Acute Stroke Management LUKE BRADBURY, MD 10/8/14 FALL WAPA CONFERENCE

Transcription

1 Objectives Acute Stroke Management LUKE BRADBURY, MD 10/8/14 FALL WAPA CONFERENCE Recognize the clinical signs of acute stroke Differentiate between stroke and some of the more common stroke mimics Review the NIH Stroke Scale Understand the basics of acute stroke imaging and pertinent findings Discuss tpa Stroke in Clinic, TIA Review emerging endovascular treatments for stroke and some of the recent literature regarding these techniques Case 1 A 66 year old man was admitted to the MICU at an outside hospital for a COPD exacerbation. She improved over the first 12 hours, but at 7:30AM then next morning her nurse noted an exam change: now with left lower face droop, left arm and leg weakness, and dysarthria. What do you want to know? Case 1 Questions Is this an acute stroke? Could this be a stroke mimic? What needs to be done immediately? Signs and Symptoms of Stroke Sudden onset of focal neurological deficits Weakness Numbness Speech/Language difficulties Vision abnormalities (double vision, field cuts) Ataxia/dysmetria Dysphagia/dysarthria/aphasia Symptoms should be localizable to a vascular territory Signs and Symptoms of Stroke Cortical Signs Aphasia Neglect/extinction Homonymous visual field deficits 1

2 Signs and Symptoms of Stroke Lacunar Signs Pure sensory (thalamic strokes, VPL) Pure motor (posterior limb of internal capsule, pons, cerebral peduncles) Lacunar Stroke Not considered embolic, due to small vessel disease Risks: Hypertension, hyperlipidemia, diabetes, smoking, age Back to Case #1 Symptoms consistent with acute stroke, what next? Know the last time normal! Labs Glucose INR Platelets Imaging Noncontrast head CT vs. CTA/P vs. MRI Case #1 Unfortunately her last normal was 10 PM the night before, no tpa was administered (but still had a very good recovery) Case 2 56 yo man s/p colonoscopy 2 hours prior; was in recovery room when he had difficulty with slurred speech, right lower facial droop (mild), and altered mental status Case 2 Stroke? Maybe, some of the symptoms lateralize Go ahead with workup as with case 1 NIH stroke scale obtained at bedside was 5 Head CT ordered CBC sent, INR from that morning was 1.1 Bedside blood glucose was 45 Given an amp of D50, within 5 6 minutes was back to his neurological baseline Stroke Mimics The evaluation for tpa is designed to try and rule out several stroke mimics by labs, exam, or history History of seizure at onset of symptoms Todd s paralysis Postictal confusion Hypoglycemia (and much less commonly hyperglycemia) 2

3 Stroke Mimics History of headache (complicated migraine, hemiplegic migraine) Exam (not necessarily NIH stroke scale) Signs of nonorganic or nonphysiologic neurological dfii deficits may indicate a psychogenic cause (conversion disorder, malingering, Munchausen s, etc.) tpa Safety in Stroke Mimics Study of 5581 patients treated with IV tpa showed 1.8% were stroke mimics Seizure (41%); Psychogenic (28%); Migraine (12%); Demyelination (5%); Encephalitis (3%); Brain tumor (2%); Peripheral vestibulopathy (1%); PRES (1%); Hypoglycemia (1%) Of the 100 patients with stroke mimics, only 1 had a symptomatic intracranial hemorrhage and he recovered completely Zinkstok, SM et al; Stroke. 2013;44: Case 3 A 24 year old man is taking his final exams at the end of his first year of law school when he collapsed in the bathroom between tests. EMS is called immediately and he arrives in the emergency department only 20 minutes after he fell. Case 3 Exam Positive Findings Eyes deviated to the right Does not move his left arm or leg at all Does not respond to pain on the left Left lower face is not moving Will not respond to examiners on the left The NIH Stroke Scale: 11 separate categories with points given for deficits Level of Consciousness, Orientation, Commands Gaze Visual Fields Facial Palsy Motor Arm (L/R) Motor Leg (L/R) The NIH Stroke Scale: 11 separate categories with points given for deficits Limb Ataxia Sensory Language Dysarthria Extinction/Inattention 3

4 NIHSS Total possible score 42 Mild strokes generally 1 4; moderate 5 9; severe >10 Limits Lowscoredoesnotnecessarily necessarily indicate little orno disability Large areas of brain can be missed (right temporal lobe, for example) Case 3 NIHSS Gaze= 2 Visual Fields= 2 Facial Palsy= 2 Motor arm left= 4 Motor leg left= 4 Sensory= 2 Dysarthria= 1 Extinction= 2 Total= 19 More on Case 3 later Case 4 81yo woman presents to the ED via EMS from an OSH after being found down by neighbors. She always opens her curtains by a certain time every morning and when her neighbors saw that they were still closed in the early afternoontheycalled they 911. Herfamily had spoken with her at 9:30PM the night before, it is now 2:30PM. Right sided weakness, aphasia, left gaze deviation Case 4 Discussion tpa candidate? No, outside of time window How does this change the evaluation? Imaging? 4

