Oral and Laryngeal Diadochokinesis Across the Life Span: A Scoping Review of Methods, Reference Data, and Clinical Applications
Journal of Speech, Language & Hearing Research
Kent, R. D., Yunjung, K., et al. (2022).
Journal of Speech, Language & Hearing Research, 65(2), 574-623.
This scoping review investigates oral and laryngeal diadochokinesis in children and adults with a clinical diagnosis and without. This review describes age-specific reference data for monosyllabic, trisyllabic, and laryngeal diadochokinetic rates for children and adults.
Ministry of Science and Technology (Taiwan)
Not stated
Published peer-reviewed articles (case studies excluded)
360
<div>"It remains to be determined if language-related differences in speaking rate, if they exist, are reflected in [diadochokinetic] rates, given that the latter presumably control for differences in phonology and other aspects of language. For the present, it is prudent to allow that language effects on [diadochokinetics] may be present so that it is preferable to use language-specific reference data in clinical or other applications" (p. 595).</div>
<div>Multiple studies observed "slow, inaccurate, and disrupted [diadochokinetics]" in children with childhood apraxia of speech (CAS; p. 596). One study purported that CAS may be distinguished from childhood dysarthria through polysyllabic production and diadochokinetics, highlighting the utility of a comparison between monosyllabic and polysyllabic rates. See Tables 1-7 and 13 for information on DDK rates in children ages 2-18.</div>
<div>Findings regarding diadochokinetic rates in children who stutter were mixed, with some studies noting typical performance, some noting atypical performance, and some noting variable performance. One study indicated that trisyllabic diadochokinetic rates may be better at discriminating children who stutter from those who do not.</div>
<div>Findings regarding diadochokinetic rates in children with speech-sound disorder were mixed. One study found children with residual errors were less accurate and more variable for trisyallabic diadochokinetic production; though, there was no difference in rate as compared to typical peers. Another study found that children with persistent speech-sound disorders and common clinical distortions had oral-motor weakness that could be observed during diadochokinetic tasks. An additional study indicated that children with phonological disorders were slower for speech diadochokinetic tasks, but not oral-motor tasks, when compared to typical peers. Because children with speech-sound disorder are a heterogenous population, rates may therefore vary.</div>
<div>Studies of individuals with amyotrophic lateral sclerosis (ALS) indicate reduced rate for both oral and laryngeal diadochokinetic tasks. Specific findings included:</div>
<div>
<ul>
<li>One study found diadochokinetic tasks were better at discriminating those with ALS from healthy controls than sustained phonation or spontaneous speech tasks.</li>
<li>Another study found diadochokinetic rates may help detect motor impairment before changes can be seen in intelligibility or reading tasks.</li>
<li>An additional study found "mean absolute difference of duration in consecutive cycles of the acoustic envelope... had a high diagnostic accuracy (.87), with 80% sensitivity and 94% specificity in differentiating individuals with ALS from healthy controls" (p. 599).</li>
</ul>
<div>See Tables 8-13 for information on DDK rates in adults.</div>
</div>
<div>Individuals with apraxia of speech have been observed to exhibit slow, irregular diadochokinetic production, particularly for sequential motion rates as compared to alternating motion rates. Diadochokinetic tasks are useful in assessment, particularly if evaluating features other than rate (e.g., articulatory placement and sequencing of movements). For individuals with progressive, nonfluent aphasia, reduced rate is considered a diagnostic indicator of apraxia of speech.</div>
<div>A distinctive feature of ataxic dysarthria is atypical diadochokinetic production as characterized by slow rate as well as irregular timing and energy. Individuals with Friedreich's dysarthria exhibited respiratory insufficiency, pitch and amplitude disturbances, and slowed diadochokinetic rate. Individuals with preataxic spinocerebellar ataxia type 2 exhibited early deficits such as reduced rate and production consistency during diadochokinetic tasks in the absence of overt dysarthria. Diadochokinetic tasks may be useful to distinguish subtypes of ataxia. Additionally, because ataxic dysarthria is characterized by disturbed prosody, "modification of the [diadochokinetic] task to incorporate syllable stress variations may prove informative" (p. 600).</div>
<div>For individuals with cerebral palsy (CP), speech diadochokinetic rates have been slow and inaccurate. Productions for double, nonspeech diadochokinetic tasks have also been atypical. Findings were mixed on the relationship between speech disorder severity and both speech and nonspeech diadochokinetic tasks. One study found diadochokinetic rate varied with type of CP, with the slowest rates for individuals with spastic quadriplegia, dyskinetic, and mixed type of CP. Individuals with ataxic and spastic diplegia had moderate rates, and the fastest rates reported for individuals with hemiplegia.</div>
