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ALGORITHMIC EVALUATION OF
COMPLEX NEUROLOGIC INJURIES
Advances in Emergency I.
II.
Introduction
Neurologic Injury: Catastrophic and Critical
Neuroradiology: Diagnoses
III. Strategic Pathways for Diagnostic Imaging
An Algorithmic Approach Craniofacial
Axial Skeleton and Spinal Cord Injuries
Appendicular Skeleton and Peripheral Neural Injuries
IV: Case Illustrations
V. Conclusions
Martin Kernberg, MD, Asst. Clinical Professor
VI. References
Steve Polevoi, MD, Assoc. Clinical Professor
Division of Emergency Medicine
Department of Medicine
University of California, San Francisco
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Neurologic Injury: Parallel Processing of
Introduction Information
Neurologic injury remains one of the leading causes of death and long term
functional deficits despite recent advances in management. The
contemporary evaluation and management of the neurologic patient
require parallel efforts to assess the patient clinically and radiologically. 1. Consider the high risk differential diagnosis, on
The timing and selection of radiological investigations remains a source
of controversy. Advancing imaging modalities yield diagnoses previously the basis of clinical history, physical
overlooked; medicolegal concerns influence clinical decisions; decision
rules and protocols designed to reduce unnecessary costs, radiation
examination, and laboratory studies.
exposure, and clinical delays can seem complex, contradictory, and
excessively rigid; resources are progressively limited. In reviewing these
2. Concurrently stabilize, initiate imaging
issues, a system is described that may prove useful in clinical practice, sequence, and/or contact appropriate surgical
with a critical review of the advantages and disadvantages of various
radiological modalities. While a set of algorithms is advocated, it is consultants.
underscored that this will vary depending on the facilities available. It is
appropriate however to be aware of the limitations of the radiological 3. Confirm benign etiologies directly, or indirectly
techniques that are utilized on a daily basis and to have a knowledge of
how selective use of advanced imaging modalities will improve patient
after formal exclusion of the catastrophic
care. differential diagnosis.
Modified from P Jaye, ME Kernberg, and T Green, “Trauma Radiology,” The Lancet,
in press, 2007.
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
3 Catastrophic conditions
How are neurologic catastrophic Intracranial hemorrhage
conditions defined? Traumatic
Subdural hematoma
Epidural hematoma
Catastrophic conditions are those which Intraventricular hemorrhage
have a significant risk of mortality, if the Vascular etiologies
Aneurysm rupture
diagnosis is emergently missed. Hemorrhagic arterio-venous malformation
Critical traumatic conditions are those Hemorrhagic Venous angioma
which have a significant risk of morbidity, Acute intra-axial ischemia and infarction
if the diagnosis is delayed (e.g., cervical Intracranial and axial infection
Meningitis
spine injuries, subacute hemorrhage, or
Diskitis
transient cerebral ischemia). Abscess
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
2 Critical Injuries: General Vital Sign Indications for
Axial and Intra-axial Trauma Catastrophic Differential Diagnosis
Axial fractures 1. Tachycardia or bradycardia (heart rate <50)
C-spine 2. Tachypnea or bradypnea (respiratory rate
T-spine <7)
Lumbosacral
3. Significant pyrexia or hypothermia
Intra-axial
Contusions 4. Hypotension and hypertension
Concussions 5. Acute hypoxia
Petechial hemorrhage 6. Pain severity
7. Weight loss
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Local Vital Sign Indications for Clinical Catastrophic Criteria
Neurologic Differential Diagnosis Acuity, severity, progression, persistence,
refractory, atypical or unexplained:
1. Glasgow Coma Score Critical acute symptoms (e.g., severe headache, neck
1. Adult pain, back pain; palpitations or respiratory
irregularity; nausea, vomiting, distension; paresthesia,
2. Pediatric weakness, or paralysis)
2. Cranial nerve functional deficits Selective physical findings (neurologic deficits; blood
1. Visual acuity pressure fluctuation, rhythm disorders, bradypnea or
tachypnea; altered bowel or urinary function
2. Hearing loss (incontinence or retention); loss of reflexes, motor
3. Anosmia… function, or sensation; hemotympanum, periorbital
ecchymosis).
