Prognostic value of early electrographic biomarkers of epileptogenesis in high-risk ischaemic stroke patients.

BACKGROUND AND PURPOSE: Post-stroke epilepsy (PSE) is frequent. Better prediction of PSE would enable individualized management and improve trial design for epilepsy prevention. The aim was to assess the complementary value of continuous electroencephalography (EEG) data during the acute phase compared with clinical risk factors currently used to predict PSE. METHODS: A prospective cohort of 81 patients with ischaemic stroke who received early continuous EEG monitoring was studied to assess the association of early EEG seizures, other highly epileptogenic rhythmic and periodic patterns, and regional attenuation without delta (RAWOD, an EEG pattern of stroke severity) with PSE. Clinical risk factors were investigated using the SeLECT (stroke severity; large-artery atherosclerosis; early clinical seizures; cortical involvement; territory of middle cerebral artery) scores. RESULTS: Twelve (15%) patients developed PSE. The presence of any of the investigated patterns was associated with a risk of epilepsy of 46%, with a sensitivity and specificity of 83% and 78%. The association remained significant after adjusting for the SeLECT score (odds ratio 18.8, interquartile range 3.8-72.7). CONCLUSIONS: It was found that highly epileptogenic rhythmic and periodic patterns and RAWOD were associated with the development of PSE and complemented clinical risk factors. These findings indicate that continuous EEG provides useful information to determine patients at higher risk of developing PSE and could help individualize care.

Anodal Cerebellar Transcranial Direct Current Stimulation Reduces Motor and Cognitive Symptoms in Friedreich's Ataxia: A Randomized, Sham-Controlled Trial.

BACKGROUND: Friedreich Ataxia is the most common recessive ataxia with only one therapeutic drug approved solely in the United States. OBJECTIVE: The aim of this work was to investigate whether anodal cerebellar transcranial direct current stimulation (ctDCS) reduces ataxic and cognitive symptoms in individuals with Friedreich's ataxia (FRDA) and to assess the effects of ctDCS on the activity of the secondary somatosensory (SII) cortex. METHODS: We performed a single-blind, randomized, sham-controlled, crossover trial with anodal ctDCS (5 days/week for 1 week, 20 min/day, density current: 0.057 mA/cm2 ) in 24 patients with FRDA. Each patient underwent a clinical evaluation (Scale for the Assessment and Rating of Ataxia, composite cerebellar functional severity score, cerebellar cognitive affective syndrome scale) before and after anodal and sham ctDCS. Activity of the SII cortex contralateral to a tactile oddball stimulation of the right index finger was evaluated with brain functional magnetic resonance imaging at baseline and after anodal/sham ctDCS. RESULTS: Anodal ctDCS led to a significant improvement in the Scale for the Assessment and Rating of Ataxia (-6.5%) and in the cerebellar cognitive affective syndrome scale (+11%) compared with sham ctDCS. It also led to a significant reduction in functional magnetic resonance imaging signal at the SII cortex contralateral to tactile stimulation (-26%) compared with sham ctDCS. CONCLUSIONS: One week of treatment with anodal ctDCS reduces motor and cognitive symptoms in individuals with FRDA, likely by restoring the neocortical inhibition normally exerted by cerebellar structures. This study provides class I evidence that ctDCS stimulation is effective and safe in FRDA. © 2023 International Parkinson and Movement Disorder Society.

Crossed Cerebellar Diaschisis Worsens the Clinical Presentation in Acute Large Vessel Occlusion.

INTRODUCTION: Initial NIHSS in anterior large vessel occlusion (LVO) correlates partially with the hypoperfusion volume. We aimed at assessing the contribution of crossed cerebellar diaschisis (CCD) from the hypoperfused territory on LVO initial clinical deficit. METHODS: CCD was retrospectively identified by brain CT perfusion imaging (CTP) in patients with anterior LVO treated by mechanical thrombectomy from January 2017 to July 2021. CCD was defined by CTP parameter alteration in the contralateral cerebellar hemisphere to the LVO. NIHSS, clinical/perfusion variables, and CCD were included in regression models to assess their interrelationships. RESULTS: 206 patients were included. CCD was present in 90 patients (69%). NIHSS scores were higher on admission and at stroke discharge among patients with CCD (17.90 ± 6.1 vs. 11.4 ± 8.4, p < 0.001; 9.6 ± 7.7 vs. 6.6 ± 7.9, p = 0.049; respectively). Patients with a CCD had higher stroke volumes (118.2 ± 60.3 vs. 69.3 ± 59.7, p < 0.001) and lower rate of known atrial fibrillation (22% vs. 41%, p = 0.021). On multivariable logistic regression, CCD independently worsened the initial NIHSS (OR 4.85 [2.37-7.33]; p < 0.001). CONCLUSION: CCD is found in 69% of LVO on admission CTP, correlates with stroke volumes, and independently worsens initial NIHSS.

