Transcranial Sonography and
Vertebrobasilar Insufficiency

This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to:    Frankp@chiro.org

FROM:   J Manipulative Physiol Ther 2002 (Mar); 25 (3): 180–183 ~ FULL TEXT

Thomas Terenzi, DO, EdD, DC

Rheumatology Fellow,
Department of Internal Medicine,
Winthrop-University Hospital,
Mineola, Long Island, New York

Submit reprint requests to:
Thomas Terenzi, DO, EdD, DC,
Winthrop-University Hospital,
50 Harding Dr,
Rye, NY 10580

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Objective:   The objective was to discuss a case illustrating the role of transcranial Doppler sonography in the screening and treatment of a patient with intermittent vertebral artery brainstem ischemia.

Clinical Features:   A 28-year-old woman had neck pain, arm pain, headaches, and dizziness. Her symptoms occurred intermittently over several years. Past care had provided little relief. De Kleyn's test, transcranial Doppler sonography, and magnetic resonance imaging/magnetic resonance angiography helped establish a diagnosis of vertebrobasilar syndrome.

Intervention and Outcome:   The patient was referred for neurosurgical evaluation. She subsequently chose to be treated with spinal manipulative therapy. Her neck pain, headaches, and radicular symptoms resolved. The dizzy spells abated to a tolerable level. The neurosurgeon subsequently re-evaluated the patient and recommended that surgery not be performed.

Conclusions:   This illustrates a case of extra-arterial mechanical compression of the vertebral arteries documented by transcranial Doppler sonography procedures. Brainstem symptoms were correlated with a documented perfusion deficit during cervical positional testing. This case also demonstrated that spinal manipulative therapy may be safely used on patients with vertebrobasilar insufficiency when the biomechanics and related flow studies are elucidated.

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From the Full-Text Article:

Discussion

This case illustrates a patient with vertebrobasilar syndrome resulting from intermittent compression of anomalous VAs. Although the patient history was suggestive of vertebrobasilar insufficiency, a false-negative De Kleyn's positional test result was produced. A TCD examination was performed because of the patient's suggestive history of vascular insufficiency. The TCD displayed classic Doppler signals of a reproducible flow deficit during cervical spine motion. She was referred for MRA, which subsequently demonstrated a circle of Willis anomaly. She was then referred for a neurosurgical evaluation and angiography but refused intervention after consultation. She chose to be treated with a trial of spinal manipulative therapy. Her cervical, radicular, and occipital pain was treated with a flexion-type technique, without a rotational component. She obtained substantial improvement in her condition. The neurosurgeon subsequently re-evaluated her and recommended that surgery not be performed. Aberrant Willis anatomy and hemodynamics put her in a high-risk category for the cervical-spine-related vertebrobasilar insufficiency. Her right VA was the major vessel supplying her basilar artery. Her left VA terminated as the posterior inferior cerebellar artery. The absence of functional posterior communicating arteries identified by TCD and MRA heightened her ischemic risk. [9–12] As the dominant right VA became compressed, collateral flow from the contralateral VA was absent. Collateral flow from the anterior circulation via the internal carotid arteries was also inhibited by the insignificant posterior communicating arteries. Studies by Hoksbergen et al [13, 14] examined PCAs by TCD and compared their diameter at autopsy. They reported that a PCA diameter of at least 0.4 to 0.6 mm is required for flow to occur. Under this criteria our patient's PCAs would be classified as hypoplastic and nonfunctional. Anatomic abnormalities of the basilar artery, VAs, or posterior communicating arteries may increase the risk of posterior circulation insufficiency.

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Conclusion

Transcranial Doppler techniques are currently used to access a diversity of conditions in addition to examining general hemodynamics. These procedures include the evaluation of acute ischemic cerebral events, monitoring recanalization during thrombolytic and percutaneous transluminal angioplasty procedures, intraoperative monitoring during enterectomy, identification of intracardiac shunts, identifying cerebral microembolic events, diagnosing vasospasm associated with subarachnoid hemorrhage, accessing stroke risk by testing physiologic vasomotor reactivity, and confirming cerebral circulatory arrest during the evaluation of brain death. The sensitivity and specificity of TCD is evaluated for each procedure. Recently, emergent TCD procedures have been examined. They are both sensitive and specific in determining arterial occlusion and stenosis in acute cerebral events. Emergent TCD had 88% accuracy for occlusion and stenosis, 87.5% sensitivity, 88.6% specificity, 87.5% positive predictive value, and 88.6% negative predictive value.15 The current limitations include ultrasound attenuation through the skull temporal window and operator dependency. For a more in-depth discussion on the of validation,see reference 1.

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