Mutations in GBA, the gene encoding glucocerebrosidase, the enzyme deficient in Gaucher disease, are common risk factors for Parkinson disease, as patients with Parkinson disease are over five times more likely to carry GBA mutations than healthy controls. Patients with GBA mutations generally have an earlier onset of Parkinson disease and more cognitive impairment than those without GBA mutations. We investigated whether GBA mutations alter the neurobiology of Parkinson disease, studying brain dopamine synthesis and resting regional cerebral blood flow in 107 subjects (38 women, 69 men). We measured dopamine synthesis with (18)F-fluorodopa positron emission tomography, and resting regional cerebral blood flow with H(2)(15)O positron emission tomography in the wakeful, resting state in four study groups: (i) patients with Parkinson disease and Gaucher disease (n = 7, average age = 56.6 ± 9.2 years); (ii) patients with Parkinson disease without GBA mutations (n = 11, 62.1 ± 7.1 years); (iii) patients with Gaucher disease without parkinsonism, but with a family history of Parkinson disease (n = 14, 52.6 ± 12.4 years); and (iv) healthy GBA-mutation carriers with a family history of Parkinson disease (n = 7, 50.1 ± 18 years). We compared each study group with a matched control group. Data were analysed with region of interest and voxel-based methods. Disease duration and Parkinson disease functional and staging scores were similar in the two groups with parkinsonism, as was striatal dopamine synthesis: both had greatest loss in the caudal striatum (putamen Ki loss: 44 and 42%, respectively), with less reduction in the caudate (20 and 18% loss). However, the group with both Parkinson and Gaucher diseases showed decreased resting regional cerebral blood flow in the lateral parieto-occipital association cortex and precuneus bilaterally. Furthermore, two subjects with Gaucher disease without parkinsonian manifestations showed diminished striatal dopamine. In conclusion, the pattern of dopamine loss in patients with both Parkinson and Gaucher disease was similar to sporadic Parkinson disease, indicating comparable damage in midbrain neurons. However, H(2)(15)O positron emission tomography studies indicated that these subjects have decreased resting activity in a pattern characteristic of diffuse Lewy body disease. These findings provide insight into the pathophysiology of GBA-associated parkinsonism.

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Purpose-To determine if decline in corpus callosum (CC) white matter integrity in patients with amyotrophic lateral sclerosis (ALS) is localized to motor-related areas.Materials and Methods-Twenty-one ALS patients and 21 controls participated. Diffusion tensor images (DTI) were acquired using 3 Tesla (T) MRI. Tract-based spatial statistics were used to examine whole-brain white matter damage. A segmentation schema was used to define CC volumes-of-interest (VOI). Fractional anisotropy (FA) and radial-and axial-diffusivity (RD, AD) were extracted from VOIs and compared between groups. DTI measurements in motor-related Area III were tested for correlation with symptoms and disease duration.Results-Extracted FA values from CC VOIs were reduced in ALS patients (P≤0.0001), particularly in Areas II and III (P≤0.01). Reduced FA in Area III correlated with disease symptomology (P≤0.05) and duration (P≤0.02). Between-group whole-brain comparisons (P≤0.05, corrected) showed reduced FA and increased RD throughout white matter regions including the CC, corona radiata, and internal capsule. AD was increased in the left corona radiata and internal and external capsules.Conclusion-FA in motor-related regions of the CC is more affected than other CC areas in ALS patients. Microstructural pathology of transcallosal fiber tracts may represent a future component of an imaging biomarker for ALS. AMYOTROPHIC LATERAL SCLEROSIS (ALS) is a progressive neurodegenerative disease affecting both upper-and lower-motor neurons. There are active efforts in the field of neuroimaging to discover a biomarker to aid in earlier diagnosis, improve the understanding of motor-neuron degeneration, and perhaps serve as an outcome measure for disease-modifying therapies. Unfortunately, early diagnosis of ALS has proven elusive as clinical confirmation can only occur after both upper (UMN) and lower motor neuron (LMN) involvement are detected by neurologic examination, which often occurs at a time point of advanced pathology (1). While noninvasive neurophysiologic techniques exist to detect subclinical LMN dysfunction, there is no sensitive tool that can similarly distinguish UMN dysfunction to aid in early diagnosis (2). For these reasons, much attention has turned toward neuroimaging as a means of identifying UMN involvement (3). KeywordsParticular interest in the use of diffusion tensor imaging (DTI) to identify UMN involvement in ALS has been growing. DTI research to date has largely replicated findings from postmortem studies indicating widespread microstructure deterioration along the UMNs of the corticospinal tract and corpus callosum (CC), validating this method as a valuable in vivo marker of the disease process (4-7). The CC in patients with ALS has consistently shown DTI changes, with decreased fractional anisotropy (FA) and increased radial and axial diffusivity (RD, AD) compared with control subjects (8). These changes may correspond to degeneration of transcallosal fibers passing between primary motor cortices observed at 1.5T (9). H...