Temporally stable beta sensorimotor oscillations and corticomuscular coupling underlie force steadiness.

As humans, we seamlessly hold objects in our hands, and may even lose consciousness of these objects. This phenomenon raises the unsettled question of the involvement of the cerebral cortex, the core area for voluntary motor control, in dynamically maintaining steady muscle force. To address this issue, we measured magnetoencephalographic brain activity from healthy adults who maintained a steady pinch grip. Using a novel analysis approach, we uncovered fine-grained temporal modulations in the beta sensorimotor brain rhythm and its coupling with muscle activity, with respect to several aspects of muscle force (rate of increase/decrease or plateauing high/low). These modulations preceded changes in force features by ∼40 ms and possessed behavioral relevance, as less salient or absent modulation predicted a more stable force output. These findings have consequences for the existing theories regarding the functional role of cortico-muscular coupling, and suggest that steady muscle contractions are characterized by a stable rather than fluttering involvement of the sensorimotor cortex.

The cognitive profile of Friedreich ataxia: a systematic review and meta-analysis.

BACKGROUND: Study the cognitive profile of individuals with Friedreich ataxia (FRDA) and seek evidence for correlations between clinical, genetic and imaging characteristics and neuropsychological impairments. METHODS: Based on PRISMA guidelines, a meta-analysis was realized using the Pubmed and Scopus databases to identify studies (1950-2021) reporting neuropsychological test results in genetically confirmed FRDA and control participants in at least one of the following cognitive domains: attention/executive, language, memory and visuo-spatial functions as well as emotion. Studies using identical outcomes in a minimum of two studies were pooled. Pooled effect sizes were calculated with Cohen's d. RESULTS: Eighteen studies were included. Individuals with FRDA displayed significantly lower performance than individuals without FRDA in most language, attention, executive function, memory visuospatial function, emotion regulation and social cognitive tasks. Among the included studies, thirteen studies examined the relationship between neuropsychological test results and clinical parameters and reported significant association with disease severity and six studies reviewed the relationship between neuroimaging measures and cognitive performance and mainly reported links between reduced cognitive performance and changes in cerebellar structure. CONCLUSIONS: Individuals with FRDA display significantly lower performances in many cognitive domains compared to control participants. The spectrum of the cognitive profile alterations in FRDA and its correlation with disease severity and cerebellar structural parameters suggest a cerebellar role in the pathophysiology of FRDA cognitive impairments.

Age of onset modulates resting-state brain network dynamics in Friedreich Ataxia.

This magnetoencephalography (MEG) study addresses (i) how Friedreich ataxia (FRDA) affects the sub-second dynamics of resting-state brain networks, (ii) the main determinants of their dynamic alterations, and (iii) how these alterations are linked with FRDA-related changes in resting-state functional brain connectivity (rsFC) over long timescales. For that purpose, 5 min of resting-state MEG activity were recorded in 16 FRDA patients (mean age: 27 years, range: 12-51 years; 10 females) and matched healthy subjects. Transient brain network dynamics was assessed using hidden Markov modeling (HMM). Post hoc median-split, nonparametric permutations and Spearman rank correlations were used for statistics. In FRDA patients, a positive correlation was found between the age of symptoms onset (ASO) and the temporal dynamics of two HMM states involving the posterior default mode network (DMN) and the temporo-parietal junctions (TPJ). FRDA patients with an ASO <11 years presented altered temporal dynamics of those two HMM states compared with FRDA patients with an ASO > 11 years or healthy subjects. The temporal dynamics of the DMN state also correlated with minute-long DMN rsFC. This study demonstrates that ASO is the main determinant of alterations in the sub-second dynamics of posterior associative neocortices in FRDA patients and substantiates a direct link between sub-second network activity and functional brain integration over long timescales.

