A Comprehensive Review of Low-Intensity Focused Ultrasound Parameters and Applications in Neurologic and Psychiatric Disorders

Abstract

Objectives: Low-intensity focused ultrasound (LIFU) is gaining increased interest as a potential therapeutic modality for a range of neuropsychiatric diseases. Current neuromodulation modalities often require a choice between high spatial fidelity or invasiveness. LIFU is unique in this regard because it provides high spatial acuity of both superficial and deep neural structures while remaining noninvasive. This new form of noninvasive brain stimulation may provide exciting potential treatment options for a variety of neuropsychiatric disorders involving aberrant neurocircuitry within deep brain structures, including pain and substance use disorders. Furthermore, LIFU is compatible with noninvasive neuroimaging techniques, such as functional magnetic resonance imaging and electroencephalography, making it a useful tool for more precise clinical neuroscience research to further understand the central nervous system.

Materials and methods: In this study, we provide a review of the most recent LIFU literature covering three key domains: 1) the history of focused ultrasound technology, comparing it with other forms of neuromodulation, 2) the parameters and most up-to-date proposed mechanisms of LIFU, and finally, 3) a consolidation of the current literature to date surrounding the clinical research that has used LIFU for the modification or amelioration of several neuropsychiatric conditions.

Results: The impact of LIFU including poststroke motor changes, pain, mood disorders, disorders of consciousness, dementia, and substance abuse is discussed.

Conclusions: Although still in its infancy, LIFU is a promising tool that has the potential to change the way we approach and treat neuropsychiatric disorders. In this quickly evolving field, this review serves as a snapshot of the current understanding of LIFU in neuropsychiatric research.

Keywords: Dementia; depression; low-intensity focused ultrasound (LIFU); neuromodulation; neuropsychiatric disorders.

Figure 1.

Schematic of primary Transcranial focused ultrasound (tFUS) stimulation parameters. [Color figure can be viewed at www.neuromodulationjournal.org]