Myoclonic seizures

Clonazepam, a typical 1 4 benzodiazepine, is effective in absence seizures, myoclonic jerks and tonic-clonic seizures and given intravenously it attenuates status epilepticus. It is less sedative than phenobarbitone but tolerance develops and its withdrawal, as... 

Phenobarbital Enhances phasic GABAa receptor responses reduces excitatory synaptic responses Nearly complete absorption not significantly bound to plasma proteins peak concentrations in Vi to 4 h no active metabolites tjy2 varies from 75 to 125 h Generalized tonic-clonic seizures, partial seizures, myoclonic seizures, generalized seizures, neonatal seizures, status epilepticus Toxicity Sedation, cognitive issues, ataxia, hyperactivity Interactions Valproate, carbamazepine, felbamate, phenytoin, cyclosporine, felodipine, lamotrigine, nifedipine, nimodipine, steroids, theophylline, verapamil, others... 

Clonazepam As for diazepam >80% bioavailability extensively metabolized but no active metabolites fiy2 20-50 h Absence seizures, myoclonic seizures, infantile spasms Toxicity Similar to diazepam Interactions Minimal... 

Clobazam Indications include absence seizures, myoclonic seizures, infantile spasms ... 

Zonisamide Blocks high-frequency firing via action on VG Na+ channels Approximately 70% bioavailable orally minimally bound to plasma proteins >50% metabolized ty2 50-70 h Generalized tonic-clonic seizures, partial seizures, myoclonic seizures Toxicity Drowsiness, cognitive impairment, confusion, poor concentration Interactions Minimal... 

Nonketotic hyperglycinemia 605899, 238300 238310 238330 Glycine cleavage system (P, H, T, L proteins) <1 100,000. Lethargy, seizures, myoclonic jerks, hypotonia, hiccups. i... 

Myoclonic seizures consist of sudden, very brief, jerking contractions that may involve the entire body or be confined to limited areas, such as the face and neck. The contractions may affect Individual muscles or groups, with simultaneous contraction of both extensor and flexor muscles. These seizures occur In all age groups, with symptoms ranging from rapid tremors to falling down. No loss of consciousness Is detectable because of the brief duration of the seizure. Myoclonic seizures often occur In combination with other seizure types. Valproate and clonazepam are used most often to treat myoclonic seizures lamotrigine and topiramate also have shown some efficacy. 

Absence seizures Myoclonic seizures Clonic seizures Tonic seizures Tonic clonic seizures Atonic seizures... 

Generalized seizures include absence, myoclonic, and tonic-clonic. Manifestations of a generalized tonic-clonic seizure include alternate contraction (tonic phase) and relaxation (clonic phase) of muscles, a loss of consciousness, and abnormal behavior. Myoclonic seizures involve sudden, forceful contractions involving the musculature of the trunk, neck, and extremities. Absence seizures, previously referred to as petit mal seizures, are seizures characterized by a brief loss of consciousness during which physical activity ceases. The seizures typically last a few seconds, occur many times a day, and may go unnoticed by others. 

Similarly, convulsive seizures and a sustained epileptic state persisted after stomach contents were pumped and activated charcoal and anticonvulsive medication were administered in a 43-year-old man who ingested approximately 260 mg/kg endosulfan (Boereboom et al. 1998). At 4 days after exposure, the man was pronounced brain dead, and autopsy revealed cerebral hernia from massive cerebral edema. Eight additional accidental and/or intentional cases of acute poisoning with endosulfan resulting in adverse neurological effects have been reported in more recent studies, six by Blanco-Coronado et al. (1992), one by Lo et al. (1995), and one by Pradhan et al. (1997) two out of the eight resulted in death. Tonic-clonic convulsions were seen in the Blanco-Coronado et al. (1992) cases, whereas Lo et al. (1995) reported the development of muscle fasciculations and episodes of convulsions in their case. In the case reported by Pradhan et al. (1997), the patient had consumed about 75 mL of hquid endosulfan (35% w/v). In this case, in addition to tonic-clonic seizures and myoclonic jerks, the patient developed... 

