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Alzheimer's disease (AD) is the most common cause of dementia, and its rising prevalence is constantly increasing the global health burden. There are currently no curative therapies for AD, and current treatment options provide only modest clinical benefit. Despite numerous clinical trials, there have been no major additions to the AD treatment armamentarium this century. The prevailing pathomechanistic hypothesis for AD begins with abnormal accumulation of amyloid β (Aβ) leading to plaque development, and disease-modifying candidate therapies have largely aimed to disrupt this process. Numerous clinical trials of monoclonal antibodies directed at various stages of Aβ plaque development have yielded mostly negative results; however, recent results suggest that a breakthrough may be on the horizon. The past two years have yielded positive results for three monoclonal antibodies (aducanumab, lecanemab, and donanemab) although questions remain regarding their clinical effectiveness. Additional clarity is needed to determine whether the clinical benefits are great enough to offset the treatment risks and the resource implications for healthcare systems. This review provides a foundational context and update on recent disease-modifying therapies for AD that have reached Phase III clinical trials. Up-to-date information on these therapies will help clinicians better inform their clinical decision-making and the counselling they can offer patients and their carers. [ABSTRACT FROM AUTHOR]

Objective: This study was undertaken to apply established and emerging cerebrospinal fluid (CSF) biomarkers to improve diagnostic accuracy in patients with rapidly progressive dementia (RPD). Overlap in clinical presentation and results of diagnostic tests confounds etiologic diagnosis in patients with RPD. Objective measures are needed to improve diagnostic accuracy and to recognize patients with potentially treatment‐responsive causes of RPD. Methods: Biomarkers of Alzheimer disease neuropathology (amyloid‐β 42/40 ratio, phosphorylated tau [p‐tau181, p‐tau231]), neuroaxonal/neuronal injury (neurofilament light chain [NfL], visinin‐like protein‐1 [VILIP‐1], total tau), neuroinflammation (chitinase‐3‐like protein [YKL‐40], soluble triggering receptor expressed on myeloid cells 2 [sTREM2], glial fibrillary acidic protein [GFAP], monocyte chemoattractant protein‐1 [MCP‐1]), and synaptic dysfunction (synaptosomal‐associated protein 25kDa, neurogranin) were measured in CSF obtained at presentation from 78 prospectively accrued patients with RPD due to neurodegenerative, vascular, and autoimmune/inflammatory diseases; 35 age‐ and sex‐matched patients with typically progressive neurodegenerative disease; and 72 cognitively normal controls. Biomarker levels were compared across etiologic diagnoses, by potential treatment responsiveness, and between patients with typical and rapidly progressive presentations of neurodegenerative disease. Results: Alzheimer disease biomarkers were associated with neurodegenerative causes of RPD. High NfL, sTREM2, and YKL‐40 and low VILIP‐1 identified patients with autoimmune/inflammatory diseases. MCP‐1 levels were highest in patients with vascular causes of RPD. A multivariate model including GFAP, MCP‐1, p‐tau181, and sTREM2 identified the 44 patients with treatment‐responsive causes of RPD with 89% accuracy. Minimal differences were observed between typical and rapidly progressive presentations of neurodegenerative disease. Interpretation: Selected CSF biomarkers at presentation were associated with etiologic diagnoses and treatment responsiveness in patients with heterogeneous causes of RPD. The ability of cross‐sectional biomarkers to inform upon mechanisms that drive rapidly progressive neurodegenerative disease is less clear. ANN NEUROL 2024;95:299–313 [ABSTRACT FROM AUTHOR]

Objective: To improve the timely recognition of patients with treatment‐responsive causes of rapidly progressive dementia (RPD). Methods: A total of 226 adult patients with suspected RPD were enrolled in a prospective observational study and followed for up to 2 years. Diseases associated with RPD were characterized as potentially treatment‐responsive or non‐responsive, referencing clinical literature. Disease progression was measured using Clinical Dementia Rating® Sum‐of‐Box scores. Clinical and paraclinical features associated with treatment responsiveness were assessed using multivariable logistic regression. Findings informed the development of a clinical criterion optimized to recognize patients with potentially treatment‐responsive causes of RPD early in the diagnostic evaluation. Results: A total of 155 patients met defined RPD criteria, of whom 86 patients (55.5%) had potentially treatment‐responsive causes. The median (range) age‐at‐symptom onset in patients with RPD was 68.9 years (range 22.0–90.7 years), with a similar number of men and women. Seizures, tumor (disease‐associated), magnetic resonance imaging suggestive of autoimmune encephalitis, mania, movement abnormalities, and pleocytosis (≥10 cells/mm3) in cerebrospinal fluid at presentation were independently associated with treatment‐responsive causes of RPD after controlling for age and sex. Those features at presentation, as well as age‐at‐symptom onset <50 years (ie, STAM3P), captured 82 of 86 (95.3%) cases of treatment‐responsive RPD. The presence of ≥3 STAM3P features had a positive predictive value of 100%. Interpretation: Selected features at presentation reliably identified patients with potentially treatment‐responsive causes of RPD. Adaptation of the STAM3P screening score in clinical practice may minimize diagnostic delays and missed opportunities for treatment in patients with suspected RPD. ANN NEUROL 2024;95:237–248 [ABSTRACT FROM AUTHOR]

