April 5, 2011 Audiology

Auditory Remediation for Patients With Landau-Kleffner Syndrome

Landau-Kleffner syndrome (LKS) is a rare neurological disorder that affects children and is characterized by aphasia that can develop suddenly or over a period of time. Often the deterioration in language is rapid, but it also may decline over several months (Miller et al, 1984).

Although there is a body of evidence to support medical treatment for LKS, there is limited information about the clinical management for the language disorder or acquired (central) auditory processing disorder [(C)APD]. The prognosis of a child with LKS is unpredictable due to variability in the time and amount of recovery and the severity of the disorder. Speech-language pathologists are often challenged with the task of maximizing language recovery. Treatment techniques have relied on visual aids such as graphic symbols and visual language systems, as well as cued speech (for a review of language treatment options, see Alpern, 2010).

Thomas Gibson and SLP Kristen Beckner

Thomas Gibson listens to dichotic sentences during his treatment session with SLP Kristen Beckner.

It also is important for clinicians to recognize auditory processing deficits associated with the acquired (C)APD that results from LKS and to offer a deficit-specific remediation plan to improve the patient's auditory processing ability. Previous reports of auditory processing deficits in LKS patients have cited difficulty listening in background noise or other degraded environments, challenges with auditory discrimination, and problems with dichotic listening tasks (Bamiou, Musiek, & Luxon, 2001). An assistive listening device such as an FM system may be useful to improve the signal-to-noise ratio. Speech-in-noise training may also improve the patient's listening ability.

Dichotic listening treatment is one type of direct remediation for (C)APD that takes advantage of the brain's lifelong capacity for plasticity and adaptive reorganization (Musiek, Chermak, & Weihing, 2007).

LKS patients have an abnormal electroencephalogram (EEG) typified by abnormal spike activity in the temporal and/or parietal regions (Deonna, Beaumanoir, Gaillard, & Assal, 1991). The abnormal EEG activity occurs predominantly in the left temporal lobe, but may be present in both temporal lobes (Deonna et al., 1991). From anatomical and physiologic dichotic listening modeling, it is reasonable that the only way to isolate the damaged auditory pathway is to force this auditory pathway to work by direct auditory stimulation—dichotic listening.

In normal listening conditions, auditory information is conducted to the auditory cortex by both ipsilateral and contralateral auditory pathways; however, during controlled dichotic listening, the ipsilateral pathway is suppressed by the dominant contralateral pathway. This dominant contralateral model was first proposed by Kimura (1961), whose data led her to hypothesize that the contralateral pathway must have greater neuronal innervation that enables it to be dominant over the ipsilateral pathway.  

Early work in the 19th century noted that most aphasia is the result of lesions in the left cerebral hemisphere, leading to the conclusion that most people are left-hemisphere-dominant for expressive and receptive language. Further, a language-related auditory signal presented to the right ear travels from the dominant contralateral right auditory pathway directly to the left hemisphere. Conversely, a language-related auditory signal directed to the left ear is conducted to the right cortex, but must be transferred to the left hemisphere via corpus callosum in order for the person to repeat what was heard in the left ear. Thus, it is not surprising that there is a slight right-ear advantage for neurologically normal listeners when listening to dichotic tasks (Kimura, 1961; Lowe, Cullen, Berlin, Thompson, & Willett, 1970; Berlin, Lowe-Bell, Cullen & Thompson, 1973).

When there is damage or a lesion in the auditory temporal lobe, the ear contralateral to the lesion will be affected in dichotic listening tasks, as the contralateral pathway is the dominant pathway. Because lesions often are found in the left temporal lobe in LKS patients, a right-ear deficit on dichotic testing is expected.

Dichotic listening training is an innovative treatment for the remediation of the compromised central auditory pathway (Musiek et al., 2007).  Dichotic interaural intensity difference (DIID) training uses dichotic listening tasks in which the signal intensity presented to the unimpaired pathway is first decreased and then slowly increased over time as the weaker, impaired pathway grows stronger. DIID training purports to target the deficit ear specifically, thus activating brain regions that receive auditory sensory input on the side of the lesion. Previous investigations have shown behavioral and electrophysiological evidence of improvement of the central auditory nervous system after DIID training (Musiek, Baran, & Shinn, 2004; Hurley & Billiet, 2007; for a complete review of the DIID procedure, see Musiek et al., 2007).

Improvement after auditory rehabilitative dichotic listening in dichotic scores and language scores also were shown in a group of children with language disorders. Until recently, dichotic listening programs could be completed only in a controlled laboratory environment; now dichotic stimuli are available on compact discs.

Dichotic exercises directly stimulate areas of the cortex, which in turn forces the auditory pathways to these areas to exercise and recruit existing neuronal connections or build new neural connections and pathways. As the integrity of these areas pathways is improved, speech stimuli can reach the language processing temporal lobe more efficiently, resulting in improvement of dichotic skills.

Annette Hurley, PhD, CCC-A, is an assistant professor in the Department of Communication Sciences at Louisiana State University Health Sciences Center in New Orleans, La. Contact her at ahurle@lsuhsc.edu.

cite as: Hurley, A. (2011, April 05). Auditory Remediation for Patients With Landau-Kleffner Syndrome. The ASHA Leader.

Dichotic Training: Case Studies

Two patients participated in dichotic listening training. "Michael" participated in dichotic listening therapy for two clinic semesters. "Thomas" lives in another state and participated in dichotic listening therapy with his speech-language pathologist.

