Seizures
Michael B O’Neill, Michelle Mary Mcevoy, Alf J Nicholson, Terence Stephenson, Stephanie Ryan in Diagnosing and Treating Common Problems in Paediatrics, 2017
Juvenile myoclonic epilepsy, also known as Janz’s syndrome, is one of the most common epilepsy syndromes. Approximately 5% of people with epilepsy have juvenile myoclonic epilepsy. The seizures typically begin in early adolescence and persist into adulthood. The seizures are characterised by early-morning jerks of the head, neck and upper limbs that usually occur shortly after waking. Myoclonic jerks are characterised by brief, bilateral, usually symmetrical synchronous muscle contractions. Seizures can be triggered by sleep deprivation, stress, menstruation, photic stimulation or alcohol consumption. Other seizure types can also occur, including generalised tonic–clonic and absence seizures. Typical EEG features are 3 Hz spike and wave discharges. Juvenile myoclonic epilepsy is inherited; however, the exact mode of inheritance is unclear. In 50% of cases there may be a positive family history.
Basic mechanisms
Timothy Betts, Lyn Greenhill in Managing Epilepsy with Women in Mind, 2005
Although comparatively rare (about 1 % of all new epilepsies) this is an important syndrome. Sometimes West syndrome passes into the Lennox-Gastaut syndrome, but most cases arise de novo usually appearing between 1 and 8 years of age. Characteristically there is a rapid onset of multiple seizure types (myoclonic jerks, atonic (drop) attacks, atypical absences and tonic and tonic-clonic seizures). There is a characteristic EEG with a slow spike wave pattern, and 90% of patients develop moderate to severe learning difficulties - sometimes the result of uncontrolled seizures. Seizures tend to be refractory to standard anticonvulsants and the ketogenic diet is still used for this condition. Lamotrigine and topiramate, however, appear to be at least moderately effective if used early, and felbamate, although potentially toxic, can also be tried. If a patient has severe atonic seizures that cannot be controlled in any other way, surgical section of the anterior two-thirds of the corpus callosum may be helpful, although there is a school of thought
Accident and Emergency
Nagi Giumma Barakat in Get Through, 2006
Other causes are hypoglycaemia, hypocalcaemia and rarely hyponatraemia. The following should also be considered: sepsis, maternal drug withdrawal, benign familial neonatal seizure, pyridoxine dependence, hypertension and inborn errors of metabolism. Seizures can be subtle, tonic, clonic and myoclonic. Neuroimaging should be performed in babies with focal seizures or with neurological deficit, developmental regression and uncontrolled seizures. EEG can also be done, but after a detailed history has been taken and after other biochemical abnormalities, different seizure types and recurrence of seizures have been ruled out, and not with the first seizure. Answer: B
Emerging drugs for the treatment of Dravet syndrome
Published in Expert Opinion on Emerging Drugs, 2018
Francesco Brigo, Pasquale Striano, Ganna Balagura, Vincenzo Belcastro
DS typically presents with prolonged seizures, often associated with fever, in the first year of age in previously healthy children [7]. Seizure types are usually focal unilateral and tonic-clonic, but also myoclonic seizures and atypical absence may occur [8]. Seizures are typically refractory to medication, and epilepsy is associated with neurodevelopmental delay, with cognitive and psychomotor impairment and personality disorders which become apparent between the age of 1 and 4 years. Electroencephalogram findings are age-dependent and variable among different patients. Patients typically show epileptiform abnormalities (focal, multifocal, or generalized) from the onset and photoparoxysmal response in up to 40% of cases [9]. Brain magnetic resonance imaging (MRI) studies in patients with DS and SCN1A mutations shown abnormal findings in a small minority of patients, including focal brain atrophy, cortical dysplasia, and hippocampal sclerosis. There is no correlation between the occurrence of MRI abnormalities and duration of epilepsy, age at seizure onset, or the frequency of episodes of status epilepticus occurred early in life [10].
Ancient Indian concepts about phenomenology, biology, and therapeutics of epilepsy
Published in Journal of the History of the Neurosciences, 2018
Although it is unknown if the ancient Indian literature delineated partial-onset and generalized-onset seizures, both appear to have been well documented. Our current definitions of partial and generalized seizures reflect our understanding of the onset of these seizure types. In the International League Against Epilepsy (ILAE) glossary for ictal semiology, a focal/partial seizure is defined as one whose “initial semiology indicates, or is consistent with, initial activation of only part of one cerebral hemisphere,” whereas generalized/bilateral seizure is defined as one with “more than minimal involvement of both cerebral hemispheres” by initial semiology (Blume et al., 2001). One of the archaic French expressions for generalized tonic-clonic seizures was grahṅ mahl, a precursor for the English grand mal, which in all probability is derived from the Sanskrit “grahan: attack, and maha: major or great” (Phythian, 1984, p. 62). In CS, there is an interesting description of the frequency of seizures, though our current understanding will not attest to it: “vitiated doshas generate paroxysmal epileptic seizures at intervals of twelve days, a fortnight, or a month, with some variation” (CS, Verse 13).
An evaluation of clobazam tablets and film (AQST-120) for the treatment of Lennox-Gastaut syndrome
Published in Expert Opinion on Pharmacotherapy, 2019
Frank M.C. Besag, Michael J. Vasey
Lennox-Gastaut syndrome (LGS) is an age-specific, chronic epileptic encephalopathy characterized by the triad of 1) multiple seizure types, primarily tonic, atonic and atypical absences 2) abnormal electroencephalogram (EEG) with waking diffuse slow (2–2.5 Hz) spike-wave patterns and paroxysmal fast rhythms during sleep, and 3) cognitive and behavioral impairment and/or regression [1]. Onset is typically before the age of 8 years, most commonly between the ages of 3 and 5 years [1]. Incidence is estimated to be between 1% and 10% of childhood epilepsies [2]. European studies estimate a prevalence of 0.1–0.28 per 1000 population [3] with boys more affected than girls (relative risk 5.31) [4]. Diagnosis is complicated by heterogeneous clinical presentations: not all patients will show the indicative seizure types at onset nor is the characteristic EEG itself pathognomonic [5]. Etiology is also diverse: genetic mutation, developmental abnormality, pre-, peri- or neo-natal brain insult, infection and tumor may all be implicated [5,6]. Approximately one-fifth of cases progress from West syndrome [2], an epileptic syndrome with onset in infancy or early childhood, typically during the first year, characterized by the clinical triad of clustered spasms, hypsarrhythmic EEG, and developmental delay or regression [7]. Cause is undetermined in 25–33% of LGS cases [6]. After seizure onset, developmental impairment or regression is seen in most patients: autistic traits and other behavioral and/or cognitive disabilities may be present in more than 50% of cases [8,9].
Related Knowledge Centers
- Absence Seizure
- Autonomic Nervous System
- Electroencephalography
- Febrile Seizure
- Status Epilepticus
- Neurology
- Seizure
- Signs & Symptoms
- Generalized Tonic–Clonic Seizure
- Focal Seizure