Prominent publications by Graham F A Harding

KOL Index score: 12425

OBJECTIVE: To estimate the prevalence of visual field defects in patients taking the anticonvulsant drug vigabatrin and to characterise the features of visual dysfunction found.

METHODS: Thirty three unselected patients attending neurology and epilepsy clinics were identified as taking vigabatrin and asked to attend for neuro-ophthalmic evaluation. A control group of 16 patients with epilepsy unexposed to vigabatrin was also evaluated. Visual fields were examined by static perimetry ...

Known for Field Defects |  Patients Vigabatrin |  Static Perimetry |  Visual Dysfunction |  Ocular Humans
KOL Index score: 8075

PURPOSE: This report summarizes background material presented to a consensus conference on visually provoked seizures, convened by the Epilepsy Foundation of America.

METHODS: A comprehensive review of literature was performed.

RESULTS: Photosensitivity, an abnormal EEG response to light or pattern stimulation, occurs in approximately 0.3-3% of the population. The estimated prevalence of seizures from light stimuli is approximately 1 per 10,000, or 1 per 4,000 individuals age 5-24 years. ...

Known for Epilepsy Foundation |  Range Hz |  Pattern Stimulation |  Seizures Light |  Abnormal Eeg Response
KOL Index score: 7889

PURPOSE: Symptomatic visual field constriction thought to be associated with vigabatrin has been reported. The current study investigated the visual fields and visual electrophysiology of eight patients with known vigabatrin-attributed visual field loss, three of whom were reported previously. Six of the patients were no longer receiving vigabatrin.

METHODS: The central and peripheral fields were examined with the Humphrey Visual Field Analyzer. Full visual electrophysiology, including ...

Known for Multifocal Electroretinography |  Visual Evoked |  Field Constriction |  Patients Vigabatrin |  Retinal Level
KOL Index score: 7743

The antiepileptic drug, vigabatrin, has been linked to a specific pattern of visual field loss. The majority of studies have not included the paediatric population due to difficulties assessing visual field function. This is a particular problem as vigabatrin is effective against infantile spasms. A field-specific visual evoked potential was developed which consisted of a central stimulus (0–5° radius) and a peripheral stimulus (30–60° radius). Both stimuli consist of black and white ...

Known for Visual Field |  Infantile Spasms |  Antiepileptic Drug |  Sensitivity Specificity |  Anticonvulsants Child
KOL Index score: 7698

PURPOSE: Vigabatrin (VGB) therapy is associated with a loss of peripheral vision. The characteristics and prevalence of VGB-attributed visual field loss (V-AVFL) and associated risk factors were evaluated in patients with epilepsy.

METHODS: The material comprised the visual fields and case notes of 88 patients with suspected V-AVFL (25 spontaneous reports and 63 cases from an open-label extension trial) and of 42 patients receiving alternative antiepileptic drugs (AEDs) from a ...

Known for Visual Field |  Vgb Attributed |  95 Confidence Interval |  Patients Epilepsy |  Vigabatrin Vision
KOL Index score: 7693

OBJECTIVE: To derive a visual-evoked potential (VEP) technique for identifying visual field defects in children with epilepsy treated with vigabatrin and unable to perform perimetry.

BACKGROUND: Studies have linked vigabatrin to a specific pattern of visual field loss. Few studies have included the pediatric population because of difficulties in assessing the visual field by perimetry below a developmental age of 9 years.

METHODS: A field-specific VEP was developed with a central (0 ...

Known for Visual Field |  Evoked Potentials |  Peripheral Stimulus |  Vep Technique |  Specific Pattern
KOL Index score: 7590

Changes in the ERG and VEP across the life span were investigated. The dark adapted and scotopic ERGs both showed a progressive increase in the implicit times of the A and B waves and a reduction in the amplitude of the AB configuration. There was also an increase in the implicit times of the oscillatory potentials of the photopic ERG.The flash and pattern onset-offset VEP both showed changes in waveform with age whilst the waveform of the pattern reversal VEP was constant. The ...

Known for Visual Evoked |  Retinal Illuminance |  Age Reduction |  Increase Implicit |  Oscillatory Potentials
KOL Index score: 7062

We describe cortical potentials evoked by balloon distension of the proximal and distal oesophagus in 8 healthy right handed volunteers. Oesophageal stimulation was performed using a pump which rapidly inflated a 2 cm silicone balloon positioned either 3 cm distal to the upper oesophageal sphincter or 5 cm proximal to the lower oesophageal sphincter, at a frequency of 0.2 Hz, using inflation volumes which produced a definite but not painful sensation. Oesophageal evoked cortical ...

Known for Cortical Potentials |  Oesophageal Stimulation |  Distal Oesophagus |  Balloon Distension |  02 Hz
KOL Index score: 6864

PURPOSE: The continued presence of EEG abnormalities in patients with a history of photosensitive seizures is used to signify the persistence of photosensitive epilepsy. The extent to which this approach places patients at risk of seizures is unclear, however. We describe those EEG abnormalities that may be tolerated with low risk of further seizures, and those that are indicative of poor seizure control.