In dichotic training, stimuli are presented at different interaural intensities with a higher intensity directed to the poorer (dichotic scoring) and lower intensity directed to better (dichotic scoring) ear. Initial presentation level is at a comfortable level to the poorer scoring ear, and a soft level to the better (dichotic scoring) ear. When the individual's target ear's score reaches >70%, the intensity level delivered to the poorer ear is increased by 1, 2, or 5 dB. This continues until there are equal intensities presented to both ears. Because of the limited amount of dichotic listening materials, available, new recordings of digits, words, sentences, CVs and short stories were created and used in the training sessions.

Case One: Michael 

Michael was the product of a normal pregnancy and birth. All developmental milestones were developing appropriately until the age of three. At that time, Michael's speech and language skills began to decline. Initially, this decline in speech and language was attributed to sibling jealousy as this decline coincided with the birth of a younger sibling.  Michael was sent for a hearing evaluation which established normal peripheral hearing. As Michael had a history of otitis media, the lack of progression in speech and language was next related to his history of ear infections. Subsequently, autism and pervasive developmental disorder were also erroneously diagnosed. With the onset of seizure activity at the age of three and a half years, the diagnosis of LKS was made after a characteristic spiking EEG. Nocturnal seizure activity continued until Michael was eleven years old, even though anticonvulsants were prescribed. At age 11, Michael had his first normal EEG.

Our involvement with Michael began when he was 12.5 years old, as he was a subject in a study examining pre and post behavioral and electrophysiological measures after Fast ForWord® training, provided by Michael's local school system. Approximately four weeks after Michael completed the Fast ForWord® program, Dichotic listening therapy began weekly for a total of twenty one hour dichotic listening training sessions.

Post-testing showed improvement in dichotic scores after dichotic listening training, as well as improvements in electrophysiologic responses (auditory late response).  In addition, unsolicited parental reports were positive. Extended family member, as well as Michael's teachers, commented that his speech was improving and that he was speaking in complete sentences and thoughts, rather than in a telegraphic-type speech. They also reported that he rarely used signs. This cannot be validated, as we did not measure pre and post mean length utterance.

Case Two: Thomas 

Thomas was the product of a normal pregnancy and birth history was normal. Gross motor development milestones were achieved at appropriate times. At age 3, Thomas had a speech-language evaluation to address articulation concerns. This assessment yielded normal results. Sleep concerns were noted as early as age 3 ½; at age 5 ½, a tonsillectomy/ adenoidectomy was performed for sleep apnea.

Early behavioral, attention, language and hearing were first noted when Thomas was in pre-school. A speech-language assessment at that time (age 6.25) indicated a severe receptive language delay. Language regression and concerns continued over the next few years.

Thomas had an abnormal EEG at age 8 years, 2 months indicated bilateral abnormalities, but left temporal lobe activity greater on the left side. Approximately six months later, an EEG indicated abnormalities on the right side, as well.  Thomas is currently managed medically for his abnormal nocturnal EEG. In July, 2009, Thomas was formally diagnosed with Landau-Kleffner Syndrome (LKS). Thomas began dichotic listening in October, 2009. He was seen at the LSU Health Sciences Center in July, 2010. Because of the geographical distance, Thomas has been working with his speech language pathologist on dichotic listening via recorded compact discs. Training began 20 minutes, twice per week, and is now listening weekly.  Although we do not have comprehensive pre and post (C)APD test results, we have dichotic test scores from an assessment in July, 2009. Scores previously abnormal are now within normal limits. 



References

Alpern, C. A. (2010). Identification and Treatment of Landau-Kleffner Syndrome. ASHA Leader, September 21, 34–35.

Bamiou, D. E., Musiek, F. M., & Luxon, L. M. (2001). Aetiology and clinical presentations of auditory processing disorders—a review. Archives of Disease in Children, 85, 361–365.

Berlin, C. I., Lowe-Bell, S. S., Culen, J. K., Jr., & Thompson, C. L. (1973). Dichotic speech perception: an interpretation of right-ear advantage and temporal offset effects. Journal of the Acoustical Society of America, 53, 699–709.

Berlin, C. I., Lowe-Bell, S. S., Jannetta, P. J., & Kline, D. G. (1972). Central auditory deficits after temporal lobectomy. Archives of Otolaryngology,96, 4–10.

Deonna, T., Beaumanoir, A., Gaillard, F., Assal, G. (1977). Acquired aphasia in childhood with seizure disorder: a heterogeneous syndrome. Neuropadiatrie 8, 263–273.

Hurley, A., & Billiet, C. (2009). Dichotic interaural intensity difference (DIID) training; auditory remediation after CVA. Poster Presentation at the annual ASHA Convention. Chicago, IL.

Kimura, D. (1961). Cerebral dominance and the perception of verbal stimuli. Canadian Journal of Psychology, 15, 166–171.

Lowe, S. S., Cullen, J. K., Jr., Berlin, C. I., Thompson, C. L., & Willett, M. E. (1970). Perception of simultaneous dichotic and monotic monosyllables. Journal of Speech and Hearing Research 13, 812-822.

Miller, J. F., Campbell, T. F., Chapman, R. S., & Weismer, S. E. (1984). Language behavior in acquired childhood aphasia. In A. Holland (Ed.), Language disorders in childhood: Recent advances (pp. 57–99). San Diego: College Hill Press.

Musiek, F. E., Chermak, G., & Weihing, J. (2007). Auditory training. InIn. F.E. Musiek and G. D. Chermak (Eds.), Handbook of (Central) Auditory Processing Disorder: Comprehensive Intervention, (Vol II, pp. 77-106). San Diego: Plural Publishing, 2007.

Musiek, F. E., Baran, J. A., & Shinn, J. (2004). Assessment and remediation of an auditory processing disorder associated with head trauma. Journal of the American Academy of Audiology, 15, 117–132.



  

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