COVID-19-Associated Acute Asymmetric Hemorrhagic Necrotizing Encephalopathy: A Case Report.

Background: Coronavirus disease 2019 (COVID-19) has been associated with many neurological complications affecting the central nervous system. Purpose: Our aim was to describe a case of COVID-19 associated with a probable variant of acute necrotizing encephalopathy (ANE). Results: A 60-year-old man who presented with a 3-day history of dyspnea, fever, and cough tested positive for severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Five days following his admission, the patient was intubated secondary to respiratory failure. Following his extubation 16 days later, he was found to have a left-sided weakness. Magnetic resonance imaging (MRI) of the brain showed hemorrhagic rim-enhancing lesions involving the right thalamus, left hippocampus, and left parahippocampal gyrus. These lesions showed decreased relative cerebral blood flow on MR perfusion and restricted on diffusion-weighted imaging. These neuroimaging findings were consistent with ANE. The left-sided weakness gradually improved over the subsequent weeks. Conclusions: We concluded that COVID-19 can be associated with ANE, a condition believed to be the result of an immune-mediated process with activation of the innate immune system. Future studies must address whether biological drugs targeting the pro-inflammatory cytokines could prevent the development of this condition.

Bilateral Reappearance of the N20 Potential in a Normothermic Young Woman Post-Anoxic Brain Injury.

SUMMARY: Hypoxic-ischemic brain injury is a well-known consequence of cardiac arrest and providing an accurate prognostication remains a challenge, especially in decisions related to withdrawal of care. Bilateral absence of the cortical response (N20 potential) on median somatosensory evoked potentials, on days 1 to 3 after the return of spontaneous circulation, is widely considered as the most reliable predictor of poor outcome with a high specificity and a low false-positive rate. The authors describe the case of a young comatose woman after hypoxic injury because of cardiac arrest whose initial median somatosensory evoked potentials revealed bilateral absence of the N20 response associated with evidence of selective injury to both perirolandic cortices and basal ganglia on brain MRI. This patient made a substantial recovery associated with bilateral reappearance of the N20 potential and resolution of the neuroimaging abnormalities.This case revealed that an acute selective and reversible hypoxic injury to both perirolandic cortices may lead to a temporary loss of the N20 responses and an inaccurate prediction of poor outcome after cardiac arrest. It emphasizes on the importance of adopting a multimodal approach in the prognostic assessment of survivors of cardiac arrest.

The importance of acknowledging diagnostic uncertainty in patients with new-onset paroxysmal spells.

OBJECTIVE: The aims of this study were to evaluate the frequency of paroxysmal spells of indeterminate nature (PSIN) in a large cohort of children and adults with suspected new-onset seizures, to evaluate the reasons for including patients in this category, and to calculate the rate of erroneous diagnoses if the epileptologists were compelled to label those events as epileptic seizures or nonepileptic paroxysmal spells. METHODS: Patients identified for this study participated in a prospective study evaluating patients with suspected new-onset unprovoked seizures. The workup included a detailed history and a thorough description of the spells, a 3-hour video EEG recording, and an epilepsy protocol brain MRI. Based exclusively on a detailed description of the ictal events, two epileptologists were asked to independently classify each patient into those with a definite diagnosis of unprovoked seizures or a definite diagnosis of a nonepileptic paroxysmal spells (group 1) and those with PSIN (group 2). RESULTS: A total of 1880 consecutive patients were enrolled with 255 (13.6%) included in the PSIN group. Patients with PSIN were significantly younger than those with a definite diagnosis, and PSIN were significantly more frequent in children with developmental delay. The most common reason for including patients in the PSIN group was the inability to categorically discriminate between a seizure and a nonepileptic mimicker. When the raters were compelled to classify the spells in the PSIN group, the frequencies of erroneous diagnoses ranged between 32% and 38%. The final diagnoses on those patients were made based on the results of the EEG, MRI, and follow-up visits. SIGNIFICANCE: Our data indicate that a diagnostic category of PSIN should be recognized and ought to be used in clinical practice. Acknowledging this uncertainty will result in lower frequencies of erroneous diagnoses, possible stigma, and potential exposure to unnecessary antiseizure medications.

A novel possible familial cause of epilepsy of infancy with migrating focal seizures related to SZT2 gene variant.

