Snapshot A 60-year-old woman is immediately brought to the emergency department due to slurred speech and right arm and leg weakness. The patient was eating breakfast with her husband prior to developing these symptoms. Her husband denies his wife having any head trauma or recent surgeries. It has been one hour since her symptoms began. Medical history is significant for hypertension and type II diabetes mellitus. On physical exam, the patient can comprehend but speech is impaired. There is 0/5 strength in both right upper and lower extremities. Non-constrast computerized tomography (CT) of the head does not show any intracranial bleeds. After further evaluation, she was started on intravenous tPA. Introduction Clinical definition a sudden loss of blood supply to an area of the brain leading to a neurologic deficit the deficit depends on which area of the brain is affected Epidemiology incidence 3rd leading cause of death in the United States risk factors hypertension diabetes smoking atrial fibrillation mechanical valves valvular abnormalities patent foramen ovale significant decreased ejection fraction hypercoagulable state family history prior history of stroke vascular disease Pathogenesis ↓ blood supply to a region of the brain for enough time to result in infarcted (liquefactive necrosis) cerebral tissue the most vulnerable to ischemic hypoxia is the hippocampus after 5 minutes, irreversible neuronal damage occurs causes of this ↓ blood supply include embolic infarction a clot (typically) from one region of the body travels in the blood stream and occludes a vessel supplying the brain consider in cases of sudden neurologic deficit maximal neurologic deficit occurs at onset large vessel infarcts are commoly due to an embolism thrombotic infarction a clot is locally formed in the wall of the blood vessel usually where an atherosclerotic plaque is found typically has a stuttering course Large vs. Small Vessel Infarcts Type Comments Large vessel Occlusion of the major blood vessels such as the middle cerebral artery Occlusion is most often caused by emboli Small vessel Occlusion of the small penetrating arteries that supply the deep cerebral structures such as basal ganglia thalamus internal capsule Sometimes called lacunar infarcts Ischemic Stroke Syndromes Ischemic Stroke Syndromes Anterior Circulation Stroke Findings Middle cerebral artery (MCA) stroke Symptoms contralateral weakness and sensory loss in the face and upper limb hemineglect if the non-dominant hemisphere is involved aphasia Broca's aphasia if the superior division of the MCA is involved in the dominant hemisphere Wernicke's aphasia if the inferior division of the MCA is involved in the dominant hemisphere may also result in a right superior quadrant visual field defect Lesion localization motor and sensory cortices distributed by the MCA Wernicke's or Broca's area Anterior cerebral artery (ACA) stroke Symptoms contralateral weakness and sensory loss in the lower extremity Lesion localization motor and sensory cortices supplied by the ACA Lenticulostriate artery stroke Symptoms contralateral weakness and sensory loss in the face and body in the absence of cortical signs (e.g., neglect) Comments a common site of lacunar infarcts secondary to chronic hypertension leading to lipohyalinosis Posterior Circulation Stroke Findings Medial medullary (Dejerine) syndrome Secondary to occlusion of the paramedian branches of the anterior spinal artery and/or vertebral artery Symptoms triad ipsilateral hypoglossal palsy contralateral hemiparesis contralateral lemniscal sensory loss (e.g., proprioception) Lesion localization lateral corticospinal tract caudal medulla medial lemniscus Lateral medullary (Wallenberg) syndrome Secondary to occlusion of the posterior inferior cerebellar artery (PICA) or vertebral artery Symptoms dysphagia hoarsness ↓ gag reflex vertigo ↓ pain and temperature sensation of the ipsilateral face contralateral body Horner's syndrome ataxia Lesion localization lateral medulla involving the nucleus ambiguus vestibular nuclei lateral spinothalamic tract spinal trigeminal nucleus sympathetic fibers inferior cerebellar peduncle Lateral pontine syndrome Secondary to anterior inferior cerebellar artery Symptoms facial paralysis ↓ salivation, lacrimation, and taste from the anterior tongue (2/3rd) vertigo ↓ pain and temperature sensation of the ipsilateral face contralateral body ipsilateral Horner's ataxia Lesion localization Lateral pons involving the facial nucleus vestibular nuclei spinothalamic tract spinal trigeminal nucleus sympathetic fibers middle and inferior cerebellar peduncle Locked-in syndrome Secondary to occlusion of the basilar artery Symptoms quadraplegia bulbar manifestations able to perform vertical eye movements preserved conciousness Lesion localization ventral pons, lower midbrain, and medulla affecting the corticospinal and corticobulbar tracts oculomotor nerve nuclei paramedian pontine reticular formation