neurological emergencies stephen deputy, md

Neurological EmergenciesStephen Deputy, MD

Acute Ischemic Stroke Intracranial Hemorrhage Status Epilepticus Guillan-Barre Syndrome Acute Myelopathy Myasthenic Crisis

Acute Ischemic Stroke

AIS is caused by the sudden loss of blood circulation to an area of the brain resulting in ischemia and corresponding loss of neurological function.

Within seconds to minutes of loss of perfusion, an ischemic cascade is unleashed resulting in a central area of irreversible infarction surrounded by an area of potentially reversible ischemic penumbra.

The goal of treatment for AIS is to preserve the area of oligemia in the ischemic penumbra. This is done by limiting the severity of injury (neuronal protection) and by restoring blood flow to the penumbra.

Acute Ischemic StrokeIschemic Cascade

Loss of O2 and Glucose delivery to the neuron results in cellular depolarization as ATP is depleted and the Na-K ATP-as pump fails.

The resulting Ca influx results in the release of many excitatory neurotransmitters including glutamate which binds to the NMDA receptor resulting in further Ca influx and further depolarization and release of glutamate.

Massive Ca influx results in activation of various degrative enzymes which damage cellular membranes.

The release of free radicals, arachadonic acid and nitric oxide further damage neurons.

Acute Ischemic Stroke

Ischemic Cascade Within hours to days, activation of apoptotic

and other genes results in the release of cytokines and further inflammatory molecules, resulting in further inflammation and microcirculatory compromise.

Ultimately, the ischemic penumbra is consumed by these progressive insults, coalescing within the ischemic core, often within hours of the onset of the AIS.

Acute Ischemic StrokeClinical Presentation

No clinical feature reliably distinguishes AIS from hemorrhagic stroke, though headache, N/V, and altered mental status make hemorrhagic stroke more likely.

Common symptoms of AIS include the abrupt onset of hemiparesis, monocular visual loss, ataxia, vertigo, aphasia, or sudden depressed level of consciousness.

Establishing the onset of symptoms is essential when considering possible thrombolytic therapy.

Acute Ischemic Stroke

Transient Ischemic Attack TIA’s are defined as a transient ischemic

neurological deficit that resolves within 24 hours

80% resolve within 60 minutes TIA’s precede 30% of AIS Left untreated, 30% of TIA’s progress to AIS

(20% within the first month and 50% within the first year)

Acute Ischemic StrokePhysical Examination

Goal of PE is to look for extra cranial causes of AIS and to distinguish AIS from stroke mimics (seizures, tumors, toxic-metabolic disturbances, positional vertigo, etc).

HEENT: Look for trauma signs and nuchal rigidity, listen for cranial or cervical bruits, evaluate pulse strength. Fundoscopy to look for emboli, hemorrhage, papilledema.

C/V: Signs of CHF, Atrial fibrillation, arrhythmias. Ext: Signs of venous thrombosis and arterial

emboli.

Acute Ischemic StrokeNeurological Exam

Goal is to establish baseline for monitoring response to therapy and to determine size and location of AIS

MS, CN, Motor, Coordination, Sensory and Gait need to be covered, however speed is of the essence!

MCA: Contralateral : Hemiparesis, Hemianopsia and Sensory loss

Ipsilateral: Gaze preference. Dominant Hemisphere: Aphasia Non-Dominant Hemisphere: Hemi-neglect

and cortical sensory deficits

Acute Ischemic StrokeNeurological Exam

ACA: Disinhibition, primitive reflexes, contralateral

hemiparesis (legs>arms), urinary incontinence.

PCA: Contralateral hemianopsia, cortical blindness,

altered mental status, impaired memory.

Vertebrobasilar: Vertigo, nystagmus, ataxia. Crossed findings (ipsilateral cranial

nerve deficits along with contralateral long track signs).

Lacunar Infarcts: Pure motor, pure sensory, ataxia/hemiparesis.