This review makes the case that idiopathic normal pressure hydrocephalus (iNPH) is an outdated term because new information indicates that the syndrome is less idiopathic and that the cerebrospinal fluid (CSF) pressure of normal individuals is affected by several factors such as body mass index, age, and sex. Our review updates the epidemiology of iNPH and provides a clinical approach to the management of these patients. All the clinical features of iNPH are common in older individuals, and each has many causes, so the diagnosis is difficult. The first step in reaching an accurate diagnosis is to address the possible contributory factors to the gait abnormality and determine what if any role iNPH may be playing. The two best diagnostic tests are neuroimaging and cerebrospinal fluid (CSF) diversion (large volume lumbar puncture or external lumbar drainage) with pre/ post gait evaluation. This review provides an update on the growing evidence that vascular disease, impaired CSF absorption, congenital, and genetic factors all contribute to the pathogenesis of iNPH. We suggest replacing the term iNPH with the term Hakim syndrome (HS) in acknowledgement of the first person to describe this syndrome. Lastly, we discuss the improvements in shunt technology and surgical techniques that have decreased the risks and long-term complications of shunt surgery. [ABSTRACT FROM AUTHOR]

This article provides an overview of lesioning therapies used to treat neurological conditions, specifically focusing on thalamotomy for tremor. It compares different techniques, such as radiofrequency and gamma knife thalamotomy, to deep brain stimulation (DBS) and magnetic resonance-guided focused ultrasound (FUS). The article discusses the varying levels of evidence for the efficacy of these surgical options and their safety profiles. It concludes that while FUS and DBS have the strongest evidence for efficacy, stereotactic radiotherapy is still supported by evidence. The article also discusses different treatment options for movement disorders and emphasizes the importance of clinicians being aware of these options and referring patients to high-volume centers for better outcomes. [Extracted from the article]

Background: Advances in MRI technology have increased interest in direct targeting for deep brain stimulation (DBS). Various imaging sequences have been shown to provide increased contrast of numerous common DBS targets, such as T1-weighted, Fast Gray Matter Acquisition T1 Inversion Recovery (FGATIR), gray matter nulled, and Edge-Enhancing Gradient Echo (EDGE); however, the continual increase in the number of necessary sequences has led to an increase in imaging time, which is undesirable. Additionally, carefully timed inversion pulses can often lead to less-than-ideal contrast in some subjects, particularly in ultra-high field MRI, where B1+ field inhomogeneity can lead to substantial contrast variation. Objectives: This study proposes using 3D MP2RAGE-based T1 maps to retrospectively synthesize images of any desired inversion time, including T1-weighted, FGATIR, and EDGE contrasts, to visualize specific DBS targets at both 3T and 7T. Method: First, a systematic sequence optimization framework was applied to optimize MP2RAGE T1 mapping sequence parameters for the purpose of DBS planning. Next, we show that synthetic inversion-time images can be generated through a mathematical transformation of the T1 maps. The sequence was then applied to patients undergoing preoperative planning for DBS at 3T and 7T to generate synthetic contrasts used in surgical planning. Results: We show that synthetic image contrasts can be generated across a full range of inversion times at 3T and 7T, including commonly used sequences for DBS targeting, such as T1-weighted, FGATIR, and EDGE. Acquisition through a single sequence shortens scan time compared to acquiring the sequences independently without affecting image quality or contrast. Conclusions: The generation of synthetic images for DBS targeting allows faster acquisition of many key sequences, as well as the ability to optimize contrast properties post-acquisition to account for the variable B1+ effects present in ultra-high field MRI. The proposed approach has the potential to reduce imaging time and improve the accuracy of DBS targeting at 1.5T, 3T, and 7T. [ABSTRACT FROM AUTHOR]

