Visual snow: A thalamocortical dysrhythmia of the visual pathway?

@article{Lauschke2016VisualSA,
  title={Visual snow: A thalamocortical dysrhythmia of the visual pathway?},
  author={Jenny L. Lauschke and Gordon T. Plant and Clare L. Fraser},
  journal={Journal of Clinical Neuroscience},
  year={2016},
  volume={28},
  pages={123-127}
}

Tables from this paper

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...

References

SHOWING 1-10 OF 44 REFERENCES

'Visual snow' - a disorder distinct from persistent migraine aura.

It is suggested that 'visual snow' is a unique visual disturbance clinically distinct from migraine aura that can be disabling for patients and systematic studies of its clinical features, biology and treatment responses need to be commenced to begin to understand what has been an almost completely ignored problem.

fMRI evidence that precision ophthalmic tints reduce cortical hyperactivation in migraine

The normalization of cortical activation and SF tuning in the migraineurs by POTs suggests a neurological basis for the therapeutic effect of these lenses in reducing visual cortical hyperactivation in migraine.

Should ‘visual snow’ and persistence of after-images be recognised as a new visual syndrome?

The visual experience is likened to ‘television (TV) snow’ or ‘TV noise’ which is the random dot pattern of static displayed when there is no signal on an analoguei TV monitor, hence, the term ‘visualSnow’.

[The visual snow phenomenon.]

Disorders of visual perception

A functional anatomical classification of all disorders linked to visual perception, whatever the clinical context in which they arise, including those disorders that bridge vision, emotion, memory, language and action is attempted.

Ophthalmological assessment of cannabis-induced persisting perception disorder: Is there a direct retinal effect?

A direct effect of cannabinoids on the retina and retinal pigment epithelium function is suggested, which may be involved in disturbances of the visual function experienced after drug consumption.

Migraine: Multiple Processes, Complex Pathophysiology

Attempts to understand the headache pain itself point to activation of the trigeminovascular pathway as a prerequisite for explaining why the pain is restricted to the head, often affecting the periorbital area and the eye, and intensifies when intracranial pressure increases.

A neural mechanism for exacerbation of headache by light

It is proposed that photoregulation of migraine headache is exerted by a non–image-forming retinal pathway that modulates the activity of dura-sensitive thalamocortical neurons.

A nosographic analysis of the migraine aura in a general population.

The intra-individual variation of aura symptoms shown in this study indicates that a simplification of the International Classification of Diseases, Neurological Adaptation is appropriate and that cortical spreading depression is the mechanism underlying the migraine aura.

Treatment of photosensitive epilepsy using coloured glasses

An open trial to ascertain whether the colorimetry assessment, as it is now given, is safe for the investigation of photosensitive patients in optometry clinics, and what proportion of patients with photosensitive epilepsy is likely to benefit to the extent already described in individual cases.