Relationship of some varieties of electroencephalographic photosensitivity to clinical convulsive disorders

Reilly, Edward L.; Peters, Jon F.

doi:10.1212/wnl.23.10.1050

Cited by 95 publications

(36 citation statements)

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“…In patients who have a generalized IPS response, the likelihood of having epilepsy ranges from approximately 70% to 90%, (Jayakar and Chiappa, 1990;Kasteleijn-Nolst Trenite,1989;Reilly and Peters, 1973), and the likelihood of having visually induced seizures (termed photosensitive epilepsy) is 60% (Kasteleijn-Nolst Trenite, 1989;KasteleijnNolst Trenite et al, 2001). In epileptic patients the prevalence of photosensitivity ranges from 2% to approximately 10% and the prevalence of photosensitive epilepsy is 1 in 4000 (Verotti et al, 2004).…”

Section: Photic Stimulationmentioning

confidence: 99%

“…Furthermore, there are differing views on the significance of a prolonged or self-limited PPR and its relationship to epilepsy. Reilly and Peters (1973) found that a prolonged PPR (in which the fast component outlasts the stimulus by at least 100 ms suggests probable epilepsy (93%), whereas a selflimited discharge was not diagnostic. Others support the view that only the generalized spike-and-wave response shows a strong association with epilepsy, particularly if it is selfsustaining and continues after the stimulus (Binnie, 1999;Kasteleijn-Nolst Trenite, 1989;Noachtar et al, 1999).…”

Section: Photic Stimulationmentioning

confidence: 99%

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Increasing the Yield of EEG

Mendez

Brenner

2006

Journal of Clinical Neurophysiology

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The EEG is the most common neurodiagnostic test performed to evaluate patients with suspected seizures. The majority of EEGs are requested in patients because of suspected seizures or for seizure management. It is unlikely that the patient's usual spell will be recorded during a routine EEG. Therefore, several activation techniques have been used in clinical EEG to help increase the occurrence of interictal epileptiform abnormalities, which are highly correlated with the diagnosis of a seizure disorder. EEG laboratories have long employed these techniques, which include hyperventilation, intermittent photic stimulation, sleep, and sleep deprivation. However, despite being utilized in routine clinical EEGs for decades, a number of differing views on the usefulness and indications for these procedures exist. This review will evaluate these procedures and review their history, technique, effectiveness, controversies, and unanswered questions.

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Section: Photic Stimulationmentioning

confidence: 99%

Section: Photic Stimulationmentioning

confidence: 99%

Increasing the Yield of EEG

Mendez

Brenner

2006

Journal of Clinical Neurophysiology

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“…The curve for the upper frequency limit is more linear, and similar increments in the percentage of patients responding would be obtained by testing every 10 Hz between 60 and 20 Hz. Although 50 and 60 Hz are above the frequency range of many photostimulators, it is important to include these frequencies where possible because they help to predict a patient's sensitivity to television (1 1). It is because the full-frame rate of European television is 25 Hz that 25-Hz stimulation is included.…”

Section: Justification For the Recommendationsmentioning

confidence: 99%

Photic Stimulation: Standardization of Screening Methods

et al. 1999

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Summary: Purpose: Differences in methodology of intermittent photic stimulation within and between countries in Europe make collaborative research and interpretation of results difficult.Method: Experts in the field of photic stimulation from European countries have given an overview of methods used in routine photic stimulation. A consensus meeting was organized in May 1996 in the Netherlands.Results: Methodology, including specification of a photoDuring intermittent photic stimulation (IPS), subtle seizures such as myoclonic jerks and absence seizures can be evoked, and even tonic-clonic seizures if no precautions are taken. The pathologic responses to IPS, consisting of generalized (poly-) spike and wave discharges, are strongly related to a history of epilepsy. In populations of patients undergoing EEG examination for clinical purposes, if the response outlasts the stimulus train, the prevalence of overt epilepsy is >90% (1,2). IPS can also evoke a number of normal, non-pathologic responses such as photic driving, often with supra-or subharmonics. The "photomyoclonic response" consists of rhythmic action potentials from the orbital and other facial muscles synchronous with the flashes, possibly with a frontal cortical component. Occipital spikes timelocked to the flash may be seen in both photosensitive and other subjects and have no strong association with epilepsy. Other ill-defined reactions to IPS, such as occipital slow waves and generalized spikes at the stimulus frequency, have no known specific significance. Responses to IPS, which are "atypical" in the sense of differing from photic following at the flash rate, are found in 510% of normal adults and 15% of normal children In many EEG laboratories in Europe and elsewhere, IPS is not performed routinely. In those laboratories that (3-5). Conclusions: Consensus was reached in setting up a safe, quick, simple and reliable method to determine whether or not patients are photosensitive. A specification of an international standard for intermittent photic stimulation in the routine EEG examination is given with the purpose of improving patient care and facilitating collaborative research.do undertake photic stimulation routinely, considerable variation exists with respect to the type of photostimulator, the test procedure, and the interpretation of the EEG response. As a result of these variations, findings are inconsistent from one laboratory to another, and this has unfortunate consequences for both patient care and collaborative research.Until now, manufacturers of EEG apparatus and photic stimulators have shown little interest in producing an optimal photostimulator. Lack of knowledge concerning important aspects of methodology can cause a misunderstanding of the photic stimulation procedures and lead to an over-, but mainly an underestimation of photosensitivity.Experts' in the field of photic stimulation from European countries came to a consensus during a meeting in May 1996 held at the instituut voor Epilepsiebestrijding,

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“…These changes are most evident in valproate naive patients but they do not disappear entirely in those on chronic therapy (Rowan et al, 1979). Furthermore, improvement in the upper sensitivity limit can be maintained for 3 months after withdrawal of chronic medication (Harding etal., 1978 (Reilley & Peters, 1973) (Rowan et al, 1979).…”

Section: Photosensitivitymentioning

confidence: 99%

Methods of assessment of antiepileptic drugs.

Milligan¹,

Richens²

1981

Brit J Clinical Pharma

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Epilepsy is a symptom with protean manifestations and as such it is a difficult disease in which to carry out a therapeutic trial. The methods available to research workers for the assessment of new antiepileptic drugs are hampered by the fact that epilepsy is a fluctuant condition. Although it is a chronic disorder open to study using cross‐over trials and within‐patient comparisons, accurate assessment cannot be easily made at any one point in time. Research workers are therefore automatically placed at a time factor disadvantage and this is especially so for those searching for quick methods of evaluating new compounds. The need for a quick and reliable method of assessing a new antiepileptic drug has long been appreciated. This article will discuss the methods currently available and we will begin by considering the most commonly used method of assessment with particular reference to some of the problems involved in conducting a controlled clinical trial in epilepsy.

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Relationship of some varieties of electroencephalographic photosensitivity to clinical convulsive disorders

Cited by 95 publications

References 0 publications

Increasing the Yield of EEG

Increasing the Yield of EEG

Photic Stimulation: Standardization of Screening Methods

Methods of assessment of antiepileptic drugs.

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