Differences
This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revisionBoth sides next revision | ||
content:dravet_syndrome [2020/02/18 15:00] – [Seizure semiology] bijuhameed | content:dravet_syndrome [2020/02/23 19:55] – [Epilepsy surgery] icna | ||
---|---|---|---|
Line 7: | Line 7: | ||
* Incidence probably less than 1 per 40,000 | * Incidence probably less than 1 per 40,000 | ||
* Males are more often affected than females, in a ratio of 2:1. | * Males are more often affected than females, in a ratio of 2:1. | ||
- | ===== History & Clinical | + | ===== Clinical |
* Dravet syndrome typically occurs in normal infants | * Dravet syndrome typically occurs in normal infants | ||
* Significant antenatal associations reported in literature include intrauterine growth retardation, | * Significant antenatal associations reported in literature include intrauterine growth retardation, | ||
Line 58: | Line 58: | ||
* The ways of propagation are very variable from one seizure to another in the same patient and even in the same recording. The relationship between the clinical events and the accompanying EEG is not always clear. | * The ways of propagation are very variable from one seizure to another in the same patient and even in the same recording. The relationship between the clinical events and the accompanying EEG is not always clear. | ||
* **Myoclonic Seizures** | * **Myoclonic Seizures** | ||
- | * The myoclonic seizures appear between the ages of 1 and 5 years | + | * myoclonic seizures appear between the ages of 1 and 5 years |
- | * They are difficult to analyze due to their variability. Sometimes | + | * they can be quite variable & sometimes |
- | * Sometimes | + | * sometimes they are isolated or grouped in brief bursts consisting of two or three jerks |
- | * The myoclonic jerks can be either | + | * they are very frequent, occurring several times a day, sometimes incessantly. |
- | * They are very frequent, occurring several times a day, sometimes incessantly. | + | |
* Interictal segmental myoclonus are often seen sometimes appearing only before a convulsive seizure with no concomitant change in the EEG. They involve either the limbs of the both sides, with a distal predominance, | * Interictal segmental myoclonus are often seen sometimes appearing only before a convulsive seizure with no concomitant change in the EEG. They involve either the limbs of the both sides, with a distal predominance, | ||
* They exist at rest, but are increased by voluntary movement. | * They exist at rest, but are increased by voluntary movement. | ||
* They are more frequent in the period with seizures, particularly in elder children with frequent nocturnal convulsive seizures, after awakening from attacks. | * They are more frequent in the period with seizures, particularly in elder children with frequent nocturnal convulsive seizures, after awakening from attacks. | ||
- | * In hyperactive children the myoclonus could be made evident by asking them to perform a precise activity such as drinking, piling up cubes, or holding a spoon. | + | * in hyperactive children the myoclonus could be made evident by asking them to perform a precise activity such as drinking, piling up cubes, or holding a spoon. |
- | * The myoclonic jerks are sometimes observed only on awakening or in the minutes preceding a seizure. | + | * the myoclonic jerks are sometimes observed only on awakening or in the minutes preceding a seizure. |
- | * They persist during drowsiness and disappear during slow sleep. | + | * they persist during drowsiness and disappear during slow sleep. |
- | * The jerks can be initiated by photic stimulation, | + | * the jerks can be initiated by photic stimulation, |
- | * They are not typically accompanied by changes in consciousness, | + | * they are not typically accompanied by changes in consciousness, |
- | * Video EEG has shown that they are accompanied by generalized or multiple spike-waves, | + | * telemetry studies indicate |
- | * Electromyography | + | * electromyography |
- | * Sometimes | + | * sometimes |
- | * **Atypical | + | * **Atypical |
* Atypical absence seizures can appear at different ages, either between 1 and 3 years, together with the myoclonic attacks, or later on, from 5 to 12 years. | * Atypical absence seizures can appear at different ages, either between 1 and 3 years, together with the myoclonic attacks, or later on, from 5 to 12 years. | ||
- | * They can be either atypical absence seizures with impaired consciousness only or with a myoclonic component as well. | + | * they can be either atypical absence seizures with impaired consciousness only or with a myoclonic component as well. |
- | * Both seizure types correspond to generalized, | + | * both seizure types correspond to generalized, |
- | * **Obtundation | + | * **Obtundation |
- | * Characterised | + | * characterised |
- | * Depending | + | * depending |
- | * Convulsive | + | * convulsive |
- | * The EEG is characterized by one diffuse slow-wave dysrrhyhmia, | + | * EEG is characterized by one diffuse slow-wave dysrrhyhmia, |