Purpose To determine if decline in corpus callosum (CC) white matter integrity in patients with amyotrophic lateral sclerosis (ALS) is localized to motor-related areas. Materials and Methods Twenty-one ALS patients and 21 controls participated. Diffusion tensor images (DTI) were acquired using 3 Tesla (T) MRI. Tract-based spatial statistics were used to examine whole-brain white matter damage. A segmentation schema was used to define CC volumes-of-interest (VOI). Fractional anisotropy (FA) and radial- and axial-diffusivity (RD, AD) were extracted from VOIs and compared between groups. DTI measurements in motor-related Area III were tested for correlation with symptoms and disease duration. Results Extracted FA values from CC VOIs were reduced in ALS patients (P≤0.0001), particularly in Areas II and III (P≤0.01). Reduced FA in Area III correlated with disease symptomology (P≤0.05) and duration (P≤0.02). Between-group whole-brain comparisons (P≤0.05, corrected) showed reduced FA and increased RD throughout white matter regions including the CC, corona radiata, and internal capsule. AD was increased in the left corona radiata and internal and external capsules. Conclusion FA in motor-related regions of the CC is more affected than other CC areas in ALS patients. Microstructural pathology of transcallosal fiber tracts may represent a future component of an imaging biomarker for ALS.

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Objective To evaluate the MRI artifact rendered by the typical injection of a ferromagnetic tracer now being intermittently used for intraoperative sentinel node (SN) identification at our institution, and to explore its impact on postoperative imaging and management. Methods This study was Institutional Review Board-approved and granted a waiver of consent. A database search tool was used to identify MRI exams performed on patients who had previously undergone breast-conserving surgery with use of a superparamagnetic iron oxide (SPIO) SN tracer between January 1, 2015, and May 1, 2020. MRI reports, images, and relevant demographic, oncologic, and surgical history were collected. The presence or absence of SPIO residue on breast MRI, as well as its impact on image quality, were extracted from the prospective reports. Results A total of 21 MRI exams were identified in 16 patients who had undergone breast-conservation therapy for cancer with use of SPIO SN tracer. Mean time from particle injection to baseline postoperative MRI exam was 10.8 months. All reports (21/21) noted evidence of SPIO residue. Of these, 5/21 were assessed as non-diagnostic; the remainder were assessed as limited. Conclusion Radiologists should be aware of the use of superparamagnetic tracers for SN identification and the impact on the quality of future MRI examinations. Alternative injection approaches are being developed and sequence parameters adjusted to minimize artifact.

The existence of numerous techniques for the creation of pneumoperitoneum at laparoscopy indicates that none have been proven totally efficacious or complication free. These methods include the standard technique of insufflation after insertion of the Veress needle via the umbilicus or less commonly via the transfundal or transforniceal routes, open laparoscopy involving dissection through the linea alba and opening of the peritoneum under direct vision, and direct trocar insertion as well as variations on these techniques. After reviewing the methods available and surveying the existing data concerning the rates of failure and complications, we conclude that no single technique can claim to be overwhelmingly superior, and that laparoscopists should, therefore, acquaint themselves with at least two of these techniques. Finally, we recommend a large-scale combined survey by the colleges of obstetricians and gynecologists and surgeons on rates of failure and complications of the varied approaches of abdominal entry for laparoscopy.