Landau-Kleffner syndrome: a rare auditory processing disorder series of cases and review of the literature

Selected rare paediatric communication neurological disorders

The purpose of this review is to discuss rare neurological disorders with respect to communication difficulties typical of children. Firstly, communication disorders with special focus on rare communication neurological disorders are discussed. Secondly, on the basis of literature review, the authors explore clinical studies on the most typical rare children's communication neurological disorders. Thirdly, on the basis of the findings from the clinical studies, they set a few recommendations for their medical therapies and management. The methodology was based on the literature review of research studies exploring the research issue. The findings show that the intervention strategies appear to have positive effects on the improvement of speech and language production among children suffering from Landau-Kleffner syndrome and childhood apraxia of speech. Nevertheless, randomized control trials are needed in order to accelerate and facilitate an early and relevant diagnosis and treatment management. In addition, a multidisciplinary approach seems to be the most appropriate for the accurate diagnosis and comprehensive treatment.

Watch the language! Language and linguistic-cognitive abilities in children with nocturnal epileptiform activity

We studied the language and linguistic-cognitive abilities of a group of children with nocturnal epileptiform activity (NEA; N=33) who were hospitalized at a tertiary epilepsy hospital. The children were compared with two groups: one age- and gender-matched group (N=33) and one group matched on language ability (vocabulary) and gender (N=66). We also examined how NEA-related variables affected language abilities. Overall, the children with NEA showed delayed language abilities and a trend for specific difficulties with phonology and naming speed. We did not find firm evidence that the amount of NEA, the use of antiepileptic drugs (AEDs), and the lateralization and localization of NEA had an effect on language. However, we found that children with right-lateralized epileptiform activity seemed to have specific difficulties with naming speed. Additionally, our results indicated that NEA located in the centrotemporal areas particularly affected phonology and orthographic skills.

Neurocognitive and behavioral profiles of children with Landau-Kleffner syndrome

This is a retrospective study of 14 cases of children with Landau-Kleffner syndrome (LKS), the most prominent feature of which is acquired aphasia. These children were followed at a tertiary care pediatric epilepsy center. From the research data base, all LKS cases with neuropsychological evaluation were extracted. Children ranged in age from 6 to 13 years (M = 9.12; SD = 2.19) at the time of assessment (1 to 10 years post-onset). The majority of the children were white males, and all but one continued to experience seizure activity. Global intellectual functioning ranged from 59 to 101 (M = 82.07; SD = 12.14). Across the 14 cases reviewed, the neuropsychological profiles are considered in the context of neurological and syndrome-related factors. For these cases, 86% demonstrated continued expressive, and 50% had receptive language problems with 57% exhibiting poor auditory processing. Furthermore, 50 to 57% had deficits in auditory working memory and verbal memory. Academically, the majority had poor reading fluency and comprehension; 50% exhibited difficulty with mathematics. Finally, 57% evidenced attentional or other behavioral problems. Better understanding of LKS can assist in targeted assessment and intervention planning.

Management of developmental speech and language disorders. Part 2: acquired conditions

Many children who present with these acquired impairments of communication have a clear preceding event such as an acquired brain injury from a road traffic accident. Children often respond differently in this situation to adult presentations. They may have a period of mutism when the prognosis might look poor and yet they subsequently make rapid progress and recover speech. They have greater potential for neural plasticity and language recovery, although they often have persisting difficulties in oral and written language. Alternatively, there may be a presentation with a paroxysmal event such as a seizure or a period of depressed consciousness, and the unusual behaviour that may accompany dysphasia and dysarthria may be misinterpreted in the child, whereas for the adult with the more common 'stroke-like' presentation, it would be immediately considered. Rarely the aphasia/dysphasia may itself be the paroxysmal event where actually recognising that the child's disrupted communication is the basis of any observed behaviours can be the greater challenge.

Evidence for normal letter-sound integration, but altered language pathways in a case of recovered Landau-Kleffner Syndrome

Landau-Kleffner Syndrome (LKS) is a rare form of acquired aphasia in children, characterized by epileptic discharges, which occur mostly during sleep. After normal speech and language development, aphasia develops between the ages of 3-7 years in a period ranging from days to months. The epileptic discharges usually disappear after reaching adulthood, but language outcomes are usually poor if no treatment focused on restoration of (non-) verbal communication is given. Patients often appear deaf-mute, but sign language, as part of the treatment, may lead to recovery of communication. The neural mechanisms underlying poor language outcomes in LKS are not yet understood. In this detailed functional MRI study of a recovered LKS patient - that is, a patient no longer suffering from epileptic discharges, audiovisual multi-sensory processing was investigated, since LKS patients are often proficient in reading, but not in speech perception. In the recovered LKS patient a large difference in the neural activation to auditory stimuli was found in the left versus the right auditory cortex, which cannot be attributed to hearing loss. Compared to healthy proficient readers investigated earlier with the same fMRI experiment, the patient demonstrated normal letter-sound integration in the superior temporal gyrus as demonstrated by the multi-sensory interaction index, indicating intact STG function. Diffusion Tensor Imaging (DTI) based fiber tracking in the LKS patient showed fibers originating from Heschl's gyrus that seem to be left-right inverted with respect to HG fiber pattern described in the literature for healthy controls. In the patient, in both hemispheres we found arcuate fibers projecting from (homologues of) Broca's to Wernicke's areas, and a lack of fibers from arcuate left inferior parietal and sylvian areas reported in healthy subjects. We observed short arcuate segments in the right hemisphere. Although speculative, our results suggest intact temporal lobe processing but an altered temporal to frontal connectivity. The altered connectivity might explain observed short-term verbal memory problems, disturbed (speech) sound-motor interaction and online feedback of speech and might be one of the neuronal factors underlying LKS.

Defective auditory processing in a child with temporal epileptic focus

A 9-year-old boy presented with intolerance to noise that was a trigger for violent temper tantrums that occasionally resembled complex partial seizures. The condition was also a cause for withdrawal from all activities and settings that could potentially be associated with noise. Both electroencephalography and magnetoencephalography clearly demonstrated a left temporal (T5) epileptic focus, although the child never had convulsive seizures. Genetic studies failed to reveal a GRIN2A mutation. We suggest that the hyperacusis in the reported child is another variation of the Landau-Kleffner spectrum.