Seizure threshold-2 (SZT2) gene variants have been associated with a decrease in seizure threshold resulting in variable phenotypic expressions ranging from mild-moderate intellectual disabilities without seizures, to an early-onset epileptic encephalopathy with severe cognitive impairment. In addition, hypotonia and distinctive facial dysmorphism, including a high forehead and to a lesser extent ptosis and down-slanting palpebral fissures, were present in the majority. We herein report a novel SZT2 variant in one of two siblings both diagnosed with epilepsy of infancy with migrating focal seizures (EIMFS). This report is the fourth to document a possible familial case in EIMFS, a condition that was not previously associated with SZT2 variant. This report expands the phenotypic expression of SZT2, corroborates the importance of genetic counseling in some cases of EIMFS, and highlights the efficacy of potassium bromide in controlling the seizures associated with this condition.

Case Report: Distinctive EEG Patterns in SCARB-2 Related Progressive Myoclonus Epilepsy.

Action myoclonus-renal failure syndrome (AMRF) is a rare, recessively inherited form of progressive myoclonus epilepsy (PME) caused by mutations in the SCARB2 gene and associated with end-stage renal failure. In addition to severe progressive myoclonus, the neurological manifestations of this syndrome are characterized by progressive ataxia and dysarthria with preserved intellectual capacity. Since its original description, an increasing number of "AMRF-like" cases without renal failure have been reported. We describe the case of a 29-year-old woman with progressive disabling myoclonus associated with dysarthria and ataxia who was found to have a novel homozygous frameshift mutation in the SCARB2 gene. In addition, this report emphasizes the presence of two EEG patterns, fixation-off phenomenon, and bursts of parasagittal spikes exclusively seen during REM sleep that appear to be characteristic of this condition.

Coma With Absent Brainstem Reflexes and a Burst Suppression on EEG Secondary to Baclofen Toxicity.

Baclofen, a muscle relaxant prescribed for the alleviation of symptoms of spasticity acts primarily at the spinal level but with high doses, it penetrates the blood-brain barrier and can result in prominent central nervous depression. Baclofen toxicity has been associated with a variety of symptoms ranging from dizziness to deep coma. We report the clinical course, management, and outcome of a case of baclofen overdose who presented in deep coma with loss of brainstem reflexes and a burst suppression (BS) pattern on his electroencephalogram (EEG). In addition, we reviewed the presentation and outcomes of all reported cases of baclofen toxicity with a BS pattern on EEG to evaluate if those cases share a common clinical presentation and for the presence of signs and symptoms that would help the clinician to consider this diagnosis. There appears to be a common clinical picture associated with severe baclofen toxicity consisting of deep coma associated with loss of all brainstem reflexes including pupillary reactivity, frequent association with seizures/myoclonic jerks, and a BS pattern on EEG. The outcome is generally good, and serial EEGs are recommended to document a reversal of the abnormal electrographic features.

A Patient with Combined CADASIL and MTHFR Homozygosity.

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is an inherited disorder caused by a mutation in the NOTCH 3 gene, characterized by early onset of subcortical lacunar infarcts in the absence of vascular risk factors and cerebral microbleeds. Homozygosity for the factor Methylenetetrahydrofolate Reductase (MTHFR) is also associated with lacunar stroke risk and cerebral small-vessel disease regardless of the homocysteine level. The coexistence of MTHFR C677T homozygosity and NOTCH 3 mutation has never been reported in the literature previously, and that brings up the challenge of antithrombotic treatment in the presence of cerebral microbleeds.

Automated survey of 8000 plan checks at eight facilities.

PURPOSE: To identify policy and system related weaknesses in treatment planning and plan check work-flows. METHODS: The authors' web deployed plan check automation solution, PlanCheck, which works with all major planning and record and verify systems (demonstrated here for mosaiq only), allows them to compute violation rates for a large number of plan checks across many facilities without requiring the manual data entry involved with incident filings. Workflows and failure modes are heavily influenced by the type of record and verify system used. Rather than tackle multiple record and verify systems at once, the authors restricted the present survey to mosaiq facilities. Violations were investigated by sending inquiries to physicists running the program. RESULTS: Frequent violations included inadequate tracking in the record and verify system of total and prescription doses. Infrequent violations included incorrect setting of patient orientation in the record and verify system. Peaks in the distribution, over facilities, of violation frequencies pointed to suboptimal policies at some of these facilities. Correspondence with physicists often revealed incomplete knowledge of settings at their facility necessary to perform thorough plan checks. CONCLUSIONS: The survey leads to the identification of specific and important policy and system deficiencies that include: suboptimal timing of initial plan checks, lack of communication or agreement on conventions surrounding prescription definitions, and lack of automation in the transfer of some parameters.

