Table 4.
The Dysarthria Index and the five Dysarthria Subtype Indices.
| Ten linguistic domains | No. | Dysarthria Index (DI) speech, prosody, and voice changes | Assessment mode
a
|
Five Dysarthria Subtype Indices (DSI)
b
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| P | A | Ataxic | Spastic | Hyperkinetic | Hypokinetic | Flaccid | |||
| Vowels | 1 | Increased percentage vowels/diphthongs distorted | X | X (2) | X (2) | ||||
| Consonants | 2 | Number of nasal emissions | X | X (2) | |||||
| 3 | Increased percentage of weak consonants | X | X (1) | ||||||
| Vowels and consonants | 4 | Increased Diacritic Modification Index class duration | X | X (1) | X (1) | ||||
| Phrasing | 5 | Increased slow/pause time | X | X (1) | X (2) | ||||
| Rate | 6 | Increased slow articulation/pause time | X | X (1) | X (2) | X (1) | |||
| 7 | Decreased average syllable speak rate (with pauses) | X | X (1) | X (2) | X (1) | ||||
| 8 | Decreased average syllable articulation rate (without pauses) | X | X (1) | X (2) | X (1) | ||||
| 9 | Increased fast rate | X | X (2) | ||||||
| 10 | Decreased stability of syllable speaking rate | X | X (1) | X (2) | |||||
| Stress | 11 | Increased excessive/equal/misplaced stress | X | X (2) | X (1) | ||||
| 12 | Increased reduced/equal stress | X | X (2) | ||||||
| Loudness | 13 | Decreased stability of Speech Intensity Index | X | X (2) | X (2) | ||||
| 14 | Increased stability of Speech Intensity Index | X | X (1) | X (2) | X (1) | ||||
| 15 | Increased soft utterances | X | X (2) | X (1) | |||||
| 16 | Decreased Speech Intensity Index (difference dB) | X | X (2) | X (1) | |||||
| Pitch | 17 | Increased low pitch/glottal fry | X | X (2) | X (1) | ||||
| 18 | Increased low pitch | X | X (2) | X (1) | |||||
| 19 | Decreased F0 on vowels & diphthongs | X | X (2) | X (1) | |||||
| 20 | Decreased F0 range on vowels/diphthongs | X | X (1) | X (1) | X (2) | X (1) | |||
| 21 | Decreased stability of F0 on vowels & diphthongs | X | X (1) | ||||||
| Laryngeal quality | 22 | Increased breathiness | X | X (1) | X (2) | ||||
| 23 | Increased rough | X | X (1) | X (1) | |||||
| 24 | Increased strained | X | X (1) | X (1) | |||||
| 25 | Number of utterances with [Tremulous] comment | X | X (1) | ||||||
| 26 | Increased break/shift/tremulous | X | X (2) | X (1) | |||||
| 27 | Increased multiple laryngeal features | X | X (2) | X (2) | |||||
| 28 | Number of diplophonic utterances | X | X (2) | ||||||
| 29 | Increased percentage of jitter on vowels/diphthongs | X | X (1) | ||||||
| 30 | Decreased stability of jitter for vowels | X | X (1) | ||||||
| 31 | Increased percentage of shimmer on vowels | X | X (1) | ||||||
| 32 | Decreased stability of shimmer on vowels | X | X (1) | ||||||
| Resonance quality | 33 | Increased nasal | X | X (1) | X (1) | X (1) | X (2) | ||
| 34 | Decreased F1 for /ɑ/ | X | X (1) | X (1) | X (1) | X (2) | |||
| Totals | |||||||||
| Unweighted | 18 | 16 | 12 | 15 | 19 | 11 | 10 | ||
| Weighted | 18 | 16 | 15 | 23 | 22 | 19 | 15 | ||
a
A = acoustic; P = perceptual.
b
The DI includes all 34 items, unweighted. The bolded “X” and number in parenthesis indicate items that are weighted 2 points rather than 1 point within the five DSI. The criteria for a classification of motor speech disorder–dysarthria (MSD-DYS) are a DI score below 80%, two unweighted DSI indices below 70%, and at least one DSI ≤ 10th percentile.