Summary: Cognitive deficits associated with long-COVID can show substantial improvement within three to four days following alternating non-invasive brain stimulation using microcurrents.
Source: IOS Press
Many people who recover from COVID-19 continue to experience persistent cognitive problems—impaired memory, reduced attention, difficulty understanding language, trouble multitasking—and pronounced fatigue. These symptoms often last for weeks or months after the initial infection has resolved and can severely affect daily functioning and the ability to work.
A new case report shows that these cognitive deficits in long-COVID can be rapidly reduced using alternating non-invasive brain stimulation with microcurrents (NIBS). The authors describe noticeable improvements in cognition and partial reversal of visual field loss in two long-COVID patients after only a few days of treatment.
The findings were published in Restorative Neurology and Neuroscience and reported by lead investigator Bernhard A. Sabel, PhD, Director of the Institute of Medical Psychology at Otto-von-Guericke University, Magdeburg, Germany.
“COVID infection can lead to delayed and sometimes severe cognitive impairments,” Dr. Sabel explained. “Common long-COVID complaints include fatigue, breathlessness, shortened attention span, and loss of short-term memory—symptoms that dramatically reduce quality of life. Until now, clinicians have had few effective options that produce rapid improvements in visual and cognitive function.”
The research team focused on vascular dysfunction as a likely contributor to long-COVID symptoms. Vascular problems in the retina and brain can impair neuronal metabolism and function; because many patients report vision changes, the investigators reasoned that restoring vascular regulation through NIBS might also reactivate underperforming neurons and improve cognition. Prior clinical experience in glaucoma patients suggested NIBS could enhance visual function by improving blood flow and neuronal synchronization.
Two female patients with long-COVID symptoms received alternating current stimulation targeting the eyes and brain for 45 minutes daily over 10 and 13 days, respectively. Both had significant vision problems and severe cognitive impairments that prevented normal work and daily activities. One patient, age 40, developed symptoms after infection with SARS-CoV-2; the other, age 72, developed symptoms following an AstraZeneca vaccination.
Before and after the treatment course, the researchers assessed cognition through interviews and standardized testing, and they measured visual fields with perimetry. One patient also underwent a full cognitive test battery and retinal dynamic vascular analysis (DVA), which serves as a noninvasive marker of vascular dysregulation that can reflect brain microvascular status.
Both patients experienced marked cognitive improvement and partial recovery of visual fields within three to four days of starting NIBS. Improvements included reduced fatigue, better short-term memory, enhanced attention, and improved multitasking ability. Both patients were able to resume work. Objective cognitive testing in one patient demonstrated recovery of 40–60% across specific cognitive subfunctions, and perimetry showed stable visual-field gains that persisted at follow-up.
Retinal DVA measurements supported a vascular mechanism: NIBS appeared to normalize vessel dynamics by reducing dysregulation of dilation and constriction, with notable effects in small arterial and venous microvessels. The authors propose that hypometabolic or “silent” neurons—cells rendered underactive by reduced blood flow and oxygenation—are a plausible biological basis for long-COVID visual and cognitive deficits. By improving microvascular function and reoxygenating these neurons, NIBS may reactivate residual neuronal capacity and restore function.
Co-author Andreas Gonschorek, MD, from the BG Clinic, Neurocenter Hamburg, Germany, emphasized the clinical importance of these observations: “An estimated 20–30% of COVID-19 patients develop lasting cognitive deficits after recovery, and the rate is even higher among hospitalized patients. Many experience persistent problems with speech, learning, memory, and executive function, as well as mood disturbances such as depression and reduced stress resilience.”
Dr. Sabel concluded, “This case report is the first demonstration that cognitive impairment related to long-COVID can improve within just a few days of NIBS treatment. While NIBS is already available in some clinical settings, controlled clinical trials are necessary to confirm these results, refine protocols, and clarify mechanisms of action.”
About this neurology and COVID-19 research news
Author: Diana Murray
Source: IOS Press
Contact: Diana Murray – IOS Press
Image: The image is in the public domain
Original Research: Open access. “Non-invasive brain microcurrent stimulation therapy of long-COVID-19 reduces vascular dysregulation and improves visual and cognitive impairment” by Bernhard A. Sabel et al., Restorative Neurology and Neuroscience.
Abstract
Non-invasive brain microcurrent stimulation therapy of long-COVID-19 reduces vascular dysregulation and improves visual and cognitive impairment
Background:
Long-COVID patients often experience persistent visual and cognitive symptoms—impaired attention, memory deficits, language comprehension problems, and debilitating fatigue—yet effective rapid treatments are lacking.
Objective:
Because COVID-19 can reduce cerebral blood flow and thereby inactivate neurons, the investigators tested whether non-invasive brain stimulation using microcurrent (NIBS), which can enhance blood flow and neuronal synchronization, can reduce these symptoms.
Methods:
Two female long-COVID patients underwent 10–13 days of alternating current stimulation directed at the eyes and brain for 45 minutes daily. One patient’s symptoms followed confirmed SARS-CoV-2 infection (age 40); the other developed symptoms after AstraZeneca vaccination (age 72). Assessments before and after therapy included subjective interviews, perimetry to quantify visual fields, and—for one patient—a formal cognitive test battery and retinal dynamic vascular analysis (DVA) as a surrogate marker of cerebral microvascular dysregulation.
Results:
Both patients showed marked cognitive improvement and partial reversal of visual field loss within three to four days after beginning NIBS. Formal cognitive testing confirmed recovery of 40–60% across several cognitive subfunctions in one patient. Perimetry documented stable visual-field improvements at follow-up. DVA data indicated normalization of vessel dynamics, with reduced vascular dysregulation especially in peripheral microvessels.
Conclusions:
In these two cases, NIBS improved visual and cognitive deficits associated with long-COVID, with recovery linked to restored vascular autoregulation. The authors propose that hypometabolic “silent” neurons underlie long-COVID neurological symptoms and that reoxygenation via improved microvascular function supports neuronal reactivation and clinical recovery. Larger, controlled trials are needed to validate these promising preliminary results.