Background: Patients with the precipitous onset of cognitive symptoms (i.e., suspected rapid progressive dementia [RPD]) may continue to decline (true RPD) or may stabilize or improve (non‐RPD). Recognizing patients with RPD early in the disease course is important to support clinical care and enrollment in research. Method: Patients referred for the evaluation of suspected RPD were prospectively enrolled and followed for up to 2 years at Mayo Clinic in Florida (Jacksonville, FL; Jan‐2020 – Oct‐2023) and Washington University in St. Louis (Saint Louis, MO; Jun‐2016 – Dec‐2019). Clinical data were independently reviewed by two dementia specialists who established clinical diagnoses, referencing published criteria. Patients were diagnosed with RPD if they progressed to dementia (global Clinical Dementia Rating® [CDR] ≥1) within 1 year or incapacitation (CDR ≥2) within 2 years of symptom onset. Univariate statistics compared demographics, clinical details, and test results between patients with RPD and non‐RPD. Variables with p<0.1 were entered into a multivariate logistic regression model to identify factors associated with RPD. Result: Of 248 patients referred for suspected RPD, 187 (75.4%) met stated criteria for RPD. Patients with RPD were older (62.6±14.4 years vs 55.0±18.3 years; p<0.001), and more likely to be diagnosed with Alzheimer disease or related dementias (28.3% vs 9.8%; p = 0.003) or Creutzfeldt‐Jakob (19.1% vs 4.6%; p = 0.008). Non‐RPD cases were more often attributed to autoimmune/inflammatory disease (42.6% vs 29.4%, p = 0.061) or other causes (e.g., psychiatric, neoplasms, toxic/metabolic; 34.4% vs 16.6%, p = 0.006). After controlling for age, hallucinations (OR, 2.81; 95%CI: 1.21‐6.52), elevated CSF protein (OR, 2.43; 95%CI: 1.17‐5.03), and CSF white blood cell count <5 cells/mm3 (OR, 2.77; 95%CI: 1.32‐5.85) were independently associated with RPD. Cortical visual loss (15/183, 8.2%) and substantial brain atrophy on MRI (27/184, 14.7%) were specific to patients with RPD, representing additional distinguishing features. Conclusion: Hallucinations, cortical visual loss, substantial atrophy on MRI, elevated CSF protein, and normal CSF white blood cell count were independently associated with RPD. Early detection of these features in patients with suspected RPD may inform clinical care and enrollment in research studies of RPD. [ABSTRACT FROM AUTHOR]

Introduction: The neuropsychological profile of CSF1R-related leukoencephalopathy (CRL) is undefined. This study defines the profile, contrasts it with that of other dementia syndromes, and highlights measures sensitive to cognitive impairment. Methods: We administered a standardized battery of neuropsychological tests to five consecutive CRL cases. Results: The neuropsychological profile of CRL reflects impaired general cognitive function, processing speed, executive function, speeded visual problem solving, verbal fluency, and self-reported depression and anxiety. Confrontation naming and memory are preserved. Within cognitive domains, certain measures more frequently identified impairment than others. Discussion: CRL impairs general cognitive function, processing speed, executive function. Language and visual problem solving may be impaired if processing speed is required. Confrontation naming and memory are uniquely preserved, contrasting CRL to other dementia syndromes. Cognitive screens excluding processing speed and executive function may not detect CRL cognitive manifestations. Findings sharply define cognitive impairment of CRL and inform cognitive test selection. [ABSTRACT FROM AUTHOR]

Background: No studies have reported the rate of motor complications (MC) and response to medical and surgical treatment in a population-based cohort of young-onset Parkinson's Disease (YOPD) patients and a cohort of sex-matched late-onset Parkinson's Disease (LOPD). Objective: To assess the outcomes of dopaminergic treatment in YOPD and LOPD, explore treatment-induced MC, medical adjustment, and rate of deep brain stimulation (DBS). Methods: We used the expanded Rochester Epidemiology Project (eREP) to investigate a population-based cohort of YOPD between 2010 and 2015 in 7 counties in Minnesota. Cases with onset ≤55 years of age were included as YOPD. An additional sex-matched cohort of LOPD (onset at ≥56 years of age) was included for comparison. All medical records were reviewed to confirm the diagnoses. Results: In the seven counties 2010–15, there were 28 YOPD patients, which were matched with a LOPD cohort. Sixteen (57%) YOPD had MC, as compared to 9 (32%) LOPD. In YOPD, 9 had motor fluctuations (MF) and Levodopa-induced dyskinesia (LID) together, whereas 3 had LID only and 4 MF only. In LOPD, 3 had MF and LID, 3 MF only, and 3 LID only. Following medical treatment for MC, 6/16 YOPD (38%) and 3/9 (33%) LOPD had symptoms resolution. In YOPD, 11/16 (69%) were considered for DBS implantation, in LOPD they were 2/9 (22%), but only 7 (6 YOPD and 1 LOPD) underwent the procedure. YOPD had significantly higher rates in both DBS candidacy and DBS surgery (respectively, p = 0.03 and p = 0.04). Among DBS-YOPD, 5/6 (83%) had positive motor response to the surgery; the LOPD case had a poor response. We report the population-based incidence of both YOPD with motor complications and YOPD undergoing DBS, which were 1.17 and 0.44 cases per 100,000 person-years, respectively. Conclusion: Fifty-seven percent of our YOPD patients and 32% of the LOPD had motor complications. Roughly half of both YOPD and LOPD were treatment resistant. YOPD had higher rates of DBS candidacy and surgery. Six YOPD and 1 LOPD underwent DBS implantation and most of them had a positive motor response after the surgery. [ABSTRACT FROM AUTHOR]

