Localizing apraxia in corticobasal syndrome: a morphometric MRI study.

Apraxia localization has relied on voxel-based, lesion-symptom mapping studies in left hemisphere stroke patients. Studies on the neural substrates of different manifestations of apraxia in neurodegenerative disorders are scarce. The primary aim of this study was to look into the neural substrates of different manifestations of apraxia in a cohort of corticobasal syndrome patients (CBS) by use of cortical thickness. Twenty-six CBS patients were included in this cross-sectional study. The Goldenberg apraxia test (GAT) was applied. 3D-T1-weighted images were analyzed via the automated recon-all Freesurfer version 6.0 pipeline. Vertex-based multivariate General Linear Model analysis was applied to correlate GAT scores with cortical thickness. Deficits in imitation of meaningless gestures correlated with bilateral superior parietal atrophy, extending to the angular and supramarginal gyri, particularly on the left. Finger imitation relied predominantly on superior parietal lobes, whereas the left angular and supramarginal gyri, in addition to superior parietal lobes, were critical for hand imitation. The widespread bilateral clusters of atrophy in CBS related to apraxia indicate different pathophysiological mechanisms mediating praxis in neurodegenerative disorders compared to vascular lesions, with implications both for our understanding of praxis and for the rehabilitation approaches of patients with apraxia.

Clinical, Neuroimaging, and Genetic Markers in Cerebral Amyloid Angiopathy-Related Inflammation: A Systematic Review and Meta-Analysis.

BACKGROUND: There are limited data regarding the prevalence of distinct clinical, neuroimaging and genetic markers among patients diagnosed with cerebral amyloid angiopathy-related inflammation (CAA-ri). We sought to determine the prevalence of clinical, radiological, genetic and cerebrospinal fluid biomarker findings in patients with CAA-ri. METHODS: A systematic review and meta-analysis of published studies including patients with CAA-ri was conducted to determine the prevalence of clinical, neuroimaging, genetic and cerebrospinal fluid biomarker findings. Subgroup analyses were performed based on (1) prospective or retrospective study design and (2) CAA-ri diagnosis with or without available biopsy. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using Cochran-Q and I2-statistics. RESULTS: We identified 4 prospective and 17 retrospective cohort studies comprising 378 patients with CAA-ri (mean age, 71.5 years; women, 52%). The pooled prevalence rates were as follows: cognitive decline at presentation 70% ([95% CI, 54%-84%]; I2=82%), focal neurological deficits 55% ([95% CI, 40%-70%]; I2=82%), encephalopathy 54% ([95% CI, 39%-68%]; I2=43%), seizures 37% ([95% CI, 27%-49%]; I2=65%), headache 31% ([95% CI, 22%-42%]; I2=58%), T2/fluid-attenuated inversion recovery-hyperintense white matter lesions 98% ([95% CI, 93%-100%]; I2=44%), lobar cerebral microbleeds 96% ([95% CI, 92%-99%]; I2=25%), gadolinium enhancing lesions 54% ([95% CI, 42%-66%]; I2=62%), cortical superficial siderosis 51% ([95% CI, 34%-68%]; I2=77%) and lobar macrohemorrhage 40% ([95% CI, 11%-73%]; I2=88%). The prevalence rate of the ApoE (Apolipoprotein E) ε4/ε4 genotype was 34% ([95% CI, 17%-53%]; I2=76%). Subgroup analyses demonstrated no differences in these prevalence rates based on study design and diagnostic strategy. CONCLUSIONS: Cognitive decline was the most common clinical feature. Hyperintense T2/fluid-attenuated inversion recovery white matter lesions and lobar cerebral microbleeds were by far the most prevalent neuroimaging findings. Thirty-four percent of patients with CAA-ri have homozygous ApoE ε4/ε4 genotype and scarce data exist regarding the cerebrospinal fluid biomarkers and its significance in these patients.

Rehabilitation on cerebellar ataxic patients with multiple sclerosis: A systematic review.