Corpus callosum thinning in autosomal dominant hereditary spastic paraplegia associated with a novel TUBß4A mutation.

Siblings with hereditary spastic paraplegia and corpus callosum thinning associated with a novel TUBß4A mutation.

Intracranial Vessel Wall MRI in Cryptogenic Stroke and Intracranial Vasculitis.

INTRODUCTION: Intracranial vasculopathies easily elude classic stroke work-up. We aim in this work to show that vessel wall-MRI could prove an efficient alternative to digital subtraction angiography for the diagnosis of intracranial vasculopathies by identifying intracranial arterial vessel walls anomalies and contrast enhancement, suggestive of angiitis of the central nervous system. MATERIALS AND METHODS: Clinical and imaging characteristics of stroke patients diagnosed with primary angiitis of the central nervous system based on vessel wall-MRI were retrospectively reviewed and the clinical and imaging features of angiitis associated with intracranial vessel walls anomalies and contrast enhancement detailed. RESULTS: Twenty patients were included (mean age was 59 years old). All patients were admitted for focal neurological deficits of sudden onset that were recurrent in 13 subjects. Cognitive impairment, headache and seizures occurred in, respectively, 13, 5, and 2 patients. Cerebrospinal fluid analysis was abnormal in 15 patients. In MRI, FLAIR sequences showed ischemic infarcts in 20 patients and DWI showed acute infarct in 15 patients. Digital subtraction angiography was performed in 11 patients and disclosed proximal and distal multifocal stenosis in 10 patients along distal irregularities in different vascular territories in 7. For all of our patients, VW-MRI revealed a concentric contrast enhancement of arterial walls, localized in multiple vascular territories, suggesting angiitis. Abnormalities on digital subtraction angiography and/or MR-Angiography, and vessel wall-MRI were consistent in all patients. CONCLUSIONS: This report underlies the added value of vessel wall-MRI to the diagnosis of underlying intracranial vasculopathy, particularly primary angiitis of the central nervous system, without the use of invasive endovascular techniques and the yield of vessel wall-MRI in the work-up of cryptogenic stroke.

Synchrony, metastability, dynamic integration, and competition in the spontaneous functional connectivity of the human brain.

The human brain is functionally organized into large-scale neural networks that are dynamically interconnected. Multiple short-lived states of resting-state functional connectivity (rsFC) identified transiently synchronized networks and cross-network integration. However, little is known about the way brain couplings covary as rsFC states wax and wane. In this magnetoencephalography study, we explore the synchronization structure among the spontaneous interactions of well-known resting-state networks (RSNs). To do so, we extracted modes of dynamic coupling that reflect rsFC synchrony and analyzed their spatio-temporal features. These modes identified transient, sporadic rsFC changes characterized by the widespread integration of RSNs across the brain, most prominently in the ß band. This is in line with the metastable rsFC state model of resting-state dynamics, wherein our modes fit as state transition processes. Furthermore, the default-mode network (DMN) stood out as being structured into competitive cross-network couplings with widespread DMN-RSN interactions, especially among the ß-band modes. These results substantiate the theory that the DMN is a core network enabling dynamic global brain integration in the ß band.

Endovascular treatment of intracranial aneurysms with the p64 flow diverter stent: mid-term results in 35 patients with 41 intracranial aneurysms.