Background: Colony‐stimulating factor‐1 receptor (CSF1R)‐related leukoencephalopathy is a rapidly progressive neurodegenerative disease for which there is currently no cure. Hematopoietic stem cell transplantation (HSCT) has been proposed as a disease‐modifying treatment. Objective: The objective of this study was to determine the effect of HSCT on disease progression. Methods: We collected all available clinical data from a cohort of 7 patients with CSF1R‐related leukoencephalopathy who underwent HSCT at our institutions. Clinical data included detailed neurological examination by a board‐certified neurologist, serial cognitive screens, formal neuropsychological evaluations, and serial brain magnetic resonance imaging (MRI). Results: Our patients had an average disease duration of 27.6 months at the time of transplant, and we have 87 months of total posttransplant follow‐up time (median, 11; range, 2–27). One patient died in the periprocedural period. The remaining patients showed a variable response to treatment, with 6 of 7 patients trending toward stabilization on motor examination, cognitive scores, and/or MRI abnormalities, especially with white matter lesion burden. Conclusions: This is the largest series of patients with CSF1R‐related leukoencephalopathy receiving HSCT. We conclude that HSCT can stabilize the disease in some patients. Variability in patient responsiveness suggests that measures of disease heterogeneity and severity need to be considered when evaluating a patient's candidacy for transplant. HSCT appears to be the first disease‐modifying therapy for CSF1R‐related leukoencephalopathy. This milestone may serve as a foothold toward better understanding the disease's pathomechanism, thus providing new opportunities for better disease‐specific therapies. © 2021 International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

The global prevalence of dementia is expected to triple by the year 2050. This impending health care crisis has led to new heights of public awareness and general concern regarding cognitive impairment. Subsequently, clinicians are seeing more and more people presenting with cognitive concerns. It is important that clinicians meet these concerns with a strategy promoting accurate diagnoses. We have diagramed and described a practical approach to cognitive impairment. Through an algorithmic approach, we determine the presence and severity of cognitive impairment, systematically evaluate domains of function, and use this information to determine the next steps in evaluation. We also discuss how to proceed when cognitive impairment is associated with motor abnormalities or rapid progression. [ABSTRACT FROM AUTHOR]

Parkinsonism is usually designated a movement disorder. However, cognitive impairment comprises a major part of many parkinsonian syndromes, and inversely correlates with quality of life. Parkinsonian features are largely attributed to subcortical dopaminergic dysfunction, although other brain regions and neurotransmitters also contribute. This is illustrated by phenotypic differences among different parkinsonian syndromes. Slowed processing speed and executive dysfunction are generally expected in parkinsonian patients, but additional cognitive features can suggest specific pathological substrates, e.g. apraxia in corticobasal degeneration. Similarly, motor symptoms generally include combinations of bradykinesia, rigidity, rest tremor, and postural instability, although nuanced differences and associated clinical features often help differentiate between parkinsonian syndromes. Human gait requires complex synchronisation at every level of the nervous system, yet occurs with minimal conscious effort on behalf of the walker. Deviations from the normal gait pattern can result from otherwise unnoticeable insults to the body, both intrinsic and extrinsic to the nervous system. Gait is almost always abnormal in parkinsonism, ranging from subtle arm swing asymmetry to discrete episodes of gait freezing. Moreover, one’s cognitive state can directly affect one’s quality of gait. The notion that a gait profile could in fact be a disease-specific biomarker is an area of great research interest. This review focuses on the manifestations of, and correlations between, cognitive and gait impairment in common parkinsonian conditions, and provides guidance for a clinical approach to assessing them. [ABSTRACT FROM AUTHOR]

