Random noise stimulation in the treatment of patients with neurological disorders

Random noise stimulation technique involves applying any form of energy (for instance, light, mechanical, electrical, sound) with unpredictable intensities through time to the brain or sensory receptors to enhance sensory, motor, or cognitive functions. Random noise stimulation initially employed mechanical noise in auditory and cutaneous stimuli, but electrical energies applied to the brain or the skin are becoming more frequent, with a series of clinical applications. Indeed, recent evidence shows that transcranial random noise stimulation can increase corticospinal excitability, improve cognitive/motor performance, and produce beneficial aftereffects at the behavioral and psychological levels. Here, we present a narrative review about the potential uses of random noise stimulation to treat neurological disorders, including attention deficit hyperactivity disorder, schizophrenia, amblyopia, myopia, tinnitus, multiple sclerosis, post-stroke, vestibular-postural disorders, and sensitivity loss. Many of the reviewed studies reveal that the optimal way to deliver random noise stimulation-based therapies is with the concomitant use of neurological and neuropsychological assessments to validate the beneficial aftereffects. In addition, we highlight the requirement of more randomized controlled trials and more physiological studies of random noise stimulation to discover another optimal way to perform the random noise stimulation interventions.