Acute Ischemic Stroke

Work Up Labs: CBC with platelets, CMP, PT, PTT,

cardiac biomarkers, EKG. Imaging: Emergent non-contrast CT

Distinguishes hemorrhagic from ischemic stroke Defines age and anatomic distribution of stroke Large hypodense area seen within 3 hours brings

into question of timing of AIS and may predict poor outcome

Hyperdense MCA sign, insular ribbon sign, obscuration of lentiform nucleus, loss of gray-white junction

Hyperdense MCA Sign

Large Cortical Hypodensity

Acute Ischemic StrokeOther Imaging Studies

CT Angiography MRI:

Diffusion-Perfusion mismatch (correlates to the core area of infarction and surrounding area of the ischemic penumbra)

More sensitive than CT to early ischemic changes MR Angiography Conventional Cerebral Angiography Echocardiography: (CHF, akinetic wall,

vegetation/clots, septal defects, PFO) Carotid Doppler Ultrasound: Carotid stenosis

evaluation

Acute Ischemic Stroke

Treatment ABCD’s

Airway: Intubation for GCS < 9 or lack of airway protective reflexes

Breathing: O2 if hypoxic. Keep PCO2 32-36 mmHg

Circulation: Maintain adequate CPP (MAP-ICP). Do not treat HTN unless > 200/120

D = Dextrose. Maintain normoglycemia (even if insulin is needed) as hyperglycemia worsens neurological outcome

Acute Ischemic Stroke

Treatment Fever: Hyperthermia worsens ischemic injury Cerebral edema: Peaks 72-96 hours.

Hyperventilation can decrease CPP. Mannitol may leak across compromised BBB. No evidence of benefit for steroids. Decompressive craniectomy and resection

of necrotic tissue may be indicated, especially in the setting of hemorrhagic transformation.

Seizure control: Prophylactic AED is not indicated unless malignant elevated ICP is present

Acute Ischemic StrokeAcute Thrombolysis

Balance restoration of blood flow and hemorrhage risk

No evidence of hemorrhage on CT Hypodensity on CT < 1/3 of hemisphere Onset of symptoms within 3 hours of rTPA use SBP < 185 DBP < 110 INR < 1.7, Platelets > 100,000, No ASA or

anticoagulation, No trauma or recent surgery rTPA: 0.9 mg/kg IV over 60 minutes with 10% of

dose given over the 1st minute

Acute Ischemic Stroke

Strategies for Reducing Future Strokes Anti-Platelet Therapy Warfarin: (Atrial Fibrillation, Arterial

Dissection) Carotid Endarterctomy / Stent Placement PFO Closure Reducing Stroke Risk Factors

(Hypercholesterolemia, Hypertension, Diabetes, Obesity, Lack of Exercise, Smoking, OCP’s)

Intracranial Hemorrhage(non-traumatic)

Location of Hemorrhage Intraventricular Hemorrhage Intraparenchymal Hemorrhage Subarachnoid Hemorrhage Subdural Hematoma Epidural Hematoma

Intracranial Hemorrhage

Intraventricular Hemorrhage Accounts for 3% of all non-traumatic ICH Hypertension is the most common etiology Often results from an intraparenchymal

hemorrhage that extends into the ventricular system

S/S: Headache, N/V, Progressive deterioration of consciousness, raised ICP, Nuchal rigidity

Survivors may develop post-hemorrhagic hydrocephalus

Intracranial Hemorrhage

Intraparenchymal Hemorrhage Basal Ganglia Hemorrhage

Contralateral hemiparesis, hemichorea, hemisensory loss, and hemi-neglect are common neurological deficits

Putaminal Hemorrhage is the most common location of intraparenchymal hemorrhage secondary to HTN

Putaminal Hemorrhage, if massive, will result in Uncal Herniation(Ipsilateral blown pupil, contralateral hemiparesis, depressed LOC

