Vertebral Artery Flashcards
Vertebral Artery supplies what percentage of blood to the brain?
20%
Vertebral Artery originates from what artery?
Subclavian Artery
The vertebrobasilar artery system consists of what three vessels?
2 vertebral arteries
1 basilar artery
Two vertebral arteries come together at the midline to form what artery?
Basilar artery
Portion of vertebral artery that originates at subclavian artery to point of entry to cervical spine.
Proximal portion. VA enters the transverse foreman of C6 in most people
2nd portion of VA runs from C6 to transverse foramen of C2
Transverse portion. Surrounded by periosteal sheath in transverse canal
Complications in Transverse portion
Prone to compression from osteophyte formation. Subluxation from facet joint. Adjacent to anterior spinal roots. VA close in proximity to uncinate processes of each vertebral body.
Portion that exits tat the axis (C2) to its point of penetration into the spinal canal
Suboccipital portion
4 divisions of the suboccipital portion
- Within transverse foramen of C2
- Btw C2 and C1
- In the transverse foramen of C1
- Btw posterior arch of atlas and entry into foramen magnum
Where is VA most vulnerable to compression and stretching
At level of C1-C2 with cervical rotation
Suboccipital portion VA vulnerable to impingement from what?
- Cervical extension at the CV joints
- Excursion of the transverse mass of C1 during rotation
- Ossification of the atlantoaxial membrane
Portion of VA from foramen magnum to formation of the basilar artery at the lower border of the pons
Intracranial portion
Intracrnial portion of the VA is prone to what mechanical obstructions?
atherosclerotic plaques and stenosis
Branches of the VA
- Meningeal Branch:
- Anterior Spinal Artery
- Posterior Spinal Artery
- Muscular Branches
- Posterior Inferior Cerebellar Artery
What does the meningeal branch of the VA supply?
Bone and dura mater (cerebellar fossa)
Vertebrobasilar Insufficiency
Damage and occlusion of vertebral arteries felt to occur because close proximity of VA and bony and ligamentous structures of the cervical spine.
Additional Reasons for vertebrobasilar insufficiency
- Atherosclerotic involvement of the artery
- Sickle cell disease
- RA
- Arterial fibroplasias
- Arteriovenous fistula
- Number of congenital syndromes
Most common mechanism for non-penetrating trauma injury to VA
Hyperextension of the neck, with or without cervical rotation or SB
VBI - Internal Causes
- Atherosclerosis
- Thrombosis
- Arterial fibrodysplasia
- Arteriorvenous Fistulas (abnormal connection or passageway btw artery and vein)
- Klippel-Trenaunay Syndrome
Klippel Trenaunay Syndrome
Condition that affects development of blood vessels, soft tissue, and bones
Clinical Manifestations of VBI
- Dizziness/vertigo
- Drop attacks
- Diplopia
- Dysarthria
- Dysphagia
- Nausea
- Numbness
- Nystagmus
- Tinnitus
- HA
- Gait ataxia
- Clonus
- Hyperreflexia
- babinski
- Hoffman or Oppenheimm Sign
- Hemifacial paralysis
- Periodic LOC
Major Risk factors for Arterial Intimal Damage (stroke)
- Hypertension (BP > 140/90)
- Hypercholesterolemia
- Hyperlipidemia
- Diabetes
- Family history of myocardial infarct, anginaTIA
- Smoking
- BMI > 30
- Repeated/recent injury (including repeated manipulations)
- Upper cervical instability
Minor Risk factors for Arterial Intimal Damage (stroke risk)
- Estrogen-based contraceptive
- Hormone replacement therapy
- Infection (systemic)
- Poor diet
- RA or other connective tissue syndrome
- Blood-clotting disorder
- Fibromuscular dysplasia
- Hypermobility
- Erective dysfunction
- BMI 25-29
Imaging Studies VA
- Conventional angiography = gold standard
- Magnetic resonance angiographic (MRA)
- Doppler Sonography
Conventional Angiography
Gold standard. Shows arterial lumen. Allows extensive characterization of dissection of Vas
Magnetic Resonance Angiographic (MRA)
Less invasive. Replacing conventional angiography as gold standard. MRA highly sensitive and specific in identifying stenosis and occlusions
Doppler Sonography
Allows direct visualization of vascular tree. Assesses blood flow velocity and pressure waveforms
Suspect possible subdural hematoma?
Worst headache of my life
Examination of VA
5 Ds And 3 Ns.
- stop test if pt. doesn’t feel good.
- observe for changes in pupil size, nystagmus, speech,
Horner’s Syndrome
Results in decreased pupil size, a drooping eyelid, and decreased sweating of the affected side of your face
No neck pain/HA then have thunderclap onset of worst HA/pain of life?
Signs of stroke
Two strongest risk factors for stroke?
HA and dizziness
SMT on cervical Spine? (Avoid)
Avoid…
- Excessive rotation
- Non physiological movements in joints
- Agressive forceful maneuvers, instead gradually build rom gentle mobilization to higher amplitude and velocity mobilizations
Absolute contraindications to manual therapy
Infection Acute circulatory problems malignancy open wounds recent fractures hematomas hypersensitivity to skins inappropriate end feels advanced diabetes cellulitis severe pain extensive radiation of pain
Relative Contraindications to MT
Joint Inflammation effusion RA Neurological signs Osteoporosis Pregnancy Dizziness Steroid or anticoagulant therapy
