Programming Algorithm for the Management of Speech Impairment in Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease.

OBJECTIVES: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) for Parkinson's disease (PD) has an ambiguous relation to speech. Speech impairment can be a stimulation-induced side effect, and parkinsonian dysarthria can improve with STN-DBS. Owing to the lack of an up-to-date and evidence-based approach, DBS reprogramming for speech impairment is largely blind and greatly relies on the physician's experience. In this study, we aimed to establish an evidence- and experience-based algorithm for managing speech impairment in patients with PD treated with STN-DBS. MATERIALS AND METHODS: We performed a single-center retrospective study to identify patients with STN-DBS and speech impairment. Onset of speech impairment, lead localization, and assessment of DBS-induced nature of speech impairment were collected. When DBS settings were adjusted for improving speech, the magnitude and duration of effect were collected. We also performed a systematic literature review to identify studies describing the effects of parameter adjustments aimed at improving speech impairment in patients with PD receiving STN-DBS. RESULTS: In the retrospective study, 245 of 631 patients (38.8%) with STN-DBS had significant speech impairment. The probability of sustained marked improvement upon reprogramming was generally low (27.9%). In the systematic review, 23 of 662 identified studies were included. Only two randomized controlled trials have been performed, providing evidence for interleaving-interlink stimulation only. Considerable methodologic heterogeneity precluded the conduction of a meta-analysis. CONCLUSIONS: Speech impairment in STN-DBS for PD is frequent, but high-quality evidence regarding DBS parameter adjustments is scarce, and the probability of sustained improvement is low. To improve this outcome, we propose an evidence- and experience-based approach to address speech impairment in STN-DBS that can be used in clinical practice.

Reliability and validity of the Dutch-language version of the Viking Speech Scale in children with cerebral palsy.

PURPOSE: The Viking Speech Scale is used to classify speech performance in children with cerebral palsy (CP). A Dutch-language version (VSS-NL) has recently become available. This study aimed to determine the reliability and validity of the VSS-NL and the association with motor type of CP, Gross Motor Function Classification System (GMFCS), Manual Ability Classification System (MACS) and Communication Function Classification System (CFCS). METHODS: A total of 90 children with CP, recruited throughout the Netherlands, took part in the study. VSS-NL classifications by speech and language therapists unfamiliar (SLT1) and familiar (SLT2) with the child, parents and physicians were compared. Convergent and discriminant validity were determined with the Intelligibility in Context Scale-Dutch (ICS-NL) and the Computer Based Instrument for Low Motor Language Testing (C-BiLLT). Inter- and intrarater reliability were determined by weighted Kappa (ƙw ). Validity and associations between VSS-NL and GMFCS, MACS and CFCS were determined with Spearman's coefficient. Association between VSS-NL and motor type of CP was determined with Fisher's exact test. RESULTS: Interrater reliability was excellent between SLT1-SLT2 (ƙw  = 0.93, 95% confidence interval [CI] 0.87-0.99), good between SLT1-parent (ƙw = 0.71, 95% CI 0.60-0.83), SLT1-physician (ƙw = 0.70, 95% CI 0.58-0.81), SLT2-parent (ƙw = 0.71, 95% CI 0.57-0.84), SLT2-physician (ƙw = 0.73, 95% CI 0.62-0.85) and parent-physician (ƙ = 0.72, 95% CI 0.60-0.85). Intrarater reliability was excellent for SLTs familiar and unfamiliar to the child (ƙw = 1.00, 95% CI 1.00-1.00), and very good for physicians (ƙw = 0.89, 95% CI 0.75-1.00) and parents (ƙw = 0.72, 95% CI 0.62-1.00). Convergent validity was very strong (r = -0.81, p < 0.001) and discriminant validity moderate (r = -0.56, p < 0.001). Association with motor type of CP was significant (χ2 = 27.558, p < 0.001) and strong with GMFCS (r = 0.62, p < 0.001), MACS (r = 0.63, p < 0.01) and CFCS (r = 0.69, p < 0.001). CONCLUSION: The VSS-NL is a reliable and valid system to classify speech performance in children with cerebral palsy. Classifications can be performed by SLTs, parents and physicians.

Spoken language comprehension of phrases, simple and compound-active sentences in non-speaking children with severe cerebral palsy.

BACKGROUND: Children with severe cerebral palsy (CP) (i.e. 'non-speaking children with severely limited mobility') are restricted in many domains that are important to the acquisition of language. AIMS: To investigate comprehension of spoken language on sentence type level in non-speaking children with severe CP. METHODS & PROCEDURES: From an original sample of 87 non-speaking children with severe CP, 68 passed the pre-test (i.e. they matched at least five spoken words to the corresponding objects) of a specifically developed computer-based instrument for low motor language testing (C-BiLLT), admitting them to the actual C-BiLLT computer test. As a result, the present study included 68 children with severe CP (35 boys, 33 girls; mean age 6;11 years, SD 3;0 years; age range 1;9-11;11 years) who were investigated with the C-BiLLT for comprehension of different sentence types: phrases, simple active sentences (with one or two arguments) and compound sentences. The C-BiLLT provides norm data of typically developing (TD) children (1;6-6;6 years). Binomial logistic regression analyses were used to compare the percentage correct of each sentence type in children with severe CP with that in TD children (subdivided into age groups) and to compare percentage correct within the CP subtypes. OUTCOMES & RESULTS: Sentence comprehension in non-speaking children with severe CP followed the developmental trajectory of TD children, but at a much slower rate; nevertheless, they were still developing up to at least age 12 years. Delays in sentence type comprehension increased with sentence complexity and showed a large variability between individual children and between subtypes of CP. Comprehension of simple and syntactically more complex sentences were significantly better in children with dyskinetic CP than in children with spastic CP. Of the children with dyskinetic CP, 10-13% showed comprehension of simple and compound sentences within the percentage correct of TD children, as opposed to none of the children with spastic CP. CONCLUSION & IMPLICATIONS: In non-speaking children with severe CP sentence comprehension is delayed rather than deviant. Results indicate the importance of following comprehension skills across all age groups, even beyond age 12 years. Moreover, the subtype of CP should be considered when establishing an educational programme for sentence comprehension, and augmentative and alternative communication support. In addition, educational programmes for children with severe CP should take into account the linguistic hierarchy of sentence comprehension when focusing on the input and understanding of spoken language comprehension.

