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Atypical absence seizure

MedGen UID:
108888
Concept ID:
C0595948
Disease or Syndrome
Synonym: Atypical absence seizures
SNOMED CT: Atypical absence seizure (23374007)
 
HPO: HP:0007270

Definition

An atypical absence seizure is a type of generalized non-motor (absence) seizure characterized by interruption of ongoing activities and reduced responsiveness. In comparison to a typical absence seizure, changes in tone may be more pronounced, onset and/or cessation may be less abrupt, and the duration of the ictus and post-ictal recovery may be longer. Although not always available, an EEG often demonstrates slow (<3 Hz), irregular, generalized spike-wave activity. [from HPO]

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • Atypical absence seizure

Conditions with this feature

Pachygyria-intellectual disability-epilepsy syndrome
MedGen UID:
333107
Concept ID:
C1838491
Disease or Syndrome
This autosomal recessive neurodevelopmental disorder is characterized by pachygyria, impaired intellectual development, seizures, and diffuse localization of arachnoid cysts. It most likely represents a neuronal migration disorder within the lissencephaly spectrum (summary by Guzel et al., 2007).
Congenital bilateral perisylvian syndrome
MedGen UID:
337000
Concept ID:
C1845668
Disease or Syndrome
Polymicrogyria (PMG) is a malformation of cortical development in which the brain surface is irregular and the normal gyral pattern replaced by multiple small, partly fused gyri separated by shallow sulci. Microscopic examination shows a simplified 4-layered or unlayered cortex. Several patterns of PMG, including bilateral frontal, bilateral perisylvian, and bilateral mesial occipital PMG, have been described on the basis of their topographic distribution. All but the perisylvian form appear to be rare. Bilateral perisylvian PMG (BPP) often results in a typical clinical syndrome that is manifested by mild mental retardation, epilepsy, and pseudobulbar palsy, which causes difficulties with expressive speech and feeding (Kuzniecky et al., 1993). PMG may be a feature of other conditions as well (see, e.g., 300643).
Episodic ataxia type 5
MedGen UID:
356142
Concept ID:
C1866039
Disease or Syndrome
An extremely rare form of hereditary episodic ataxia with characteristics of recurrent episodes of vertigo and ataxia lasting several hours.
Epilepsy, idiopathic generalized, susceptibility to, 9
MedGen UID:
413424
Concept ID:
C2750887
Finding
For a general phenotypic description and a discussion of genetic heterogeneity of idiopathic generalized epilepsy, see 600669. Juvenile myoclonic epilepsy is a subtype of idiopathic generalized epilepsy; see 254770 for a general phenotypic description and a discussion of genetic heterogeneity of JME.
Developmental and epileptic encephalopathy, 18
MedGen UID:
815954
Concept ID:
C3809624
Disease or Syndrome
Developmental and epileptic encephalopathy-18 (DEE18) is a severe autosomal recessive neurologic disorder characterized by lack of psychomotor development apparent from birth, dysmorphic facial features, and early onset of refractory seizures. Brain imaging shows a thick corpus callosum and persistent cavum septum pellucidum on brain imaging (summary by Basel-Vanagaite et al., 2013). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 26
MedGen UID:
863556
Concept ID:
C4015119
Disease or Syndrome
Developmental and epileptic encephalopathy-26 (DEE26) is a neurologic disorder characterized by onset of variable types of seizures late in infancy or in the first years of life. Affected children show developmental delay with intellectual disability, poor speech, and behavioral abnormalities. EEG shows multifocal epileptic discharges, and may show hypsarrhythmia (summary by Torkamani et al., 2014). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 31
MedGen UID:
894942
Concept ID:
C4225357
Disease or Syndrome
Developmental and epileptic encephalopathy-31A (DEE31A) is an autosomal dominant neurologic disorder characterized by the global developmental delay apparent in early infancy. Most individuals have onset of various types of refractory seizures in the first months or years of life, which exacerbates the psychomotor deficits. Patients have hypotonia and profound intellectual disability with absent speech and inability to walk or ataxic gait. Some patients may have additional features, including dysmorphic features or cortical visual impairment (summary by the EuroEPINOMICS-RES Consortium et al., 2014 and Deciphering Developmental Disorders Study, 2015). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 43
