Benchmarking energy consumption and latency for neuromorphic computing in condensed matter and particle physics

The massive use of artificial neural networks (ANNs), increasingly popular in many areas of scientific computing, rapidly increases the energy consumption of modern high-performance computing systems. An appealing and possibly more sustainable alternative is provided by novel neuromorphic paradigms, which directly implement ANNs in hardware. However, little is known about the actual benefits of running ANNs on neuromorphic hardware for use cases in scientific computing. Here we present a methodology for measuring the energy cost and compute time for inference tasks with ANNs on conventional hardware. In addition, we have designed an architecture for these tasks and estimate the same metrics based on a state-of-the-art analog in-memory computing (AIMC) platform, one of the key paradigms in neuromorphic computing. Both methodologies are compared for a use case in quantum many-body physics in two dimensional condensed matter systems and for anomaly detection at 40 MHz rates at the Large Hadron Collider in particle physics. We find that AIMC can achieve up to one order of magnitude shorter computation times than conventional hardware, at an energy cost that is up to three orders of magnitude smaller. This suggests great potential for faster and more sustainable scientific computing with neuromorphic hardware.Comment: 7 pages, 4 figures, submitted to APL Machine Learnin

A Randomized Trial of Intravenous Alteplase before Endovascular Treatment for Stroke

The value of administering intravenous alteplase before endovascular treatment (EVT) for acute ischemic stroke has not been studied extensively, particularly in non-Asian populations. METHODS We performed an open-label, multicenter, randomized trial in Europe involving patients with stroke who presented directly to a hospital that was capable of providing EVT and who were eligible for intravenous alteplase and EVT. Patients were randomly assigned in a 1:1 ratio to receive EVT alone or intravenous alteplase followed by EVT (the standard of care). The primary end point was functional outcome on the modified Rankin scale (range, 0 [no disability] to 6 [death]) at 90 days. We assessed the superiority of EVT alone over alteplase plus EVT, as well as noninferiority by a margin of 0.8 for the lower boundary of the 95% confidence interval for the odds ratio of the two trial groups. Death from any cause and symptomatic intracerebral hemorrhage were the main safety end points. RESULTS The analysis included 539 patients. The median score on the modified Rankin scale at 90 days was 3 (interquartile range, 2 to 5) with EVT alone and 2 (interquartile range, 2 to 5) with alteplase plus EVT. The adjusted common odds ratio was 0.84 (95% confidence interval [CI], 0.62 to 1.15; P=0.28), which showed neither superiority nor noninferiority of EVT alone. Mortality was 20.5% with EVT alone and 15.8% with alteplase plus EVT (adjusted odds ratio, 1.39; 95% CI, 0.84 to 2.30). Symptomatic intracerebral hemorrhage occurred in 5.9% and 5.3% of the patients in the respective groups (adjusted odds ratio, 1.30; 95% CI, 0.60 to 2.81). CONCLUSIONS In a randomized trial involving European patients, EVT alone was neither superior nor noninferior to intravenous alteplase followed by EVT with regard to disability outcome at 90 days after stroke. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups

A giant basilar artery perforator aneurysm

Basilar artery perforator aneurysms (BAPA's) are a rare entity. Their natural history and treatment are unclear. We describe the largest BAPA reported thus far in literature in a 64-year-old Caucasian woman. This patient did not present with subarachnoid hemorrhage, but with left hemiparesis due to pontine ischemia. The aneurysm was initially misdiagnosed as a tumoral mass in a referring center. Angiography confirmed the presence of a BAPA and a flow diverter was successfully placed. This case shows us that a BAPA can mimic a tumoral mass and can cause ischemia due to mass effect without having ruptured. Both conservative and flow diverter placement seems viable treatment options. Individual patient characteristics and preferences should be considered in decision-making for treatment

Oligodendrogliomas tend to infiltrate the frontal aslant tract, whereas astrocytomas tend to displace it

Introduction MR-tractography is increasingly used in neurosurgical practice to evaluate the anatomical relationships between glioma and nearby subcortical tracts. In some patients, the subcortical tracts seem displaced by the glioma, while in other patients, the subcortical tracts seem infiltrated without displacement. At this point, it is unknown whether these different patterns are related to tumor type. The aim of this exploratory study was to investigate whether tumor type is related to the spatial tractography pattern of the frontal aslant tract (FAT) in low-grade gliomas (LGGs). Methods In 64 IDH-mutated LGG patients, the FAT was generated using a pipeline for automatic tractography. In 41 patients, the glioma adjoined the FAT, and four blinded reviewers independently assessed the following two dichotomous categories (yes/no): (i) glioma displaces the tract, and (ii) glioma infiltrates the tract. Results Fisher’s exact tests demonstrated strong and significant positive associations between displacement and astrocytomas (p = .002, φ = .497) and infiltration and oligodendrogliomas (p = .004, φ = .484). The interobserver agreement was good for both categories: (i) κ = 0.76 and (ii) κ = 0.71. Conclusion High sensitivity but low specificity for displacement in astrocytomas demonstrates that in the case of an astrocytoma, the tract is most likely displaced, but that displacement in itself is not necessarily predictive for astrocytomas, as oligodendrogliomas may both infiltrate and displace a tract. Overall, these results demonstrate that oligodendrogliomas tend to infiltrate the nearby subcortical tract, whereas astrocytomas only tend to displace it

