Wenke et al. (2011)




SOURCE:  Wenke, R. J., Theodoros, D., & Cornwall, P.  (2011).  A comparison of the effects of the Lee Silverman Voice Treatment and traditional therapy on intelligibility, perceptual speech features, and everyday communication in nonprogressive dysarthria.  Journal of Medical Speech-Language Pathology, 19 (4), 1-25.




DATE: 7.27.12          ASSIGNED  GRADE for QUALITY:  B+


TAKE AWAY:  Indicates that LSVT can successfully improve rate and loudness as well as other aspects of communication in Ps with nonprogressive dysarthria.


1.  What type of evidence was identified?  


1a.  What was the type of evidence?   Prospective, Randomized Group Design with Controls (PRG); 10 Ps previously reported in research

1b.  What was the level of support associated with the type of evidence?  A         


2.  How was group membership determined?


2a.  If there were groups, were participants randomly assigned to groups?          Yes


3.  Was administration of intervention concealed?              

a.  from participants? No

b.  from clinicians?  No

c.  from analyzers? Yes;  for the most part—some measures were by the treating slp


4.  Were the groups adequately described?Yes


4a.  How many participants were involved in the study?

•  total # of participants:  # of groups:  26

•  how many groups:  2

•  # of participants in each group?:  13

4b.  The following variables/characteristics were described:   


•  ageMean =  49 years

•  gender16m, 19f

•  cognitive skillsvaried

•  post onset:  6 months 21 years

•  English:  all fluent speakers

•  severity of dysarthria:  mild/mild-moderate or moderate/moderate-severe

•  etiology:  TBI, CVA, MVA. Hypoxia

•  site of lesion:  varied


The following characteristics were controlled (excluded): significant aphasia, hearing loss, dementia, apraxia, posttraumatic amnesia, significant respiratory dysfunction, preexisting laryngeal pathology/dysfunction unrelated to the neurologic disorder.


4c.  Were the groups similar before intervention began?  Unclear; no significant differences for age and time post onset.

4d.  Were the communication problems adequately described?     Yes

•  persistent nonprogressive dysarthria with either a respiratory or phonatory impairment.

•  Type of dysarthria varied:  flaccid-spastic, spastic-ataxic. Hypokinetic, spastic, ataxic, flaccid, spastic-hypokinetic, unilateral upper motor neuron

•  functional level: stimulable volume or quality


5.  Was membership in groups maintained throughout the study?  No


a.  Did each of the groups maintain at least 80% of their original members? No Due to illness or equipment failure:

•  4/26 Ps participated in only one post1 assessment session

Due to  moving:

•  7/26 did not participate in post2 assessment

•  missing data were statistically estimated

b.  Were data from outliers removed from the study?  No


6.  Were the groups controlled acceptably? Yes


a.  Was there a no intervention group?   No      

b.  Was there a foil intervention group?  No

c.  Was there a comparison group? Yes

d.  Was the time involved in the foil/  comparison and the target groups constant?  Yes


7.  Were the outcomes measure appropriate and meaningful? Yes

•  outcomes were  measured 3 times: pre, post1 (immediately after therapy), post2 (3 mos after therapy)

•  2 testing sessions  for @ time; results were averaged


7a.  List outcomes (dependent variables):


Perceptual Battery

1.  Assessment of Intelligibility of Dysarthria Speech  (ASSID):  word intelligibility, sentence intelligibility; words per minute (WPM), communication efficiency ratio (CER)

2.  Paired comparison rating of intelligibility in reading sample

3.  Speech features in read samples:  perceived rate, perceived loudness, perceived stress—Direct Magnitude of Effect (DME)


Everyday Day Communication Measures

4.  AusTOM—patient self report of impairment, activity, well-being

5.  Patient Questionnaire

6.  Communicative Partner Questionnaire


7b  Are the outcome measures subjective?      Yes

7c. Are the outcome measure objective?           No      



8.  Were reliability measures provided?


a.  Interobserver for analyzers? Yes for some


Values for outcomes        

1.  provided in the literature

2.  .76

3.  .72

4.  no

5.  no


b.  Intraobserver for analyzers? Yes for some

Values for outcomes

1.  already established in literature

2.  .63

3.  rater1 = .87; rater2 = .89

4.  no

5.  no


c.  Treatment fidelity for clinicians? No


9.  What were the results of the statistical (inferential) testing?


9a.   If the different clinical groups are compared, the order of improvement on the outcome measure from most to least improvement:


OUTCOME 1:  LSVT has significantly lower WPM than TRAD        

OUTCOME 2:  Not significant           

OUTCOME 3:  Not significant      

OUTCOME 4:  Not significant

OUTCOME 5:  Significant differences in initiations with strangers; LVST group was closer to normal function.