Introduction. Cognitive impairment is common in Parkinson’s Disease, but the impact of predictive factors on incidence and rate of cognitive decline is incompletely understood. We aimed to determine the effects of sex and APOE allele status on cognitive performance in patients with Parkinson’s Disease (PD). Material and methods. We conducted a retrospective analysis of 325 clinically diagnosed PD patients who underwent one or more cognitive screenings with a Mini-Mental Status Examination (MMSE) or Mattis Dementia Rating Scale (DRS-2). We used proportional odds regression models to estimate odds ratios for higher versus lower cognitive scores in association with age, sex, education, disease duration, and APOE allele status. Results. Higher cognitive scores were independently associated with female sex on the MMSE (OR 2.43; 95% CI 1.14, 5.14) and DRS-2 total (OR 4.14; 95% CI 2.01, 8.53). APOE ε4 dose was associated with lower DRS-2 totals (OR 0.42; 95% CI 0.22, 0.81), but there was no evidence of association with MMSE. Higher education level was also associated with higher scores on the MMSE (OR 1.22; 95% CI 1.07, 1.38) and DRS-2 total (OR 1.31; 95% CI 1.15, 1.50). Disease duration was not associated with cognitive performance on any measure when adjusting for age. Conclusion. Male sex and APOE ε4, along with age and lower education level, were associated with poorer cognitive performance among a population of predominantly non-demented PD patients. [ABSTRACT FROM AUTHOR]

Background:With increasing demand for neurologists, nontraditional health care delivery mechanisms have been developed to leverage this limited resource. Introduction:Telemedicine has emerged as an effective digital solution. Over the past three decades, telemedicine use has steadily grown; however, neurologists often learn on the job, rather than as part of their medical training. The current literature regarding telestroke training during neurology training is sparse, focusing on cerebrovascular fellowship curricula. We sought to enhance telestroke training in our neurology residency by incorporating real-life application. Materials and Methods:We implemented a formal educational model for neurology residents to use telemedicine for remote acquisition of the National Institutes of Health Stroke Scale (NIHSS) for patients with suspected acute ischemic stroke (AIS) before arrival at our comprehensive stroke center. This three-phase educational model involved multidisciplinary classroom didactics, simulation exercises, and real-world experience. Training and feedback were provided by neurologists experienced in telemedicine. Results:All residents completed formal training in telemedicine prehospital NIHSS acquisition and had the opportunity to participate in additional simulation exercises. Currently, residents are gaining additional experience by performing prehospital NIHSS acquisition for patients in whom AIS is suspected. Our preliminary data indicate that resident video encounters average 10.6 min in duration, thus saving time once patients arrive at our hospital. Discussion:To our knowledge, this is the first report of a telestroke-integrated neurology residency program in a comprehensive stroke center resulting in shortened time to treatment in patients with suspected AIS. Conclusions:We present a model that can be adopted by other neurology residency programs as it provides real-world telemedicine training critical to future neurologists. [ABSTRACT FROM AUTHOR]

Background: The causes of rapidly progressive dementia are heterogeneous, including neurodegenerative, vascular, and autoimmune/inflammatory diseases. Overlap in presenting symptoms and signs, results of cognitive testing, and findings on brain imaging and other common diagnostic tests confounds the etiologic diagnosis, contributing to diagnostic delays, missed opportunities for treatment, and poorer outcomes in patients with RPD. New tools and approaches are needed to improve diagnostic accuracy, with particular emphasis on improving early recognition of patients with potentially treatable causes of RPD. Methods: Established and emerging biomarkers of Alzheimer disease neuropathology (Aβ42/40, p‐tau181, p‐tau231), neuroaxonal and neuronal injury (neurofilament light [NfL], VILIP‐1, total tau), neuroinflammation (YKL‐40, sTREM2, GFAP, MCP‐1), and synaptic dysfunction (SNAP‐25, neurogranin) were measured in cerebrospinal fluid obtained at presentation from 78 prospectively accrued patients with RPD due to neurodegenerative (n = 35), vascular (n = 9), and autoimmune/inflammatory (n = 34) diseases, and 72 age‐ and sex‐similar cognitively normal individuals (controls). Causes of RPD were further classified as potentially treatment‐responsive or nonresponsive, referencing the extant literature. Biomarker levels were compared across etiologic diagnoses and by treatment responsiveness, referencing control values. Analyses were adjusted for the effects of age (ANCOVA). Results: Alzheimer disease biomarkers (low Aβ42/40 and elevated p‐tau181 and p‐tau231) were associated with neurodegenerative causes of RPD (ANCOVA, p = 0.02 p = 0.30, p = 0.15), while high NfL (p = 0.61), low VILIP‐1 (p = 0.009), and elevated markers of inflammation (sTREM2, p = 0.009; YKL‐40, p<0.001) identified patients with autoimmune/inflammatory diseases (Figure). MCP‐1 levels were highest in patients with vascular causes of RPD (p = 0.08). 44 patients (56.4%) had potentially treatment‐responsive causes of RPD. Treatment responsiveness was associated with higher levels of CSF Aβ42/40 (p = 0.003), NfL (p<0.001), sTREM2 (p<0.001) and YKL‐40 (p<0.001); and lower levels of p‐tau‐181 and p‐tau231 (p<0.001, p<0.001) and VILIP‐1 (p<0.001). Conclusion: Selected biomarkers measured in CSF at presentation associate with etiologic diagnosis and treatment responsiveness in patients with neurodegenerative, vascular, and autoimmune/inflammatory causes of RPD. Biomarker panels may be adapted to improve recognition of patients with treatment‐responsive causes of RPD early in the symptomatic course when treatments may be most effective. [ABSTRACT FROM AUTHOR]

