Landau–Kleffner syndrome (LKS), also called infantile acquired aphasia, acquired epileptic aphasia, or aphasia with convulsive disorder, is a rare neurological syndrome that develops during childhood.
It is named after William Landau and Frank Kleffner, who characterized it in 1957 with a diagnosis of six children.
Signs and symptoms
Landau–Kleffner syndrome is characterized by the sudden or gradual development of aphasia (the inability to understand or express language) and an abnormal electroencephalogram (EEG). LKS affects the parts of the brain that control comprehension and speech (Broca's area and Wernicke's area). The disorder usually occurs in children between the ages of 3 and 7 years. There appears to be a male dominance in the diagnosis of the syndrome (ratio of 1.7:1, men to women).
Typically, children with LKS develop normally, but then lose their language skills. While many affected individuals have clinical seizures, some only have electrographic seizures, including electrographic status epilepticus of sleep (ESES). The first indication of the language problem is usually auditory verbal agnosia. This is demonstrated in patients in multiple ways including the inability to recognize familiar noises and the impairment of the ability to lateralize or localize sound. In addition, receptive language is often critically impaired, however in some patients, impairment in expressive language is the most profound. In a study of 77 cases of Landau–Kleffner syndrome, 6 were found to have this type of aphasia. Because this syndrome appears during such a critical period of language acquisition in a child's life, speech production may be affected just as severely as language comprehension.
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Note: EEG = electroencephalographic; ESES = electrical status epilepticus of sleep; RL = receptive language; S = sociability
- Continuous spike and wave of slow-wave sleep (>85% of slow-wave sleep).
Treatment
Treatment for LKS usually consists of medications, such as anticonvulsants and corticosteroids (e.g., prednisone), and speech therapy, which should be started early. Some patients improve with the use of corticosteroids or adrenocorticotropin hormone (ACTH) which lead researches to believe that inflammation and vasospasm may play a role in some cases of acquired epileptic aphasia. in which multiple incisions are made through the cortex of the affected part of the brain beneath the pia mater, severing the axonal tracts in the subjacent white matter. The cortex is sliced in parallel lines to the midtemporal gyrus and perisylvian area to attenuate the spread of the epileptiform activity without causing cortical dysfunction. There is a study by Morrell et al. in which results were reported for 14 patients with acquired epileptic aphasia who underwent multiple subpial transections. Seven of the fourteen patients recovered age-appropriate speech and no longer required speech therapy. Another 4 of the 14 displayed improvement of speech and understanding instructions given verbally, but they still required speech therapy. Eleven patients had language dysfunction for two or more years. Another study by Sawhney et al. reported improvement in all three of their patients with acquired epileptic aphasia who underwent the same procedure.
Various hospitals contain programs designed to treat conditions such as LKS like the Children's Hospital Boston and its Augmentative Communication Program. It is known internationally for its work with children or adults who are non-speaking or severely impaired. Typically, a care team for children with LKS consists of a neurologist, a neuropsychologist, and a speech pathologist or audiologist. Some children with behavioral problems may also need to see a child psychologist and a psychopharmacologist. Speech therapy begins immediately at the time of diagnosis along with medical treatment that may include steroids and anti-epileptic or anti-convulsant medications.
Patient education has also proved to be helpful in treating LKS. Teaching them sign language is a helpful means of communication and if the child was able to read and write before the onset of LKS, that is extremely helpful too.
Prognosis
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. Short-term remissions are not uncommon in LKS but they create difficulties in evaluating a patient's response to various therapeutic modalities.
The following table demonstrate the Long-Term Follow-up of Acquired Epileptic Aphasia across many different instrumental studies:.
Globally, more than 200 cases of acquired epileptic aphasia have been described in the literature. Between 1957 and 1980, 81 cases of acquired epileptic aphasia were reported, with 100 cases generally being diagnosed every 10 years.