Multiple Sclerosis (MS) is a chronic inflammatory, autoimmune disease of the Central Nervous System with a vast spectrum of clinical phenotypes. A major aspect of its clinical presentation is cerebellar ataxia where physiotherapy and treatment modalities play a significant role on its management. This systematic review aims to investigate the physiotherapeutic rehabilitation techniques regarding the management of cerebellar ataxia due to MS and secondary to stratify each protocol as part of a multi structural personalized rehabilitation approach based on the gravity of the symptoms. A Pubmed Medline, Scopus and Web of Science research was performed using the corresponding databases. The results were screened by the authors in pairs. In our study, six (6) non-pharmacological interventional protocols, 3 Randomized Controlled Trials and 3 pilot studies, were included with a total of 145 MS patients. Physiotherapeutic techniques, such as NDT-Bobath, robotic and visual biofeedback re-education protocols and functional rehabilitation techniques were included. In most cases cerebellar ataxic symptoms were decreased post-treatment. The overall quality of the studies included was of moderate level (level B). Rehabilitation in cerebellar ataxia due to MS should be based on multicentric studies with the scope of adjusting different types of treatments and physiotherapeutic techniques based on the severity of the symptom.

Safety of COVID-19 vaccines in multiple sclerosis: A systematic review and meta-analysis.

BACKGROUND: Data are sparse regarding the safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with multiple sclerosis (MS). OBJECTIVE: To estimate (1) the pooled proportion of MS patients experiencing relapse among vaccine recipients; (2) the rate of transient neurological worsening, adverse events, and serious adverse events; (3) the previous outcomes of interest for different SARS-CoV-2 vaccine types. METHODS: Systematic review and meta-analysis of pharmacovigilance registries and observational studies. RESULTS: Nineteen observational studies comprising 14,755 MS patients who received 23,088 doses of COVID-19 vaccines were included. Mean age was 43.3 years (95% confidence interval (CI): 40-46.6); relapsing-remitting, secondary-progressive, primary-progressive MS and clinically isolated syndrome were diagnosed in 82.6% (95% CI: 73.9-89.8), 12.6% (95% CI: 6.3-20.8), 6.7% (95% CI: 4.2-9.9), and 2.9% (95% CI: 1-5.9) of cases, respectively. The pooled proportion of MS patients experiencing relapse at a mean time interval of 20 days (95% CI: 12-28.2) from vaccination was 1.9% (95% CI: 1.3%-2.6%; I2 = 78%), with the relapse risk being independent of the type of administered SARS-CoV-2-vaccine (p for subgroup differences = 0.7 for messenger RNA (mRNA), inactivated virus, and adenovector-based vaccines). After vaccination, transient neurological worsening was observed in 4.8% (95% CI: 2.3%-8.1%) of patients. Adverse events and serious adverse events were reported in 52.8% (95% CI: 46.7%-58.8%) and 0.1% (95% CI: 0%-0.2%) of vaccinations, respectively. CONCLUSION: COVID-19 vaccination does not appear to increase the risk of relapse and serious adverse events in MS. Weighted against the risks of SARS-CoV-2-related complications and MS exacerbations, these safety data provide compelling pro-vaccination arguments for MS patients.

Dopamine transporter SPECT imaging in Parkinson's disease and atypical Parkinsonism: a study of 137 patients.

