Predicting Early Bulbar Decline in Amyotrophic Lateral Sclerosis: A Speech Subsystem Approach

Table 1

The key variables and the corresponding weights that comprise the principal components of each speech subsystem. The composite variables are spelt out below.

Principal components	Composite variables	Weights
PCresp1	SubGlotPrssMax_Pi	1.00
PCresp2	Pause_Event	0.51
	PerPause	0.76
	Pause_Duration	0.40
PCphon1	Max_F0	0.97
PCart1	BBP_MaxVel_LL_RBHo	−0.40
	BBP_MaxVel_UL_LLo	−0.56
	BBP_MinVel_LL_RBHo	0.40
	BBP_MinVel_UL_LLo	0.56
PCart2	APA_MaxVel_LL_RBHo	0.58
	APA_MaxVel_UL_LLo	0.79
PCart3	Reps_DDK	0.99
PCreso1	NasalFlow_Pi	1.00
PCreso2	Naso_BBP	1.00

Notes.
SubGlotPrssMax_Pi = peak intraoral pressure during /pi/.
PerPause = percent of pausing time.
Pause_Event = number of pauses.
Pause_Duration = duration of pauses.
Max_F0 = maximum fundamental frequency during a high pitch task.
BBP_MaxVel_LL_RBHo = maximum velocity of lower lip movement riding on the jaw during “Buy Bobby a puppy.”
BBP_MaxVel_UL_LLo = maximum velocity of lip opening during “Buy Bobby a puppy.”
BBP_MinVel_LL_RBHo = minimum velocity of lower lip movement riding on the jaw during “Buy Bobby a puppy.”
BBP_MinVel_UL_LLo = minimum velocity of lip opening during “Buy Bobby a puppy.”
APA_MaxVel_LL_RBHo = maximum velocity of lower lip movement riding on the jaw during /aCa/.
APA_MaxVel_UL_LLo = maximum velocity of lip opening during /aCa/.
Reps_DDK = repetitions of syllable during the diadochokinetic rate test.
NasalFlow_Pi = peak nasal airflow during /pi/.
Naso_BBP = Mean nasalance score of the sentence “Buy Bobby a puppy.”