<div>For individuals with myasthenia gravis, one study found diadochokinetic productions were characterized by a lengthening of intersyllabic intervals.</div>
<div>For individuals with Parkinson's Disease (PD), "optimum use of [diadochokinetics] DDK requires consideration of syllable composition, task instructions, and methods of analysis. Regarding syllable composition, voiceless stops (when part of the inventory in a particular language) may be more sensitive to disruption than voiced stops. Among the voiceless stops, the dorsal /k/ probably is preferable to its bilabial or coronal counterparts, presumably because it requires movement of the bulk of the tongue. For task instruction, both a self-selected comfortable rate and a maximum rate appear useful. Finally, for methods of analysis, measures should be selected that reveal the temporal pattern of syllable repetition" (p. 603).<br><br>Individuals with progressive supranuclear palsy (PSP) had greater instability during diadochokinetic tasks than individuals with PD. Diadochokinetic tasks may help differentially diagnose individuals with PSP and multiple system atrophy from individuals with PD.</div>
<div>For individuals with nonfluent aphasia, diadochokinetic productions were characterized by reduced rate and instability in laryngeal diadochokinetic rates. One study found individuals with focal unilateral upper motor neuron lesions had slow and irregular diadochokinetic productions while another found monosyllabic diadochokinetic productions were more often impaired than trisyllabic diadochokinetic productions. For individuals with upper motor neuron dysarthria, slower rates of repetitive lip movements were observed. <br><br>Another study found that patients with stroke demonstrated slow and variable diadochokinetic productions due to lengthening of syllables and inter-syllable gaps. Voicing was also present during the inter-syllable gap.</div>
<div>Due to cognitive impairment, reduced DDK rates may not distinguish TBI from motor speech disorders. See Tables 8-13 for information on DDK rates in adults.</div>
<div>Deaf children (aged 6-7 years) and adolescents who are hard of hearing showed reduced diadochokinetic rates. For adolescents, the magnitude of the reduced rate is related to the degree of overall hearing loss.</div>
<div>Laryngeal diadochokinetic has been used to assess laryngeal function for individuals with voice disorder. Women with dysphonia, vocal tremor, and spasmodic dysphonia have been found to produce diadochokinetics with atypical rate and stability.<br><br>In terms of measures following treatment, laryngeal diadochokinetic for the vowel /i/ was "more stable in temporal and intensity features following laryngeal manual therapy" (p. 604). Diadochokinetic was also highly correlated with perceptual judgments of substitution voice (i.e., voicing without two true vocal folds).</div>
<div>Adults with cognitive impairment exhibit reduced diadochokinetic rate, possibly due to the cognitive burden of the task.</div>
<div>Limited evidence demonstrated that, when included as part of a bedside swallow evaluation, diadochokinetic task performance may predict dysphagia and aspiration. Reduced diadochokinetic rates for /pa/ were associated with declining labial motor function and dysphagia. Reduced diadochokinetic rates for monosyllables were associated with oral phase prolongation during swallow of solids. Laryngeal diadochokinetic was negatively correlated with scores on the Dysphagia Handicap Index for older adults. See Tables 8-13 for information on DDK rates in adults.</div>
<div>Individuals with Down Syndrome exhibit slow rate, temporal variability, and inaccurate articulation in diadochokinetic production. Another study found more attempts at task completion for polysyllabic diadochokinetics.</div>
<div>Atypical diadochokinetic production has been found in young adults with attention-deficit/hyperactivity disorder. Increased symptom severity was associated with decreased monosyllabic diadochokinetic rate.</div>
<div>Individuals with Huntington's disease exhibit reduced diadochokinetic rate, with some studies noting reduced stability as well. Diadochokinetic rates may indicate motor impairment before other clinical symptoms manifest. Huntington's Disease impacts oral motor performance including oral diadochokinetic productions.</div>
<div>For individuals with multiple sclerosis (MS), diadochokinetic rates are slow and irregular. Oral diadochokinetic rates decrease with increased articulation disorder severity. Acoustic studies revealed slowed rate was due to "longer stop gap durations" and "durations of vowels" (p. 601). Some studies indicate that temporal rather than energy measures may aid in differentiating among individuals with dysarthria due to MS, individuals with dysarthria due to Parkinson's disease, and healthy controls. Acoustic analysis of loudness variation may differentiate type of MS.</div>