INTRODUCTION: Differential diagnosis between Parkinson's disease (PD) and multiple system atrophy-parkinsonian type (MSA-P), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), collectively termed atypical Parkinsonism (AP), is challenging. Dopamine transporter density imaging with Ioflupane I123 (DaTscan) is a marker of presynaptic nigrostriatal dysfunction. The primary aim of this study was to investigate the utility of DaTscan in the differential diagnosis of MSA-P, CBD, and PSP. METHODS: Patients examined at Eginition Hospital (2011-2021), with available DaTscan data and a diagnosis of probable AP, clinically established PD, as well as a neurological control (NC) group were included. Mean binding specific index (BSI), BSI of the most affected side, asymmetry index, laterality, and caudate/putamen ratio were recorded. Analyses were performed by Kruskal-Wallis and ANCOVA. RESULTS: 137 patients were included (CBD: [Formula: see text]; MSA-P: [Formula: see text]; PSP: [Formula: see text]; PD: [Formula: see text]; NC: [Formula: see text]). There were significant differences when comparing CBS, PSP, and NC vs. all other groups combined. Pairwise between-group comparisons revealed significant differences between PSP and CBD (mean striatum BSI>1.95; sensitivity 74.1%; specificity 85.0%), CBD and MSA-P (mean striatum BSI>2.04; sensitivity 70.4%; specificity 86.7%), and CBD and PD (mean striatum BSI>2.11; sensitivity 66.7%; specificity 100.0%). There were no differences between PSP, MSA-P, and PD. PSP, MSA-P, and PD differed from NC subjects, with 100% specificity and high sensitivity. Differentiation of NC from CBD was suboptimal. DISCUSSION: CBD patients exhibit relatively mild DaTscan abnormalities. DaTscan may assist in the differentiation of CBD from PSP. DaTscan does not differentiate among PD, MSA-P, and PSP.

Prevalence of Clinical and Neuroimaging Markers in Cerebral Amyloid Angiopathy: A Systematic Review and Meta-Analysis.

BACKGROUND: Limited data exist regarding the prevalence of clinical and neuroimaging manifestations among patients diagnosed with cerebral amyloid angiopathy (CAA). We sought to determine the prevalence of clinical phenotypes and radiological markers in patients with CAA. METHODS: Systematic review and meta-analysis of studies including patients with CAA was conducted to primarily assess the prevalence of clinical phenotypes and neuroimaging markers as available in the included studies. Sensitivity analyses were performed based on the (1) retrospective or prospective study design and (2) probable or unspecified CAA status. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using the Cochran Q and I2 statistics. RESULTS: We identified 12 prospective and 34 retrospective studies including 7159 patients with CAA. The pooled prevalence rates were cerebral microbleeds (52% [95% CI, 43%-60%]; I2=93%), cortical superficial siderosis (49% [95% CI, 38%-59%]; I2=95%), dementia or mild cognitive impairment (50% [95% CI, 35%-65%]; I2=97%), intracerebral hemorrhage (ICH; 44% [95% CI, 27%-61%]; I2=98%), transient focal neurological episodes (48%; 10 studies [95% CI, 29%-67%]; I2=97%), lacunar infarcts (30% [95% CI, 25%-36%]; I2=78%), high grades of perivascular spaces located in centrum semiovale (56% [95% CI, 44%-67%]; I2=88%) and basal ganglia (21% [95% CI, 2%-51%]; I2=98%), and white matter hyperintensities with moderate or severe Fazekas score (53% [95% CI, 40%-65%]; I2=91%). The only neuroimaging marker that was associated with higher odds of recurrent ICH was cortical superficial siderosis (odds ratio, 1.57 [95% CI, 1.01-2.46]; I2=47%). Sensitivity analyses demonstrated a higher prevalence of ICH (53% versus 16%; P=0.03) and transient focal neurological episodes (57% versus 17%; P=0.03) among retrospective studies compared with prospective studies. No difference was documented between the prevalence rates based on the CAA status. CONCLUSIONS: Approximately one-half of hospital-based cohort of CAA patients was observed to have cerebral microbleeds, cortical superficial siderosis, mild cognitive impairment, dementia, ICH, or transient focal neurological episodes. Cortical superficial siderosis was the only neuroimaging marker that was associated with higher odds of ICH recurrence. Future population-based studies among well-defined CAA cohorts are warranted to corroborate our findings.

CADASIL in Greece: Mutational spectrum and clinical characteristics based on a systematic review and pooled analysis of published cases.