Age- and Gender-Associated Differences in Electrical Impedance Values of Skeletal Muscle

Electrical impedance measurements of skeletal muscle may be sensitive to age-associated declines in muscle health. In an effort to evaluate this concept further, we performed electrical impedance myography (EIM) using a handheld array on 38 individuals aged 19–50 years and 41 individuals aged 60–85 years. Individuals either had 7 upper extremity or 7 lower extremity muscles measured. The 50 kHz reactance, resistance and phase were used as the major outcome variables. Although the phase values were similar in both groups, both reactance and resistance values were lower in the lower extremities of the older individuals as compared to the younger (−23 ± 6%, p = 0.001 for reactance and −27 ± 7%, p = 0.005 for resistance), whereas changes in upper extremity values were not significantly different (−9 ± 5%, p = 0.096 for reactance and +5 ± 9%, p = 0.55 for resistance). When analyzing the genders separately, it became clear that this reduction in lower extremity values was most pronounced in men and less consistently present in women. These findings suggest that age- and gender-associated differences in muscle condition are detectable using EIM. The relationship of these easily obtained parameters to standard functional, imaging, and pathological markers of sarcopenia deserves further study

Endovascular treatment of dural arteriovenous fistulas with sinus drainage: Do we really need to protect the sinus?

Background and purpose: Dural arteriovenous fistulas (DAVFs) with direct antegrade sinus drainage have a benign natural history but bruit can be disabling. Disconnection of the draining sinus is considered curative. We present the treatment results of 14 patients with a dural arteriovenous fistula with antegrade sinus return with emphasis on functionality of the involved sinus and the need for sinus patency. Materials and methods: Between January 2009 and January 2018, 14 patients with a DAVF with direct antegrade sinus drainage were treated in our institution. There were two men and 12 women (1: 6) with a mean age of 61 years (median 61, range 43–78). Clinical presentation was unbearable pulsatile bruit in all cases. Thirteen were draining in the sigmoid or transverse sinus and one drained into the inferior petrosal sinus. Results: Twelve of 14 (86%) patients had a draining sinus non-functional for the brain. In ten of these 12 patients the sinus was occluded with liquid embolic or coils. In the two patients with a functional sinus, the fistula was successfully occluded without occluding the sinus. One patient with inferior petrosal sinus drainage required transvenous embolization. There were no permanent adverse events of treatment. Conclusions: Patients with DAVFs with direct antegrade sinus drainage were cured using a strategy of endovascular transarterial and transvenous embolization. Most patients had a non-functional sinus that could be occluded for cure

Endovascular treatment of dural arteriovenous fistulas with sinus drainage: Do we really need to protect the sinus?

Background and purpose: Dural arteriovenous fistulas (DAVFs) with direct antegrade sinus drainage have a benign natural history but bruit can be disabling. Disconnection of the draining sinus is considered curative. We present the treatment results of 14 patients with a dural arteriovenous fistula with antegrade sinus return with emphasis on functionality of the involved sinus and the need for sinus patency. Materials and methods: Between January 2009 and January 2018, 14 patients with a DAVF with direct antegrade sinus drainage were treated in our institution. There were two men and 12 women (1: 6) with a mean age of 61 years (median 61, range 43–78). Clinical presentation was unbearable pulsatile bruit in all cases. Thirteen were draining in the sigmoid or transverse sinus and one drained into the inferior petrosal sinus. Results: Twelve of 14 (86%) patients had a draining sinus non-functional for the brain. In ten of these 12 patients the sinus was occluded with liquid embolic or coils. In the two patients with a functional sinus, the fistula was successfully occluded without occluding the sinus. One patient with inferior petrosal sinus drainage required transvenous embolization. There were no permanent adverse events of treatment. Conclusions: Patients with DAVFs with direct antegrade sinus drainage were cured using a strategy of endovascular transarterial and transvenous embolization. Most patients had a non-functional sinus that could be occluded for cure