Review and Outcome of Prolonged Cardiopulmonary Resuscitation.

The maximal duration of cardiopulmonary resuscitation (CPR) is unknown. We report a case of prolonged CPR. We have then reviewed all published cases with CPR duration equal to or more than 20 minutes. The objective was to determine the survival rate, the neurological outcome, and the characteristics of the survivors. Measurements and Main Results. The CPR data for 82 patients was reviewed. The median duration of CPR was 75 minutes. Patients mean age was 43 ± 21 years with no significant comorbidities. The main causes of the cardiac arrests were myocardial infarction (29%), hypothermia (21%), and pulmonary emboli (12%). 74% of the arrests were witnessed, with a mean latency to CPR of 2 ± 6 minutes and good quality chest compression provided in 96% of the cases. Adjunct therapy included extracorporeal membrane oxygenation (18%), thrombolysis (15.8%), and rewarming for hypothermia (19.5%). 83% were alive at 1 year, with full neurological recovery reported in 63 patients. Conclusion. Patients undergoing prolonged CPR can survive with good outcome. Young age, myocardial infarction, and potentially reversible causes of cardiac arrest such as hypothermia and pulmonary emboli predict a favorable result, especially when the arrest is witnessed and followed by prompt and good resuscitative efforts.

Automating checks of plan check automation.

While a few physicists have designed new plan check automation solutions for their clinics, fewer, if any, managed to adapt existing solutions. As complex and varied as the systems they check, these programs must gain the full confidence of those who would run them on countless patient plans. The present automation effort, planCheck, therefore focuses on versatility and ease of implementation and verification. To demonstrate this, we apply planCheck to proton gantry, stereotactic proton gantry, stereotactic proton fixed beam (STAR), and IMRT treatments.

Intensity modulated proton therapy for postmastectomy radiation of bilateral implant reconstructed breasts: a treatment planning study.

BACKGROUND AND PURPOSE: Delivery of post-mastectomy radiation (PMRT) in women with bilateral implants represents a technical challenge, particularly when attempting to cover regional lymph nodes. Intensity modulated proton therapy (IMPT) holds the potential to improve dose delivery and spare non-target tissues. The purpose of this study was to compare IMPT to three-dimensional (3D) conformal radiation following bilateral mastectomy and reconstruction. MATERIALS AND METHODS: Ten IMPT, 3D conformal photon/electron (P/E), and 3D photon (wide tangent) plans were created for 5 patients with breast cancer, all of whom had bilateral breast implants. Using RTOG guidelines, a physician delineated contours for both target volumes and organs-at-risk. Plans were designed to achieve 95% coverage of all targets (chest wall, IMN, SCV, axilla) to a dose of 50.4 Gy or Gy (RBE) while maximally sparing organs-at-risk. RESULTS: IMPT plans conferred similar target volume coverage with enhanced homogeneity. Both mean heart and lung doses using IMPT were significantly decreased compared to both P/E and wide tangent planning. CONCLUSIONS: IMPT provides improved homogeneity to the chest wall and regional lymphatics in the post-mastectomy setting with improved sparing of surrounding normal structures for woman with reconstructed breasts. IMPT may enable women with mastectomy to undergo radiation therapy without the need for delay in breast reconstruction.

Practical quantitative measurement of graticule misalignment relative to collimator axis of rotation.

We design a practical procedure for measuring translational and rotational misalignment of graticule with collimator axis of rotation and collimator jaws, respectively. The procedure's quantitative results are accurate to less than 0.2 mm (at isocenter) and do not assume alignment of radiation focal spot with collimator axis of rotation. When provided with these quantitative results, the manufacturer can custom-adjust graticules to the purchaser's collimator head.

Evaluating target cold spots by the use of tail EUDs.

