Landau Kleffner Syndrome
Landau Kleffner syndrome (LKS) is named for two doctors who studied children who, after one or more seizures, develop language difficulties and exhibit autistic characteristics. As a true epileptic syndrome, LKS is rather rare. Some doctors do not consider it to be a form of epilepsy, as not all children with LKS have seizures. When seizures are present, they add 'with epilepsy' to the diagnosis or refer to LKS as acquired epileptic aphasia. Children with LKS first show signs of the disorder between 3 and 9 years of age. Before LKS, they usually grow and develop normally. The syndrome may be caused by an illness, such as chicken pox, ear infection, or trauma such as when an infant falls from a changing table to the floor, or surgery.
SYMPTOMS
The symptoms of LKS include:
• difficulty in communicating with speech and language, e.g., problems understanding what is said (receptive dysphasia) and difficulty putting thoughts into words (expressive dysphasia).
• auditory verbal agnosia, e.g., struggling to find words for familiar objects.
• difficulty in understanding words spoken or written by others. This symptom is often mistaken for a hearing problem, as the child seems to ignore people.
Other aspects of learning are probably not affected by LKS, and it is rare for children to suffer from damage to their intellectual abilities. About two-thirds of affected children
exhibit hyperactivity (hyperkinesia). Seizures occur in about 75% of children with LKS, usually within a few weeks of the first signs of language difficulty. They are either tonic-clonic or complex partial seizures. Some children may only have a single seizure or status epilepticus in the early days of LKS.
DIAGNOSIS
On EEG, LKS is diagnosed by signs of malfunction on both sides of the brain. Usually, spike-and-wave activity is more prominent in the dominant half of the brain, which deals with language function. In most children, these malfunctions appear on the left side.
Some children show greater activation of EEGs during sleep. They may have almost continual epileptic discharges (continuous spike waves of sleep) or, more commonly, electrical status epilepticus of sleep (ESES). If ESES exists, a newly developed therapy with high bedtime doses of Valium or, at times, prolonged treatment with steroid hormones may be needed.
TREATMENT
In the early stages, most children need antiepileptic drugs to control the partial seizures. When persistent seizures are associated with continuing language problems, surgery may help. This therapeutic option follows a careful selection process.
A careful assessment of a child's educational strengths and weaknesses is also important in order to find an appropriate school. This kind of educational support decreases the possibility that a child will become frustrated and confused. Speech therapy, when used early, has proven to be very effective.
PROGNOSIS
The long-term outlook for most children is positive. Seizures usually disappear when children are between 10 and 15 years of age. In half of children, language difficulties disappear within a few months or years. In the remainder, some improvement occurs over time. Most children recover their speech functions before adulthood. In about 20% of cases, language difficulties remain indefinitely. Children make the best recovery when language problems start after 6 years of age, when speech and language skills are already well developed.
SOURCES
Frank H. Duffy, MD, Clinical Neurophysiology
Laboratory, Boston Children's Hospital, Boston,
Mass., USA
Epilepsy Today, www.epilepsy.org.uk
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