BACKGROUND: Differences have been noted in the clinical presentation and mutational spectrum of CADASIL among various geographical areas. The aim of the present study was to investigate the mode of clinical presentation and genetic mutations reported in Greece. METHODS: After a systematic literature search, we performed a pooled analysis of all published CADASIL cases from Greece. RESULTS: We identified 14 studies that reported data from 14 families comprising 54 patients. Migraine with aura was reported in 39%, ischemic cerebrovascular diseases in 68%, behavioral-psychiatric symptoms in 47% and cognitive decline in 60% of the patients. The mean (±SD) age of onset for migraine with aura, ischemic cerebrovascular diseases, behavioral-psychiatric symptoms and cognitive decline was 26.2 ± 8.7, 49.3 ± 14.6, 47.9 ± 9.4 and 42.9 ± 10.3, respectively; the mean age at disease onset and death was 34.6 ± 12.1 and 60.2 ± 11.2 years. With respect to reported mutations, mutations in exon 4 were the most frequently reported (61.5% of all families), with the R169C mutation being the most common (30.8% of all families and 50% of exon 4 mutations), followed by R182C mutation (15.4% of all families and 25% of exon 4 mutations). CONCLUSIONS: The clinical presentation of CADASIL in Greece is in accordance with the phenotype encountered in Caucasian populations, but differs from the Asian phenotype, which is characterized by a lower prevalence of migraine and psychiatric symptoms. The genotype of Greek CADASIL pedigrees is similar to that of British pedigrees, exhibiting a high prevalence of exon 4 mutations, but differs from Italian and Asian populations, where mutations in exon 11 are frequently encountered.

Dopamine transporter SPECT imaging in corticobasal syndrome: A peak into the underlying pathology?

BACKGROUND: Multiple pathologies may underlie corticobasal syndrome (CBS), including Alzheimer's disease (AD). Dopamine transporter density imaging with Ioflupane 123 I SPECT (DaTscan) may be normal in CBS. No studies to date have examined the relationship between DaTscan status and underlying pathology in CBS. OBJECTIVES: The main objective of the study was to test whether a normal DaTscan in CBS patients is indicative of an underlying AD pathology, as determined by cerebrospinal fluid (CSF) biomarkers. METHODS: Eighteen CBS patients were included. They were divided into patients with an AD and a non-AD disease pathology, based on their cerebrospinal fluid biochemical profile. A typical AD CSF profile was defined as an increase in total and phosphorylated at threonine 181 tau protein in addition to a decrease in amyloid-beta with 42 amino acids. DaTscan data were compared in these two groups. RESULTS: Eight of the 18 CBS patients (44%) had a normal DaTscan. Seven of the 18 CBS patients (39%) had an AD cerebrospinal fluid biochemical profile. Two of seven CBS patients with AD biomarker profile had abnormal DaTscans. Three of 11 CBS patients with a non-AD biomarker profile had normal DaTscans. A normal DaTscan was indicative of AD pathology with suboptimal (~70%) sensitivity and specificity. Semi-quantitative DaTscan analysis did not differentiate between AD from non-AD CSF biomarker profile in CBS. CONCLUSION: A normal DaTscan is indicative of AD in CBS, but the sensitivity and specificity of DaTscan as an in vivo marker of AD pathology is suboptimal.

Classical Cerebrospinal Fluid Biomarkers in Dementia with Lewy Bodies.

The use and interpretation of diagnostic cerebrospinal fluid (CSF) biomarkers for neurodegenerative disorders, such as Dementia with Lewy bodies (DLB), represent a clinical challenge. According to the literature, the composition of CSF in DLB patients varies. Some patients present with reduced levels of amyloid, others with full Alzheimer Disease CSF profile (both reduced amyloid and increased phospho-tau) and some with a normal profile. Some patients may present with abnormal levels of a-synuclein. Continuous efforts will be required to establish useful CSF biomarkers for the early diagnosis of DLB. Given the heterogeneity of methods and results between studies, further validation is fundamental before conclusions can be drawn.