INTRODUCTION: The p64 flow diverter (FD) device is a fully resheathable and detachable stent dedicated for endovascular treatment (EVT) of intracranial aneurysms (IAs). We report our mid-term experience with this device. METHODS: Between January 2015 and February 2016, we retrospectively identified, in our prospectively maintained database, all patients treated with p64 FDs in two institutions. Independent clinical follow-up was performed by a vascular neurologist. Imaging follow-up included a digitalized subtraction angiography (DSA) at 3, 6, and 12 months and a magnetic resonance angiography (MRA) at 12 months. RESULTS: Thirty-nine patients (22 women/17 men; median age 54 years) with 48 IAs (median aneurysm size 6.2 mm; mean neck size 3.4 mm) were identified. All IAs were saccular and unruptured. Failure of safe stent delivery occurred in 15% of cases (7/48 IAs) which were excluded. Transient neurological morbidity occurred in 2/35 patients (5.7%) including one delayed thromboembolic complication. No permanent morbidity or mortality was encountered. Complete aneurysmal occlusion at 3, 6, and 12 months was 20/30 (66.6%), 18/27 (66.6%), and 24/28 (85.7%), respectively. Intra-stent stenosis was observed in 9/29 patients (31%) and classified as moderate in 4/29 (13.7%) and mild in 5/29 patients (17.2%). These stenoses gradually improved over time, with only mild stenoses being identified at 6 months and at 12 months. CONCLUSION: In our small case series, the p64 FD stent appears safe and effective for EVT of IAs. A high occlusion rate and a low morbidity rate were observed.

The Prognostic Value of 48-h Continuous EEG During Therapeutic Hypothermia After Cardiac Arrest.

BACKGROUND: The aim of this study was to evaluate the prognostic value of continuous electroencephalogram (cEEG) during the first 48 h following cardiac arrest (CA) in patients treated with targeted temperature management (TTM). METHODS: We reviewed data from 92 comatose post-CA patients over a 6 year-period; cEEG recordings were performed during TTM and restoration of normothermia. EEG findings were divided into four time-periods: 0-8, 8-16, 16-24, and 24-48 h after CA. Background EEG findings were defined as moderate encephalopathy (diffuse slowing with reactivity/variability), severe encephalopathy (diffuse slowing without reactivity/variability), burst suppression or suppression, and dichotomized as malignant (suppression/burst suppression/severe encephalopathy) or benign (moderate encephalopathy). Epileptiform activity was defined as the presence of seizures, sporadic epileptiform discharges, or periodic discharges. Neurological outcome was assessed at 3 months using the cerebral performance categories (CPC) score (good outcome: CPC 1-2). RESULTS: 26/92 (28%) patients had a good outcome. Malignant patterns were associated with a poor outcome at all time-points, with a high positive predictive value (94-97%) but a poor negative predictive value (44-56%). Epileptiform activity did not influence the prognostic value of EEG patterns. All patients with moderate encephalopathy and seizures or generalized periodic discharges had a poor outcome. CONCLUSIONS: cEEG can identify patients with poor outcome from the first hours following CA, with limited predictive value for good outcome. Epileptiform activity did not improve the prognostic accuracy of EEG, but seizures and generalized periodic discharges were associated with poor outcome even when developing on a benign EEG pattern.

Transient Neurologic Deficits: Can Transient Ischemic Attacks Be Discriminated from Migraine Aura without Headache?

BACKGROUND: Transient neurologic deficits (TNDs) are often considered first to be transient ischemic attacks (TIAs) but TND with normal brain imaging is also characteristic of other prevalent conditions like migraine aura leading to potential confusion. We aimed to determine if migraine aura with headache (MA) and migraine aura without headache (MAWH) can be distinguished from TIA on clinical or paraclinical ground using validated international criteria. METHODS: Clinical and paraclinical data from 32 patients with TIA were compared with 32 patients with MAWH and 32 with MA. Participants underwent a thorough evaluation including standardized clinical examination, laboratory testing, magnetic resonance imaging of the brain, cardiovascular work-up, and electroencephalogram. RESULTS: Patient with TIA were significantly older (65.41 ± 16.93 years) than patients with MAWH (50.41 ± 19.69, P = .002) or MA (40.56 ± 11.72, P = .00001), and were mostly male (male:female = .82) compared with the 2 other groups. History of stroke, high blood pressure, and dyslipidemia were significantly more frequent in patients with TIA. Visual deficits occurred in 63% of patients with MAWH, 41% for patients with MA, and 10% for patients with TIA. In patients with TIA, the TND was inaugural in 94% of cases, conversely to MAWH and MA in which TND was inaugural in only 19% and 38%, respectively (P ≤ .0001). CONCLUSIONS: Despite some sociodemographic, clinical, and paraclinical differences in the presentation of these TND, there is no feature accurately distinguishing between TIA and TND associated with migrainous phenomena when validated actual criteria are used, leading to probable confusion in most studies. There is a need to develop reliable criteria and/or tests for this purpose.

