Neuro emergencies Flashcards
Causes of coma:
DAMN
Drugs - Ethanol, Drug overdose - eg, opiates, benzodiazepines, neuroleptics, Sedatives., Ecstasy, Cocaine, Poisons- eg, carbon monoxide, solvents.
Anoxia - post-arrest, hypoxia, CO poisoning, MI, CVA
Metabolic - Hypoglycaemia or hyperglycaemia., Hyponatraemia or hypernatraemia., Hypercalcaemia.
Hypopituitarism. Hypercapnia. Hypothyroidism. Acid base disturbances. Liver failure. Renal failure.
Neurological - Epilepsy and status, Raised ICP,
Intracerebral bleed. Extradural/subdural bleed,
Hypertensive encephalopathy. Infective: Meningitis.
Encephalitis. Septicaemia. Abscess. Malaria. Toxoplasmosis.
Where is the centre of consciousness?
Reticular formation in the brainstem (midbrain, pons and medulla)
3 abnormal respirations
Cheyne-Stokes - alternate hyperpnoea and hypopnoea/apnoea - cause: heart failure, stroke, sleep apnoea
Kussmaul (deep) - acidosis (e.g. DKA)
Shallow - overdose
Coma:
a) Screening investigations (other than the standard bloods)
b) Management
c) Two reversible drugs that may be given
d) Other possible drugs to give
a) Urine dipstick and pregnancy test (especially if seizures have occurred in a woman of child-bearing age). Urine drug screen. Paracetamol and salicylate levels. ECG. Skull XR, CT head, ?LP.
b) A-E
c) Naloxone and Flumazenil
d) Thiamine, glucose, antibiotics, mannitol
Assessment of the unconscious patient
a) History
b) Examination
a) Circumstance of event from Relatives, Friends, Ambulance, Nursing, GP
Previous events, suicide notes, travel Hx
PMHx: General ( DM,Renal,CNS,Liver), Psychiatry Hx, Head Injury, Alcohol Hx
Drug Hx: Insulin, antiepileptics, Access, recreational
b) A - E, vital signs, breath odour (alcohol, ketones, alert bracelets, glucose, AVPU/GCS, neurology (pupils, reflexes, fundoscopy, signs of raised ICP), evidence of head injury
Vomiting centre in brain
Area postrema in the medulla
Posterior reversible encephalopathy syndrome:
a) Symptoms
b) Cause
c) MRI appearance
d) Management
a) Headache, seizures, confusion
b) Acute hypertension usually (often on background of liver or renal disease), may be eclamptic
c) Bilateral white-matter abnormalities in vascular watershed areas in the posterior regions of both cerebral hemispheres, affecting mostly the occipital and parietal lobes
d) Remove trigger (BP lowering, delivery of baby if eclamptic), treat with antiepileptics, ABC management
Spinal shock:
a) Define
b) 4 phases
c) Different to neurogenic shock - what is this?
a) Spinal shock: complete transverse lesion, loss of all motor & sensory & autonomic/sphincter function below the lesion, areflexia, flaccid (but may have other UMN signs e.g Babinski)
b) Phase 1, (0–1 day) areflexia/hyporeflexia.
Phase 2, (1–3 days), initial reflex return.
Phase 3, (1–4 weeks), initial hyper-reflexia.
Phase 4, (1–12 months), final hyperreflexia
c) Neurogenic shock is a distributive type of shock resulting in low blood pressure, occasionally with a slowed heart rate, that is attributed to the disruption of the autonomic pathways within the spinal cord. It can occur after damage to the central nervous system, such as spinal cord injury (above T6 - autonomic dysreflexia).
The sensation loss is experienced in a shawl-like distribution over the arms, shoulders and upper body, pain and temperature affected first - cause?
Syringomyelia
Brainstem death
a) Reflexes
b) Added test
a) - Pupillary, corneal, gag, cough
- Vestibulo-cochlea reflex
- No pain response
b) Apnoea test should only be performed once the absence of brainstem reflex activity has been confirmed. The aim is to produce an acidaemic respiratory stimulus (pH<7.4) without inducing hypoxia or cardiovascular instability
