Abstract Background Epileptic seizures are an established comorbidity of Alzheimer’s disease (AD). Subclinical epileptiform activity (SEA) as detected by 24-h electroencephalography (EEG) or magneto-encephalography (MEG) has been reported in temporal regions of clinically diagnosed AD patients. Although epileptic activity in AD probably arises in the mesial temporal lobe, electrical activity within this region might not propagate to EEG scalp electrodes and could remain undetected by standard EEG. However, SEA might lead to faster cognitive decline in AD. Aims 1. To estimate the prevalence of SEA and interictal epileptic discharges (IEDs) in a well-defined cohort of participants belonging to the AD continuum, including preclinical AD subjects, as compared with cognitively healthy controls. 2. To evaluate whether long-term-EEG (LTM-EEG), high-density-EEG (hd-EEG) or MEG is superior to detect SEA in AD. 3. To characterise AD patients with SEA based on clinical, neuropsychological and neuroimaging parameters. Methods Subjects ( n = 49) belonging to the AD continuum were diagnosed according to the 2011 NIA-AA research criteria, with a high likelihood of underlying AD pathophysiology. Healthy volunteers ( n = 24) scored normal on neuropsychological testing and were amyloid negative. None of the participants experienced a seizure before. Subjects underwent LTM-EEG and/or 50-min MEG and/or 50-min hd-EEG to detect IEDs. Results We found an increased prevalence of SEA in AD subjects (31%) as compared to controls (8%) ( p = 0.041; Fisher’s exact test), with increasing prevalence over the disease course (50% in dementia, 27% in MCI and 25% in preclinical AD). Although MEG (25%) did not withhold a higher prevalence of SEA in AD as compared to LTM-EEG (19%) and hd-EEG (19%), MEG was significantly superior to detect spikes per 50 min ( p = 0.002; Kruskall–Wallis test). AD patients with SEA scored worse on the RBANS visuospatial and attention subset ( p = 0.009 and p = 0.05, respectively; Mann–Whitney U test) and had higher left frontal, (left) temporal and (left and right) entorhinal cortex volumes than those without. Conclusion We confirmed that SEA is increased in the AD continuum as compared to controls, with increasing prevalence with AD disease stage. In AD patients, SEA is associated with more severe visuospatial and attention deficits and with increased left frontal, (left) temporal and entorhinal cortex volumes. Trial registration Clinicaltrials.gov, NCT04131491. 12/02/2020.
To retrospectively compare image quality of a lowered dose CT protocol to a standard CT protocol in children with suspicion of craniosynostosis. Forty-eight patients (age 0- 35 months), who presented with a cranial deformity underwent cranial 3D CT to assess sutural patency: between 2009 – 2010, 24 patients were imaged with a standard protocol (CTDIvol 32.18 mGy), from 2011-2012, 24 underwent a low dose protocol (0.94 mGy) combined with iterative reconstruction. Image quality was evaluated by both expert reading and objective analysis. Differences were assessed by independent t-test and Mann-Whitney U test, interreader agreement by Cohen's Kappa test. Effective dose of the low dose protocol was 0.08 mSv, corresponding to a reduction of 97 %. Image quality was similar in both groups in terms of overall diagnostic acceptability, objective noise measurements, subjective cranial bone edge sharpness and presence of artefacts. For objective sharpness of cranial bone-brain interface and subjective perception of noise, the images of the low dose protocol were superior. For all evaluated structures, interreader agreement was moderate to almost perfect. In the diagnosis of craniosynostosis in children with cranial deformities, a dedicated sub 0.1 mSv cranial 3DCT protocol can be used without loss in image quality. • 3DCT is used for the diagnosis of craniosynostosis. • Imaging protocols should be optimized to minimize radiation exposure to children. • Combining 80 kVp with iterative reconstruction can help to reduce dose. • A sub 0.1 mSv cranial 3DCT protocol can be used without loss of diagnostic quality.
Skin lesions can be a sign of internal disease. When they are associated with persisting systemic signs, the possibility of an internal malignancy should always be considered. We describe a 25-year-old man who presented with weight loss, fatigue, subpyrexia, xerostomia and skin rash of 6 months duration. Physical examination showed a dry red skin, most prominent in the face, the palms of the hands and the soles of the feet. Laboratory investigations revealed signs of inflammation and a high level of antinuclear antibodies. Retroperitoneal lymph nodes were visualized on a CT scan of the abdomen. CT-guided biopsy of an abdominal lymph node revealed the presence of an anaplastic large cell lymphoma (ALCL), ALK-positive. A biopsy of the skin showed non-specific signs of inflammation.The patient underwent 8 cycles of chemotherapy according to the CHOP protocol. A complete remission was obtained. Non-Hodgkin lymphoma can indeed be associated with skin lesions. They result from direct invasion by malignant cells or are of paraneoplastic origin, as was the case in this patient.
Introduction: CT perfusion (CTP) is an integral part of the diagnosis and treatment pathway for acute ischemic stroke patients, however CTP protocols vary in scan duration and radiation dose across institutions. An ideal protocol would customize scan acquisition for each individual patient in real-time to avoid truncation-related postprocessing errors and minimize time and radiation dose. We explore the potential time and radiation dosage savings if such an ideal adaptive CTP protocol were implemented across institutions. Methods: We retrospectively assessed 148 CTP scans across two institutions, postprocessed by an expert reader with the CT perfusion 4D Neuro software package (GE Healthcare). Bolus arrival, peak and exit time for the arterial input (AIF) and venous output (VOF) functions were determined via inflection point analysis of time-attenuation curves. An empirically determined customized adaptive scan protocol (Figure) was generated based on each patient’s AIF/VOF curves. Resultant reduction in radiation dose, scan acquisition time and total protocol time were calculated. Results: With the adaptive protocol, all scans would have optimal diagnostic image quality, which addresses the 3% and 18% exams of sub diagnostic quality at the two institutions respectively. Average total protocol time decreased by 153 s and 12 s (59% and 9%) and average radiation dose decreased by 61% and 12% respectively, in comparison to current protocols at the two institutions. Scan acquisition time increased for 7% (11 of 148) of exams. Conclusions: An adaptive CTP protocol would realize significant time and radiation savings across institutions. Methods for real-time identification of VOF end times are currently under development.