In addition to the above main categories seizures can be just myoclonic, isolated clonic jerks, or atonic, loss of postural control with just head drooping or the patient actually falling. 

Myoclonic Single and very brief jerks of all major muscle groups. Patients with these may not lose consciousness, due to the seizure lasting less than 3 to 4 seconds. Patients may describe these seizures as shoulder shrugs or spinal chills. Myoclonic seizures may cluster and build into a generalized tonic-clonic seizure. 

Juvenile myoclonic epilepsy (JME) A primary generalized epilepsy syndrome that usually starts in the early to middle teenage years and has a strong familial component. Patients have myoclonic jerks and tonic-clonic seizures and may also have absence seizures. 

Lennox-Gostaut syndrome (LGS) Patients with this syndrome have cognitive dysfunction and mental retardation. Their seizures usually consist of a combination of tonic-clonic, absence, atonic, and myoclonic seizures. 

Outside of the evidence-based guidelines, other pharmacologic treatments are commonly used or avoided. For initial treatment of absence seizures, ethosuximide and valproate are commonly used, not only in the United Kingdom, but also in the United States. Zonisamide may be also used for initial treatment of absence and myoclonic seizures. In absence and myoclonic seizures, carbamazepine, oxcarbazepine, gabapentin, tiagabine, and pregabalin should be avoided, as they have been associated with an exacerbation of these types of seizures. 

BC, a 22-year-old woman, was diagnosed 2 years ago with juvenile myoclonic epilepsy. She has been treated with valproate 1500 mg/day. Since starting valproate she has gained 45 pounds (20.5 kg), continues to have occasional myoclonic jerks, had a generalized tonic-clonic seizure 3 months ago, and is sexually active. Additionally, she complains of easily falling asleep during the day. Due to adverse effects, poor seizure control, and the risk of birth defects with valproate, the decision is made to switch to a different antiepileptic drug. 

Generalized epilepsy with febrile seizures plus (GEFS+), severe myoclonic epilepsy of infancy (SMEI)... 

Intrauterine seizures may occur. The electroencephalogram often displays a hypsarrhythmia or a burst-suppression pattern. Patients display myoclonic jerks, hiccuping and a profound hypotonia. The few patients who survive past the first week usually sustain profound mental retardation and neurological disability. Brain imaging shows atrophy and a loss of myelin. Rarely, patients present later in life with psychomotor retardation and growth failure. Others have had initial normal development followed by a progressive loss of developmental milestones. Some patients have manifested spinocerebellar degeneration and other symptoms of motor dysfunction [27],... 

It is first-line therapy for primary generalized seizures, such as absence, myoclonic, and atonic seizures, and is approved for adjunctive and monotherapy treatment of partial seizures. It can also be useful in mixed seizure disorders. 

Benzodiazepines are the drugs of choice for status epilepticus (see above) however, development of tolerance renders them less suitable for long-term therapy. Clonazepam is used for myoclonic and atonic seizures. Clobazam, a 1,5-benzodiazepine exhibiting an increased anticonvulsant/seda-tive activity ratio, has a similar range of clinical uses. Personality changes and paradoxical excitement are potential side effects. 

Once aldrin is absorbed, it is rapidly metabolized to dieldrin. In a study of five workers exposed to concentrations of aldrin of up to 8.5mg/m who had suffered convulsive seizures or myoclonic limb movements, the probable concentration of dieldrin in the blood during intoxication ranged from 16 to 62 pg/lOOg of blood in healthy workers the concentration of dieldrin ranged up to 22 pg/lOOg of blood. ... 

Seizure disorder Alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures. May be useful in patients with absence seizures (petit mal) who have failed to respond to succinimides (see Anticonvulsant section). 

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