Caudate Hemorrhage is most likely to rupture into ventricles

Basal Ganglia Intraparenchymal Hemorrhage

Intracranial Hemorrhage

Intraparenchymal Hemorrhage Thalamic Hemorrhage

Contralateral hemiparesis, hemisensory loss and depressed LOC (wake center) are common deficits

Extension into ventricular system common resulting in obstructive hydrocephalus with 3rd ventricular enlargement => Parinaud’s Syndrome (Paralysis of voluntary upward gaze, light-near dissociation, convergence-retraction nystagmus, eyelid retraction)

Thalamic Intraparenchymal Hemorrhage

Intracranial Hemorrhage

Intraparenchymal Hemorrhage Pontine Hemorrhage

Abrupt onset of coma, pinpoint pupils, autonomic instability, horizontal gaze paralysis, and quadriparesis

The miotic pupils and depressed LOC may mimic opiate overdose

Pontine Intraparenchymal Hemorrhage

Intracranial Hemorrhage

Cerebellar Hemorrhage Sudden onset of vertigo, severe N/V, and

ataxia leading to altered mental status and coma over a few hours

Obstructive hydrocephalus can contribute to brainstem herniation

Urgent posterior fossa decompression is essential for survival

Intraparenchymal Cerebellar Hemorrhage

Intracranial Hemorrhage

Lobar Intraparenchymal Hemorrhage This is often a clinically silent lesion S/S depend on location of hemorrhage,

though hemiparesis, aphasia, hemianopsia, and hemisensory loss common

Mimics lobar AIS

Lobar Intraparenchymal Hemorrhage

Intraparenchymal HemorrhageEtiology

Hypertension is the #1 cause in adults Hyalinization of small penetrating arteries

(replacement of smooth muscle by collagen => increased friability of vessels

Cerebral Amyloid Angiopathy Elderly with dementia and multiple bleeds

Anticoagulation and Anti-Platelet Meds Systemic anticoagulated states (eg. DIC) Sympathomimetic Drugs Aneurysms, AVM’s, Cavernous Angiomas Brain Tumors

Metastatic (renal cell CA, malignant melanoma, prostate, and lung CA) GBM and Hemangioblastoma

Intraparenchymal HemorrhageTreatment

ABCD’s Intubation Treat Hypertension to keep SBP < 160 mmHg

Fluid and Electrolyte Management Use Normal Saline, avoid Dextrose Watch for SIADH and Cerebral Salt Wasting

Prevent Hyperthermia Seizure Prophylaxis Correct Underlying Coagulopathy

FFP, platelet Infusions, Vitamin K

Intraparenchymal HemorrhageTreatment

Recombinant Factor VII Dosing ranges between 40 and 160 micrograms Beneficial if given within 4 hours of onset Risk of myocardial infarction and AIS

Management of ICP Hyperventilate to keep PaCO2 around 30 mmHg Avoid Mannitol (can leak into hematoma) External Ventricular Drain (if hydrocep0halus present) Surgical Evacuation of Hematoma (controversial)

Subarachnoid Hemorrhage(non-traumatic)

Aneurysmal rupture accounts for 80% of cases Risk Factors

Advancing age, Smoking, HTN, Cocaine use, Hypertension, Heavy Alcohol use, Connective Tissue Disorders, Sickle Cell Disease, First Degree Relatives with Aneurysms

Fatality rate is 50% within 2 weeks 30% of survivors require lifelong care 15% of patients will have > 1 aneurysm Outcome largely dependent on clinical

presentation and CT findings

Subarachnoid Hemorrhage

Subarachnoid Hemorrhage

Clinical presenting signs Sudden-Onset “Thunderclap Headache” “Worst Headache of my life” CN III palsy (p. comm aneurysm) CN VI palsy (raised ICP) Retinal Hemorrhages Altered Mental Status Nuchal Rigidity

