JJJL I f
FIGURE 36.1 An 8-year-old self inducing a photoconvulsive seizure by waving his fingers before his eyes. Note how the physical induction precedes the polyspike discharge and clinical absence.
FIGURE 36.1 An 8-year-old self inducing a photoconvulsive seizure by waving his fingers before his eyes. Note how the physical induction precedes the polyspike discharge and clinical absence.
TABLE 36.1
Epilepsy types
Somatosensory Touch
Proprioception Memory
Epilepsy
Partial
Partial
Origin
Somatosensory cortex
Limbic
Audiogenic Musicogenic Speech-induced Photosensitive Flash
Geometric pattern Color
Partial Primary auditory cortex
Temporal, limbic cortex
Generalized Primary visual cortex
Thinking
Generalized Nondominant parietal
Praxis
Generalized Nondominant parietal, prefrontal
Reading
Generalized Temporoparietal
Startle Generalized Supplementary somatosensory, prefrontal
Seizure types
Tonic
Focal motor
Focal motor Complex-partial Focal motor Complex-partial
Myoclonic
Absence
Tonic-clonic
Myoclonic
Absence
Tonic-clonic
Myoclonic
Absence
Tonic-clonic
Myoclonic
Absence
Tonic-clonic
TonicMyoclonic
Ki Oi CO
Notes
Often have Jacksonian component
"Hot water," "eating," "toothbrashing" variants
Walking-induced variant
LGIl-associated; prominent in Fragile X syndrome
Associated with stimulus induction
"Arithmetic," "mental imagery," "chess," "Rubik's cube" and "Mah Jong" variants, among numerous others
Utensil-induced variant ยป
Likelihood of seizure may increase with duration or complexity of material of a
Seen typically in children with mental retardation and/or diffuse cortical ^
anomalies ^
The boy presented in the vignette has photic flicker-induced seizures, and his presentation is consistent with simple reflex epilepsy. He self-induces his seizures via the stroboscopic effect of light seen through his waving fingers These seizures can be a challenge to treat, as standard antiepileptic treatment may not fully extinguish the photoconvulsant effect . In addition, the wide range of environmental light triggers, combined with the patient's pleasurable secondary gain, can make for a uniquely challenging scenario.
Flicker-induced seizures may be seen in generalized epilepsy syndromes, as well as in focal occipital lobe epilepsies . In addition, a number of varieties of photic stimulation-sensitive seizures have been described, including color (wavelength) and frequency-sensitive seizures, seizures induced by certain geometric patterns, seizures triggered by stepping into the light after emerging from a dark area, and seizures triggered by diverting one's attention away from an item of visual interest ("fixation-off" seizures). An overlap of photosensitive epilepsy with migraine may be seen, and an association of headache with occipital spiking has been described within this association
Self-induced reflex seizures were first described by Radovici (1932) . There is a peculiar tendency of some patients with photosensitive epilepsy to actively seek out the very light that, in turn, may provoke an attack The motivation of patients with this so-called "sunflower syndrome" may perhaps be understood with the realization that photosensitive seizures may be pleasurable for some patients, and patients will thus engage in hand-waving, finger-flapping, or staring at the television in order to purposefully induce seizures . Many children that stimulate their own photosensitive seizures may have comorbid mental retardation, but a significant proportion of them are cognitively normal Intentional provocation of seizures in order to avoid school or a stressful life event has been reported Some patients also report that they may induce seizures at a convenient time in order to take advantage of the relative refractory period that follows
Post a comment