Acquired Epileptic Aphasia: Landau Kleffner Syndrome

Landau Kleffner Syndrome (LKS) previously known as Acquired Epileptic Aphasia, is a rare childhood epilepsy syndrome where seizures are associated with loss of receptive and expressive language skills, as well as cognitive problems. LKS typically affects more boys than girls and typically presents between the ages of 2 and 9 years. 

Causes

It was previously thought that the seizures were causing the language deficits but it has also been found that in a minority of cases there is a genetic component to LKS involving the GRIN2A gene. However, no cause is yet known for the majority of cases

Characteristics

The initial signs are seizures or abrupt or gradual loss of speech and expressive language and the ability to comprehend (receptive language). Seizures develop in most of the children in up to 70% of cases and include absence seizures, atonic seizures and also tonic-clonic and focal seizures which often occur in sleep. Children may have silent electrical seizures during sleep in the part of the brain responsible for language which are detectable on EEG. Seizures in LKS are usually treatable with medication.

The child’s language difficulties may be pronounced enough that they cannot comprehend speech or recognize voices and are often misunderstood to have a hearing defect, mutism or autism. With time the difficulties may extend to being unable to differentiate everyday sounds and the child’s speech may be incomprehensible or cease altogether. Considerable variations and fluctuations in performance can be seen in short periods, even over the course of a day.

Other difficulties with behaviour and mood may emerge with attention and concentration issues, hyperactivity, mood changes and impulsivity. Learning issues may be seen in respect of verbal, reading and comprehension skills although non verbal skills may be retained.

In some cases the child may show co-ordination and movement difficulties related to LKS.

Prognosis

The prognosis is favourable for the epileptic seizures and these tend to cease in the mid teens. However, the language, behaviour and learning problems may persist in children with LKS and a minority will not have impaired language or learning skills into the future. Multidisciplinary assessment and intervention from professionals in neurology, neuropsychology and speech and language are important in the planning of educational and therapeutic supports for children with LKS. Some children will benefit from special education interventions and settings to support language and communication skills.

While some children will recover speech and language comprehension others may only partially regain language skills. Children who show LKS symptoms after age 6 have a good chance of improving with immediate speech and language intervention. Recovery from LKS is prolonged with variations of improvements and relapse over the course of that time.

Diagnosis

A clinical history of the child’s seizures and development will be taken at the outset. Children with LKS have typically had normal language development prior to the onset of seizures or loss of language skills although there are cases of LKS emerging in the context of language delay. Investigations such as CT scans and MRI are typically normal. EEG findings are diagnostic of LKS. Abnormalities are typically seen on a routine EEG. A sleep EEG may show more pronounced abnormalities called continuous spike and waves in slow sleep (CSWSS) or Electrical Status Epilepticus in Sleep (ESES).

Treatment

Anti-Seizure Medications

Anti-seizure medications are effective in treating seizures in LKS and the ASM’s used include Ethosuximide, (Zarontin), Sodium Valproate (Epilim), Clobazam (Frisium) and Levetiracetam (Keppra) and Sulthiame (Ospolot). Steroids such as Prednisolone may be used on a short term basis. Some medications such as Carbamazepine (Tegretol), Phenobarbitone and Phenytoin (Epanutin)  are not effective and may aggravate the seizures in LKS. Prolonged seizures will  require the administration of emergency medication to prevent status epilepticus and your child’s neurology team will advise on a care plan and protocol for administering emergency medication.

Ketogenic Diet

The ketogenic diet has not been used with many children with LKS but there may be a role for it if ASM’s fails to control the seizures.

Surgery

Epilepsy surgery called a multiple subpial transection may rarely be considered if ASM’s and dietary therapies are unsuccessful at controlling seizures and if the child is suitable for this kind of surgery.

Further Information