Myoclonus epilepsy with ragged-red fibers
Nov. 06, 2023
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Clinical expression of temporal lobe seizures depends on the localization of the epileptogenic zone, type of the epileptogenic lesion, and age. Focal seizures in neocortical temporal lobe epilepsies may manifest with or without impaired awareness (21; 20).
Neocortical temporal lobe focal aware seizures (previously classified as simple partial seizures or auras) can be brief, frequently with auditory features, such as buzzing, roaring, radio- or motor-like sounds, and distortions in sounds and words (21; 20). However, the focal seizures often occur with impaired awareness, which may present with auditory symptoms, visual misperceptions, language impairment (ictal aphasia), or ill-defined cephalic or vertiginous sensations. These seizures may progress to a bilateral tonic-clonic seizure (focal onset bilateral tonic-clonic seizure) (21; 20). Preschool children with neocortical temporal lobe epilepsy have nonspecific seizure patterns without the classic auras, and up to 11% may have infantile spasms as seizure manifestations (22).
The EEG abnormalities are more complex in infants and children than in adults. Motor manifestations, including tonic, clonic, or complex behaviors as well as infantile spasms, predominate in infants. Classical impaired awareness focal seizures with behavioral arrest and automatisms and clear lateralizing signs are rare in young children and mainly occur after two years of age (22).
• The most common lesions causing neocortical epilepsies are low-grade tumors, malformations of cortical development, posttraumatic, ischemic, and inflammatory-infectious scars, and cavernous angioma.
• Neocortical temporal lobe seizure semiology varies considerably according to the area of the temporal lobe involved.
• Classical lateral temporal focal seizures are characterized by auditory, language, or visual symptoms or ill-defined cephalic or vertiginous sensations.
Although nonconvulsive seizures with complex behaviors have been recognized since antiquity (60), their relationship to temporal lobe origin was first described in the late 1800s by Jackson (34; 35). The psychic and motor characteristics of these seizures first prompted the designation of psychomotor seizures (28; 27). With the advent of electroencephalography and the increased interest in surgical intervention, the anatomical significance of these seizures led to them being labeled temporal lobe seizures (59).
Most temporal lobe seizures originates in the mesial structures, primarily in the hippocampus, with the rest beginning in various temporal neocortical regions (66; 38).
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