This patient met criteria for a diagnosis of probable PSP with predominant parkinsonism based upon slowed and incomplete vertical saccades, levodopa non-responsive parkinsonism, and postural instability.[4] Tachymicrographia may help clinicians distinguish PSP from other parkinsonisms during early disease stages. Keywords: parkinsonism; micrographia; tachygraphia; PSP EN parkinsonism micrographia tachygraphia PSP 1217 1218 2 08/29/23 20230801 NES 230801 Fifty-eight-year-old man presented with difficulty in speech and handwriting for 2 years. The speech pattern of some atypical parkinsonisms (MSA and PSP) can be like PD; however, MSA tends to cause more scanning and ataxic qualities while spastic speech is more common in PSP. [Extracted from the article]

Background: Rapidly progressive dementia (RPD) includes patients with less than two years from the onset of cognitive impairment to incapacitation due to dementia. Although RPD is often associated with fatal neurodegenerative diseases, including early‐onset Alzheimer disease or Creutzfeldt‐Jakob disease, treatable forms of RPD are increasingly recognized. Early recognition of patients with potentially treatable causes of RPD is key to the timely provision of therapies required to achieve the best possible long‐term outcomes. Method: 155 patients with RPD were prospectively enrolled from February 2016 to August 2022 via two tertiary care centers. Etiologic diagnoses were independently assigned by two neurologists with good agreement (>90%). Causes of RPD were further classified as treatment‐responsive or nonresponsive, referencing the extant literature. Demographic, clinical, and paraclinical features associated with treatable causes of RPD were identified using stepwise multivariate logistic regression and validated with 5‐fold cross validation. Result: 87/155 patients (56.1%) had a potentially treatable cause of RPD, including autoimmune/inflammatory disease (n = 52, 59.8%), vasculitis (n = 13, 14.9%), primary psychiatric disease (n = 4, 4.6%), or nutritional deficiency (n = 4, 4.6%). Multivariable analyses identified seven features that were independently associated with treatment‐responsiveness: age‐at‐symptom onset (OR: 0.62 per decade, 95%CI: 0.42‐0.93), seizures (OR: 9.81, 95%CI: 2.84‐33.89), MRI suggestive of autoimmune encephalitis (OR: 23.08, 95%CI: 2.28‐233.40), CSF white blood cell count ≥10 cells/mm3 (OR: 32.24, 95%CI:5.80‐179.21), movement abnormalities (OR: 4.99, 95%CI: 1.76‐14.10), presence of disease‐associated tumor (OR: 13.82, 95%CI: 2.25‐85.11), and mania (OR: 18.47, 95%CI: 1.76‐193.61). Model performance was excellent (c‐statistic = 0.88, 95%CI: 0.82‐0.94; p<0.001): 71 patients (81.6%) with potentially treatable causes of RPD and 56 patients (82.4%) with non‐treatable causes of RPD were correctly classified (PPV = 85.5%; NPV = 77.8%). Conclusion: Treatment‐responsive causes of RPD were common in our series. Younger age, seizures, movement abnormalities, or mania at presentation, and paraclinical tests suggesting inflammation (MRI or CSF) or tumor in patients with RPD should prompt consideration of treatable causes of RPD and initiation of treatment when indicated. [ABSTRACT FROM AUTHOR]

