Convulsive Disorders Year 4 Paediatrics Notes OmpathStudy

Convulsive Disorders Year 4 · Paediatrics Collection: 4TH YEAR ALL NOTES / PAEDS / PAEDS 4.3 / Munge / CNS -- Slide 1 Seizures in Childhood Dr Rose Munge Slide 2 A seizure is a transient occurrence of signs and/or symptoms resulting from abnormal excessive or synchronous neuronal activity in the brain.\n The International League Against Epilepsy (ILAE) operational classification of seizure types divides epileptic seizures into four categories based on the presumed mode of seizure onset: focal, generalized, unknown onset, and unclassified. Slide 3 In focal (formerly known as partial) seizures, the first clinical and EEG changes suggest initial activation of a system of neurons limited to part of one cerebral hemisphere. Focal seizures can be described as motor or nonmotor seizures and are further characterized by preserved or impaired consciousness, which is used synonymously with the term awareness.\n Simple partial seizure is an outdated term that refers to a focal seizure with no alteration in consciousness; the current term is focal aware seizure.\n Complex partial seizure is also an outdated term that denotes focal seizures with altered awareness of the surroundings; they are currently referred to as focal seizures with impaired awareness. Slide 4 In generalized seizures, the first clinical and EEG changes indicate synchronous involvement of all of both hemispheres.\nA seizure may be labeled as being of unknown onset if there is not enough clinical information available to determine if the seizure is focal or generalized.\nIf the clinical characteristics of a seizure are unusual and a determination of onset cannot be made despite an adequate workup, the seizure may be labeled as unclassified.\n30% of patients who have a first afebrile seizure later develop epilepsy; the risk is approximately 20% if the neurologic exam, EEG, and neuroimages are normal. Slide 5 Febrile seizures are a separate category. \nAcute symptomatic or provoked seizures occur secondary to an acute problem affecting brain excitability, such as an electrolyte imbalance; most children with these types of seizures do well.\n Sometimes these seizures signify major structural, inflammatory, or metabolic disorders of the brain, such as meningitis, encephalitis, acute stroke, or brain tumor. Slide 6 An unprovoked seizure is one that is not an acute symptomatic seizure.\n A remote symptomatic seizure is one that is considered to be secondary to a distant brain injury, such as an old stroke. Reflex seizures are a type of seizure precipitated by a sensory stimulus. These types of seizures can be caused by a variety of stimuli, including visual (flickering lights, patterns, reading), auditory (music), somatosensory, or proprioceptive stimuli; praxis; eating; bathing in hot water; or being startled Slide 7 Epilepsy is a disorder of the brain characterized by an enduring predisposition to generate seizures and by the neurobiologic, cognitive, psychological, and social consequences of this condition.\n The clinical diagnosis of epilepsy usually requires the occurrence of at least one unprovoked epileptic seizure with either a second such seizure or enough EEG and clinical information to convincingly demonstrate an enduring predisposition to develop recurrences.\n Epilepsy is considered present when two or more unprovoked seizures occur in a time frame of longer than 24 hr. Slide 8 Approximately 4–10% of children experience at least one seizure (febrile or afebrile) in the first 16 yr of life. The cumulative lifetime incidence of epilepsy is 3%, and more than half of the disorders start in childhood.\n The annual prevalence is 0.5–1.0%.\n The occurrence of a single seizure or of febrile seizures does not necessarily imply the diagnosis of epilepsy Slide 9 Seizure disorder is a general term that is usually used to include any one of several disorders, including epilepsy, febrile seizures, and, possibly, single seizures and symptomatic seizures secondary to metabolic, infectious, or other etiologies. An epileptic syndrome is a disorder that manifests as one or more specific seizure types and has a specific age of onset and a specific prognosis. An epileptic encephalopathy is an epilepsy syndrome in which there is a severe EEG abnormality that is thought to result in cognitive and other impairments.\nDevelopmental encephalopathy denotes a disorder in which the underlying etiology contributes to a developmental delay independently of the patient's seizure burden and/or EEG abnormalities. Slide 10 Mechanisms of Seizures There are 4 distinct processes in the pathophysiology of epilepsy;\nFirst is the underlying etiology- any pathology or pathologic process that can disrupt neuronal function and connectivity and leads to the second process (epileptogenesis), which makes the brain epileptic.\nSometimes the underlying etiology can directly increase excitability even without the contribution of the downstream effects of epileptogenesis. In some genetic epile