Table 1

PET studies included in the meta-analysis for the group of premanifest Huntington’s disease gene expansion carriers

Study and group	Radioligand	N		Age (years)		Prob to onset		CAGr
Study and group	Radioligand	Total	Male (%)	Mean	Range	p5 years†	90% p to onset‡	Mean	Range
D₂ receptor
Antonini et al 40	[¹¹C]raclopride
HC		14	–	30	21–49
Premanifest HD		10	50	30	21–41	0.12	26.7	43.9	40–47
Politis et al 46	[¹¹C]raclopride
HC		9	89.5	41.2	5.5*
Premanifest HD		10	50	41.9	32–61	0.33	16.9	43.4	39–48
van Oostrom et al 47	[¹¹C]raclopride
HC		11	54	48.4	30–65
Premanifest HD		18	44	39.9	29–56	0.21	19.5	43	39–47
Tang et al 51	[¹¹C]raclopride
HC		12	42.5	50.1	15.6*
Premanifest HD		12	46.8	48.3	11.0*	0.33	10.3	41.6	1.7*
Microglial activation
Politis et al 46	[¹¹C]PK11195
HC		10	89.5	56.7	11.7*
Premanifest HD		10	50	41.9	32–61	0.33	16.9	43.4	39–48
Politis et al 57	[¹¹C]PK11195
HC		12	58.3	39.4	28–65
Premanifest HD		12	41.7	41.1	29–59	0.32	17.9	43.7	40–48
Glucose metabolism
Antonini et al 40	[¹⁸F]FDG
HC		20	-	34	22–44
Premanifest HD		13	50	30	21–41	0.17	23.7	43.9	40–47
Feigin et al 45	[¹⁸F]FDG
HC		12	42.5	50.1	15.6*
Premanifest HD		12	46.8	48.3	11.0*	0.33	10.3	41.6	1.7*
Ciarmiello et al 49	[¹⁸F]FDG
HC		21	57.1	68.1	48–91
Premanifest HD		43	55.8	37.3	19–59	0.25	18	43.8	39–54
Herben-Dekker et al 54	[¹⁸F]FDG
HC		11	33	42.5	26–54
Premanifest HD		22	36	38.7	31–56	0.19	22.4	42.6	39–47
Phosphodiesterase 10A
Russell et al 55	[¹⁸F]MNI-659
HC		9	55	46.1	29–71
Premanifest HD		3	0	32.4	32–34	0.18	22.3	44.3	42–47
Niccolini et al 56	[¹¹C]IMA107
HC		12	66.7	40	28–50
Premanifest HD		12	58.3	41.1	32–52	0.16	25	41.8	40–44
Adenosine A₁ receptor
Matusch et al 52	[¹⁸F]CPFPX
HC		36	63.9	49.6	16*
Premanifest HD		13	23.1	39.1	7*	0.19	13	42.8	1.4*

*SD.
*†p5 years=5-year probability to symptoms onset according to the Langbehn formula.10
‡90% p to onset=predicted years to HD symptoms onset (90% probability) calculated on the basis of the variant of the survival analysis formula described by Langbehn.5
HC, healthy controls; HD, Huntington’s disease; PET, positron emission tomography.