Total 14 clinical symptoms reported for Developmental and epileptic encephalopathy 94 
Bilateral tonic-clonic seizure A bilateral tonic-clonic seizure is a seizure defined by a tonic (bilateral increased tone, lasting seconds to minutes) and then a clonic (bilateral sustained rhythmic jerking) phase.
 
Synonyms:Bilateral convulsive seizures; Generalised tonic-clonic seizure (without specification of onset); Generalized convulsion; Generalized tonic-clonic seizure (without specification of onset); Grand mal; Grand mal seizures; Seizures, tonic-clonic; Tonic-clonic convulsion; Tonic-clonic convulsions
Very frequent
Developmental regression Loss of developmental skills, as manifested by loss of developmental milestones.
 
Synonyms:Loss of acquired milestones; Loss of developmental milestones; Loss of milestones; Mental deterioration in childhood; Neurodevelopmental regression; Psychomotor regression; Psychomotor regression beginning in infancy; Psychomotor regression in infants; Psychomotor regression, progressive
Very frequent
Generalized myoclonic seizure A generalized myoclonic seizure is a type of generalized motor seizure characterized by bilateral, sudden, brief (<100 ms) involuntary single or multiple contraction of muscles or muscle groups of variable topography (axial, proximal limb, distal). Myoclonus is less regularly repetitive and less sustained than is clonus.
 
Synonyms:Generalised epileptic myoclonus; Generalised myoclonic seizure; Generalized epileptic myoclonus; Generalized myoclonic seizures; Myoclonus seizures
Very frequent
Global developmental delay A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
 
Synonyms:Delayed cognitive development; Delayed development; Delayed developmental milestones; Delayed intellectual development; Delayed milestones; Delayed psychomotor development; Developmental delay; Developmental delay in early childhood; Developmental delay, global; Developmental retardation; GDD; Lack of psychomotor development; Motor and developmental delay; Motormental retardation; Psychomotor delay; Psychomotor development deficiency; Psychomotor development failure; Psychomotor developmental delay; Retarded development; Retarded mental development; Retarded psychomotor development
Very frequent
Intellectual disability The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.
 
Synonyms:Intellectual disability; Mental deficiency; Mental retardation; Mental retardation, nonspecific; Mental-retardation; Nonprogressive intellectual disability; Nonprogressive mental retardation
Very frequent