METHODS: Fifty patients with EEG evidence of persistent photosensitive epilepsy ...

Known for Photosensitive Epilepsy |  Photic Stimulation |  Clinical Significance |  Seizures Patients |  Abnormalities Ips
KOL Index score: 6854

PATIENTS suffering from photosensitive epilepsy show generalized discharges in their electroencephalogram (EEG) during intermittent photic stimulation. In some patients, these discharges are preceded by occipital spikes, suggesting a focal onset. Hishikawa et al.1 have reported that the occipital spikes obtained in photo-sensitive epileptics have the same latency as some components of the visual evoked responses (VER), and suggested, that this might explain the origin of the occipital ...

Known for Occipital Spikes |  Intermittent Photic Stimulation |  Photosensitive Epilepsy |  Visual Evoked Responses |  Evoked Potentials
KOL Index score: 6613

The aim of this study was to use the technique of magnetoencephalography (MEG) to determine the effects of strabismic amblyopia on the processing of spatial information within the occipital cortex of humans. We recorded evoked magnetic responses to the onset of a chromatic (red/green) sinusoidal grating of periodicity 0.5-4.0 c deg-1 using a 19-channel SQUID-based neuromagnetometer. Evoked responses were recorded monocularly on six amblyopes and six normally-sighted controls, the stimuli ...

Known for Strabismic Amblyopia |  Evoked Responses |  Occipital Cortex |  Contrast Sensitivity |  Interocular Differences
KOL Index score: 6612

The aim of this study was to establish whether there is non-geniculostriate input to the extrastriate motion-sensitive area V5 in humans. Responses were measured with a SQUID neuro-magnetometer to motion stimuli presented within the blind hemifield of GY, a well-documented subject with a complete absence of the left primary visual cortical area V1. The motion stimulus was a 0.5c/deg, rapidly drifting (16Hz) achromatic sinusoidal grating. With this stimulus, the magnetic responses ...

Known for Area V5 |  Motion Stimuli |  Magnetic Responses |  Complete Absence |  Geniculostriate Visual
KOL Index score: 6523

Previous work has indicated recreational use of methylenedioxymethamphetamine (MDMA or ecstasy) is associated with elevated scores on self-report measures of depression. We sought to examine the long-term effects of consumption on depression in a group of individuals who had consumed large quantities of the drug in the past, but were now leading relatively drug free lives. Respondents to this study (n = 29) had consumed an average of 1.5 ecstasy tablets in the last month, 8.4 in the last ...

Known for Mdma Ecstasy |  Chronic Users |  Life Stress |  Levels Depression |  Depressive Symptoms


Graham F A Harding: Influence Statistics

Sample of concepts for which Graham F A Harding is among the top experts in the world.
Concept World rank
morphology transient veps #1
epilepsies stimulation #1
ips pattern stimulation #1
abnormalities photic #1
nongeniculostriate visual input #1
vigabatrin visual fields #1
erg retina scotoma #1
vestigial echo #1
sensory receptors seizures #1
100 p100m time #1
electroretinography epilepsy #1
components pattern veps #1
primary presenile #1
evidence photosensitivity #1
regulations television #1
visual mechanisms photosensitivity #1
visual stimuli electroencephalogram #1
television evokes #1
20position grid #1
flash pattern reversal #1
seizures child electroencephalography #1
subtense screen #1
increase implicit #1
component thirty subjects #1
isoluminant point #1
control groups17 #1
equivalent age dementia #1
dementia flash #1
magnetic p100m #1
formal television video #1
amblyopic stimuli #1
blank annulus #1
vpa male prognosis #1
threeway doubleblind study #1
television abnormalities #1
35 39 children #1
contact lens stimulator #1
photosensitive epilepsy abnormalities #1
residual luminance variation #1
ips hz #1
hz patterned #1
13 spontaneous reports #1
years photosensitivity #1
electrical magnetic response #1
green sinusoids #1

Key People For Photosensitive Epilepsy

Top KOLs in the world
Graham F A Harding
photosensitive epilepsy visual evoked photic stimulation
Colin D Binnie
temporal lobe epileptic seizures wada test
Arnold Jonathan Wilkins
visual discomfort coloured overlays pattern glare
P M Jeavons
occipital spikes photosensitive epilepsy sodium valproate
Dorothée G A Kasteleijn‐Nolst Trenité
photosensitive epilepsy photic stimulation hemicrania epileptica
Renzo Guerrini
dravet syndrome cortical development epilepsy surgery

Graham F A Harding:Expert Impact

Concepts for whichGraham F A Hardinghas direct influence:Photosensitive epilepsy,  Visual evoked,  Occipital spikes,  Eeg abnormalities,  Photic stimulation,  Visual evoked potential,  Evoked potentials,  Pattern reversal.

Graham F A Harding:KOL impact

Concepts related to the work of other authors for whichfor which Graham F A Harding has influence:Evoked potentials,  Visual field,  Photosensitive epilepsy,  Photic stimulation,  Infantile spasms,  Antiepileptic drugs,  Photoparoxysmal response.



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