Landau-Kleffner syndrome is a rare childhood disorder. Syndrome usually appears when a child is from 3 to 7 years old. Children develop a progressive loss of speech accompanied by the seizures or not. Affected individuals present behavioral changes such as hyperactivity, depression and aggressiveness.
The cause of the disease is unknown, although in some patients with mutations in the GRIN2A gene and other genes, including RELN, BSN, EPHB2 and NID2 were found.
The family history of epilepsy may indicate the risk of developing the LKS among the offspring. Males are more predisposed to the development of such condition.
The first symptoms of the disease include so-called “word deafness”, when children stop reacting to the voice commands even with a raised voice. Later the child seems not to hear any other noises and sounds (auditory agnosia). Some parents may think that the child has hearing problems, although hearing tests are normal and the problem is rather brain-related. The progression of the disease leads to total unresponsiveness and impaired communication or even total inability to speak (mutism). Sometimes children use own gesture system of communication or sign-like language to express themselves.
The severity of the language impairment is connected with the age of the child when the first symptoms occur. If the disorder develops when a child is older, the speech impairment is less severe, because the child has already developed communicative .
Seizures usually appear at night and by the age of 15 they stop occurring.
The child may also have problems with fine motor coordination and movement (dribbling, messy eating, clumsiness, shakiness) and behavioral disorders. The child develops depression or aggressiveness, hyperactivity and temper outbursts. The intellectual abilities are usually preserved, although sometimes the child’s IQ is decreased.
[See also:Cyclic vomiting syndrome (CVS)]
To assess the diagnosis EEG is performed. The characteristic features of LKS are sleep-activated EEG paroxysms predominating over the temporal or parieto-occipital regions and brain waves in the temporal lobe during wakefulness.
Brain imaging with MRI is recommended to exclude structural lesions in the brain. Other testing include behavioral testing, audiometry and standardized psychometric and speech/language testing.
The management of the disorder includes intake of corticosteroids (prednisone), anticonvulsant drugs (divalproex, ethosuximide, levitiracetam, and benzodiazepines) and speech therapy. Sign language training may be used for some affected children to improve their communicating skills.
Drugs such as carbamazepine, phenytoin, phenobarbitone should be avoided, because they can worsen the state of the affected child.