3. Motor strength Aberrant laboratory, electrocardiographic, or plain
4. Reflex changes radiographic abnormalities (e.g., axial imaging).
5. Peripheral sensory deficits
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Craniofacial Injury: Strategy
Imaging Modalities
Catastrophic
Craniofacial Findings
Conventional Radiographs and Special Views
Standard Advanced Imaging
Clinical Information
Diagnostic Testing Options
CT: Incremental, Spiral, Angiographic
US: Gray Scale, Color Doppler, Amplitude Vital Signs 1. Laboratory 1. CT/CTA
Angiography
History 2. XR 2. MRI
MR: MRI and MRA
Neurologic
Arterial Catheterization Examination
3. Angiography
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
Principles of facial imaging
Case 1
If you can name the particular bone, plain film imaging is 30 year old homeless
appropriate:
Nasal spine male, intoxicated, is
Mandible series (preferred: orthopantomogram) involved in fistfight,
with multiple facial
If two or more bones are involved, CT is indicated. Do not
order (but your institution may require): abrasions, and
Facial films paranasal sinus
Sinus series
tenderness.
Orbit series
TMJ series
Skull series
Div. of Emergency Medicine, UCSF
Case 1 Case 1
Case 1 Case 1
Emergency Chest Radiology
Principles of Cranial Imaging
Universal decision rule: CT versus MRI: Controversy
Acuity, severity, progression, persistence, refractory,
atypical and unexplained
Symptoms CT vs. MR MRI CT
Headache, nausea and vomiting, confusion, vertigo, Sensitivity (ICH) 100% 97%
sensory deficit; weakness, paresthesia, ataxia; bleeding
from the ear, new rhinorrhea. Radiation dose 0 1/1000 cancer rate
Physical findings
IQ impact No known change Diminished IQ
GCS decline
Neurologic deficits HS graduation rate No known change Diminished rate
Supraclavicular injuries
Laboratory, electrocardiographic, or plain film findings,
such as
Respiratory acidosis
ST segment depression or elevation
Associated injuries: C-spine fractures
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
CT versus MRI: Controversy SAH: Emerging controversy
CT versus MRI MRI CT Imaging sequence CT MRI
Sedation Often in children Often in children 1. Non-contrast CT 1. MRI
Cost per machine 0.25 million 1.0 million 2. Lumbar puncture 2. CTA if MRI + ICH.
Cost per study High Intermediate 3. CTA if LP + ICH.
After hours access Difficult Easy
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Types of Intracranial Hemorrhage
Epidural hematoma
Common mechanism: meningeal artery laceration,
often associated with temporo-parietal fractures
Intraparenchymal hematoma
Common mechanism: contusion with potential for
progression
Subdural hematoma
Common mechanism: injury to bridging dural veins
Subarachnoid hemorrhage
Common mechanism: traumatic aneurysm rupture
Intraventricular hemorrhage
Common mechanism: extension of intraparenchymal
hematoma
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
Case 2
75 yo Chinese-
American male, with
no prior medical
history, awoke at
2300 hours with n/v
and left sided
weakness,
progressing to
witnessed seizures.
Div. of Emergency Medicine, UCSF
Case 2: CT and MRI Case 3
61 year old Hispanic
female with severe
headache and
nausea, become
apneic in transport,
with run of
ventricular
tachycardia.
Case 3 Case 3
Emergency Chest Radiology
Case 3
Contusions and Intracerebral
Hematomas
Contusions can, in a period of hours or
days, evolve or coalesce to form an
intracerebral hematoma requiring
immediate surgical evacuation.