Background: Slow walking speed is associated with numerous negative health outcomes including global cognitive decline.1 More detailed gait analysis can differentiate among different dementia subtypes,10 but the predictive power of baseline gait metrics for domain‐specific cognitive decline needs further characterization. Method: We conducted a follow up study on 534 participants of the Mayo Clinic Study of Aging who underwent evaluations every 15 months (median follow‐up = 5.4 years). We analyzed quantitative gait metrics, acquired with a pressure‐sensing walkway (GAITRite® instrument), and cognitive scores using a linear mixed effects model to identify correlations between z‐scored baseline gait metrics (cadence, swing time, stance time, velocity, double support time (DST), stride length, stride length standard deviation (SD), stride time SD, swing time SD, stance time SD, DST SD) and cognitive domain z‐scores (memory, attention, language, visuospatial, global) at baseline and over time. Models controlled for age, sex, and probable REM sleep behavior disorder at baseline. Result: The table includes both baseline associations and difference in slopes (Δ), relative to the average person, in cognitive domains. These slopes ranged from about ‐0.05 for visuospatial to ‐0.12 for attention. Conclusion: Increased gait velocity and stride length are associated with less severe domain‐specific and global cognitive decline while increased swing time SD and DST are associated with more severe rates of decline in some domains. These findings suggest that baseline gait characteristics could be a helpful predictor of future cognitive changes. References: 1. Savica R, Wennberg AMV, Hagen C, et al. Comparison of Gait Parameters for Predicting Cognitive Decline: The Mayo Clinic Study of Aging. Journal of Alzheimer's disease : JAD. 2017;55(2):559. doi:10.3233/JAD‐160697 2. Mc Ardle R, del Din S, Galna B, Thomas A, Rochester L. Differentiating dementia disease subtypes with gait analysis: feasibility of wearable sensors? Gait & Posture. 2020;76:372–376. doi:10.1016/j.gaitpost.2019.12.028 [ABSTRACT FROM AUTHOR]

Background: Overlap in the presenting clinical features and test results in patients with rapidly progressive dementia (RPD) confounds the etiologic diagnoses of RPD, contributing to diagnostic delays, missed treatment opportunities, and poorer outcomes. There is a need to improve diagnostic accuracy in patients with RPD, with particular emphasis on identifying patients with potentially treatment‐responsive causes of RPD early in the symptomatic course. Method: Patients with RPD were prospectively enrolled and evaluated in inpatient settings and outpatient subspecialty (memory) clinics at Washington University (Saint Louis, MO; 2016–2019) and Mayo Clinic (Jacksonville, FL; 2020–2021). Etiologic diagnoses were independently assigned by two dementia specialists integrating clinical features and the results of widely accessible diagnostic testing and referencing established diagnostic criteria. Diagnostic disagreements were resolved via blinded review by a third specialist. Clinicopathologic correlation was evaluated using neuropathological and genetic data when available. Result: 160 patients with RPD were assessed, with average age‐at‐symptom onset 60.0±15.9 years; 50% were female. Diagnostic inter‐rater reliability (91% agreement; Cohen's κ = 0.88, p<0.001) and clinicopathologic correlation were excellent (100% agreement in 24 patients with neuropathologic or genetic data). Autoimmune encephalitis was the leading cause of RPD (39%), followed by Alzheimer disease and related dementias (29%—i.e., frontotemporal dementia, Lewy body dementia, vascular cognitive impairment), Creutzfeldt‐Jakob disease (15%), and other causes (15%—e.g., neurosarcoid, metabolic disruptions, neoplastic disease). The average age of patients with potentially treatable causes (AE and selected "other" causes; 54.4±18.2) was younger than those with neurodegenerative dementing illnesses (67.3±9.5) or CJD (67.4±7.9; p<0.001). Patients with potentially treatable causes were more likely to present with altered level of consciousness and seizures (p<0.05). CSF pleocytosis (>5 WBC/hpf) was more common in AE patients (p<0.05). Conclusion: Etiologic diagnoses can be reliably established in RPD patients using available clinical data. Treatment‐responsive causes of RPD are common warranting consideration, particularly in younger patients with altered consciousness, seizures, and CSF pleocytosis. [ABSTRACT FROM AUTHOR]