Transient CNS deficits and migrainous auras in individuals without a history of headache.

OBJECTIVE: To demonstrate that benign transient focal neurological symptoms represent equivalents of migraine auras without headache. BACKGROUND: Benign focal neurological symptoms suggesting cerebral dysfunction are common and usually prompt an extensive diagnostic workup, but their etiology is often not elucidated. We hypothesized that benign transient focal neurological symptoms represent equivalents of migraine auras without headache, even in subjects who have never experienced migraine headaches. METHODS: We led a cross-sectional study and identified individuals who presented at least 1 episode of unexplained transient focal neurological symptoms suggestive of cerebral dysfunction, but no history of migraine headache, among physicians and inpatients of an academic hospital. Cortical hyperexcitability, assessed by occipital transcranial magnetic stimulation (oTMS), was used as a marker of possible migraine auras without headache. RESULTS: Frequency of transient focal neurological symptoms suggestive of cerebral dysfunction among the physicians who responded was 9% (21/233), vs 0.09% (6/690) of inpatients. Most episodes resembled typical visual migrainous auras. Motor, sensory, and language dysfunction were more common among inpatients than among physicians. oTMS induced phosphenes in 12/16 (75%) subjects and in none of 10 controls. CONCLUSION: Benign focal neurological symptoms were common in our population and likely represent migraine aura without headache. Non-visual symptoms are less common and lead to medical consultation. oTMS is abnormal in most cases, supporting the diagnosis of migraine aura without headache and helping separate this benign condition from transient ischemic attacks.

EEG patterns compatible with nonconvulsive status epilepticus are common in elderly patients with delirium: a prospective study with continuous EEG monitoring.

INTRODUCTION: Delirium is a leading cause of hospitalization and morbidity in elderly persons. Nonconvulsive status epilepticus (NCSE) and delirium share many risk factors. We tested the hypothesis that NCSE plays an important role in delirium by performing continuous EEG (cEEG) monitoring in elderly patients with delirium of any cause. MATERIAL AND METHODS: Patients over 65 years old presenting with delirium in the emergency room were prospectively included and underwent either routine 20-minute EEG or cEEG within 24h after admission. Clinical, biological, and imaging characteristics, length of hospitalization, and outcome were compared between patients with possible NCSE and patients without epileptic discharges. RESULTS: There were 32 patients in each group. Continuous EEG detected patterns compatible with NCSE in 28% and focal interictal epileptiform discharges (IEDs) in 16% of the patients. Routine EEG detected patterns compatible with NCSE in 6% and focal IEDs in 16% of the patients. History of cognitive impairment and use of antibiotics and hypernatremia were significantly associated with the presence of possible NCSE. Delirium in patients with possible NCSE was initially attributed to another cause in over 80% of the cases. Patterns compatible with NCSE were associated with a longer hospitalization stay and a higher mortality rate. CONCLUSION: Electroencephalographic patterns compatible with NCSE are found in 28% of elderly with delirium when cEEG monitoring is performed. No clinical or paraclinical parameter can reliably distinguish elderly patients with delirium with or without patterns compatible with NCSE in the absence of cEEG monitoring. Elderly patients with delirium and patterns compatible with NCSE have significantly higher mortality rates and longer hospital stays.

An intrinsic mechanism of corticogenesis from embryonic stem cells.

The cerebral cortex develops through the coordinated generation of dozens of neuronal subtypes, but the mechanisms involved remain unclear. Here we show that mouse embryonic stem cells, cultured without any morphogen but in the presence of a sonic hedgehog inhibitor, recapitulate in vitro the major milestones of cortical development, leading to the sequential generation of a diverse repertoire of neurons that display most salient features of genuine cortical pyramidal neurons. When grafted into the cerebral cortex, these neurons develop patterns of axonal projections corresponding to a wide range of cortical layers, but also to highly specific cortical areas, in particular visual and limbic areas, thereby demonstrating that the identity of a cortical area can be specified without any influence from the brain. The discovery of intrinsic corticogenesis sheds new light on the mechanisms of neuronal specification, and opens new avenues for the modelling and treatment of brain diseases.