This occurs in approximately 20% of
patients and is best detected by
repeating the head CT scan within 12 to
24 hours after the initial scan. ATLS
Div. of Emergency Medicine, UCSF
Axial Skeletal Trauma: Diagnostic Strategy
C-spine interpretation:
Architectural principles
Catastrophic
Axial Skeletal Findings
Lateral projections Anterior projections
Standard Advanced Imaging
Clinical Information
Diagnostic Testing Options
Counting (Marshall’s law) Symmetry
Are all the vertebral Dens and C1
bodies visible, including C1 and C2
Vital Signs 1. Laboratory 1. CT/CTA T1?
Continuity Sinusoidal configuration
Are anatomic curves Lateral masses
continuous?
History 2. XR 2. MRI Conformance Scoliosis
Are the transitions
between vertebral bodies Muscle spasm
regular, with respect to Ligamentous injury
Neurologic size and intervertebral Occult fracture
Examination
3. Angiography spaces?
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
C-spine interpretation
guidelines C-spine: the lateral view of
the lateral masses
Prevertebral STS Contour transitions
Anterior longitudinal
line
Posterior longitudinal
line
Spinolaminar line
Posterior process line
Dens-basion distance
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
C-spine: the AP view of the C-spine: the AP view of the
dens dens
Symmetry Symmetry
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Indications for C-spine Films:
C-spine: the AP view of the Severe pain
Midline tenderness*
lateral masses Unrestrained occupant
Ejection
Neurologic deficit*
Sinusoidal contour Radiculopathy
Intoxication*
Altered level of consciousness*
Mechanism
Velocity
Intrusion
Rollover
Other injuries
Brain
Distracting pain*
*= NEXUS exclusion criteria (NEJM Jul,
2000): implicit indications for imaging.
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
NEXUS NEXUS
N Engl J Med 2000 Jul 13;343(2):94-9. Five criteria to be classified as low probability of
injury:
Validity of a set of clinical criteria to rule no midline cervical tenderness
out injury to the cervical spine in patients no focal neurologic deficit
with blunt trauma. National Emergency normal alertness
X-Radiography Utilization Study Group. no intoxication
no painful, distracting injury
Hoffman JR, Mower WR, Wolfson AB,
Individual criteria not compared
Todd KH, Zucker MI. NPV 99.8%
34,069 patients
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
Canadian C-Spine Rule (I)
Nexus Study 8924 Adults
100% Sensitivity and 42.5% Specificity
34,000 Patients, 23 Centers 1) Is there any high-risk factor that mandates
radiography (i.e. age > 65, dangerous
5 Criteria: No posterior midline tenderness, mechanism of injury, or paresthesias)?
intoxication, altered consciousness, 2) Is there any low-risk factor present that
neurological deficits, distracting injuries. allows safe assessment of range of motion (i.e.
simple rear-end motor vehicle collision, sitting
99.6% Sensitivity, but 12% Specificity. position in ED, ambulatory at any time since
injury, delayed onset of neck pain, or absence
of midline tenderness?
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Canadian C-Spine Rule (II) C-spine: dens injury
3) Is the patient able to actively rotate Asymmetry
neck 45 degrees to left and right
regardless of pain?
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
CT C-spine: the lateral view of CT C-spine: the axial view of
the dens the dens
Technique: Asymmetry
Finest possible cuts of
level of abnormality
Beware of motion
artifacts
Cortical discontinuity
Double density sign
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
CT of C1-C2 More Sensitive Than
Plain Films
Study of 202 patients with traumatic brain
injury, Link, et al, found 5.4% of patients had
C1 or C2 fractures and 4% had occipital condyle
fractures not visualized on three-view
radiographs.
Blacksin and Lee evaluated 100 consecutive
trauma patients, found 8% frequency of
fractures of the occipital condyle (3%) and C1-
C2 (5%) not detected on cross-table lateral c-
spine.
http://www.east.org
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Flexion-extension Films: ATLS
guidelines PEDIATRIC C-SPINE
Persistent neck pain, without Increased cranial size, with increased
radiographic changes ligamentous laxity
Non-acute CT scan, with suspected Pseudosubluxation of C2 on C3 and C3
degenerative or chronic spondylolisthesis on C4 OK below age 8. Use posterior
The degree of angulation must be cervical line to rule out pathology
determined by the patient, and limited by
level of tolerance.