Silent Pauses and Speech Indices as Biomarkers for Primary Progressive Aphasia.

Background and Objectives: Recent studies highlight the importance of investigating biomarkers for diagnosing and classifying patients with primary progressive aphasia (PPA). Even though there is ongoing research on pathophysiological indices in this field, the use of behavioral variables, and especially speech-derived factors, has drawn little attention in the relevant literature. The present study aims to investigate the possible utility of speech-derived indices, particularly silent pauses, as biomarkers for primary progressive aphasia (PPA). Materials and Methods: We recruited 22 PPA patients and 17 healthy controls, from whom we obtained speech samples based on two elicitation tasks, i.e., cookie theft picture description (CTP) and the patients' personal narration of the disease onset and course. Results: Four main indices were derived from these speech samples: speech rate, articulation rate, pause frequency, and pause duration. In order to investigate whether these indices could be used to discriminate between the four groups of participants (healthy individuals and the three patient subgroups corresponding to the three variants of PPA), we conducted three sets of analyses: a series of ANOVAs, two principal component analyses (PCAs), and two hierarchical cluster analyses (HCAs). The ANOVAs revealed significant differences between the four subgroups for all four variables, with the CTP results being more robust. The subsequent PCAs and HCAs were in accordance with the initial statistical comparisons, revealing that the speech-derived indices for CTP provided a clearer classification and were especially useful for distinguishing the non-fluent variant from healthy participants as well as from the two other PPA taxonomic categories. Conclusions: In sum, we argue that speech-derived indices, and especially silent pauses, could be used as complementary biomarkers to efficiently discriminate between PPA and healthy speakers, as well as between the three variants of the disease.

Lentiform fork sign in a patient with systemic lupus erythematosus.

The "lentiform fork sign" is a rare MRI sign which affects the posterior limb of the internal capsule, the external capsule, and extends posteriorly to form a fork-like appearance. It has been reported exclusively in disorders with metabolic acidosis, such as uremic encephalopathy, mitochondrial disorders, methanol/ethylene glycol intoxication, etc. It is considered to represent vasogenic edema and is often reversible. We describe a 73-year old female with a 2-month history of rapidly deteriorating imbalance, bradykinesia, confusion, and disorientation. At examination, she was encephalopathic. She had a pyramidal and rigid-akinetic parkinsonian syndrome, with signs of polyneuropathy. MRI revealed the "lentiform fork sign". She exhibited a high ANA titer, positive anti-dsDNA, anti-ENA, and anti-ß2GPI-IgM antibodies, as well as positive cerebrospinal fluid IgG and albumin indices. No metabolic acidosis was recorded. A diagnosis of systemic lupus erythematosus (SLE) was established. She was treated initially with methylprednisolone, followed by hydroxychloroquine, with complete remission of her symptoms and disappearance of the "lentiform fork sign". We present a case of a patient with SLE, harboring the "lentiform fork sign", in the absence of metabolic acidosis. Differential diagnosis of the "lentiform fork sign" should be expanded to include autoimmune disorders, even in the absence of metabolic acidosis.

Circulating Brain-enriched MicroRNAs for detection and discrimination of idiopathic and genetic Parkinson's disease.