5 Acute Stroke Imaging Noncontrasted Head CT Standard since the 1996 NINDS tpa study (NINDS tpa study group, N Engl J Med 1995;333:1581 7) More Imaging CT angiogram Can be done quickly with noncon head CT May show vessel obstruction CT Perfusion Blood Volume: how much blood is in that region at a given time (ml/100g) Mean Transit Time: how long it takes contrast (blood) to get in and out of a region of brain (seconds) Blood Flow: how quickly the blood is flowing (ml/100g/sec) CTA CTP 5

6 MRI Some institutions use acute MRI scans for stroke Shown to be just as effective in ruling out hemorrhage (Chalela et al, Lancet Jan 27;369(9558):293 8) MRI Diffusion/ADC DWI ADC Tissue Plasminogen Activator The only FDA approved therapy for acute stroke Binds to fibrin and helps convert plasminogen to plasmin Timing is crucial, the earlier the better 3 hours after last known normal golden hour is the goal for most hospitals now Only 1 7% of patients with ischemic strokes get tpa, most miss the time window Dose: 0.9mg/kg with a maximum of 90mg First 10% is given over 1 minute, the remaining 90% over 1 hour Pooled analysis of ECASS, ATLANTIS, NINDS, EPITHET tpa Absolute Contraindications Intracranial hemorrhage (or suspected subarachnoid hemorrhage even if imaging is negative) Intracranial, spinal, or major surgery within the last 3 months History of previous intracranial hemorrhage Blood pressure >185/110 tpa Absolute Contraindications Cont. Seizure at onset Active internal bleeding Intracranial neoplasm or vascular malformation INR > 1.7 Platelet count < 100,000 Outside of the three hour time window* 6

7 tpa Relative contraindications NIH stroke scale > 22 Early signs of major infarct on CT scan (midline shift, substantial edema, mass effect) Age > 75 Very small stroke scale or with rapidly improving symptoms Blood glucose < 50 or > 400 tpa 4.5 hour time window The European Cooperative Acute Stroke Study 3 (ECASS 3) study looked at given tpa within 4.5 hours and found it to be safe Not yet FDA approved but accepted practice in the US Four additional exclusions: age > 80 years; any anticoagulant use regardless of INR; history of stroke AND diabetes; NIHSS > 25 tpa Clinical judgment Should tpa be delayed while waiting for an INR in a patient who is not taking warfarin? If their blood glucose goes from 40 to 220 with correction and focal neurological ldfiit deficits remain should ldtpa still be considered? What if the patient is at 4:31 minutes after last known normal? Stroke in Clinic 84 year old woman lives at home alone, performs all of her ADLs (sort of) Eldest daughter is her neighbor, checks on her several times most days, helps with shopping, does laundry, cleaning Eldest daughter is on vacation for 10 days and youngest daughter checks in on mom, but also is dealing with her child s graduation On arriving back home, eldest daughter realizes that the patient has been falling and dragging her left leg for eight days Stroke in Clinic They call her primary care doctor, what to do? Call the stroke clinic To the ED Should she be admitted? Order imaging CT vs MRI Vascular imaging Echocardiogram Cardiac monitoring Send labs TIAs in Clinic TIA: Focal neurological deficits lasting less than 24 hours Should be less than 20 minutes for many of us This is a hospital admission as well Carotid stenosis? PFO, valve abnormality? Atrial fibrillation? BP control? Load with antiplatelet agent? 7

8 Clinic After Stroke Varies depending on severity of the stroke Large disability: possibly living in skilled facility with spasticity, endogastric tube feeding, catheter care regimens, seizures, etc Moderate disability: Facility vs home; may need assistive devices for walking/driving, ongoing PT/OT needs, disability paperwork, home modifications Minor/no disability: assistive devices, reassurance, surveillance for stroke prevention (carotid dopplers, echocardiograms, CT/MR angiograms) Everyone: lipids, glucose, blood pressure,?anticoagulants, antiplatelet agent(s), smoking cessation Endovascular Acute Stroke Treatment Several devices on the market, most recent are the Solitaire and Trevo retrievable stents Endovascular IMS III: compared IV tpa vs. IV tpa with endovascular therapy Stopped early due to futility, but (essentially) only the older devices were used Back to Case 3 NIHSS is 19 CTA shows long clot in right ICA extending to his right MCA Treated with tpa and send for endovascular intervention Leaves hospital with NIHSS of 2, finishes law school only one semester later than previously scheduled Summary Recognize the clinical signs of acute stroke Focal neurological deficits localizing to a vascular territory Differentiate between stroke and some of the more common stroke mimics Seizures; migraines; psychogenic; metabolic Review the basics of the NIH Stroke Scale Limitations: does not necessarily indicate amount of brain affected or future disability Understand the basics of acute stroke imaging and pertinent findings Preferred is noncontrasted head CT in most institutions, some may also use CT angiograms and CT perfusion imaging to help guide treatment Summary Review issues in clinic with stroke, before and after Know the important indications and contraindications for tpa and the dosing Review emerging endovascular treatments for stroke and some of the recent literature t regarding these techniques Changing field, new devices are much faster and successful but still not standard of care bradbury@neurology.wisc.edu 8