pet poison helpline), treat symptoms (muscle relaxer, anti-seizure), non-specific - IV fluids, Intravenous lipids, Ion trapping, Hemodialysis
What is the equation for Cerebral Perfusion Pressure?
CPP = MAP-ICP
(Want around 50mmHG)
What is normal ICP? Why so low?
ICP is normally 0-15mmHg
Low because there is not a lot of room between the skull and thehinflammation
What are some things that increase intercranial pressure?
Edema, Inflammation, CSF, Tumor and trauma
How can you decrease CPP?
Increase MAP or decrease CPP needed to perfuse brain
If ICP 200-300mmHg what occurs?
Reflex bradycardia
What is the Cushing’s Reflex?
When you have decreased cerebral blood flow (b/c increased ICP), raised Co2, meduallary vasomotor center, symatheric stimulation, increase MAP that increase CPP and ICP and Carotid baroreceptor that increased vagal stimulation and leads to reflex bradycardia
What are some signs of increased ICP?
Pupil Changes (myotic or mydriatic non-responsive) , Tetraparesis, ataxia, proprioception defects, cranial nerve defects, decerebrate posture
How do we decrease ICP?
Decrease edema (manitol, hypertonic saline, steroids, diuretics), Craniectomy, remove space occupying lesion (tumor, granuloma, depressed skull fracture)
How does the brain try to decrease ICP?
Push out skull
What are some primary neurologic diseases?
Encephalitis, Brain tumor, vascular accident, head trauma
If it is primary neurologic what do you do?
Stabilize or decrease ICP to buy time and send to neurologist
When is surgery the only option?
BP over 300
What is status epilepticus?
Failure of seizures to terminate, meaning last longer than 5 min, or more than 2 without return to normal conciousness
TRUE EMERGENCY
What the cascade that leads to brain damage?
Glutamate release, NMDA receptor - calcium influx, 2nd messencer, ca release and mitocondrial damage or Cosium influx, cytotoxic edema, cell death