Subarachnoid Hemorrhage

Diagnostic Work Up CT Imaging

Will pick up > 90% SAH (get thin cuts through skull base)

Sensitivity drops to < 50% after 2 weeks Carefully evaluate basilar cisterns for

hemorrhage

Subarachnoid Hemorrhage

Diagnostic Work Up Lumbar Puncture

Perform if high index of suspicion and negative CT

Elevated Opening Pressure Increased RBC count that does not

“clear” between tubes one and tube four Xanthochromia (rule of 2’s)

Starts at 2 hours, Peaks at 2 days, Clears by 2 weeks

Subarachnoid Hemorrhage

Diagnostic Work Up Angiography

Digital Subtraction Angiography is gold standard

CT Angiography MR Angiography Look for Multiple Aneurysms

ConventionalAngiogram

CT Angiogram

MR Angiogram

Subarachnoid HemorrhageTreatment

General Measures ABCD’s

Intubation for GCS < 9 Treat HTN: SBP 90-140 prior to aneurysm treatment, < 200

mmHg after Rx Glucose between 80 and 120 mg/dl Euvolemia (CVP 5-8 mmHg unless vasospasm, then CVP 8-12

mmHg) Temperature Quiet Room / Sedation GI (H2 blocker, stool softener, NPO) Vasospasm

Nimodipine 60 mg po q 4 hrs for 21 days Seizures (Phenobarbital or Lorazepam)

Subarachnoid Hemorrhage

Treating the Aneurysm Surgical Intervention Endovascular Coiling

Status Epilepticus

Definitions A single seizure or back-to-back

seizures without return of consciousness lasting > 45 minutes (primate studies) >30 minutes (WHO definition) >10 minutes (working definition)

Status Epilepticus

Epidemiology 10% of all individuals with epilepsy will

have at least one episode of SE in their lifetime

10% of patients experiencing a first unprovoked seizure will present in SE

Risk of recurrent SE: Greatest for those with remote symptomatic

etiologies Not any higher in those with idiopathic or

febrile etiologies

Status EpilepticusEtiologies

Idiopathic (24%) No precipitating event, pt is neurologically and developmentally normal

Febrile (24%) Includes “febrile seizures” and seizures in the setting of a febrile illness

Remote Symptomatic (23%) Prior neurological insult or developmental brain malformation

Acute symptomatic (23%) Progressive Degenerative (6%)

Status EpilepticusAcute Symptomatic Etiologies

Vascular Stroke (Hemorrhagic > Ischemic) Subarachnoid Hemorrhage Hypoxic Ischemic Encephalopathy

Toxic Cocaine and other sympathomimetics Alcohol withdrawal Various Medications (Isoniazid, TCA’s,

various chemotherapy agents) AED non-compliance or withdrawal

Status EpilepticusAcute Symptomatic Etiologies

Metabolic Hyper or Hypo-Natremia Hypoglycemia Hypocalcemia Liver or Renal failure

Infectious Meningoencephalitis Brain Abscess

Trauma Neoplastic

Status Epilepticus

Treatment ABCD’s

Airway: Risk of aspiration, suction to bedside

Breathing: Give supplemental O2 C/V: Initial tachycardia giving way to

hypotension (especially when Benzos or Barbiturates are given)

Dextrose: Symptomatic hypoglycemia is causing irreversible brain injury until corrected

Status Epilepticus History

Fever, pre-existing epilepsy, trauma, baseline AED’s and their dosing

Physical Exam Signs of trauma, nuchal rigidity, end

organ injury Subtle signs of seizures (tachycardia,

pupil dilation and hippus, nystagmus, irregular respirations)

Work Up Lytes, glucose, AED levels, CPK, LFT’s,

ABG, NH3 CT of brain LP (when stable) if indicated. Empiric

antibiotics.