Comprehension of spoken language in non-speaking children with severe cerebral palsy: an explorative study on associations with motor type and disabilities.

AIM: To assess spoken language comprehension in non-speaking children with severe cerebral palsy (CP) and to explore possible associations with motor type and disability. METHOD: Eighty-seven non-speaking children (44 males, 43 females, mean age 6y 8mo, SD 2y 1mo) with spastic (54%) or dyskinetic (46%) CP (Gross Motor Function Classification System [GMFCS] levels IV [39%] and V [61%]) underwent spoken language comprehension assessment with the computer-based instrument for low motor language testing (C-BiLLT), a new and validated diagnostic instrument. A multiple linear regression model was used to investigate which variables explained the variation in C-BiLLT scores. Associations between spoken language comprehension abilities (expressed in z-score or age-equivalent score) and motor type of CP, GMFCS and Manual Ability Classification System (MACS) levels, gestational age, and epilepsy were analysed with Fisher's exact test. A p-value <0.05 was considered statistically significant. RESULTS: Chronological age, motor type, and GMFCS classification explained 33% (R=0.577, R(2) =0.33) of the variance in spoken language comprehension. Of the children aged younger than 6 years 6 months, 52.4% of the children with dyskinetic CP attained comprehension scores within the average range (z-score ≥-1.6) as opposed to none of the children with spastic CP. Of the children aged older than 6 years 6 months, 32% of the children with dyskinetic CP reached the highest achievable age-equivalent score compared to 4% of the children with spastic CP. No significant difference in disability was found between CP-related variables (MACS levels, gestational age, epilepsy), with the exception of GMFCS which showed a significant difference in children aged younger than 6 years 6 months (p=0.043). INTERPRETATION: Despite communication disabilities in children with severe CP, particularly in dyskinetic CP, spoken language comprehension may show no or only moderate delay. These findings emphasize the importance of introducing alternative and/or augmentative communication devices from early childhood.

Developmental trajectories of receptive and expressive communication in children and young adults with cerebral palsy.

AIM: The aim of this study was to determine the developmental trajectories of expressive (speech) and receptive (spoken and written language) communication by type of motor disorder and intellectual disability in individuals with cerebral palsy (CP). METHOD: The development of 418 participants (261 males, 157 females; mean age 9y 6mo [SD 6y 2mo], range 1-24y; Gross Motor Function Classification System (GMFCS) level I [n=206], II [n=57], III [n=59], IV [n=54], V [n=42]) was followed for 2 to 4 years in a longitudinal study. Communication performance was measured using the Vineland Adaptive Behavior Scales. The type of motor disorder was differentiated by type of CP as unilateral spastic (USCP, n=161), bilateral spastic (BSCP, n=202), and non-spastic (NSCP, n=55), while intellectual disability was determined by IQ or school type (regular or special). A multilevel analysis was then used to model the developmental trajectories. RESULTS: The most favourable development of expressive communication was seen in USCP (vs BSCP ß [SE]-2.74 [1.06], NSCP ß [SE]-2.67 [1.44]). The difference between the development trajectory levels of children with and without intellectual disability was smaller for children with USCP than for those with BSCP and NSCP. For receptive communication, the most favourable development was found for all children with USCP and for BSCP or NSCP without intellectual disability (vs intellectual disability ß [SE]-4.00 [1.16]). Development of written language was most favourable for children without intellectual disability (vs intellectual disability ß [SE]-23.11 [2.85]). INTERPRETATION: The development of expressive communication was found to be most closely related to type of motor disorder, whereas the development of receptive communication was found to be most closely related to intellectual disability.

Assessing comprehension of spoken language in nonspeaking children with cerebral palsy: application of a newly developed computer-based instrument.

This paper describes the development of an instrument to assess comprehension of spoken language in children with severe cerebral palsy (CP) who cannot speak, and for whom standard language assessment measures are not appropriate due to severe motor impairment. This instrument, the Computer-Based instrument for Low motor Language Testing (C-BiLLT), was administered to 42 children without disabilities (aged 14 months to 60 months) and to 18 children with severe CP (age 19 months to 71 months). Preliminary data showed that the instrument was acceptable to the children. Convergent validity was investigated by correlating C-BiLLT scores with test results on the well-established Reynell Developmental Language Scales (RDLS). Clinical implications and recommendations for future research are discussed.