* EEG corresponding to a complex partial status with either continuous posterior localized irregular slow waves or spike-waves during unconsciousness with deviations of both eyes to the right or irregular spike-wave complexes over the left hemisphere, predominantly in the occipitotemporal area have also been reported. | * EEG corresponding to a complex partial status with either continuous posterior localized irregular slow waves or spike-waves during unconsciousness with deviations of both eyes to the right or irregular spike-wave complexes over the left hemisphere, predominantly in the occipitotemporal area have also been reported. | ||
- | * **Focal | + | * **Focal |
* Focal seizures can appear early, from 4 months to 4 years. | * Focal seizures can appear early, from 4 months to 4 years. | ||
- | * They are either Simple partial seizures (SPS) of motor type or more commonly complex partial seizures (CPS), with prominent autonomic symptoms. When the symptomatology is mild, it is difficult to distinguish them from atypical absences without concomitant EEG. The partial seizures could be secondarily generalized. | + | * they are either Simple partial seizures (SPS) of motor type or more commonly complex partial seizures (CPS), with prominent autonomic symptoms. When the symptomatology is mild, it is difficult to distinguish them from atypical absences without concomitant EEG. The partial seizures could be secondarily generalized. |
- | * **Tonic | + | * **Tonic |
- | * Tonic seizures are exceptional in Dravet syndrome and are mainly detected by sleep EEG recordings. When present they resemble the axial tonic seizures of the [[Lennox–Gastaut syndrome]] (LGS), sometimes with a myoclonic component but unlike LGS not frequently repeated in the same recording nor the interictal sleep EEG commonly shows rapid rhythms and multiple SWs like in LGS. | + | * tonic seizures are exceptional in Dravet syndrome and are mainly detected by sleep EEG recordings. When present they resemble the axial tonic seizures of the [[Lennox–Gastaut syndrome]] (LGS), sometimes with a myoclonic component but unlike LGS not frequently repeated in the same recording nor the interictal sleep EEG commonly shows rapid rhythms and multiple SWs like in LGS. |
===== Neurophysiology ===== | ===== Neurophysiology ===== | ||
Line 97: | Line 96: | ||
* localized findings are usually seated in the central areas, bilaterally, | * localized findings are usually seated in the central areas, bilaterally, | ||
* The EEGs contain more generalized paroxysms when myoclonic jerks are present. The relationship between the seat of the interictal paroxysms and the ictal discharges are not always clear. | * The EEGs contain more generalized paroxysms when myoclonic jerks are present. The relationship between the seat of the interictal paroxysms and the ictal discharges are not always clear. | ||
- | * The response to **Hyperventilation: | + | * **Hyperventilation: |
* **Eye closure:** The eye closure may facilitate the occurrence of localized and generalized abnormalities. | * **Eye closure:** The eye closure may facilitate the occurrence of localized and generalized abnormalities. | ||
* **Sleep:** Sleep is usually well structured with physiological patterns and cyclic organization, | * **Sleep:** Sleep is usually well structured with physiological patterns and cyclic organization, | ||
Line 180: | Line 179: | ||
===== Epilepsy surgery ===== | ===== Epilepsy surgery ===== | ||
Andrade et al (2010)[(: | Andrade et al (2010)[(: | ||
+ | |||
+ | The presumed topography of the epileptogenic areas involves preferentially the mesial frontal lobe, the central area, sometimes the parietal and, even, the occipital lobes. Few interictal foci are localized in the temporal area. Surprisingly a hippocampal sclerosis has not been shown in the MRI of these patients who had prolonged and repeated severe FS[(: | ||
===== Cannabidiol ===== | ===== Cannabidiol ===== | ||
* Clinical trials show that cannabidiol reduces the number of convulsive and non-convulsive seizures when compared with usual care[(: | * Clinical trials show that cannabidiol reduces the number of convulsive and non-convulsive seizures when compared with usual care[(: | ||
Line 252: | Line 253: | ||
There is a wide variation among the phenotypes in these conditions and is possibly due to the strong influence of the genetic background. | There is a wide variation among the phenotypes in these conditions and is possibly due to the strong influence of the genetic background. | ||
- | ===== Classification | + | ===== References |
- | Dravet syndrome is classified under Electroclinical syndromes in the Revised ILAE Classification and Terminology (2010). In the majority of cases, no etiology has been found. A mitochondrial cytopathy has been reported in rare cases. | + | ~~REFNOTES~~ |
- | The presumed topography of the epileptogenic areas involves preferentially the mesial frontal lobe, the central area, sometimes the parietal and, even, the occipital lobes. Few interictal foci are localized in the temporal area. Surprisingly a hippocampal sclerosis has not been shown in the MRI of these patients who had prolonged and repeated severe FS. | ||