Status Epilepticus

Anticonvulsant Therapy Benzodiazepine Therapy (10

minutes) Long-Acting AED Therapy (10 to 30

minutes) Refractory Status Therapy (>30

minutes)

Status EpilepticusBenzodiazepine Therapy

Lorazepam 0.1 mg/kg max: 4 mg/dose Has 8 hour effective t½

Diazepam 0.3 to 0.5 mg/kg max: 10 mg/dose Fat-soluble so pr dosing possible Diastat (Dosing about double that of IV)

Status EpilepticusLong-Acting Anticonvulsant Therapy

Phenytoin 20 mg/kg over 20 minutes (regardless of

weight) C/R monitor during load No dextrose in line Extravasation injuries are severe Cerebyx

20 mgPE/kg over 8 minutes No precipitation in dextrose Less severe extravasation injury (more

neutral pH)

Status Epilepticus

Long-Acting Anticonvulsant Therapy Phenobarbital

20 mg/kg over 20 minutes Watch for respiratory suppression

(especially if the patient has received Benzodiazepines)

Watch for hypotension Good for Febrile Status Epilepticus

Status EpilepticusRefractory Status

Secure airway Transfer to ICU Extra lines for hypotension treatment EEG Monitoring (electrical-clinical

dissociation) Medications

Pentobarbital Other agents (Midazolam drip, Propofol,

Lidocaine, inhalation anesthetics, other AED’s)

Guillan-Barre´SyndromeDefinition

Progressive ascending weakness along with various cranial neuropathies

Areflexia Minimal sensory deficits (though radicular

pain is common) Progression over days to 4 weeks Preceding infection or Immunization: 1 to

4 weeks prior to onset of weakness (C. jejuni, CMV, Mycoplasma, dT, OPV, VZV)

Guillan-Barre´Syndrome

GBS Variants Acute Inflammatory Demyelinating

Polyneuropathy Acute Motor Axonal Neuropathy Acute Motor Sensory Axonal Neuropathy Miller Fisher Syndrome Chronic Inflammatory Demyelinating

Polyneuropathy(> 4weeks of progression or future

relapses)

Guillan-Barre´SyndromePhysical Exam

Look for the Tick! Bulbar and Respiratory Compromise Relatively Symmetric Ascending

Weakness Diminished/Absent DTR’s No Sensory Level Radicular Pain/Paresthesias Autonomic Dysfunction: Increased or

Decreased SNS or PNS Function (tachy-brady arrhythmias, hyper/hypotension, urinary retention, decreased GI mobility)

Guillan-Barre´SyndromeLaboratory Support

CSF: Albuminocytological Dissociation Elevated Protein without Pleocytosis

Nerve Conduction: Multifocal, asymmetrical demyelination

with secondary axonal degeneration Slowing of Nerve Conduction Velocities Temporal Dispersion and Conduction

Block

Guillan-Barre´SyndromeTreatment

ABC’s Airway/Breathing: (Serial Examinations)

Forced Vital Capacity: (want > 15 ml/kg) Negative Inspiratory Force (want > - 40

mmHg) ABG’s : Look for rising Pa CO2 Clinical Exam (accessory muscles, SOB,

diminished exhalation strength) Elective Intubation if Respiratory

Insufficiency or significant Bulbar Weakness

Guillan-Barre´Syndrome

Treatment ABC’s

Cardiovascular C/R and BP Monitoring Careful when treating hypo or

hypertension Excessive Vagal Response with GI pain,

Intubation, Tracheal Suctioning and other Procedures

ICU Monitoring Until Patient Reaches Nadir of Weakness

Guillan-Barre´Syndrome

Treatment IVIG

5 day infusion of 0.4 g/kg per day Plasmapharesis

5 exchanges (40-50 ml/kg) given on alternate days using saline and albumin as replacement fluid

No Role for Steroids

Guillan-Barre´Syndrome

Outcome 10% to 20% require mechanical

ventilation Mortality 2% to 5% After nadir, plateau phase lasts 2-4

weeks 70% complete recovery within 1 yr,

82% by 2 yrs 3% will go on to have relapse (CIDP)

