Table 1 PET and SPECT in Huntington’s disease

 1982 Kuhl et al. [4]

PET

[¹⁸F]FDG

Regional glucose metabolism

13 HD, 15 offspring of HD patients, 40 HC

C/Pu hypometabolism began shortly after symptom onset and prior to tissue loss/atrophy

 1986 Young et al. [3]

PET

[¹⁸F]FDG

Regional glucose metabolism

15 HD, 14 HC

C/Pu hypometabolism, degree of which correlated with stage on Shoulson and Fahn scale

 2001 Feigin et al. [2]

PET

[¹⁸F]FDG

Regional glucose metabolism

18 pre-HD, 13 early HD, 8 gene negative relatives

C/Pu hypometabolism in pre-HD and early HD

 2012 Ciarmiello et al. [8]

PET

[¹⁸F]FDG

Regional glucose metabolism

43 pre-HD

Reduction in C metabolism can predict time to phenoconversion

 2014 Herben-Dekker et al. [6]

PET

[¹⁸F]FDG

Regional glucose metabolism

22 pre-HD, 11 HC

C/Pu, GP hypometabolism; on 2-year follow-up all phenoconverted patients exhibited Pu hypometabolism; Pu metabolism remained normal in asymptomatic gene carriers

 2002 Reynolds et al. [52]

SPECT

^99mTc exametazime, ^99mTc Bicisate

Regional cerebral perfusion

34 HD, 12 pre-HD

Most HD patients and 5/12 pre-HD exhibited C hypoperfusion, 7/12 pre-HD showed normal C perfusion

 1999 Andrews et al. [9]

PET

[¹¹C]SCH 23390, [¹¹C]raclopride

D1 and D2

9 pre-HD, 10 HD, 11 at risk HD (6 gene negative, 5 not tested)

Progressive reduction in D1 and D2 receptor binding in C/Pu in pre-HD

 1999 Leslie et al. [51]

SPECT

[¹²³I]IBZM

D2

21 HD (varying stages), 11 HC

Reduced in striatum in moderate-severe stages of HD; normal in pre-HD and early symptomatic HD

 2003 Pavese et al. [12]

PET

[¹¹C]raclopride

D2

12 HD

Progressive reduction in C/Pu D2 receptor binding (not associated with UHDRS motor scores), progressive reduction in D2 binding in frontal cortex and temporal cortex

 2009 Van Oostrom et al. [10]

PET

[¹¹C]raclopride

D2

27 pre-HD, 14 HC

At baseline and 2-year follow-up reduced D2 binding in Pu in pre-HD, weakly correlating with probability of symptom onset within next 5 years

 2010 Gamez et al. [47]

SPECT

¹²³-I-FP-CIT

Presynaptic dopamine transporters

12 HD

Reduced in C/Pu in the majority

 2011 Esmaeilzadeh et al. [13]

PET

[¹¹C]FLB 457

D2

9 HD, 9 HC

Decreased D2 binding in Pu correlated with maximal chorea score (UHDRS item 12) and scores on cognitive testing; reduced D2 binding in C correlated with modified motor score (UHDRS items 4–10, 13–15)

 2013 Hwang et al. [50]

SPECT

[⁹⁹Tc]TRODAT-1, [¹²³I]IBZM

Dopamine transporter, D2

3 HD (related family members), 1 mutation negative member of HD family, 7 HC

Reduced D2 binding in striatum of HD patients, striatal dopamine transporter binding reduced only in the most symptomatic HD patient

 2013 Kiferle et al. [48]

SPECT

¹²³-I-FP-CIT

Presynaptic dopamine transporters

12 HD, 12 HC

Reduced in C/Pu in HD

 2014 Gamez et al. [49]

SPECT

¹²³-I-FP-CIT

Presynaptic dopamine transporters

4 HD

Progressive reduction in C/Pu on 2-year follow-up

 2014 Russell et al. [17]

PET

[¹⁸F]MNI-659

PDE 10

3 pre-HD, 8 HD, 9 HC

Progressive decrease in pre-HD and HD in C/Pu, GP strongly correlated with UHDRS motor subscores

 2016 Russell et al. [18]

PET

[¹⁸F]MNI-659

PDE 10

2 pre-HD, 6 HD, 11 HC

Progressive decrease in C/Pu, GP correlated with HD disease progression

 1996 Antonini et al. [5]

PET

[¹⁸F]FDG, [¹¹C]raclopride

Regional glucose metabolism, D2

8 HD, 10 pre-HD, 9 gene negative members of HD families

C/Pu hypometabolism in HD/pre-HD, reduced [¹¹C] raclopride binding in C/Pu in HD/pre-HD; both correlated with CAG repeat number

 2007 Feigin et al. [11]

PET

[¹⁸F]FDG, [¹¹C]raclopride

Regional glucose metabolism, D2

12 pre-HD

Elevated baseline thalamic metabolism in pre-HD with subsequent subnormal thalamic metabolism after symptom onset, progressive reduction in C/Pu D2 binding

 2008 Politis et al. [14]

PET

[¹¹C]raclopride, [¹¹C]-PK

D2, marker of microglial activation

9 HD, 10 pre-HD, 9 HC in [¹¹C]raclopride study and 10 HC for [¹¹C]-PK

Reduced D2 binding and microglial activation in the hypothalamus in HD and pre-HD

 2013 Tang [7]

PET

[¹⁸F]FDG, [¹¹C]raclopride

Regional glucose metabolism, D2

47 pre-HD (longitudinal imaging performed in 21), 62 HC

Progressive reduction in glucose metabolism in C/Pu, thalamus, insula, and posterior cingulate gyrus, prefrontal cortex, occipital cortex. Progressive increase in glucose metabolism in cerebellum, pons, hippocampus, orbitofrontal cortex. Reduction in baseline D2 binding in C/Pu in pre-HD with subsequent linear decline in D2 binding in C/Pu binding which correlated with disease progression