Landau-Kleffner Syndrome
A rare disease with multiple variants

Is it LKS?

A difficult disorder to diagnose, LKS may look like a hearing impairment or any of the following: • Autism • Pervasive developmental disorder (PDD) • Learning disability • Auditory/verbal processing disorder • Attention deficit disorder • Mental retardation • Childhood schizophrenia • Emotional/behavioral problems Early examination to rule out LKS is important because it becomes more difficult to differentiate between disorders as symptoms progress. Also, the outlook for language recovery is better when treatment begins early.

Michael Scarpetti was 4 when he had his first febrile seizure. His parents were concerned, but their pediatrician said a referral to a neurologist was not absolutely necessary. As months passed, the Scarpettis noticed Michael was forgetting numbers and his ABCs. Diagnostic tests at school were inconclusive. Following this regression, his pediatrician referred him to a neurologist, who scheduled an electroencephalogram (EEG). Michael was then diagnosed with Landau-Kleffner Syndrome (LKS)—a rare epileptic disorder characterized by language regression and an abnormal EEG.

James Riviello, MD, a neurologist who specializes in epilepsy and seizures, considers Michael to be a "pure LKS" child because he had normal development prior to his presentation. Of the children referred to Children's for language disorders, few have classic or "pure LKS," but Dr. Riviello admits the hospital's strict definition may eliminate many children who others consider to have this disorder.

"One of the problems you run in to is 'what is the definition of LKS?'" says Dr. Riviello.

While he thinks a child should have normal development prior to presenting, hallmark characteristics for LKS and its variants include a child who begins to lose language skills, initially not understanding words—called a word deafness or a verbal auditory agnosia—in combination with an abnormal EEG with sleep-activated spike or spike and wave discharges. Some variants include children who have pervasive developmental disorder (PDD), autism with regression, a congenital disorder such as developmental speech delay, or another epileptic syndrome called electrical status epilepticus of sleep (ESES).

David Urion, MD, a neurologist who specializes in language disorders and is the director of Children's Learning Disabilities/Behavioral Neurology Program, says the idea of variants emerged when, "People began asking, 'Well what if [children presented] before they actually developed words? Would they still be considered to have the syndrome?' There's been a huge debate back and forth." Children who develop their symptomatology earlier than the actual onset of language acquisitions are considered variants of LKS.

Neuropsychological testing is important because while children with PDD, autism, or LKS may have the same EEG findings, they do not interact on the same level. "There is a wide spectrum," says Dr. Riviello, "and in any one child it may be hard to say where they fit into that spectrum."

Typically, a child with LKS should have good eye contact. "You can tell by looking at them that they're trying to understand what you say or they're trying to be engaged or involved in their surroundings," says Dr. Riviello. Children with autism who have regression do not seem involved in an examination, or when interacting with other people, exhibit poor eye contact and no language.

Moreover, children who have autism typically regress somewhere between 18 and 24 months of age—earlier than children with pure LKS who typically present between 3 and 6 years of age. Dr. Riviello says his pure LKS children "all had language definitely established before they regressed," whereas many of the variants did not.

About two-thirds of children with LKS will have seizures and two-thirds will have behavioral problems, but the primary cognitive dysfunction remains loss of language. Speech therapy should begin at the time of diagnosis. An intensive language-based speech program is best when continued throughout the educational years. "Direct contact with a speech-language pathologist and small group or classroom work are commonly combined, especially if the child continues to have academic difficulty," says Dr. Urion. The abnormal EEG, especially in the setting of language dysfunction, is a marker for potential antiepileptic drug (AED) treatment. Someone born with a language problem who does not have an epileptiform disturbance might only need speech or educational therapy, but specific AED therapy is not required.

Before LKS can be treated, it is necessary to identify the etiology of the child's language regression. In general, when there has been either general developmental regression or specifically, language regression, without an underlying cause, children should get an EEG to check for an epileptic disturbance. If the child has an epileptic disturbance, "generally, we would start treatment with AEDs to see if that would improve both the language and the EEG," says Dr. Riviello.

"For a substantial percentage of children with LKS, regardless of whether they have convulsions, treating them with AEDs appears to be associated with an improvement in the rate at which language recovers," says Dr. Urion.

Providers who suspect LKS should refer the child to a neurologist as soon as possible. A neurologist can make an initial diagnosis to determine appropriate therapies for your patient, including medication, speech therapy and behavioral therapy. For children with LKS, a care team may—in any combination—consist of a neurologist, neuropsychologist, speech pathologist or audiologist. Some children with behavioral problems also need to see a child psychologist or psychopharmacologist.

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