BACKGROUND: A minimally invasive test for early detection and monitoring of Parkinson's disease (PD) is a highly unmet need for drug development and planning of patient care. Blood plasma represents an attractive source of biomarkers. MicroRNAs (miRNAs) are conserved noncoding RNA molecules that serve as posttranscriptional regulators of gene expression. As opposed to ubiquitously expressed miRNAs that control house-keeping processes, brain-enriched miRNAs regulate diverse aspects of neuron development and function. These include neuron-subtype specification, axonal growth, dendritic morphogenesis, and spine density. Backed by a large number of studies, we now know that the differential expression of neuron-enriched miRNAs leads to brain dysfunction. OBJECTIVES: The aim was to identify subsets of brain-enriched miRNAs with diagnostic potential for familial and idiopathic PD as well as specify the molecular pathways deregulated in PD. METHODS: Initially, brain-enriched miRNAs were selected based on literature review and validation studies in human tissues. Subsequently, real-time reverse transcription polymerase chain reaction was performed in the plasma of 100 healthy controls and 99 idiopathic and 53 genetic (26 alpha-synucleinA53T and 27 glucocerebrosidase) patients. Statistical and bioinformatics analyses were carried out to pinpoint the diagnostic biomarkers and deregulated pathways, respectively. RESULTS: An explicit molecular fingerprint for each of the 3 PD cohorts was generated. Although the idiopathic PD fingerprint was different from that of genetic PD, the molecular pathways deregulated converged between all PD subtypes. CONCLUSIONS: The study provides a group of brain-enriched miRNAs that may be used for the detection and differentiation of PD subtypes. It has also identified the molecular pathways deregulated in PD. © 2019 International Parkinson and Movement Disorder Society.

Midbrain morphology in idiopathic normal pressure hydrocephalus: A progressive supranuclear palsy mimic.

INTRODUCTION: Various MRI markers have been applied to support the diagnosis of progressive supranuclear palsy (PSP), such as midbrain diameter and surface, superior cerebellar peduncle (SCP) width, midbrain to pons (m/p) diameter and surface ratio and the Magnetic Resonance Parkinsonism Index (MRPI). These markers provide excellent diagnostic accuracy in discriminating Richardson's syndrome from other causes of Parkinsonism. Idiopathic normal pressure hydrocephalus (iNPH) may mimic Richardson's syndrome, particularly in cases of subtle opthalmokinetic abnormalities. The aim of this study was to compare these MRI markers in PSP and iNPH and examine their diagnostic accuracy. MATERIALS AND METHODS: Forty-three patients with probable PSP, 17 patients with iNPH, and 29 controls were included. Midbrain diameter and surface, SCP width, m/p diameter and surface ratio and the MRPI were recorded. The "hummingbird sign," "morning glory sign" and "mickey mouse sign" were also evaluated. Analysis of covariance, chi-squared test, and ROC curve analysis were used as appropriate. RESULTS: All MRI measurements differed significantly among the three study groups. Comparison of PSP and iNPH patients produced the following significant differences: midbrain diameter (P < .0001), m/p diameter ratio (P < .0001), SCP width (P = .050), and MRPI (P = .049). None of these markers produced combined high (>80%) specificity and sensitivity. Qualitative MRI signs were specific, but lacked sensitivity. DISCUSSION: Midbrain morphology in iNPH may resemble that of PSP. Established MRI markers of midbrain and SCP atrophy cannot confidently differentiate PSP from iNPH. MRI markers do not provide combined high sensitivity and specificity for the differential diagnosis of PSP from iNPH.

In vivo Prevalence of Alzheimer Biomarkers in Dementia with Lewy Bodies.

BACKGROUND: Neuropathological studies indicate concomitant Alzheimer's disease (AD) pathology in patients with dementia with Lewy bodies (DLB). OBJECTIVES: To measure cerebrospinal fluid (CSF) levels of ß-amyloid peptide with 42 amino acids (Aß42), total tau protein (τT), and tau phosphorylated at threonine 181 (τP-181) in 38 patients fulfilling the diagnostic criteria of probable DLB according to the most recent (4th consensus) report. METHODS: Double-sandwich commercial ELISAs (Innotest; Fujirebio, Gent, Belgium) were used for measurements. RESULTS: According to the current cutoff values of our laboratory, 4 biomarker profiles were noted: abnormal levels of Aß42 only (44.7%), full AD profile (39.5%), abnormal levels of τT only (5.3%), and normal levels of all 3 biomarkers (10.5%). AD profile was associated with female sex, older age, lower education, and lower MMSE scores. CONCLUSIONS: Reduction in Αß42 in DLB may be more common (>80% of patients) than previously thought, and ∼40% may have the typical CSF AD biomarker profile. AD biochemistry in DLB may be an evolving process showing increasing frequency with disease progression.