PURPOSE: To propose a new measure of target underdose that can be used in the evaluation and optimization of radiotherapy dose distributions. METHODS AND MATERIALS: We compare various formulations of the equivalent uniform dose (EUD) and introduce a modification of existing EUD definitions, which we call tail EUD. Tail EUD is a measure of "cold spots" below the prescription dose in the target dose distribution, using units of gray (Gy). We investigate the mathematical properties of various target EUD concepts, including tail EUD. We apply the tail EUD measure retrospectively to intensity modulated radiation therapy (IMRT) treatment plans from our plan database. We also use tail EUD as an optimization objective in the optimization of prostate, pancreas, and head-and-neck plans. RESULTS: Tail EUD has desirable mathematical properties. In particular, it is convex and it leads to convex level sets (i.e., no local minima) if the EUD from which it is derived is concave. The tail EUD value is correlated with the subjective degree of target coverage. Constraining tail EUDs to a certain level in plan optimization leads to comparable target coverage in different plans and treatment sites. CONCLUSIONS: The newly introduced concept of tail EUD appears to be useful for both plan evaluation and optimization. In addition it can potentially be applied in the design of new clinical protocols.

An approach for practical multiobjective IMRT treatment planning.

PURPOSE: To introduce and demonstrate a practical multiobjective treatment planning procedure for intensity-modulated radiation therapy (IMRT) planning. METHODS AND MATERIALS: The creation of a database of Pareto optimal treatment plans proceeds in two steps. The first step solves an optimization problem that finds a single treatment plan which is close to a set of clinical aspirations. This plan provides an example of what is feasible, and is then used to determine mutually satisfiable hard constraints for the subsequent generation of the plan database. All optimizations are done using linear programming. RESULTS: The two-step procedure is applied to a brain, a prostate, and a lung case. The plan databases created allow for the selection of a final treatment plan based on the observed tradeoffs between the various organs involved. CONCLUSIONS: The proposed method reduces the human iteration time common in IMRT treatment planning. Additionally, the database of plans, when properly viewed, allows the decision maker to make an informed final plan selection.

Approximating convex pareto surfaces in multiobjective radiotherapy planning.

Radiotherapy planning involves inherent tradeoffs: the primary mission, to treat the tumor with a high, uniform dose, is in conflict with normal tissue sparing. We seek to understand these tradeoffs on a case-to-case basis, by computing for each patient a database of Pareto optimal plans. A treatment plan is Pareto optimal if there does not exist another plan which is better in every measurable dimension. The set of all such plans is called the Pareto optimal surface. This article presents an algorithm for computing well distributed points on the (convex) Pareto optimal surface of a multiobjective programming problem. The algorithm is applied to intensity-modulated radiation therapy inverse planning problems, and results of a prostate case and a skull base case are presented, in three and four dimensions, investigating tradeoffs between tumor coverage and critical organ sparing.

Dose-volume objectives in multi-criteria optimization.

Unlike conventional optimization with dose-volume (DV) constraints, multi-criteria optimization (MCO) with DV objectives provides tradeoff information which we believe is necessary for choosing better treatment plans. We show that the MCO formulation with DV objectives is better suited to convex approximation than conventional formulations with DV constraints. We provide a relaxation of the integer programming formulation which reduces the computation time for a single plan from over 5 h to about 2 min, without significantly compromising the results. We also derive a heuristic to improve on the relaxed solutions, adding only a few additional minutes of computation time. We apply these techniques to a skull based tumour case and a paraspinal tumour case. Based on a careful examination of the driving terms in the relaxed formulation and the heuristic, we argue that our techniques should apply more generally for DV objectives in multi-objective IMRT treatment planning.

Exploration of tradeoffs in intensity-modulated radiotherapy.

The purpose of this study is to calculate Pareto surfaces in multi-criteria radiation treatment planning and to analyse the dependency of the Pareto surfaces on the objective functions used for the volumes of interest. We develop a linear approach that allows us to calculate truly Pareto optimal treatment plans, and we apply it to explore the tradeoff between tumour dose homogeneity and critical structure sparing. We show that for two phantom and two clinical cases, a smooth (as opposed to kinked) Pareto tradeoff curve exists. We find that in the paraspinal cases the Pareto surface is invariant to the response function used on the spinal cord: whether the mean cord dose or the maximum cord dose is used, the Pareto plan database is similar. This is not true for the lung studies, where the choice of objective function on the healthy lung tissue influences the resulting Pareto surface greatly. We conclude that in the special case when the tumour wraps around the organ at risk, e.g. prostate cases and paraspinal cases, the Pareto surface will be largely invariant to the objective function used to model the organ at risk.