Aktuelle Neurologie 2009; 36 - V187
DOI: 10.1055/s-0029-1238402

Tract-based spatial statistics in adult Tourette patients indicate white matter changes in the anterior limb of the internal capsule

I Neuner 1, Y Kupriyanova 1, T Stöcker 1, R Huang 1, O Posznansky 1, F Schneider 1, M Tittgemeyer 1, NJ Shah 1
  • 1Jülich, Köln, Aachen

Introduction: Tourette-Syndrom (TS) is a chronic neuropsychiatric disorder characterised by motor and vocal tics. The severity of the tics waxes and wanes over time. TS is often accompanied with comorbidities such as obsessive-compulsive disorder (OCD), depression, and ADHS. For treatment, different pharmacological strategies are available. In treatment resistant patients, deep brain stimulation offers a chance of improvement. Different target points are used currently, the medial portion of the thalamus, the internal part of the globus pallidus internus and the nucleus accumbens/anterior limb of the internal capsule.

Methods: With the aim to elucidate the underlying neuroanatomical changes in TS with respect to the white matter changes, we investigated 19 adult Tourette's patients and a healthy control group. At 1.5T (Siemens, Sonata, Germany) we performed a diffusion-weighted (DW) MRI study using a diffusion-weighted EPI sequence (TR=11000ms; TE=89ms; voxel size=(2mm) 3 isotropic; FOV=256×256; slice thickness=2mm; 71 transverse slices; 30 diffusion directions, three acquisitions. Data were analyzed using FSL (www.fmrib.ox.ac.uk/fsl) and a custom written software package (Tittgemeyer et al, MPI Köln, Germany). All voxel-wise group comparisons were performed using two-sample unpaired T-tests (t – threshold t >3, P<0.005), and the results were overlaid on the mean FA skeleton.

Results: For FA values, the contrast patients vs. controls showed the most significant changes in the corpus callosum (body, splenium, genu), in the cingulum as well as at different levels of the corticospinal tracts, e.g. anterior limb of the internal capsule and in the brainstem.

Discussion: The present study in adult Tourette patients has demonstrated that changes of white matter occur in the corticospinal tract on different levels, e.g., in the anterior limb of the internal capsule. With focus on deep brain stimulation, the anterior limb of the internal capsule could be a promising target point for Tourette patients as a single case report indicated (Flaherty et al. 2001, Neuner et al. 2008). The three Tourette subsamples (based on medication, comobidity) did not differ significantly as assessed by Mann-Whitney-U-test in the FA-values of the white matter skeleton.

Figure 1 shows the FA changes in Tourette patients in red (upper row MNI coordinates x,y,z: 0 13 3, lower row MNI coordinates x,y,z: 10 10 12).