Neurons in many brain regions release endocannabinoids from their dendrites that act as retrograde signals to transiently suppress neurotransmitter release from presynaptic terminals. Little is known, however, about the physiological mechanisms of short-term endocannabinoid-mediated plasticity under physiological conditions. Here we investigate calcium-dependent endocannabinoid release from cartwheel cells (CWCs) of the mouse dorsal cochlear nucleus (DCN) in the auditory brainstem that provide feedforward inhibition onto DCN principal neurons. We report that sustained action potential firing by CWCs evokes endocannabinoid release in response to submicromolar elevation of dendritic calcium that transiently suppresses their parallel fiber (PF) inputs by>70%. Basal spontaneous CWC firing rates are insufficient to evoke tonic suppression of PF synapses. However, elevating CWC firing rates by stimulating PFs triggers the release of endocannabinoids and heterosynaptic suppression of PF inputs. Spike-evoked suppression by endocannabinoids selectively suppresses excitatory synapses, but glycinergic/GABAergic inputs onto CWCs are not affected. Our findings demonstrate a mechanism of transient plasticity mediated by endocannabinoids that heterosynaptically suppresses subsets of excitatory presynaptic inputs to CWCs that regulates feedforward inhibition of DCN principal neurons and may influence the output of the DCN. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) is a complex neurodegenerative disease in which combinations of motor and non‐motor symptoms result in a wide range of phenotypic presentations and disease progression. Precise characterization of these clinical endophenotypes can guide clinical practice. Such endophenotypes can also be powerful to identify genetic factors for complex diseases, like PD. Given the prevalence and impact of cognitive impairment in PD, we aimed to characterize cognitive endophenotypes in a cohort of PD patients with longitudinal assessments. Method: We reviewed the medical records of 1028 individuals diagnosed with PD by a movement disorders specialist at our institution. We extracted scores from all available Mini‐Mental Status Examinations (MMSE). We fit proportional odds models with patient specific random effects to estimate odds ratios for higher versus lower cognition in association with age, sex and follow‐up time. Result: Among the 237 patients with at least one MMSE, 108 had ≥2 time points and 118 were cognitively impaired (MMSE<27). The mean age was 71 years, 63 (27%) were female and the mean follow‐up time was 2.56 years. Overall, females with PD had higher MMSE scores than males with an odds ratio at age 70 of 2.43 (95% CI: 1.29, 4.97). However, MMSE scores decline with age at a faster rate in females than males (p=0.002) with ORs for a 1 year of 0.85 (0.79, 0.91) and 0.94 (95%CI: 0.91, 0.97), respectively. Within patients, declines in MMSE per year had an OR of 0.76 (0.60, 0.97) for females and 0.85 (0.75, 0.95) for males though this difference was not statistically significant. Corresponding expected MMSE trajectories are shown in the figure. Conclusion: Our findings demonstrate sex differences in the cognitive phenotypes of PD. In particular, cognitive scores tend to be higher in females compared to males, but decline faster in females. These findings have clinical implications regarding counseling of patients with PD. We are currently expanding this approach to specific cognitive domains, other validated tests of cognition, and investigating the influence of genetic risk factors, such as APOE on cognitive decline in PD. [ABSTRACT FROM AUTHOR]

We present a case in which a movement disorder neurologist developed two different hyperkinetic movements due to corticospinal tract hyperexcitability, which resolved completely with surgical removal of an epidural spinal canal tumor. The first-hand description of these movements creates a unique opportunity for enhanced insight into these complex movement phenomena. [ABSTRACT FROM AUTHOR]

Introduction: Accumulation of polyglutamine (polyQ) ataxin-3 (ATXN3) contributes to the pathobiology of spinocerebellar ataxia type 3 (SCA3). Recently, we showed that polyQ ATXN3 is elevated in the plasma and cerebrospinal fluid (CSF) of SCA3 patients, and has the potential to serve as a biological marker for this disease [1]. Based on these findings, we investigated whether polyQ ATXN3 can also be detected in urine samples from SCA3 patients.Methods: We analyzed urine samples from 30 SCA3 subjects (including one pre-symptomatic subject), 35 subjects with other forms of ataxia, and 37 healthy controls. To quantify polyQ ATXN3 protein levels, we used our previously developed immunoassay.Results: PolyQ ATXN3 can be detected in the urine of SCA3 patients, but not in urine samples from healthy controls or other forms of ataxia. There was a significant statistical association between polyQ ATXN3 levels in urine samples and those in plasma. Further, the levels of polyQ ATXN3 urine associated with an earlier age of SCA3 disease onset.Conclusion: As clinical trials for SCA3 advance, urine polyQ ATXN3 protein has potential to be a useful, non-invasive and inexpensive biomarker for SCA3. [ABSTRACT FROM AUTHOR]