Neurology OSCE Flashcards
GBS
- Acute inflammatory demyelinating polyneuropathy- Progressive symmetrical ascending weakness with sensory and autonomic instability- Inx - vasculitic screen, Abs, CXR, MRI, LP for normal WCC and oligoclonal bands, Nerve conduction studies- search for prodromal infection - bld, stool MC&S- Mx - steroids, IVIG, PLEX
Plasmapheresis and PLEX
Extracorporeal removal of plasma by membrane filtration or centrifugation.PLEX - replacement with albumin or FFP30-40mls/kg removed per exchangeUsed in:- GBS- Myasthenia- TTP- Myeloma- ANCA/Anti-GBM- Severe SLEComplications- Related to vascular access - Infection, haemorrhage, local structures, air embolus- Related to replacement fluid - Tx reactions, hypothermia, coagulopathy, low Ca
CT Heads
DAI - loss of grey-white, loss of sulci, small haemorrhagesAcute subdural - comment on midline shift, ventricle effacementMCA infarct - MCA syndrome - numerous RCTs show improved mortality but significant morbidity
Stroke - thrombectomy
NHS England - 20% improved chance of being functionally independent at 90 days.Generally treatment best within 6 hrs of onset but with evidence of salvageable brain tissue on imaging this can be done up to 12 hrs or 24hrs in extreme.Criteria:1 - Timings as above 2 - Either inadequate response to thrombolysis or thrombolysis contraindicated 3 - Proximal occlusion4 - NIHSS > 55 - Prev idependent (Mod Rankin score < 3)
NIHSS
Areas scored: consciousness, vision, sensation, movement, speech and languageScored 0-420 - no stroke5-15 - moderate stroke16-20 - mod/severe stroke21-42 - severe stroke
Myasthenia Gravis
Fatiguable weaknessDiff Dx: stroke, ICH, GBS, MND, malignancyPrecipitatants: Surgery, infection, stress events, Meds - macrolides, anminoglyc., BBB, CBB, ketamine
Myasthenia Gravis
Fatiguable weaknessDiff Dx: stroke, ICH, GBS, MND, malignancyPrecipitatants: Surgery, infection, stress events, Meds - macrolides, anminoglyc., BBB, CBB, ketamine
ICP monitoring
Normal ICP 5-15mmHg20mmHg - escalate treatmentCauses: 1 - Brain volume - Tumour, oedema2 - CSF - hydrocephalus3 - Blood vol - drug induced vasodilation, venous hypertensionIndications ICP monitoring in trauma:1 - any abnormal CT scan with GCS < 82 - GCS < 8 with a normal CT scan if > 40 yrs, SBP < 90, or motor posturing3 - Mod TBI who need to stay anaesthetised 4 - Multiply injury patient Contraindications:All relative - severe coagulopathy, plts < 10, INR >1.3, infection over target areaMethods:1 - EVD - surgically into ventricle (gold standard, can be calibrated, cheap, therapeutic - infection, traumatic)2 - Intraparenchymal catheter (less invasive and easier to place, can’t be calibrated, may only measure local ICP, not always MR safe)3 - ICP bolt - enters subdural space4 - Transcranial Doppler - poor AUROCICP waveform3 pulse waves P1 = arterial pulse, P2 = cerebral compliance, P3 = aortic valve closureICP high then P2 increasesLundberg A waves - steep increases lasting 10 mins - critically high ICP Lubbers B waves - oscillations 1-2 every min - unstable ICP Lundberg C wave - oscillations 4-8 waves/min - healthy Mx: Osmotherapy - expand plasma, increases CO, improves microcirc, reduces plasma viscosity, secondary osmotic effect with fluid moving from intracelluar to intravascular space HHS - 1-2mls/kg 3% or 5%Rpt is Na < 155 and osmol < 320Ventriculitis5 - 20%Reduced with silver impregnated cathetersIntraventricular Abx - sys abx - ceftriaxone/vancomycin RFs: CSF leak, poor infection control, repeated access
Neuroprognostication
DifficultAt 72 hrs, unconscious with M = 1 or 2 and:1 - Bilateral absent pupils and corneal reflexesOr2 - Bilateral absent SSEP N20 ——————————- Poor outcomeWait 24hrs then:
2 out of the following 1 - Status myoclonus at < 48 hrs 2 - High NSE level 3 - Burst suppression or status on EEG 4 - CT/MRI showing diffuse anoxic brain injury ———— Poor outcome
Disorders or consciousness
Coma - absent wakefulness and absent awareness Persistent vegetative state - some wakefulness but no awarenessMinimally conscious state - wakefulness with some minimal signs of awarenessLocked-in - wakefulness and awareness but no movement due to brain stem pathology
SAH
WFNS classification:1 - GCS 15, no motor 2 - GCS 13-14, no motor 3 - GCS 13-14, motor4 - GCS 7-125 - GCS 3-6Fisher - based on CT findings - vol blood - correlates with DCI
Complications:RebleedSeizuresDCI - peaks at 4-10 day - nimodipine, hypertension, avoid hypovolaemia HydrocephalusAdrenergic storm/myocardial dysfunctionSodium issues
Mx:Airway controlVentilation optimisedCVS - BP <160CT, normothermia, normoglycaemiaClipping, coilingISAT trial - coiling vs clipping - death or dependence less in coiling group at 1 year but long term have an increased risk of re-bleed
