content:epilepsy_aphasia_disorders

Epilepsy aphasia spectrum

The epilepsy-aphasia spectrum is a group of conditions that have overlapping signs and symptoms. A key feature of these conditions is impairment of language skills (aphasia). The language problems can affect speaking, reading, and writing. The conditions are also charactarised by distinct EEG patterns. Individuals with the condition develop recurrent seizures and have mild to severe intellectual disability.

The conditions in the epilepsy-aphasia spectrum, which all begin in childhood, include Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep syndrome (ECSWS), autosomal dominant rolandic epilepsy with speech dyspraxia (ADRESD), intermediate epilepsy-aphasia disorder (IEAD), atypical childhood epilepsy with centrotemporal spikes (ACECTS), and childhood epilepsy with centrotemporal spikes (CECTS).

LKS and ECSWS are at the severe end of the spectrum. In both these conditions the EEG shows a continuous spike and waves during slow-wave sleep (CSWS).

Most children with LKS develop normally in early childhood, although some speak later than their peers. However, affected children lose language skills beginning around age 5. This loss typically begins with verbal agnosia. As LKS develops, the ability to express speech is also impaired. Approximately 70 percent of children with LKS develop focal(partial) seizures.

About half of children with ECSWS develop normally in early childhood, while others have delayed development of speech and motor skills. Although children with ECSWS typically lose a range of previously acquired skills, including those involved in language, movement, learning, or behavior, not everyone with ECSWS has aphasia. Seizures occur in approximately 80 percent of children with ECSWS and can include atypical absence seizures, hemiclonic seizures or generalized tonic-clonic seizures.

CECTS is at the mild end of the epilepsy-aphasia spectrum. Affected children have rolandic seizures involving the rolandic region of the brain. The seizures, which usually occur during sleep, cause twitching, numbness, or tingling of the face or tongue, often causing drooling and impairing speech. In most people with CECTS, the seizures disappear by the end of adolescence. Most affected individuals develop normally, although some have impairment of language skills.

The other conditions in the epilepsy-aphasia spectrum are less common and fall in the middle of the spectrum. Children with IEAD usually have delayed development or regression of language skills. Some have seizures and most have abnormal sleep EEGs although not prominent enough to be classified as CSWS. ACECTS features seizures and developmental regression that can affect movement, language, and attention. Children with ACECTS have abnormal EEG sometimes charactaristic of CSWS. ADRESD is characterized by focal seizures, speech difficulties due to dyspraxia, and learning disability.

  • mutations in the GRIN2A gene can result in conditions in the epilepsy-aphasia spectrum.
  • The GRIN2A gene provides instructions for making the GluN2A protein, a subunit of a subset of NMDA receptors.
  • NMDA receptor signalling is involved in normal brain development, synaptic plasticity, learning, and memory and also play a role in brain signalling during slow-wave sleep.
  • GRIN2A variants are found in up to 20 percent of people with LKS or ECSWS and about 5 percent of people with CECTS.
  • even in individuals with GRIN2A variants some have a mild condition while others are severely affected even within the same family. The cause of this is not known
  • there are possibly other unidentified genes associated with epilepsy-aphasia spectrum disorders. Environmental factors may also play a role in the development of these conditions.
  • content/epilepsy_aphasia_disorders.txt
  • Last modified: 6 months ago
  • by icna