EBQ:Denver Screening Criteria

Background

• Used to screen for vertebral and carotid artery dissection and/or injury after blunt head and neck trauma (BCVI - blunt cerebrovascular injury)
• A CTA to evaluate for VAI should be obtained in those meeting the modified Denver Criteria
• BCVI has the highest association with cervical hyperextension and rotation, hyperflexion, or direct blunt force to head and neck
• Most injuries are diagnosed after the development of symptoms secondary to central nervous system ischemia resulting in neurologic morbidity of up to 80% and associated mortality of up to 40%.

Algorithm for evaluation of BCVI with high risk criteria based on Memphis and Denver Screening Criteria

Clinical Question

• Can clinical criteria and injury profile and risk factors successfully identify patients at risk for BCVI?

Conclusion

Denver criteria can successfully identify trauma patients at risk for vascular injury.

• 5% of trauma patients were screened
• 18% of screened patients had a vascular injury

Denver screening criteria for blunt cerebrovascular injury

The Denver Screening Criteria are divided into risk factors and signs and symptoms

Signs and Symptoms

• Arterial hemorrhage
• Cervical bruit
• Expanding neck hematoma
• Focal neurologic deficit
• Neuro exam inconsistent with head CT
• Stroke on head CT

Stroke Syndromes

Anterior Circulation

• Blood supply via internal carotid system
• Includes ACA and MCA

Internal Carotid Artery

• Tonic gaze deviation towards lesion
• Global aphasia, dysgraphia, dyslexia, dyscalculia, disorientation (dominant lesion)
• Spatial or visual neglect (non-dominant lesion)

Anterior Cerebral Artery (ACA)

Signs and Symptoms:

• Contralateral sensory and motor symptoms in the lower extremity (sparing hands/face)
• Urinary and bowel incontinence
• Left sided lesion: akinetic mutism, transcortical motor aphasia
• Right sided lesion: Confusion, motor hemineglect
• Presence of primitive grasp and suck reflexes
• May manifest gait apraxia

Middle Cerebral Artery (MCA)

Patient with stroke (forehead sparing).

Signs and Symptoms:

• Hemiparesis, facial plegia, sensory loss contralateral to affected cortex
• Motor deficits found more commonly in face and upper extremity than lower extremity
• Dominant hemisphere involved: aphasia
  • Wernicke's aphasia (receptive aphasia) -> patient unable to process sensory input and does not understand verbal communication
  • Broca's aphasia (expressive aphasia) -> patient unable to communicate verbally, even though understanding may be intact
• Nondominant hemisphere involved: dysarthria (motor deficit of the mouth and speech muscles; understanding intact) w/o aphasia, inattention and neglect side opposite to infarct
• Contralateral homonymous hemianopsia
• Gaze preference toward side of infarct
• Agnosia (inability to recognize previously known subjects)

Posterior circulation

• Blood supply via the vertebral artery
• Branches include, AICA, Basilar artery, PCA and PICA

Signs and Symptoms:

• Crossed neuro deficits (i.e., ipsilateral CN deficits w/ contralateral motor weakness)
• Multiple, simultaneous complaints are the rule (including loss of consciousness, nausea/vomiting, alexia, visual agnosia)
• 5 Ds: Dizziness (Vertigo), Dysarthria, Dystaxia, Diplopia, Dysphagia
• Isolated events are not attributable to vertebral occlusive disease (e.g. isolated lightheadedness, vertigo, transient ALOC, drop attacks)
• Approximately 25% associated with aortic dissection

Basilar artery

Signs and Symptoms:

• Quadriplegia, coma, locked-in syndrome
• "Crossed signs" in which a patient has unilateral cranial nerve deficits but contralateral hemiparesis and hemisensory loss suggest brainstem infarction
  • Millard-Gubler syndrome (ventral pontine syndrome) -- ipsilateral CN VI and VII palsy with contralateral hemiplegia of extremities
• Sparing of vertical eye movements (CN III exits brainstem just above lesion)
  • Thus, may also have miosis b/l
• One and a half syndrome (seen in a variety of brainstem infarctions)
  • "Half" - INO (internuclear ophthalmoplegia) in one direction
  • "One" - inability for conjugate gaze in other direction
  • Convergence and vertical EOM intact
• Medial inferior pontine syndrome (paramedian basilar artery branch)
  • Ipsilateral conjugate gaze towards lesion (PPRF), nystagmus (CN VIII), ataxia, diplopia on lateral gaze (CN VI)
  • Contralateral face/arm/leg paralysis and decreased proprioception
• Medial midpontine syndrome (paramedian midbasilar artery branch)
  • Ipsilateral ataxia
  • Contralateral face/arm/leg paralysis and decreased proprioception
• Medial superior pontine syndrome (paramedian upper basilar artery branches)
  • Ipsilateral ataxia, INO, myoclonus of pharynx/vocal cords/face
  • Contralateral face/arm/leg paralysis and decreased proprioception

Superior Cerebellar Artery (SCA)

• ~2% of all cerebral infarctions
• May present with nonspecific symptoms - nausea/vomiting, dizziness, ataxia, nystagmus (more commonly horizontal)
• Lateral superior pontine syndrome
  • Ipsilateral ataxia, nausea/vomiting, nystagmus, Horner syndrome, conjugate gaze paresis
  • Contralateral loss of pain/temperature in face/extremities/trunk, and loss of proprioception/vibration in LE > UE

Posterior Cerebral Artery (PCA)

Signs and Symptoms:

• Common after CPR, as occipital cortex is a watershed area
• Unilateral headache (most common presenting complaint)
• Visual field defects (contralateral homonymous hemianopsia, unilateral blindness)
• Visual agnosia - can't recognize objects
• Possible macular sparing if MCA unaffected
• Motor function is typically minimally affected
• Lateral midbrain syndrome (penetrating arteries from PCA)
  • Ipsilateral CN III - eye down and out, pupil dilated
  • Contralateral hemiataxia, tremor, hyperkinesis (red nucleus)
• Medial midbrain syndrome (upper basilar and proximal PCA)
  • Ipsilateral CN III - eye down and out, pupil dilated
  • Contralateral paralysis of face, arm, leg (corticospinal)

Anterior Inferior Cerebellar Artery (AICA)

• Lateral inferior pontine syndrome
• Ipsilateral facial paralysis, loss of corneal reflex (CN VII)
• Ipsilateral loss of pain/temperature (CN V)
• Nystagmus, nausea/vomiting, vertigo, ipsilateral hearing loss (CN VIII)
• Ipsilateral limb and gait ataxia
• Ipsilateral Horner syndrome
• Contralateral loss of pain/temperature in trunk and extremities (lateral spinothalamic)

Posterior Inferior Cerebellar Artery (PICA)

Signs and Symptoms:

• Lateral medullary/Wallenberg syndrome
• Ipsilateral cerebellar signs, ipsilateral loss of pain/temperature of face, ipsilateral Horner syndrome, ipsilateral dysphagia and hoarseness, dysarthria, vertigo/nystagmus
• Contralateral loss of pain/temp over body
• Also caused by vertebral artery occlusion (most cases)

Internal Capsule and Lacunar Infarcts

• May present with either lacunar c/l pure motor or c/l pure sensory (of face and body)
  • Pure c/l motor - posterior limb of internal capsule infarct
  • Pure c/l sensory - thalamic infarct (Dejerine and Roussy syndrome)
• C/l motor plus sensory if large enough
• Clinically to cortical large ACA + MCA stroke - the following signs suggest cortical rather than internal capsule:
  • Gaze preference
  • Visual field defects
  • Aphasia (dominant lesion, MCA)
  • Spatial neglect (non-dominant lesion)
• Others
  • Ipsilateral ataxic hemiparesis, with legs worse than arms - posterior limb of internal capsule infarct
  • Dysarthria/Clumsy Hand Syndrome - basilar pons or anterior limb of internal capsule infarct

Anterior Spinal Artery (ASA)

Superior ASA

• Medial medullary syndrome - displays alternating pattern of sidedness of symptoms below
• Contralateral arm/leg weakness and proprioception/vibration
• Tongue deviation towards lesion

Inferior ASA

• ASA syndrome
• Watershed area of hypoperfusion in T4-T8
• Bilateral pain/temp loss in trunk and extremities (spinothalamic)
• Bilateral weakness in trunk and extremities (corticospinal)
• Preservation of dorsal columns

Risk Factors

• Midface Fractures (Le Fort II or III)
• Basilar Skull Fracture with carotid canal involvement
• Diffuse axonal injury with GCS<6
• Cervical spine fracture
• Hanging with anoxic brain injury
• Seat belt abrasion or other soft tissue injury of the anterior neck resulting in significant swelling or altered mental status
  • Isolated seatbelt sign without other neurologic symptoms has not been identified as a risk factor

• Kerwin et al: Using the above criteria for both symptomatic and asymptomatic patients, found a 44% positive angiography rate in 1941 patients.
• Fabian et al: Reported a drop in BCI-associated mortality from 24% to 13% after instituting a broad screening protocol.

Major Points

• The Denver Screening Criteria identify trauma patients at risk for blunt cerebrovascular injury (BCVI)
• Screening 5% of all trauma patients using clinical criteria captured 18% with confirmed vascular injury
• Early identification of BCVI allows initiation of antithrombotic therapy to prevent devastating stroke
• Implementation of screening protocols has been associated with reduced BCVI-related mortality

Study Design

• Prospective, single-center observational study
• Denver Health Medical Center, Level I Trauma Center
• Screening criteria applied to all blunt trauma patients presenting to the ED
• Positive screening triggered 4-vessel cerebral angiography

Population

Inclusion Criteria

• All blunt trauma patients presenting to the trauma center
• Patients meeting one or more Denver screening criteria

Exclusion Criteria

• Penetrating trauma
• Patients who died before screening could be completed

Interventions

• No therapeutic intervention; this was a screening accuracy study
• Patients meeting Denver criteria underwent 4-vessel cerebral angiography
• Positive patients received antithrombotic therapy (heparin or antiplatelet agents)

Outcomes

• 5% of all trauma patients met screening criteria
• 18% of screened patients had confirmed vascular injury on angiography
• Kerwin et al validation: 44% positive angiography rate in 1,941 patients using liberalized criteria
• Fabian et al: BCVI-associated mortality decreased from 24% to 13% after instituting screening

Criticisms

• The Denver Criteria have not been externally validated in a large multicenter study
• CTA has largely replaced conventional angiography for screening, and the criteria were developed in the angiography era
• Sensitivity of the criteria is unknown; some BCVI may be missed in patients not meeting screening criteria
• Optimal antithrombotic treatment protocol for identified BCVI remains debated
• The Memphis criteria provide an alternative screening tool with similar variables

Funding

• None reported

Validation

• The Denver Criteria has not been externally validated
• The Memphis Criteria which includes many of the same criteria screened 3.9% of patients and found an incidence of 29% vascular injury in screened patients.
  • Cervical Spine Fracture
  • Neuro deficit not explained by brain imaging
  • Horner's Syndrome
  • Leforte 2 or 3 fracture
  • Basilar Skull Fracture involving the carotid Canal
  • Seatbelt Sign
  • Neck Hematoma
  • Hanging Mechanism

See Also

• Blunt neck trauma
• Vertebral and carotid artery dissection