Acute Myelopathy

Clinical FindingsThe spinal cord contains closely

approximated ascending and descending tracts that will result in multiple deficits in the setting of injury. Some of the more clinically important tracts include:

Descending Corticospinal Tract Ascending Spinothalamic Tract Ascending Posterior Columns Descending Autonomic Nervous System

Acute MyelopathyClinical Deficits

Acute Flaccid Paralysis (Ipsilateral to side of lesion) Dropped DTR’s below the level of the lesion Anterior Horn Cell dysfunction at the level of

the lesion Distinguish from dropped DTR’s due to GBS Plantar Responses will be Extensor Superficial Reflexes absent below the level of

the lesion Superficial Abdominal Reflex Cremaster Reflex Bulbocavernosus Reflex

Acute Myelopathy

Clinical Deficits Sensory Level

Pain and Temperature (Contralateral to side of lesion) Spinothalamic Tract

Vibration and Joint Position Sense (Ipsilateral) Posterior Columns

Acute MyelopathyClinical Deficits

Autonomic Nervous System Horner’s Sign

Ptosis, Meiosis, Anhydrosis Ipsilateral Descending SNS (C1-T2)

Bladder Dysfunction Sphincter Dysynergy Spastic Bladder with Incontinence

Bowel Dysfunction Constipation or Incontinence Diminished Rectal Tone

Acute Myelopathy

Etiologies Trauma

High-Dose Methylprednisolone Protocol Spontaneous Epidural or Subdural

Hematoma Neoplastic

Metastatic or Primary Tumors Vascular

Ischemia (Aortic Surgery, Hypotension, Spinal Surgery)

Hemorrhagic (Vascular Malformations, Coagulopathy)

Acute Myelopathy

Etiologies Demyelinating

Transverse Myelitis (Isolated or as part of MS)

Vasculitis (SLE) Infectious

Epidural/Subdural Abscess Osteomyelitis/Discitis

Acute MyelopathyEtiologies

Acute Myelopathy should be considered to be caused by a mass lesion compressing the cord until proven otherwise!

Emergent Imaging is warranted MRI of Spine is preferred CT Myelogram is second choice

Emergent Neurosurgical Consultation Time is of the essence!

Myasthenic CrisisMG is an auto-immune disorder characterized by a humoral-mediated immune attack on Acetylcholine receptors on skeletal muscle

Myasthenic Crisis

Clinical Features Opthalmoparesis and Ptosis Bulbar Weakness Respiratory Muscle Weakness Key Point: Weakness is Fatigable

Progressive Weakness with Repetitive Testing

Myasthenic CrisisDiagnosis

Clinical Fatigable weakness Preserved DTR’s Tensilon Test (Acetylcholine Esterase

Inhibitor) Electrophysiology

Decremental CMAP amplitudes with repetitive stim.

Lab Acetylcholine Receptor Antibodies

Myasthenic Crisis

Myasthenic Crisis

Treatment of MG Acetylcholine Esterase Inhibitors

(Mestinon) Immunosupression

Steroids IVIg Plasmapharesis

Thymectomy

Myasthenic CrisisTreatment of Myasthenic Crisis

ABC’s Secure the airway with intubation if there is

any doubt Look for and Rx any underlying infection Remove medications which can

exacerbate MG Gentamycin, steroids, anticholinergics Never increase Mestinon to try and get out

of a myasthenic crisis It may be reasonable to D/C or lower

Mestinon if one cannot exclude a cholinergic crisis (SLUDGE)

Myasthenic Crisis

Treatment of Myasthenic Crisis High dose Methylprednisolone IVIg Plasmapharesis

Clinical Neurosciences Clerkship

Now you are ready to go out there and confidently

handle patients presenting with these various

Neurological Emergencies!