Ultrasound in Neurology.

PURPOSE OF REVIEW: Low cost, avoidance of irradiation, and high temporal resolution are inherent advantages of ultrasound imaging that translate into multiple clinical uses in many domains of neurology. This article presents clinical uses of ultrasound examination in cerebrovascular, neurodegenerative, and peripheral nervous system diseases. RECENT
FINDINGS: Modern treatment and prevention of ischemic stroke rely on prompt diagnosis. Ultrasonography has found a place as a noninvasive screening test and bedside technique that provides estimates of the degree of stenosis as well as hemodynamic and structural information about intracranial and extracranial vessels in real time. Other standard applications of neurosonology include detection of vasospasm in patients with subarachnoid hemorrhage, selection of appropriate candidates for blood transfusion among patients with sickle cell anemia (primary stroke prevention), right-to-left shunt testing, emboli detection, vasomotor reactivity assessment, and noninvasive confirmation of cerebral circulatory arrest. Improvement in image quality permits novel uses of ultrasonography in neurodegenerative and peripheral nervous system disorders, providing clinically important information that is complementary to the clinical examination and electrophysiology. Transcranial parenchymal sonography may assist in the differential diagnosis of movement disorders, while peripheral nerve ultrasound using high-frequency probes may provide structural information regarding the underlying etiology of entrapment neuropathies.
SUMMARY: The indications for neurosonology are rapidly expanding, increasing its applicability outside the field of cerebrovascular diseases. Ultrasound testing is a noninvasive easily repeatable bedside investigation providing clinically relevant information on a wide spectrum of neurologic disorders.