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Thoracic Imaging: Radiologic Thoracic and Neurologic Trauma: Strategy
Sequence Catastrophic Chest
Findings
Imaging evaluation of acute chest trauma divides Clinical Information
Standard Advanced Imaging
into five typical paths:
Diagnostic Testing Options
1. Chest Radiograph: general survey
2. Thoracic spine series
Vital Signs 1. Laboratory 1. US
3. US (e.g., myocardial contusion and pericardial
effusions) Cardiovascular and
Pulmonary History
2. ECG 2. CT/CTA
4. CT/CTA (e.g., pulmonary contusion, aortic
transection, pericardial injury)
Auscultation 3. CXR 3. Angiography
5. MRI: assessment of cord injury
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
T and LS-spine interpretation: Classical Algorithm for Abdominal Trauma
Acute Abdomen
Architectural principles History and PDx
Lateral projections Anterior projections Laboratory
Counting (Marshall’s law) Conventional Imaging
Are all the vertebral bodies visible Symmetry
for the selected level? Vertebral bodies
Are the vertebral bodies the same Transverse processes Consultation
height anteriorly and posteriorly?
Are the vertebral bodies the same Posterior processes
density throughout? Regular transitions Initial X-sectional
Continuity Bifid artifacts
Imaging
Are anatomic curves continuous?
Assess subluxation. CT US
Conformance Scoliosis
Are the transitions between Muscle spasm
vertebral bodies regular, with Secondary Imaging
respect to size and intervertebral Ligamentous injury
spaces?
Occult fracture
Nuclear Medicine GI Contrast Studies Angiography
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Parallel Algorithm for Abdominal Case 4
Trauma 71 year old with hx of
chronic back pain,
depression, and seizures,
Acute Abdomen
increasing over the past
several months, and
History and PDx Laboratory Conventional Imaging
1. CXR
Imaging Consultation worse today.
2. Abdominal Series
PDx: extreme weakness.
US CT
1. Color Doppler 1. IV, Oral, Rectal
2. Power Doppler 2. CT Angiography
Div. of Emergency Medicine, UCSF
Case 4
Case 4
Emergency Chest Radiology
Universal Decision Rule in Axial and
Severe Pelvic Fractures Extremity Injuries
If focal skeletal tenderness is demonstrated, conventional
radiographs.
Comparison view in children (or use of Keats).
Early transfer to CT (or MRI) for atypical, asymmetric, askew, or avulsed findings.
Advise patients that “occult fractures and internal derangements
a Trauma Center cannot be excluded, and interval evaluation may be required.”
Splint
Strongly Hard collar for cervical spine strain.
recommended Appropriate splint for extremity injuries.
Formal radiologic interpretation in less than 24 hours.
(ATLS) Formal follow-up:
Diminished or asymmetric range of motion in children, concurrent
orthopedic discussion or consultation.
Neurologic deficits, central or peripheral: emergent consultation.
Instability: concurrent orthopedic discussion or consultation.
Interval evaluation in adults in <7 days with appropriate specialist
(e.g., orthopedist, maxillofacial, neurosurgical, or otolaryngologist).