Posterior cerebral artery (PCA) occlusion Symptoms contralateral hemianopsia with macular sparing Lesion localization occipital lobe Presentation Symptoms dependent on which area of the brain is involved review chart above Physical exam dependent on which area of the brain is involved review chart above Imaging Computerized tomography (CT) indications a non-contrast head CT should be performed in patients presenting with symptoms concerning for stroke and to exclude intracerebral hemorrhage CT angiography should be performed to assess for a thrombus and to evaluate the carotid and vertebral neck arteries Magnetic resonance imaging (MRI) indications MRI/MRA can aid in assessing infarct volume for further management Studies Labs complete blood count basal metabolic panel prothrombin time partial thromboplastin time cardiac enzymes Histology Histology Time after Ischemic Event Histologic findings 12-24 hours Red neuron the cytoplasm is eosinophilic the nuclei is pyknotic cell body shrinkage loss of Nissl substance 1-3 days Tissue necrosis Neutrophillic infiltration 3-5 days Macrophage (microglial) infiltration 1-2 weeks Reactive gliosis Vascular proliferation > 2 weeks Glial scar Differential Transient ischemic attack Hemorrhagic stroke Treatment Medical intravenous tPA indication used in patients presenting with stroke symptoms, excluded to have an intracranial hemorrhage, and time since symptom onset is within the last 3-4.5 hours Operative mechanical thrombectomy indication used in patients presenting with stroke symptoms, excluded to have an intracerebral hemorrhage, and a proximal large artery occlusion involving the anterior circulation whether or not the patient received tPA time since symptom onset within the last 8 hours Complications Intracerebral hemorrhage Seizures Aspiration pneumoniae
QUESTIONS 1 of 12 1 2 3 4 5 6 7 8 9 10 11 12 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.4671) A 74-year-old African-American woman is brought to the emergency department by her home health aid. The patient was eating breakfast this morning when she suddenly was unable to lift her spoon with her right hand. She attempted to get up from the table, but her right leg felt weak. One hour later in the emergency department, her strength is 0/5 in the right upper and right lower extremities. Strength is normal in her left upper and lower extremities. Sensation is normal bilaterally. An emergency CT of the head does not show signs of hemorrhage. Subsequent brain MRI shows an infarct involving the internal capsule. Which of the following is true about her disease process? Review Topic QID: 107131 1 The most important risk factors are hypertension and diabetes 82% (9/11) 2 The most common cause is embolism originating from the left atrium 0% (0/11) 3 It is caused by ischemia to watershed areas 18% (2/11) 4 IV thrombolysis cannot be used 0% (0/11) 5 The most important risk factors are ethnicity and sex 0% (0/11) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 1 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.4671) A 75-year-old woman with a history of stroke 1 year ago was found unconscious on the floor of her home by her son. The patient was brought to the emergency department by ambulance but expired prior to arrival. An autopsy was performed and showed the cause of death to be a massive ischemic stroke. The coroner also examined sections taken from the area of her prior stroke. Which histologic finding would be prominent in the area of her stroke from one year prior? Review Topic QID: 107142 1 Red neurons 5% (3/66) 2 Necrosis and neutrophils 2% (1/66) 3 Macrophages 3% (2/66) 4 Reactive gliosis and vascular proliferation 35% (23/66) 5 Cyst formed by astrocyte processes 55% (36/66) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.33) A patient is transferred from an outside hospital by family request. The patient is a 76-year-old gentleman who developed acute onset left-sided weakness four days ago with the imaging findings seen in Figure A. Despite aggressive care, the patient dies shortly after transfer. The family requests an autopsy. What histological finding would you expect to find on evaluation of the patient's brain? Review Topic QID: 101697 FIGURES: A 1 Red neurons 9% (9/100) 2 Neutrophilic infiltration and necrosis 19% (19/100) 3 Macrophage infiltration and phagocytosis 54% (54/100) 4 Reactive gliosis and vascular proliferation 10% (10/100) 5 Glial scarring 6% (6/100) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.38) A 58-year-old man with history of diabetes and hypertension suffers a cardiac arrest at home. The family calls 911, yet no one performs CPR. Five minutes after the arrest, EMS arrives to begin resuscitation. At this point, which region of the CNS is most likely to suffer ischemic damage? Review Topic QID: 101702 1 Thalamus 12% (12/98) 2 Spinal cord 0% (0/98) 3 Pons 2% (2/98) 4 Medulla 6% (6/98) 5 Hippocampus 78% (76/98) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 5