Vertebral and carotid artery dissection

Background

• Most frequent cause of CVA in young and middle-aged patients (median age - 40yrs)
• Symptoms may be transient or persistent
• Consider in trauma patient who has neurologic deficits despite normal head CT
• Consider in patient with CVA + neck pain

Risk Factors

• Neck trauma (often minor)
• Coughing
• Connective tissue disease
• History of migraine

Clinical Features

Internal Carotid Dissection

• Unilateral headache, face pain, anterior neck pain
  • Pain can precede other symptoms by hours-days (median 4d)
  • Headache most commonly is frontotemporal; severity may mimic SAH or preexisting migraine
• Partial Horner syndrome (miosis and ptosis)
• Cranial nerve palsies

Vertebral Artery Dissection

• Posterior neck pain, HA
  • May be unilateral or bilateral
  • HA is typically occipital
• Unilateral facial paresthesia
• Dizziness
• Vertigo
• N/V
• Diplopia and other visual disturbances
• Ataxia

Differential Diagnosis

Neck Trauma

• Penetrating neck trauma
• Blunt neck trauma
  • Vertebral and carotid artery dissection
  • Strangulation
  • Whiplash injury
• Cervical injury
  • Cervical fractures and dislocations
  • Cervical injury (peds)
  • Cervical spine clearance
• Neurogenic shock
• Spinal cord injury

Diagnosis

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

If positive, CTA or MRA

• 

  CTA brain showing filling defect in the R carotid artery (circled)

Management

Anti-coagulation followed by vascular repair is the generally accepted treatment. Anti-coagulation prevents clot propagation along the dissecting lumen

tPA

• Do not give if dissection enters the skull (ie Intracranial)
• Do not give if aorta is involved
• Otherwise, give according to same guidelines as for ischemic CVA (see CVA (tPA))

Antiplatelet vs Anticoagulation Therapy

Very controversial with poor data

• Heparin: If dissection causes neuro deficits and is EXTRACRANIAL
• Aspirin: If dissection is INTRACRANIAL
• Aspirin: If dissection is extracranial but no neuro deficit, for prevention of thrombo-embolic event
• If tPA was given, wait 24hr before starting antiplatelet therapy
• Do not give if NIHSS score ≥ 15 (risk of hemorrhagic transformation)

Endovascular Therapy

• Emergent consultation with vascular surgery.
• tPA use does not exclude patients from endovascular therapy

Complications

• CVA
  • Risk of stroke or recurrent stroke is highest in the first 24hr after dissection
• SAH (if dissection extends intracranially)

See Also

• Blunt neck trauma