MedGen UID:
934679
Concept ID:
C4310712
Disease or Syndrome
Developmental and epileptic encephalopathy-43 (DEE43) is a neurologic disorder characterized by the onset of various types of seizures usually in the first year of life. The age at onset is highly variable, ranging from the neonatal period to about 12 months of age. Later onset may rarely occur. Seizure types include febrile, infantile spasms, focal, tonic-clonic, and myoclonic; they tend to be refractory to treatment. Affected individuals show global developmental delay with mild to moderate intellectual disability, although some may have normal early development before the onset of seizures. EEG shows focal, multifocal, or generalized sharp waves associated with seizures, sometimes with hypsarrhythmia. Additional more variable features include tube feeding, hypotonia, peripheral hypertonia, ataxia, dyskinesia, and behavioral difficulties, including aggression, ADHD, stereotypic, and impulsive behavior (summary by the Epi4K Consortium, 2016). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 52
MedGen UID:
1376462
Concept ID:
C4479236
Disease or Syndrome
Developmental and epileptic encephalopathy-52 (DEE52) is a severe autosomal recessive seizure disorder characterized by infantile onset of refractory seizures with resultant delayed global neurologic development. Affected individuals have impaired intellectual development and may have other persistent neurologic abnormalities, including axial hypotonia and spasticity; death in childhood may occur (summary by Patino et al., 2009 and Ramadan et al., 2017). Some patients with DEE52 may have a clinical diagnosis of Dravet syndrome (607208), which is characterized by the onset of seizures in the first year or 2 of life after normal early development. Developmental delay, impaired intellectual development, and behavioral abnormalities usually become apparent later between 1 and 4 years of age. Dravet syndrome may also include 'severe myoclonic epilepsy in infancy' (SMEI) (summary by Patino et al., 2009). For a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 54
MedGen UID:
1392637
Concept ID:
C4479319
Disease or Syndrome
HNRNPU-related neurodevelopmental disorder (HNRNPU-NDD) is characterized by developmental delay and intellectual disability – typically moderate to severe – with speech and language delay and/or absent speech. Affected individuals may also display autistic features. There may be feeding difficulties during the neonatal period as well as hypotonia, which often remains lifelong. Dysmorphic features have been described but they are nonspecific. Affected individuals are likely to experience seizures (most commonly tonic-clonic or absence) that may be refractory to treatment. Nonspecific brain MRI findings include ventriculomegaly and thinning of the corpus callosum. Less common findings include cardiac abnormalities, strabismus, undescended testes in males, renal anomalies, and skeletal features, including joint laxity, polydactyly, and scoliosis. Rarely, abnormal breathing patterns, including hyperventilation and apnea, may be present and can lead to sleep disturbance.
Epileptic encephalopathy, infantile or early childhood, 1
MedGen UID:
1626137
Concept ID:
C4540199
Disease or Syndrome
Developmental and epileptic encephalopathy-91 (DEE91) is characterized by delayed psychomotor development apparent in infancy and resulting in severely to profoundly impaired intellectual development with poor or absent speech. Most patients never achieve independent walking. Patients typically have onset of refractory multifocal seizures between the first weeks and years of life, and some may show developmental regression. Additional features, such as hypotonia and cortical visual impairment, are more variable (summary by Myers et al., 2017). For a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 57
MedGen UID:
1621769
Concept ID:
C4540411
Disease or Syndrome
Developmental and epileptic encephalopathy-57 (DEE57) is a neurologic disorder characterized by global developmental delay with hypotonia, variably impaired intellectual development, and poor or absent language. Affected individuals have onset of refractory multifocal seizures in the first days or months of life, and may show developmental regression. EEG patterns include hypsarrhythmia, suggesting a clinical diagnosis of West syndrome, background slowing, and epilepsy of infancy with migrating focal seizures (EIMFS). Some patients may have mild dysmorphic features (summary by Ambrosino et al., 2018 and Mao et al., 2020). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Developmental and epileptic encephalopathy, 74