9b.  Was there a significant difference in outcome measures following treatment? Yes for many


Yes for the following outcomes:

#1—for both LSVT & TRAD word intelligibility for pre v post1; word intelligibility improved for both groups

#1 lower WPM in LVST v TRAD; WPM significantly better for LVST

#2  LSVT post1 sign better intelligibility than  pre.

#3  LSVT rate  (pre v post2), stress (pre v post1)  and loudness  (pre v post1) measures improve.

#4.  LVST  and TRAD significant improvement in participation, well-being

(pre v post1/post2) and impairment (pre v post1 only)

#5.  LVST and TRAD significantly reduced slurring (pre v post1/post2)

#5.  LVST significantly more conversational participation and initiation (pre v post2)

#5.  TRAD  increased intelligibility with others (pre v post1/post2)

#5.  TRAD significantly more conversational participation and initiation (pre v post1)

#5.  TRAD decreased slurring significantly more than LVST.

#6.  LSVT increased intelligibility, initiation of conversation with unfamiliar partners, overall communication ability (pre v post1/post2) and reduced repetition requests (pre v post1)

#6.  TRAD  increased intelligibility (pre v post1) and overall communication (pre vs post1/post2).


No— for any comparison not listed in yes.



9c.  What was the p value? Used ANOVA with post hoc exams; some post hocs were nonparametric:

#1  .015

#2  .007

#3  .001- .039

#4  .000-.027

#5  .001-.037

#6  .002-.05

NOTE:  did not see correction for multiple measures derived from reading sample

9d.  Was confidence interval (CI) provided?  No          


10.  What is the clinical effect?  (i.e., EBP measures)  Table 3 noted some clinically significant differences but these were not explained in the prose.




NOTE:  Follow-up assessment 3 months after end of intervention.





PURPOSE:  To compare the effectiveness of compare the effects of the Lee Silverman Voice Treatment to  traditional dysarthria therapy on prosodic and nonprosodic communication measures .

POPULATION:  nonprogressive dysarthria


MODALITY TARGETED:  expressive prosody


ELEMENTS/FUNCTIONS OF PROSODY TARGETED (do not list the specific dependent variables here)rate, loudness, stress


OTHER ASPECTS OF LANGUAGE/COMMUNICATION TARGETED (Dependent variable):  intelligibility, articulation, pragmatics, overall communication


OTHER TARGETS:  impairment, activity, participation, well-being,


DOSAGE:  16 sessions in 4 weeks; 1 hour each session; 5 -10 minutes of homework per day




STIMULI:  not clear







Homework:  carry-over activities with targeted variables



•  C was a certified user of LVST

•  C followed the program

•  Treatment focused on specific behaviors:  high effort, loud voice quality, clear/healthy voice quality

•  Authors cited reference for more specific description of intervention





Homework:  practice activities from day’s session

Intervention:   referenced the literature and a focus group to design intervention that reflected current practices.  Focus was on increasing intelligibility by modifying communication of the patient by improving function through restoration or compensation, as appropriate to the individual’s profile.  Among areas targeted were speech/articulatory mechanism, respiratory/ phonatory system, velopharyngeal system, prosody, continuous positive airway pressure, overall communication.





•  rate of word intelligibility

•  rate of sentence intelligibility

•  words per minute (WPM)

•  communication efficiency ratio (CER)

•  relative intelligibility (paired comparison)

•  perceived rate  using Direct Magnitude Estimation (DME)

•  perceived loudness using Direct Magnitude Estimation (DME)

•  perceived stress appropriateness using Direct Magnitude Estimation (DME)

•  clinician’s rating of impairment

•  clinician’s rating of activity

•  clinician’s rating of participation

•  clinician’s rating of well-being

•  patient’s rating of slurred speech

•  patient’s rating of shaky or hoarse voice quality

•  patient’s rating of intelligibility,

•  patient’s rating of conversational participation with unfamiliar people

•  patient’s rating of initiation of conversation

•  communicative partner’s rating of shaky or hoarse voice quality

•  communicative partner’s rating of intelligibility,

•  communicative partner’s rating of conversational participation with unfamiliar people

•  communicative partner’s rating of initiation of conversation

•  communicative partner’s rating of overall communication



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