Intravenous lacosamide in refractory seizure clusters and status epilepticus: comparison of 200 and 400 mg loading doses.

BACKGROUND: The treatment of refractory status epilepticus (RSE) remains largely empirical. Lacosamide (LCM) is a new anticonvulsant available in intravenous (IV) form, but its optimal dosing regimen for the treatment of RSE is unknown. We compared safety and efficacy of two loading doses: 200 and 400 mg. METHODS: Prospective observational study of all patients who received IV LCM for RSE or seizure clusters between October 2010 and December 2012. A first group received an IV load of 200 mg of LCM. After the initial part of the study, and due to poor results with this dosage, a second group received a loading dose of 400 mg. Outcome measures included response rate, time to response, and adverse events. RESULTS: There was a trend in favor of a higher response rate to LCM in the 400 mg group [7/14 (50 %) vs. 2/11 (18 %), respectively; p = 0.2]. Early responses (occurring within 3 h of initiation of LCM) were significantly more frequent in the 400 mg group [4/14 (28 %) vs. 0/11 (0 %); p = 0.026]. Overall, 9/25 patients (36 %) responded to LCM and seizures were terminated in eight more patients (32 %), by adding other anticonvulsants. The following adverse events were attributed to LCM: myoclonus and confusion, increase in seizure frequency, vertigo, ataxia, and an asymptomatic increase in liver enzymes level. All occurred in the 200 mg group. No skin rash, renal, cardiac, or hemodynamic side effects were observed in any group. CONCLUSIONS: In this small prospective observational study, an initial dose of 400 mg of IV LCM was associated with a higher proportion of early termination of RSE and with a trend toward a higher response rate.

Cognitive impairment in essential tremor assessed by the cerebellar cognitive affective syndrome scale.

Background: Essential tremor (ET) is a movement disorder characterized by cerebellar neurodegenerative changes. ET is also associated with non-motor symptoms including cognitive impairment. The neuropsychologic profile of a patient with ET could relate to cerebellar cognitive affective syndrome (CCAS). Objective: This study aimed to assess the prevalence of cognitive impairment in patients with ET and identify whether the cognitive impairment in ET corresponds to a CCAS. Methods: Cognitive functions were evaluated with the CCAS-Scale (CCAS-S) in 20 patients with ET and 20 controls matched for age, sex, and level of education. The results of the CCAS-S were compared between patients and controls. The underlying determinant of CCAS inpatients with ET was identified through the correlation between the results of the CCAS-S and age at onset of symptoms, disease duration, and the Essential Tremor Rating Assessment Scale (TETRAS). Results: On a group level, ET patients performed significantly worse than matched controls. In total, 13 individuals with ET had a definite CCAS (CCAS-S failed items ≥ 3). ASO and TETRAS scores significantly correlated with CCAS-S performances in ET patients. Conclusion: CCAS is highly prevalent in patients with ET which supports the cerebellar pathophysiology of associated cognitive impairment and supports a more systematic use of the CCAS-S to cognitively assessed patients with ET.

Proprioceptive and tactile processing in individuals with Friedreich ataxia: an fMRI study.

Objective: Friedreich ataxia (FA) neuropathology affects dorsal root ganglia, posterior columns in the spinal cord, the spinocerebellar tracts, and cerebellar dentate nuclei. The impact of the somatosensory system on ataxic symptoms remains debated. This study aims to better evaluate the contribution of somatosensory processing to ataxia clinical severity by simultaneously investigating passive movement and tactile pneumatic stimulation in individuals with FA. Methods: Twenty patients with FA and 20 healthy participants were included. All subjects underwent two 6 min block-design functional magnetic resonance imaging (fMRI) paradigms consisting of twelve 30 s alternating blocks (10 brain volumes per block, 120 brain volumes per paradigm) of a tactile oddball paradigm and a passive movement paradigm. Spearman rank correlation tests were used for correlations between BOLD levels and ataxia severity. Results: The passive movement paradigm led to the lower activation of primary (cSI) and secondary somatosensory cortices (cSII) in FA compared with healthy subjects (respectively 1.1 ± 0.78 vs. 0.61 ± 1.02, p = 0.04, and 0.69 ± 0.5 vs. 0.3 ± 0.41, p = 0.005). In the tactile paradigm, there was no significant difference between cSI and cSII activation levels in healthy controls and FA (respectively 0.88 ± 0.73 vs. 1.14 ± 0.99, p = 0.33, and 0.54 ± 0.37 vs. 0.55 ± 0.54, p = 0.93). Correlation analysis showed a significant correlation between cSI activation levels in the tactile paradigm and the clinical severity (R = 0.481, p = 0.032). Interpretation: Our study captured the difference between tactile and proprioceptive impairments in FA using somatosensory fMRI paradigms. The lack of correlation between the proprioceptive paradigm and ataxia clinical parameters supports a low contribution of afferent ataxia to FA clinical severity.

