Sign language in childhood epileptic aphasia (Landau-Kleffner syndrome)

Differential diagnosis between autism spectrum disorder and other developmental disorders with emphasis on the preschool period

BACKGROUND

Neurodevelopmental disorders are a heterogeneous group of conditions that manifest as delays or deviations in the acquisition of expected developmental milestones and behavioral changes. Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in communication and social interaction and by repetitive and restricted patterns of behavior, interests and activities. The aim of this review is to discuss the clinical features of the differential diagnoses of ASD that are prevalent among preschoolers, focusing on their similarities and disparities.

DATA SOURCES

The international medical literature search was conducted using PubMed and was revised regarding the subject using single and/or combined keywords as follows: differential diagnosis, preschoolers, diagnostic challenge, attention deficit hyperactivity disorder, intellectual disability, high abilities/giftedness, childhood apraxia of speech, social communication disorder, Landau-Kleffner syndrome, stereotyped movement disorder and excessive screen time.

RESULTS

We describe conditions commonly found in clinical practice, taking ASD as a reference. We addressed converging and divergent aspects of behavior, cognition, communication, language, speech, socialization, and stereotypes for the diagnosis of ASD and other disorders identified as potential differential or comorbid diagnoses.

CONCLUSIONS

The ranking and characterization of symptoms appear to be essential for better understanding the underlying common ground between children with developmental disorders and children with ASD, thus properly diagnosing and directing social, professional, or medication interventions. This detailed discussion adds to the literature since, although ASD differential diagnoses are frequently mentioned and discussed in textbooks and journal articles, they rarely occupy a prominent place as we aimed herein.

Cognitive linguistic Treatment in Landau Kleffner Syndrome: Improvement in Daily Life Communication

We report a case study of cognitive linguistic treatment in a teenager with chronic severe Landau Kleffner Syndrome. The effect of speech and language therapy in LKS is rarely examined and our case is unique in that we use an effective approach in adult aphasia to treat language deficits in aphasia in LKS. The results show successful acquisition of a considerable amount of new words as well as improved communication in daily life. However, auditory verbal agnosia, the most prominent feature in LKS, persisted. Cognitive linguistic treatment seems a promising treatment to improve spoken language production in LKS, but more research is needed to optimize speech and language therapy of auditory verbal agnosia and auditory language comprehension in children with LKS

Music processing deficits in Landau-Kleffner syndrome: Four case studies in adulthood

Verbal-auditory agnosia and aphasia are the most prominent symptoms in Landau-Kleffner syndrome (LKS), a childhood epilepsy that can have sustained long-term effects on language processing. The present study provides the first objective investigation of music perception skills in four adult patients with a diagnosis of LKS during childhood, covering the spectrum of severity of the syndrome from mild to severe. Pitch discrimination, short-term memory for melodic, rhythmic and verbal information, as well as emotion recognition in music and speech prosody were assessed with listening tests, and subjective attitude to music with a questionnaire. We observed amusia in 3 out of 4 patients, with elevated pitch discrimination thresholds and poor short-term memory for melody and rhythm. The two patients with the most severe LKS had impairments in music and prosody emotion recognition, but normal perception of emotional intensity of music. Overall, performance in music processing tasks was proportional to the severity of the syndrome. Nonetheless, the four patients reported that they enjoyed music, felt musical emotions, and used music in their daily life. These new data support the hypothesis that, beyond verbal impairments, cerebral networks involved in sound processing and encoding are deeply altered by the epileptic activity in LKS, well after electrophysiological normalization.

Aphasic status epilepticus as the sole symptom of epilepsy: A case report and literature review

Aphasia is a common symptom encountered by neurologists. However, the presence of aphasia as the sole manifestation of partial status epilepticus is rare. The present study reports a case of aphasic status epilepticus in a 27-year-old right-handed female who presented after the abrupt onset of aphasia, which had persisted for 1.5 days. The patient's medical history included head trauma followed by a craniectomy and cranioplasty. Computed tomography scans revealed a lesion in the patient's left parietal lobe, and an electroencephalogram showed a spike and slow wave pattern in the left hemisphere of the brain during aphasia. The patient's condition improved after the oral administration of oxcarbazepine daily. In the present study it was observed that EEGs were a simple method to diagnose aphasic seizures and therefore EEG recordings should be performed in all cases of unexplained aphasia. In addition, the present study reviewed previously reported cases of aphasic status epilepticus.

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.

Landau-Kleffner syndrome: a study of 29 patients

PURPOSE

The aim of the study was to retrospectively analyze the electroclinical features, etiology, treatment, and prognosis of 29 patients with Landau-Kleffner syndrome (LKS) with a long-term follow-up.

METHODS

Inclusion criteria were a diagnosis of LKS with: (1) acquired aphasia or verbal auditory aphasia; (2) with or without focal seizures, secondarily generalized tonic-clonic seizures, absences, or atonic seizures.

RESULTS

Mean follow-up was 12 years. All cases except six had seizures. Before the onset of aphasia, developmental language and behavioral disturbances were present in 19 and 14 patients, respectively. All patients had verbal auditory agnosia. Aphasia was severe in 24 patients and moderate in five. Nonlinguistic cognitive dysfunctions were moderate in 14 patients. Behavioral disturbances were found in 16 patients. During the continuous spike-and-wave discharges during slow sleep phase, the spike-wave index was >85% in 15, 50-85% in eight, and 30-50% in four. In two patients, the EEG recording showed occasional bilateral spikes, without continuous spike-and-wave discharges during slow sleep. In this phase, the awake EEG recording showed more frequent interictal abnormalities, predominantly in the temporal regions. Eight patients recovered language completely, but the remaining patients continue to have language deficits of different degrees.