Plasma alpha-synuclein levels in patients with Parkinson's disease: a systematic review and meta-analysis.

OBJECTIVE: To date, there are no definitive biomarkers for diagnose Parkinson's disease (PD). The detection of α-synuclein (α-Syn) in plasma of PD patients has yielded promising but inconclusive results. To determine the performance of α-Syn as a diagnostic biomarker of PD, we used a meta-analysis. METHODS: We identified 173 studies through a systematic literature review. From those, only studies reporting data on total α-Syn levels were included in the meta-analysis (10 publications, 1302 participants). Quality of studies was assessed by Newcastle-Ottawa scale. RESULTS: The α-Syn levels were significantly higher in PD patients than healthy controls (standardized mean difference [SMD] = 0.778, 95% confidence interval = 0.284 to 1.272, p = 0.002). Similar results were found after omitting any individual study from meta-analysis, with SMD ranges from 0.318 (95% CI = 0.064 to 0.572, p = 0.014) to 0.914 (95% CI = 0.349 to 1.480, p = 0.002). According to meta-regression analysis, increased mean patients age (slope = - 0.232, 95% CI = - 0.456 to - 0.008, p = 0.042), increased total number of participants (slope = - 0.007, 95% CI = - 0.013 to - 0.0004, p = 0.038), and increased percentage of males (slope = - 6.444, 95% CI = - 10.841 to - 2.047, p = 0.004) were associated with decreased SMD of α-Syn levels across studies. We did not find any significant association between the SMD in α-Syn levels and disease duration, disease severity, and quality of studies. Most of studies applied ELISA assays. CONCLUSION: Total plasma α-Syn levels were higher in PD patients than controls. Analytical factors were important limitations.

Hereditary causes of ischemic cerebral small vessel disease.

Hereditary types of ischemic cerebral subcortical small vessel disease (SSVD) are rare, usually autosomal dominant, diseases, due to an abnormality in vessel wall synthesis. They may present with various combinations of migraine with aura, ischemic events (transient ischemic attacks, lacunar strokes) and progressively worsening ischemic lesion load in brain imaging. Eventually, vascular cognitive impairment (usually of the frontal-subcortical type) develops, frequently accompanied by behavioral-psychiatric symptoms and bilateral pyramidal and pseudobulbar signs leading to severe disability and premature death. In some patients, microbleeds and hemorrhagic strokes may be present. Despite their rarity, these disorders offer a statistically homogeneous population (usually without additional pathology such as Alzheimer's disease), suitable for the study of vascular cognitive impairment. The few studies on the relative frequency of these disorders indicate that the most frequent (or rather the least rare), accounting for more than half of patients, is CADASIL, due to mutations of the NOTCH3 gene, followed by COL4A1/A2-related disease, autosomal dominant forms of HTRA1-related disease and leucoencephalopathies with calcifications and cysts. Mutations of TREX1, GLA, FOXC1 and CARASIL are less frequent. Despite the genetic nature of these disorders, their phenotype, severity and rate of progression may be adversely affected by classical cardiovascular risk factors such as hypertension, diabetes, dyslipidemia and smoking and control of these risk factors is strongly advised for all patients.

Anti-NMDA receptor encephalitis presenting as isolated aphasia in an adult.

Anti-NMDA receptor (NMDA-r) encephalitis is a relatively rare cause of autoimmune encephalitis with divergent clinical presentations. We report a case of an adult patient with anti-NMDA-r encephalitis presenting with isolated, abrupt-onset aphasia. Her condition remained unaltered over a period of 6 months. The patients' electroencephalogram findings were typical for NMDA-r encephalitis; however, her magnetic resonance imaging and cerebrospinal fluid analysis were normal. She responded well to immunotherapy, and aphasia eventually resolved. The natural course of the present case contradicts the rapidly progressive nature of typical NMDA-r encephalitis. Furthermore, it broadens the clinical spectrum of anti-NMDA-r encephalitis, to incorporate isolated, nonprogressive aphasia.

