Interhemispheric connectivity in amyotrophic lateral sclerosis: A near-infrared spectroscopy and diffusion tensor imaging study.

PURPOSE: Aim of the present study was to investigate potential impairment of non-motor areas in amyotrophic lateral sclerosis (ALS) using near-infrared spectroscopy (NIRS) and diffusion tensor imaging (DTI). In particular, we evaluated whether homotopic resting-state functional connectivity (rs-FC) of non-motor associated cortical areas correlates with clinical parameters and disease-specific degeneration of the corpus callosum (CC) in ALS. MATERIAL AND METHODS: Interhemispheric homotopic rs-FC was assessed in 31 patients and 30 healthy controls (HCs) for 8 cortical sites, from prefrontal to occipital cortex, using NIRS. DTI was performed in a subgroup of 21 patients. All patients were evaluated for cognitive dysfunction in the executive, memory, and visuospatial domains. RESULTS: ALS patients displayed an altered spatial pattern of correlation between homotopic rs-FC values when compared to HCs (p = 0.000013). In patients without executive dysfunction a strong correlation existed between the rate of motor decline and homotopic rs-FC of the anterior temporal lobes (ATLs) (ρ = - 0.85, p = 0.0004). Furthermore, antero-temporal homotopic rs-FC correlated with fractional anisotropy in the central corpus callosum (CC), corticospinal tracts (CSTs), and forceps minor as determined by DTI (p < 0.05). CONCLUSIONS: The present study further supports involvement of non-motor areas in ALS. Our results render homotopic rs-FC as assessed by NIRS a potential clinical marker for disease progression rate in ALS patients without executive dysfunction and a potential anatomical marker for ALS-specific degeneration of the CC and CSTs.

Postoperative MRI localisation of electrodes and clinical efficacy of pallidal deep brain stimulation in cervical dystonia.

INTRODUCTION: Pallidal deep brain stimulation (DBS) has been shown to be effective in cervical dystonia (CD) with an improvement of about 50-60% in the Toronto Western Spasmodic Torticollis Rating (TWSTR) Scale. However, predictive factors for the efficacy of DBS in CD are missing with the anatomical location of the electrodes being one of the most important potential predictive factors. METHODS: In the present blinded observational study we correlated the anatomical localisation of DBS contacts with the relative clinical improvement (CI %) in the TWSTR as achieved by DBS at different pallidal contacts in 20 patients with CD. Localisations of DBS contacts were derived from postoperative MRI-data following anatomical normalisation into the standard Montreal Neurological Institute stereotactic space. The CIs following 76 bilateral test stimulations of 24 h were mapped to stereotactic coordinates of the corresponding bilateral 152 active contacts and were allocated to low CI (<30%; n=74), intermediate CI (≥30%; <60%; n=52) or high CI (≥60%; n=26). RESULTS: Euclidean distances between contacts and the centroid differed between the three clusters (p<0.001) indicating different anatomical variances between clusters. The Euclidean distances between contacts and the centroid of the cluster with high CIs correlated with the individual level of CIs (r=-0.61; p<0.0001). This relationship was best fitted with an exponential regression curve (r(2)=0.41). DISCUSSION: Our data show that the clinical effect of pallidal DBS on CD displays an exponential decay over anatomical distance from an optimised target localisation within a subregion of the internal pallidum. The results will allow a comparison of future DBS studies with postoperative MRI by verifying optimised (for instance pallidal) targeting in DBS-treated patients.

Impact of DaTscan SPECT imaging on clinical management, diagnosis, confidence of diagnosis, quality of life, health resource use and safety in patients with clinically uncertain parkinsonian syndromes: a prospective 1-year follow-up of an open-label controlled study.

BACKGROUND: This study assessed the impact of DaTscan on clinical management, diagnosis, confidence of diagnosis (CoD), quality of life (QoL), health resource use (HRU) and safety during a 1-year follow-up in patients with clinically uncertain parkinsonian syndromes (CUPS). METHODS: A total of 19 university hospital centres in Europe and the USA participated in this open-label, single-dose, prospective, clinical trial in patients with CUPS who were randomised to a DaTscan imaging group or to a no-imaging (control) group. The proportion of patients with changes in clinical management, diagnosis, CoD, QoL and HRU from baseline through 1 year post-DaTscan was compared between groups. RESULTS: There were 273 patients randomised (135 DaTscan, 138 control). Significantly more patients in the DaTscan imaging group had at least one change in their actual clinical management after 12 weeks (p=0.002) and after 1 year (p<0.001) compared with patients in the control group. In addition, significantly more DaTscan patients had changes in diagnosis and an increased CoD at 4 weeks, 12 weeks and 1 year (all p<0.001) compared with control patients. No significant differences in total score for QoL or HRU were observed between groups during the 1-year follow-up period. DaTscan was safe and well tolerated. One patient in the imaging group had an adverse event (headache) with suspected relationship to DaTscan post-administration. CONCLUSIONS: DaTscan had a significant impact on clinical management, diagnosis and CoD in patients with CUPS. DaTscan is safe and well tolerated, and is a useful adjunct to differentiate a diagnosis of CUPS. Trial registration number http://ClinicalTrials.gov Identifier: NCT00382967.