CONCLUSION

Landau-Kleffner syndrome is an epileptic encephalopathy characterized by acquired verbal auditory aphasia and seizures in most of the patients associated with continuous or almost continuous spike-and-wave discharges during slow wave sleep. The most commonly used treatments were clobazam, ethosuximide, sulthiame. High-dose steroids were also administered. Adequate and early management may avoid language and cognitive deterioration.

Changing perspectives on Landau-Kleffner syndrome

Landau-Kleffner syndrome (LKS) is a childhood disorder characterized by an acquired aphasia that emerges in association with epileptiform electroencephalographic abnormalities. The language loss is often characterized by a severe disturbance of auditory language comprehension (verbal auditory agnosia) combined with a substantial disruption of expressive language. Comorbid behavioral disturbances commonly involve hyperactivity and attentional problems but sometimes encompass a more pervasive pattern of difficulties resembling an autism spectrum disorder. Now one the most frequently described forms of acquired aphasia in children, LKS has had a profound influence on both neurological practice and cognitive neuroscience. Here, we review current conceptualizations of LKS, consider its pleomorphic manifestations and discuss existing and future diagnostic issues and dilemmas. The potential relevance of LKS to understanding other disorders, including autistic regression, is considered.

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

OBJECTIVE

To describe the clinical presentation and treatment of 3 children with an Auditory Processing Disorder with an identifiable neurological cause: Landau-Kleffner syndrome. This classical syndrome is well recognized in pediatric neurology but the diagnosis is less well known to Pediatric Otolaryngology, Speech Language Pathology and Audiology services.

METHODS

Retrospective chart review of three patients with Landau-Kleffner syndrome.

RESULTS

In all cases, pharmacological intervention led to clinical and electroencephalographic improvement, but all patients had long-term difficulty with understanding sounds in a noisy environment. Magnetic Resonance Imaging (MRI) of the brain was normal in all three patients. Their language disturbance improved over time. Speech language intervention was helpful in addressing communication difficulties arising from the auditory processing/receptive and expressive language disorder.

CONCLUSION

A multidisciplinary assessment is the key for early diagnosis, treatment and follow-up in patients with this syndrome.

Landau-Kleffner syndrome with lateral temporal focal cortical dysplasia and mesial temporal sclerosis: a 30-year follow-up

A 39-year-old man, who presented at age 312 with Landau-Kleffner syndrome, had persisting oral and written language deficits into adulthood. Seizures were easily controlled in childhood, but reemerged in adulthood as medication-refractory complex partial seizures. Abnormal T2 signal hyperintensity was seen in the left mesial temporal area on brain MRI. Later, left temporal lobectomy revealed focal cortical dysplasia in the lateral temporal neocortex and gliosis plus neuronal loss in the hippocampus. This case suggests that focal cortical microdysgenesis may be a cause of the Landau-Kleffner syndrome. Persistent seizures in this illustrative case may have led to the evolution of dual-temporal-lobe pathology with mesial temporal sclerosis.

Landau–Kleffner syndrome is not an eponymic badge of ignorance

In a 1992 editorial article, Landau expressed the hope of collective agreement in the medical community about Landau-Kleffner syndrome (LKS) in terms of diagnosis criteria, etiology, pathophysiology and rational therapy. Since then, neurophysiological and neuroimaging studies have led to the view that LKS is an acquired aphasia, secondary to an epileptic disturbance affecting a cortical area involved in verbal processing. This fits with the hypothesis of a "functional ablation" caused by epileptic activity. Under these criteria, epileptic aphasia becomes a subgroup of the continuous spike-waves syndrome in which epileptic discharges originate from the temporal cortex. Genetic predisposition for KLS could be related to hyperexcitability and synchronization of interneurons within the perisylvian cortices, which generate the spike-waves. Activation of these waves during NREM sleep, following thalamo-cortical uncoupling, might then alter the blood brain barrier and provoke an autoimmune reaction. Interneuron hyperactivity might in turn have an antiepileptic protective effect, associated with the inhibition of a specific function, and spike-waves activity over the long term might eventuate in focal atrophy. This morphological defect might explain the poor verbal outcome in some cases of LKS. From this study we recommend a multicenter control study of good design and methodology be carried out to compare the efficacies of early versus delayed (3 months) corticosteroid treatment in patients with typical LKS that is being treated by clobazam (or diazepam) monotherapy.

The neurology of sign language

Forms of sign language have developed in a number of countries. American Sign Language, which originated from French signing, has been most extensively researched. As sign language is based on gestures executed in space and perceived visually it might be thought that it would mainly be a function of the right cerebral hemisphere when this is the non-dominant one. A number of studies are reviewed showing that sign language is a language in its own right and therefore, as with spoken language, its primary site of organization is in the dominant hemisphere. This does not mean that there is not a significant contribution from the other hemisphere with an interplay between the two. Each research project usually contributes some facet of knowledge apart from the main conclusions. These included the importance of distinguishing signs from gestures, the localization of different types of signing within the left dominant cerebral hemisphere, the fact that lesions of the right non-dominant hemisphere, although not causing a loss of signing will result in dyspraxia, and that aphasic symptoms of signing and speech are not modality dependant but reflected a disruption of language processes common to all languages. Examples are given of discoveries made by the use of the newer neuroradiological techniques such as functional magnetic resonance imaging and positron emission tomography, and no doubt these will lead to further advances in knowledge. The use of sign language in the treatment of patients with verbal aphasia is considered, especially of children with the Landau-Kleffner syndrome, but therapy of this kind can be used in children with delayed language development, and in other types of acquired aphasia at any age. Other methods of treatment than signing, such as cochlear implants may be increasingly used in the future, but it seems likely that sign language will continue to be a dominant feature in the deaf culture.