Thursday, June 20, 2013 11:42:58 MDT AM
Landau-Kleffner syndrome (LKS) is a rare, childhood neurological disorder characterized by the sudden or gradual development of aphasia (the inability to understand or express language).
LKS affects the parts of the brain that control comprehension and speech. The disorder usually occurs in children between the ages of 5 and 9 years. Typically, children with LKS develop normally but then lose their language skills for no apparent reason. The condition is twice as common in boys and only very occasionally runs in families. Very little is known about the cause or contributing factors are for LKS.
LKS is difficult to diagnose because of its unfamiliarity, and its complex effects on language and often behaviour. Diagnosis is made using the child’s history and assessment. The use of an EEG (Electroencephalogram) or brain wave record, MRI (Magnetic Resonance Imaging), CT (Computer Tomography), MEG (Magnetoencephalography) and SPECT (Single Photon Emission Computed Tomography) scans may also provide insight.
Because Laundau-Kleffner syndrome is rare it is not often thought of initially and may be misdiagnosed as autism, pervasive developmental disorder, hearing impairment, learning disability, auditory/verbal processing disorder, attention deficit disorder, childhood schizophrenia, or emotional/behavioural problems.
This syndrome was first described in 1957 by Dr. William M. Landau and Dr. Frank R. Kleffner, who at the time, identified six children with the disorder. Typically a child has normal early development, including normal speech/language development and between the ages of three and nine experiences deterioration in speech and language ability, usually proceeded by seizure activity.
• The syndrome is typically characterized by an abrupt or gradual loss of language ability and inattentiveness to sound (auditory agnosia).
• Receptive language is often severely impaired.
• Reading and writing may be preserved.
• The child may be completely mute or have severe expressive speech problems.
• Seizures occur in most cases and usually present between the ages of 4 and 10 years.
• Seizures may be partial, generalised tonic-clonic, absence or myoclonic.
• Many affected children have behavioural disturbances, including hyperactivity and decreased attention span, aggression and attacks of rage, and difficulties with social interactions .
LKS may be considered a spectrum, in which language is the first and most severely affected, but in which many other skills may be involved. It is difficult to predict outcome, as it depends on the particular child’s skill profile, the age of onset, number and severity of regressions, and response to therapies/treatments.
Treatment may consist of medications, such as anticonvulsants and corticosteroids, and speech therapy, which should be started early. A controversial treatment option involves a surgical technique called multiple subpial-transection in which the pathways of abnormal electrical brain activity are severed.
Early referral to a paediatrician should be triggered either by a seizure or loss of language abilities without overt seizures. A pediatrician should conduct an initial assessment and investigation. Ideally this should be a multi-disciplinary and include a speech and language assessment as well as a cognitive abilities assessment/developmental level screening. If LKS is suspected, a pediatric neurologist should be consulted.
LKS and related severe seizure disorders are unique in that they can cause extreme fluctuations because of the variable nature of the electrical activity. A child’s understanding and abilities may change dramatically over short periods of time, and for some children, there may be obvious variation even within the day, thus making supports for these children a significant challenge.
The prognosis for children with LKS varies. Some affected children may have a permanent severe language disorder, while others may regain much of their language abilities (although it may take months or years). In some cases, remission and relapse may occur.
The prognosis is improved when the onset of the disorder is after age 6 and when speech therapy is started early. Seizures generally disappear by adulthood.
– Dawne Hammerschmidt, Board Member of Signature Support Services