Table 3.
Diffusion weighted imaging (DWI) and diffusion tensor imaging (DTI).
| Clinical features |
Imaging |
|||||||
|---|---|---|---|---|---|---|---|---|
| ET and controls, age (SD) | ET | Cri | Results ET vs HC | Parameter | Data analysis | |||
| Martinelli et al. (2007), 1.5T DWI | 10 ET 66(11) | 10 HC 60(8) | UE, voice, head |
D | – | – | ADC b = 300, 600, 900 s/mm2 |
ROI: pons, MCP, cerebellar WM, DN, red nucleus, thalamus, caudate, putamen, pallidum, frontal and precentral WM Punc < 0.05 |
| Shin et al., (2008), 1.5T DTI | 10 ET 52.8(11.5) | 8 HC 51.3(11.1) | UE, head |
Fi | ↓ | Bilateral cerebellum, right pons, left retrorubral area of the midbrain and bilateral deep WM | FA b = 1000 s/mm2 |
WM voxel wise Punc < 0.05 |
| Nicoletti et al. (2010), | 25 ET 62.9(9.5) | 15 PD 46.6(6.3) | UE | D | ↑ | MD: SCP | FA, MD | ROI: red nucleus, MCP, SCP, |
| 1.5T DTI | 15 HC 62.4(5.4) | ↓ | FA: DN, SCP | b = 900 s/mm2 | DN, cerebellar WM, ventrolateral thalamus Punc < 0.001 |
|||
| Klein et al. (2011), 3T DTI | 14 ET 61.2(12.0) | 20 HC 60.2(8.1) | UE | D | ↑ | ROI: MD bilateral ICP Voxel wise/TBSS: Widespread MD |
FA, MD b = 1000 s/mm2 |
ROI: MCP, SCP, ICP FWE Pcor < 0.05 |
| ↓ | ROI: FA unilateral ICP | Voxel wise, TBSS TFCE Pcor < 0.05 | ||||||
| Jia et al. (2011), 3T DTI | 15 ET 65.1(11.4) | 15 HC 62.1(7.6) | UE | Ls | ↑ | ADC: red nucleus | ADC, FA b = 800 s/mm2 |
ROI: caudate, putamen, globus pallidus, thalamus, red nucleus, substantia nigra |
| Buijink et al. (2013), 3T DTI | 8 ET 48.4(17.8) | 5 HC 42.8(14.4) 7 FCMTE 39(12.2) |
UE | Ba | – | – | FA, MD b = 700 s/mm2 |
ROI cerebellum P < 0.05 |
| Saini et al. (2012), 3T DTI | 20 ET 38.2(16.5) | 17 HC 40.7(16.5) | UE, head, voice |
D | ↑ | ROI AD: ALIC, bilateral SCP, right ICP, CS ROI MD: right ALIC, left CS TBSS MD, RD: right frontoparietal WM TBSS RD: right frontoparietal WM, internal/external capsule TBSS AD: cerebral WM, thalamus, brainstem, internal/external capsule, cerebellar peduncles |
MD, RD, AD, FA b = 800 s/mm2 |
ROI: Corpus callosum, SCP, MCP, ICP, CS, ALIC Punc < 0.05 Voxel wise TBSS Pcor < 0.05 |
| ↓ | ROI FA: left SCP, right CS | |||||||
| Prodoehl et al. (2013), 3T DTI | 14 ET 61.6(11.0) | 15 PD 62.7(7.7) 14 MSAp 64.3(8.9) 12 PSP 70.7(5.6) 17 HC 62.9(9.0) |
UE | D | Combining measures to differentiate between the groups* | FA, RD, LD, MD b = 1000 s/mm2 |
ROI: Caudate, putamen, GP, SN, RN, SCP, MCP, ICP, DN | |
AD, axial diffusivity; ADC, apparent diffusion coefficient; ALIC, anterior limb of internal capsule; Ba, Bain et al. (2000); b-value, scaling value for attenuating effect; cor, multiple comparison corrected; Cri, criteria; CS, corticospinal tract; D, Deuschl and Elble (2009); DN, dentate nucleus; FA, fractional anisotropy; FCMTE, familial cortical myoclonic tremor with epilepsy: (F)ET, (familial) essential tremor; Fi, Findley (1996); FWE, family wise error; GP, globus pallidus; HC, healthy controls; head, head tremor; LD, longitudinal diffusivity; Ls, Louis et al. (2001); MCP SCP ICP, middle/superior/inferior cerebellar peduncle; MD, mean diffusivity; MSAp, multiple system atrophy with prominent parkinsonian signs; PD, Parkinson's disease; PSP, progressive supranuclear palsy; RD, radial diffusivity; RN, red nucleus; ROI, region of interest; SD, standard deviation; sn, substantia nigra; TBSS, tract-based spatial statistics; TFCE, threshold-free cluster enhancement; UE, upper extremity; Punc, multiple comparison uncorrected; voice, voice tremor; vs, versus; WM, white matter. *Not included in fig. 2