JNNP-For patients with visual abnormalities, non-invasive local cerebral blood flow monitoring explains its mechanism

Visual snow is a neurological disease.
It is defined as a continuous visual impairment in the form of countless small dots covering the entire field of vision
.

Visual snow represents a spectrum-type disease, in its worst case manifested by most of these additional symptoms, as well as distressing comorbidities such as migraine and tinnitus; in this case, this condition is Think it is very disabling

Although the pathophysiology of VSS is still largely unknown, more and more literature has begun to provide some insights into the possible biological mechanisms of the disease
.

Behavioral and neurophysiological studies have shown that the pattern of change points to increased cortical excitability and visual cortex dysfunction

Arterial spin labeling (ASL) is a quantitative, non-invasive functional MRI technology, which has been greatly developed in the past ten years; this method uses the phenomenon of neuro- vascular coupling, and uses static perfusion as An indirect but sensitive marker of neuronal activity
.

Blood vessel

In this way, Francesca Puledda of KCL in the United Kingdom and others explored the inherent differences in brain activity between VSS patients and the control group, and used ASL to determine the differences in regional cerebral blood flow (rCBF)
.

Given that VSS is characterized by perceptual abnormalities, in order to distinguish between changes in visual processing and the ongoing visual snow effect itself, they studied the conditions of subjects during rest and visual tasks that simulate visual snow experience

They conducted MRI studies and used pseudo-continuous ASL to obtain whole-brain rCBF maps
.

Twenty-four VSS patients and an equal number of gender and age-matched healthy volunteers participated in the study

They found that VSS patients had a higher rCBF than the control group in a wide range of brain networks, including bilateral wedge, precubic, auxiliary motor cortex, anterior motor cortex and posterior cingulate cortex, as well as the left primary auditory cortex and spindle.

Back and cerebellum

These areas are to a large extent similar to when the comparative patient is at rest, or when looking at "snow-like" visual stimuli
.

These areas are to a large extent similar to those when the comparative patient is at rest, or when looking at "snow-like" visual stimuli
.

These areas are to a large extent similar to those when the comparative patient is resting, or when looking at "snow-like" visual stimuli

In addition, compared with the control group, during visual stimulation, the rCBF of the right cerebral cortex of VSS subjects increased, reflecting greater changes related to the task.
In addition, compared with the control group, during visual stimulation, the VSS subjects Increased rCBF in the right cerebral cortex, reflecting greater task-related changes

These studies show that VSS patients have obvious differences in the brain processing of visual stimulation, verifying its neurobiological basis
.

Original source:
Puledda F, Schankin CJ, O'Daly O, Ffytche D, Eren O, Karsan N, Williams SCR, Zelaya F, Goadsby PJ.

Localised increase in regional cerebral perfusion in patients with visual snow syndrome: a pseudo-continuous arterial spin labelling study.
J Neurol Neurosurg Psychiatry.

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