The ASHA Leader - September 21, 2010 - (Page 34)

Identification andLandau-Kleffner SyndromeLan Treatment of Identification and Treatment of by Carol Sober Alpern illon was a bright, normally developing child with no apparent illnesses or language delay, but at about age 31/2, his nursery school teachers began to notice changes in his behavior. Hearing loss was suspected because he did not respond when called, but the results of an audiological evaluation were normal. His teachers continued to have concerns, but it was not until a full year later that Dillon experienced a severe regression in language functioning and was diagnosed with a rare epileptic disorder, Landau-Kleffner Syndrome (LKS). Because impaired language comprehension is often one of the first overt symptoms of LKS, audiologists and speech-language pathologists can play an important role in identifying the disorder and helping to prevent misdiagnosis. (A complete case study and video are posted at www.aha.org/publications/ leader.) D Because impaired language comprehension is often one of the first overt symptoms of LKS, audiologists and speech-language pathologists can play an important role in identifying the disorder. Dillon at age 5 (right), after he was diagnosed with LKS, and at 8 years old surfing on the outer banks of North Carolina last summer. • Although sleep EEG studies find epileptiform abnormalities in some children with ASD, the presence of these abnormalities does not necessarily differentiate ASD with and without regression. Communication Function Stefanatos et al., 2002). Beaumanoir (1985) reports that a familial history of epilepsy exists in 12% of the individuals who are questioned, and males are more frequently diagnosed than females (Camfield & Camfield, 2002; Mikati & Shamseddine, 2005). Incidence is difficult to calculate because some practitioners are unaware of LKS or the need for a sleep EEG for diagnosis. Language regression is usually first observed when children appear not to understand what is said. For this reason, hearing loss is suspected and audiologic assessment is carried out. Typically, children show a gradual regression in expressive language. The literature highlights a variety of expressive deficits, including reduced syntactic complexity, telegraphic speech, word-finding deficits, jargon, neologisms, paraphasias, perseveration, and mutism. Articulation deficits, apraxia, and voice disorders also have been reported (Harrison, 2000; Soprano et al., 1994; Stefanatos et al., 2002). The nature of expressive and receptive deficits suggests that the impairment is primarily in the area of auditory processing. Auditory processing deficits are reflected in reports of abnormal dichotic listening results and phonological short-term memory deficits, even in adults who demonstrate good language recovery (Metz-Lutz, 2009). In a follow-up study of some of the original patients described by Landau and Kleffner, many of the adults still had difficulty understanding speech in a noisy environment (Mantovani & Landau, 1980). Individuals who have recovered language later report that speech sounded like “blah, blah, blah” (Landau & Kleffner, 1957). One client followed by Montonvani and Kleffner recalled that the word “fly swatter” sounded like “glass of water.” The success of many children with LKS in learning to communicate through sign language or written language lends further support to the view that the disorder is an impairment of auditory processing. Nonverbal intelligence is generally thought to be preserved in LKS, but assessment of these children is difficult because most tests have some verbal component (Praline et al., 2003; Soprano et al., 1994; Stefanatos et al., 2002). In addition, behavioral problems sometimes associated with LKS—such as hyperactivity and attention deficit—can influence test results. Other reported behavioral issues include Diagnosis LKS is an acquired epileptic disorder in children that presents as a sudden or gradual loss of language skills in typically developing children (Mikati & Shamseddine, 2005). It was first described in 1957 (Landau & Kleffner, 1957) and can be difficult to diagnose. Although 70%–75% of the children show overt clinical seizures (Stefanatos, Kinsbourne, & Wasserstein, 2002), the identifying symptom is the presence of subclinical seizure activity that is detected only on electroencephalograms (EEGs). If overt seizures do occur, they do not necessarily coincide with the language loss and may occur months before or after. Furthermore, medication to control the overt seizures does not necessarily result in improved language skills (Ballaban-Gil & Tuchman, 2000; Rapin, 1995). Children must have an EEG during sleep for LKS to be diagnosed (Stefanatos et al., 2002). No typical pattern of abnormal epileptiform activity absolutely differentiates LKS syndrome from other epileptiform disorders. Typically, abnormalities are seen in the temporal or parietal areas and can be either bilateral or lateralized to either hemisphere (Stefanatos et al., 2002). The relationship between these subclinical seizures and language loss is not necessarily any clearer than the relationship to overt seizures. For example, even when EEGs are normalized following medication, language recovery does not always occur (Soprano, Garcia, Caraballo, & Fejerman, 1994). Other neurological findings such as computed tomography scans (CT) and magnetic resonance imaging (MRI) are usually normal (Ballaban-Gil, & Tuchman, 2000). The etiology of the disorder is not known (Van Bogaert & Pacquier, 2009). Case reports relate LKS to a number of medical conditions but the relationships are inconclusive (Mikati & Shamseddine, 2005; Relationship to ASD Because both LKS and some forms of autism are characterized by apparently normal development followed by language deterioration, there is a great deal of discussion in the literature about the relationship between LKS and autism. Similarities include: • The presence of abnormal epileptiform activity on EEG recordings in a significant number of children with autism spectrum disorders (ASD) who have a history of language regression (Tuchman & Rapin, 1997). • Similar behavior patterns in ASD and LKS including resistance to change, echolalia, over-sensitivity to auditory stimuli, and social withdrawal (Stefanatos et al., 2002). Although some researchers conclude that the shared features of LKS, ASD, and other forms of acquired aphasia suggest that these disorders be located on a “spectrum of common pathophysiology” (Stefanatos et al., 2002, p. 218), many researchers caution against this view. Tuchman (2009) points to several clinical differences between LKS and ASD: • The mean age of regression is earlier in ASD than in LKS (21 months vs. 5–7 years). The language that is lost in ASD is at most single words, not fully developed language as in LKS. • Children with ASD demonstrate more severe social deficits and repetitive behaviors than those with LKS. 34 September 21, 2010 http://www.aha.org/publications/leader http://www.aha.org/publications/leader

Table of Contents for the Digital Edition of The ASHA Leader - September 21, 2010

The ASHA Leader - September 21, 2010
Contents
Teens at Risk: "We're on the Edge of an Epidemic"
Bottom Line
Audiology
New Fluency, Cognition Diagnosis Codes
Schools 2010: Learning and Leadership in Las Vegas
RTI Progress-Monitoring Tools
Classroom Acoustics: What Possibly Could Be New?
Schools Practice: New Research and Online Resources
From the President
Schools Survey Caseload Data
Internet
Identification and Treatment of Landau-Kleffner Syndrome
Buyers Guide
Classifieds
First Person on the Last Page

The ASHA Leader - September 21, 2010