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Appendicular Skeletal Trauma
Catastrophic
Appendicular Findings
2 Catastrophic neurologic
injuries
Standard Advanced Imaging
Clinical Information
Diagnostic Testing Options
Child abuse, with potential fatal outcome
Neurologic compromise from fracture-
Vital Signs 1. Laboratory 1. CT/CTA
dislocations
History 2. XR 2. MRI
Extremity
3. Angiography
Examination
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Critical Injuries:
Local Vital Sign Indications for
Axial and Extremity Trauma
Traumatic Differential Diagnosis
Fractures 1. Injury site related pain or tenderness
Dislocations 2. Aberrant range of motion
3. Aberrant muscle strength (scale of 5)
Subluxation
4. Aberrant sensation
5. Aberrant pulses
1. Diminished pulse to palpation
2. Peripheral capillary refill
3. Peripheral pulse oximetry
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
Imaging Modalities
Clinical Catastrophic Criteria
Conventional Radiographs and Special Views
Acuity, severity, progression, persistence,
refractory, atypical or unexplained:
CT: Incremental, Spiral, Angiographic
Critical acute symptoms (i.e., pain at rest, pain with
motion, immobility, subjective paresthesia)
Selective physical findings (diminished range of US: Gray Scale, Color Doppler, Amplitude
motion, severe tenderness to palpation, loss of motor Angiography
function, loss of sensation, loss of pulses, pallor,
presence of extensive hematoma).
MR: MRI and MRA
Aberrant laboratory (declining Hematocrit, aberrant
peripheral or central pulse oximetry; plain radiographic
abnormalities). Arterial Catheterization
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Universal Decision Rule in Axial and Appendicular Skeletal Trauma
Extremity Injuries Catastrophic
Appendicular Findings
If focal skeletal tenderness is demonstrated, conventional
radiographs.
Comparison view in children (or use of Keats). Standard Advanced Imaging
Clinical Information
CT (or MRI) for atypical, asymmetric, askew, or avulsed findings. Diagnostic Testing Options
Advise patients that “occult fractures and internal derangements
cannot be excluded, and interval evaluation may be required.”
Splint
1. Laboratory 1. CT/CTA
Hard collar for cervical spine strain. Vital Signs
Appropriate splint for extremity injuries.
Formal radiologic interpretation in less than 24 hours.
Formal follow-up:
History 2. XR 2. MRI
Diminished or asymmetric range of motion in children, or
neurovascular compromise, concurrent orthopedic discussion or
consultation.
Instability: concurrent orthopedic discussion or consultation.
Extremity
Interval evaluation in adults in <7 days with appropriate specialist Examination
3. Angiography
(e.g., orthopedist, maxillofacial, neurosurgical, or otolaryngologist).
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Trauma: Universal Diagnostic Strategy
References
Catastrophic
Findings
1. Kernberg ME, Polevoi SK, Lewin M, and Murphy C,
Catastrophic errors: algorithmic solutions, 3rd
Mediterranean Emergency Medicine Conference, Nice,
Clinical Information
Standard Advanced Imaging France, September 4, 2005 (Catastrophic errors
Diagnostic Testing Options evaluated in a consecutive case series of 125,000
emergency room patients).
2. P Jaye, ME Kernberg, and T Green, Trauma
Vital Signs 1. Laboratory 1. US Radiology, The Lancet, in press, 2007.
3. Scott A. Hoffinger, Pediatric Emergency Radiology,
Topics in Emergency Medicine, (ME. Kernberg, MD,
Editor), 2004
History 2. ECG 2. CT/CTA
4. Radiation Risks and Pediatric Computed Tomography
(CT): A Guide for Health Care Providers, National Cancer
Institute (USA) and Society for Pediatric Radiology, 2002
Physical (modified for Table 1).
5. Weissleder R, Rieumont MJ, and Wittenberg J, Primer
3. XR 3. MRI
Examination
of Diagnostic Imaging, MGH, 1997
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
Discussion Slides After a closed head injury, with transient loss of
consciousness, a 2 year old female infant has
persistent nausea and vomiting. Imaging should
include:
1. Craniofacial 2. Appendicular 1. None
Nexus rules skeleton
Canadian c-spine rules Ottawa rules 2. Skull films
Head CT scanning Ankle
3. Head CT scan
Knee
Hip 4. Head MRI
Pelvis
Shoulder
Other lumbo-sacral
spine
Div. of Emergency Medicine, UCSF Div. of Emergency Medicine, UCSF
Emergency Chest Radiology
