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Imaging
Table 2: Dopaminergic Scan Studies
Study Ligand Number of Participants MMSE (mean±SD) SPECT Analysis and Efficacy Comments
Donnemiller
123
I-β-CIT DLB (n=7) DLB (20.1±5.2) Semi-quantitative: Occipital hypoperfusion also
et al., 1997
13
AD (n=6) AD (12.8±8.8) ↓ DAT binding compared with AD found on HMPAO SPECT
Ransmayr
123
I-β-CIT DLB (n=20) Not reported Semi-quantitative: No efficacy data available
et al., 2001
17
PD (n=24) ↓ DAT binding in the DLB group compared
Controls (n=10) with controls, DLB dopaminergic loss more
marked and less asymmetrical
compared with PD
Walker
123
I-FP-CIT DLB (n=27) DLB (16.2±6.2) Semi-quantitative: Consensus of 91% (κ 0.82)
et al., 2002
15
AD (n=17) AD (21.5±5.3) ↓ dopaminergic uptake in the caudate, between ROIs and the
PD (n=19 PD (27.7) anterior and posterior putamen visual assessment
Controls (n=16) Controls (28.9) compared with controls and AD
Ceravolo
123
I-FP-CIT DLB (n=24) DLB (21.0±1.8) Lower ratio of specific (striatal) No efficacy data
et al., 2003
16
AD (n=24) AD (20.6±2.3) to non-specific binding
O’Brien
123
I-FP-CIT DLB (n=23) DLB (16.3±5.8) Visual analysis: Consensus panel diagnosis
et al., 2004
19
PDD (n=36) PDD (19.1±5.6) Sensitivity 78%, specificity 85%, PPV 78%
PD (n=38) PD (26.5±2.1) Semi-quantitative:
AD (n=34) AD (17.3±4.9) Sensitivity 78%, specificity 94%, PPV 89%
Controls (n=33)
McKeith
123
I-FP-CIT Probable DLB (n=88) Probable DLB (20.0±4.5) Visual analysis: Consensus panel diagnosis
et al., 2007
20
Possible DLB (n=56) Possible DLB (20.9±4.2) Sensitivity 77.7%, specificity 90.4%,
Non-DLB (n=144) Non-DLB (21.5±4.4) PPV 82.4%, NPV 87.5%
Walker
123
I-FP-CIT DLB (n=8) DLB (17.0±5.6) Visual analysis: Pathologically confirmed
et al., 2007
4
Non-DLB (n=12) AD (16.6±8.8) Sensitivity 88%, specificity 83% diagnoses
Controls (n=16) Semi-quantitative (total posterior putamen):
Sensitivity 88%, specificity 100%
Semi-quantitative (unilateral posterior putamen):
Sensitivity 100%, specificity 92%
Clinical diagnosis:
Sensitivity 75%, specificity 42%
O’Brien
123
I-FP-CIT Probable DLB (n=72) Baseline: Visual analysis: Consensus panel diagnosis
et al., 2008
21
Possible DLB (n=46) Probable DLB (20.9±4.3) Possible DLB: diagnoses at one-year
Non-DLB (n=129) Possible DLB (20.8±4.4) Sensitivity 63%, specificity 100%. follow-up
No initial diagnosis (n=17) Non-DLB (21.7±4.3) Overall diagnostic accuracy in
Follow-up: the whole sample:
Probable DLB (17.4±6.5) Sensitivity 78%, specificity 93%
Possible DLB (19.0±7.1)
Non-DLB (19.4±6.1)
MMSE = mini-mental state examination; SPECT = single photon emission computed tomography; SD = standard deviation; DLB = dementia with Lewy bodies; AD = Alzheimer’s disease; DAT =
dopamine transporter binding; PD = Parkinson’s disease; ROIs = regions of interest; PDD = Parkinson’s disease dementia; PPV = positive predictive value; NPV = negative predictive value;
HMPAO = Tc-hexamethylpropyleneamine oxime.
uptake in the caudate and increased activity in the putamen, giving a occipital deficit (sensitivity 90% and specificity 80% using a factorial
reduced caudate/putamen ratio. This was a small study and there was discriminant analysis with 15 perfusion parameters and mini-mental
overlap between DLB and AD, making it unlikely that
123
I–IBZM would state examination [MMSE] score). However, a later study
27
reported
be of much use in clinical practice. A study investigating FP-CIT and occipital hypoperfusion in 15 of 23 DLB patients (65%) compared with
IBZM SPECT in parkinsonian syndromes
25
found no abnormalities of the only nine of 50 AD cases (18%) (sensitivity 64% and specificity 86%
post-synaptic D2 receptor in six patients who were later diagnosed using stepwise discriminant analysis with left occipital perfusion and
with DLB. Direct comparisons between these two studies cannot be right temporal perfusion as dependent variables). Other studies have
made as they differ significantly in their aims and methodology. also shown occipital hypoperfusion to be more common in DLB than in
AD,
16,30,32–36
with varying sensitivities and specificities. A few studies also
Cerebral Perfusion Imaging showed relatively preserved medial temporal perfusion in DLB
Perfusion SPECT studies (see Table 3) have assessed regional compared with AD.
28,30,32,36
Sato et al.
36
reported that DLB patients more
cerebral blood flow, a marker of brain function, using frequently have occipital hypoperfusion (16 of 22 DLB patients versus
99m
Tc-hexamethylpropylene amine oxime (HMPAO),
13,26–29
99m
Tc-ethyl three of 25 AD patients) and also hyperperfusion in striatum/thalamus
cysteinate dimer (ECD)
13,16,30
or to N-isopropyl-p-[
123
I] iodoamphetamine (18 of 22 DLB patients versus eight of 25 AD patients) compared with
(IMP).
31–36
Donnemiller et al.,
13
in a study of six AD and seven AD. Combining these two measures gave good sensitivity of 95% and
DLB patients, described a “horse-shoe-like pattern” of bilateral modest specificity of 65% (see Table 3).
parieto-occipital hypoperfusion on SPECT in six out of seven DLB
patients compared with only one out of six AD cases. By contrast, the More recently, Kemp et al.
29
reported occipital hypoperfusion in only
finding of a larger study
26
of 20 AD and 20 DLB patients was diffuse 11 of 39 DLB subjects (28%) and in 14 of 45 non-DLB dementia
cortical hypoperfusion with significant frontal deficits in DLB and no cases (31%), and concluded that occipital hypoperfusion was not
84 EUROPEAN NEUROLOGICAL REVIEW
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