MedGen UID:
1680535
Concept ID:
C5193074
Disease or Syndrome
Developmental and epileptic encephalopathy-74 (DEE74) is neurologic disorder characterized by the onset of refractory seizures in the first months of life. Seizure types are variable and include infantile spasms, myoclonic, tonic, atonic, and absence, often with secondary generalization. Affected individuals have severe global developmental delay with hypotonia, severe motor impairment, roving eye movements, and absent language (summary by Shen et al., 2017). For a general phenotypic description and a discussion of genetic heterogeneity of DEE, see 308350.
Epilepsy, idiopathic generalized, susceptibility to, 16
MedGen UID:
1684869
Concept ID:
C5231421
Finding
Intellectual developmental disorder 60 with seizures
MedGen UID:
1684702
Concept ID:
C5231497
Disease or Syndrome
Autosomal dominant intellectual developmental disorder-60 with seizures is characterized by global developmental delay apparent in infancy, followed by onset of seizures in the first years of life. Patients have delayed walking, an ataxic gait, and moderately to severely impaired intellectual development with poor speech (summary by Helbig et al., 2019).
Lissencephaly 10
MedGen UID:
1719546
Concept ID:
C5394354
Disease or Syndrome
Lissencephaly-10 (LIS10) is a neurologic disorder characterized by variably delayed development with mildly to moderately impaired intellectual development and language delay, as well as seizures, which are often intractable. There is a spectrum of severity, with some patients having normal early development and only borderline to mild cognitive impairment. Brain imaging shows features consistent with neuronal migration defects, including posterior-predominant lissencephaly, pachygyria, agyria, and subcortical band heterotopia (summary by Tsai et al., 2020). For a general description and a discussion of genetic heterogeneity of lissencephaly, see LIS1 (607432).
Focal segmental glomerulosclerosis and neurodevelopmental syndrome
MedGen UID:
1794148
Concept ID:
C5561938
Disease or Syndrome
Focal segmental glomerulosclerosis and neurodevelopmental syndrome (FSGSNEDS) is characterized by global developmental delay and renal dysfunction manifest as proteinuria and nephrotic syndrome apparent from infancy or early childhood. Some patients present with renal disease, whereas others present with developmental delay and develop renal disease later in childhood. Renal biopsy shows focal segmental glomerulosclerosis (FSGS), but the course of the disease is variable: some patients have transient proteinuria and others require renal transplant. Neurodevelopmental features are also variable, with some patients having only mildly impaired intellectual development, and others having a severe developmental disorder associated with early-onset refractory seizures or epileptic encephalopathy. Additional features, including feeding difficulties, poor overall growth, and nonspecific dysmorphic facial features, are commonly observed (summary by Assoum et al., 2018 and Weng et al., 2021).
3-methylglutaconic aciduria, type VIIA
MedGen UID:
1813022
Concept ID:
C5676967
Disease or Syndrome
3-Methylglutaconic aciduria (MGCA7) is an inborn error of metabolism characterized primarily by increased levels of 3-methylglutaconic acid (3-MGA) associated with variable neurologic deficits and neutropenia. The phenotype is highly variable: most patients have infantile onset of a severe progressive encephalopathy with various movement abnormalities and delayed psychomotor development. Other common variable features include seizures, recurrent infections due to neutropenia, anemia, and brain imaging abnormalities (Wortmann et al., 2021). For a general phenotypic description and a discussion of genetic heterogeneity of 3-methylglutaconic aciduria, see MGCA1 (250950).
Neurodevelopmental disorder with hypotonia and speech delay, with or without seizures
MedGen UID:
1841290
Concept ID:
C5830654
Disease or Syndrome
Neurodevelopmental disorder with hypotonia and speech delay, with or without seizures (NEDHSS) is characterized by global developmental delay, impaired intellectual development with poor or absent speech, and fine and gross motor delay. Most affected individuals are severely affected and may be unable to walk, have feeding difficulties requiring tube-feeding, and develop early-onset seizures. Additional features may include cortical blindness and nonspecific structural brain abnormalities. Rare individuals present only with hypotonia and mild developmental delay (Paul et al., 2023).

