Neurological Emergencies Stephen Deputy, MD

Download Report

Transcript Neurological Emergencies Stephen Deputy, MD

Neurological Emergencies
Stephen 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 Stroke
Ischemic 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 Stroke
Clinical 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 Stroke
Physical Examination
 Goal of PE is to look for extra cranial causes of AIS and to
distinguish AIS from stroke mimics (seizures, tumors, toxicmetabolic 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 Stroke
Neurological 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 Stroke
Neurological 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 Stroke
Other 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 Stroke
Acute 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 Hemorrhage
Etiology
 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 Hemorrhage
Treatment
 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 Hemorrhage
Treatment
 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
Conventional
Angiogram
CT Angiogram
MR
Angiogram
Subarachnoid Hemorrhage
Treatment
 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 Epilepticus
Etiologies
 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 Epilepticus
Acute 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 Epilepticus
Acute 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 Epilepticus
Benzodiazepine 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 Epilepticus
Long-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 Epilepticus





Refractory 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´Syndrome
Definition
 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´Syndrome







Physical 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´Syndrome
Laboratory 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´Syndrome
Treatment
 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 Findings
The 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 Myelopathy
Clinical 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 Myelopathy
Clinical 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 Myelopathy
Etiologies
 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 Crisis
MG 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 Crisis
Diagnosis
 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 Crisis
Treatment 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!