A rare disease with multiple variants
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
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
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