Professional guidelines

PubMed

Montouris GD, Wheless JW, Glauser TA
Epilepsia 2014 Sep;55 Suppl 4:10-20. doi: 10.1111/epi.12732. PMID: 25284033

Recent clinical studies

Etiology

Yoshitomi S, Takahashi Y, Yamaguchi T, Imai K, Ishii A, Hirose S, Inoue Y
Epilepsy Res 2019 Aug;154:34-38. Epub 2019 Apr 21 doi: 10.1016/j.eplepsyres.2019.02.014. PMID: 31035242
Holder JL Jr, Quach MM
Epilepsia 2016 Oct;57(10):1651-1659. Epub 2016 Aug 24 doi: 10.1111/epi.13506. PMID: 27554343Free PMC Article
Inui T, Kobayashi T, Kobayashi S, Sato R, Endo W, Kikuchi A, Nakayama T, Uematsu M, Takayanagi M, Kato M, Saitsu H, Matsumoto N, Kure S, Haginoya K
Brain Dev 2015 Apr;37(4):449-54. Epub 2014 Aug 20 doi: 10.1016/j.braindev.2014.07.004. PMID: 25149137
Donaldson JA, Glauser TA, Olberding LS
Epilepsia 1997 Jan;38(1):68-73. doi: 10.1111/j.1528-1157.1997.tb01079.x. PMID: 9024186

Diagnosis

Yoshitomi S, Takahashi Y, Yamaguchi T, Imai K, Ishii A, Hirose S, Inoue Y
Epilepsy Res 2019 Aug;154:34-38. Epub 2019 Apr 21 doi: 10.1016/j.eplepsyres.2019.02.014. PMID: 31035242
Holder JL Jr, Quach MM
Epilepsia 2016 Oct;57(10):1651-1659. Epub 2016 Aug 24 doi: 10.1111/epi.13506. PMID: 27554343Free PMC Article
Hamano S, Mochizuki M, Morikawa T
Seizure 2002 Apr;11(3):201-4. doi: 10.1053/seiz.2001.0568. PMID: 12018965

Therapy

Yoshitomi S, Takahashi Y, Yamaguchi T, Imai K, Ishii A, Hirose S, Inoue Y
Epilepsy Res 2019 Aug;154:34-38. Epub 2019 Apr 21 doi: 10.1016/j.eplepsyres.2019.02.014. PMID: 31035242
Holder JL Jr, Quach MM
Epilepsia 2016 Oct;57(10):1651-1659. Epub 2016 Aug 24 doi: 10.1111/epi.13506. PMID: 27554343Free PMC Article
Montouris GD, Wheless JW, Glauser TA
Epilepsia 2014 Sep;55 Suppl 4:10-20. doi: 10.1111/epi.12732. PMID: 25284033
Hamano S, Mochizuki M, Morikawa T
Seizure 2002 Apr;11(3):201-4. doi: 10.1053/seiz.2001.0568. PMID: 12018965
Donaldson JA, Glauser TA, Olberding LS
Epilepsia 1997 Jan;38(1):68-73. doi: 10.1111/j.1528-1157.1997.tb01079.x. PMID: 9024186

Prognosis

Inui T, Kobayashi T, Kobayashi S, Sato R, Endo W, Kikuchi A, Nakayama T, Uematsu M, Takayanagi M, Kato M, Saitsu H, Matsumoto N, Kure S, Haginoya K
Brain Dev 2015 Apr;37(4):449-54. Epub 2014 Aug 20 doi: 10.1016/j.braindev.2014.07.004. PMID: 25149137

Clinical prediction guides

Yoshitomi S, Takahashi Y, Yamaguchi T, Imai K, Ishii A, Hirose S, Inoue Y
Epilepsy Res 2019 Aug;154:34-38. Epub 2019 Apr 21 doi: 10.1016/j.eplepsyres.2019.02.014. PMID: 31035242

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