Severely Hypoperfused Brain Tissue Correlates with Final Infarct Volume Despite Recanalization in DMVO Stroke.

Objectives: We sought to assess whether there were any parameter(s) on baseline computed-tomography-perfusion (CTP) strongly correlating with final-infarct-volume, and infarct volume progression after endovascular recanalization of acute ischemic stroke (AIS) with primary distal, medium vessel occlusion (DMVO). Materials and Methods: We performed a retrospective analysis of consecutive AIS patients who were successfully recanalized by thrombectomy for DMVO. By comparing baseline CTP and follow-up MRI, we evaluated the correlation between baseline infarct and hypoperfusion volumes, and final infarct volume and infarct volume progression. We also examined their effect on good clinical outcome at 3 months (defined as an mRS score of 0 to 2). Results: Between January 2018 and January 2021, 38 patients met the inclusion criteria (76% [29/38] female, median age 75 [66-86] years). Median final infarct volume and infarct volume progression were 8.4 mL [IQR: 5.2-44.4] and 7.2 mL [IQR: 4.3-29.1] respectively. TMax > 10 sec volume was strongly correlated with both (r = 0.831 and r = 0.771 respectively, p < 0.0001), as well as with good clinical outcome (-0.5, p = 0.001). A higher baseline TMax > 10 sec volume increased the probability of a higher final-infarct-volume (r2 = 0.690, coefficient = 0.83 [0.64-1.00], p < 0.0001), whereas it decreased the probability of good clinical outcome at 3 months (odds ratio = -0.67 [-1.17 to -0.18], p = 0.008). Conclusion: TMax > 10 sec volume on baseline CTP correlates strongly with final infarct volume as well as with clinical outcome after mechanical thrombectomy for an AIS with DMVO.

Acute confusional state of unknown cause in the elderly: a study with continuous EEG monitoring.

INTRODUCTION: Acute confusional state (ACS) is a frequent cause of emergency consultation in the elderly. Many causes of ACS are also risk factors for seizures. Both non-convulsive seizures and status epilepticus can cause acute confusion. The yield of routine EEG may not be optimal in case of prolonged post-ictal confusion. We thus, sought to evaluate the yield of CEEG in identifying seizures in elderly patients with ACS of unknown origin. METHODS: We reviewed our CEEG database for patients over 75 years with ACS and collected EEG, CEEG and clinical information. RESULTS: Thirty-one percent (15/48) of the CEEG performed in elderly patients were done for ACS. Routine EEG did not reveal any epileptic anomalies in 7/15 patients. Among those, CEEG identified interictal epileptiform discharges (IED) in 2 and NCSE in 1. In 8/15 patients, routine EEG revealed epileptiform abnormalities: 3 with IED (including 1 with periodic lateralized discharges), 3 with non-convulsive seizures (NCSz) and 2 with non-convulsive status epilepticus (NCSE). Among patients with only IED, CEEG revealed NCSz in 1 and NCSE in 2. CONCLUSION: This retrospective study suggests that NCSz and NCSE may account for more cases of ACS than what was previously thought. A single negative routine EEG does not exclude this diagnosis. Continuous EEG (CEEG) monitoring is more revealing than routine EEG for the detection of NCSE and NCSz in confused elderly. The presence of IED in the first routine EEG strongly suggests concomitant NCSz or NCSE. Prospective studies are required to further determine the role of CEEG monitoring in the assessment of ACS in the elderly and to establish the incidence of NCSz and NCSE in this setting.