Simple linear brainstem MRI measurements in the differential diagnosis of progressive supranuclear palsy from the parkinsonian variant of multiple system atrophy.

Differential diagnosis of progressive supranuclear palsy (PSP) and the parkinsonian variant of multiple system atrophy (MSA-P) from Parkinson's disease (PD) can be difficult, particularly in atypical cases or early in the disease course. The Magnetic Resonance Parkinsonism Index (MRPI) utilizes linear and surface (planimetry) measurements and has been proposed as a dual MRI biomarker, with high values indicative of PSP and low values of MSA. The aim of this study was to examine the utility of simple linear MRI brainstem measurements, without the use of MRI planimetry, in the diagnosis of patients with Parkinsonism and compare them to the MRPI. A total of 51 patients (PSP: 24, MSA-P: 9, PD: 18) and 15 healthy controls were included. Simple linear MRI distances of brainstem structures were measured. These included midbrain and pons diameters as well as superior cerebellar peduncle (SCP) and middle cerebellar peduncle (MCP) widths. All relevant indices, including ratios and products, were also calculated. The SCP by midbrain product (SCP × midbrain) provided improved sensitivity (100 vs. 91%) and identical specificity (98%) for the diagnosis of PSP, compared to the MRPI. Neither the MRPI nor any of the linear measurements were able to discriminate MSA-P from PD. The SCP by midbrain product is a novel, potent MRI biomarker for PSP.

Recognition of Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) in Two Oligosymptomatic Sisters with Low CADASIL Scale Scores and a Venous Dysplasia: Report of a Novel Greek Family.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) due to mutations of the NOTCH3 gene is the most common cause of inherited cerebral small-vessel disease and one of the genetic causes of migraine with aura. The so-called CADASIL scale has been proposed as a clinical screening tool, and a score of 15 or higher seems useful in identifying patients with high probability of carrying NOTCH3 mutations. We studied a novel Greek family with clinical features compatible with CADASIL. Genetic analysis of NOTCH3 in the 2 living patients revealed the R182C mutation. Both patients had low scores (12 and 14) in the CADASIL scale, probably due to their relatively young age (38 and 37 years, respectively) at which cognitive decline and external capsule involvement have not developed yet. Another unusual feature in the second patient was a venous dysplasia in the parietal lobe. Observations presented here add to the notion that the CADASIL scale, although useful, probably needs a revision, taking into account the patient's age at which the score is calculated.

Cerebrospinal Fluid TAR DNA-Binding Protein 43 Combined with Tau Proteins as a Candidate Biomarker for Amyotrophic Lateral Sclerosis and Frontotemporal Dementia Spectrum Disorders.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are nowadays recognized as spectrum disorders with a molecular link, the TAR DNA-binding protein 43 (TDP-43), rendering it a surrogate biomarker for these disorders. METHODS: We measured cerebrospinal fluid (CSF) levels of TDP-43, beta-amyloid peptide with 42 amino acids (Aß42), total tau protein (τT), and tau protein phosphorylated at threonine 181 (τP-181) in 32 patients with ALS, 51 patients with FTD, and 17 healthy controls. Double-sandwich commercial enzyme-linked immunosorbent assays were used for measurements. RESULTS: Both ALS and FTD patients presented with higher TDP-43 and τT levels compared to the control group. The combination of biomarkers in the form of the TDP-43 × τT / τP-181 formula achieved the best discrimination between ALS or FTD and controls, with sensitivities and specificities >0.8. CONCLUSION: Combined analysis of TDP-43, τT, and τP-181 in CSF may be useful for the antemortem diagnosis of ALS and FTD.