Molecular Subgrouping Based on Immunohistochemistry in Medulloblastoma: a Single-Center Experience.

AIM: Medulloblastomas (MBs) are the most commonly observed malignant brain tumors affecting children; they can be classified into molecular subgroups based on the 2016 and 2021 WHO classifications, as WNT-activated, SHH-activated and TP53-wild type, SHH-activated and TP53-mutant, and non-WNT/non-SHH. However, the molecular methods to determine these subgroups are not easily accessible for routine testing as they are expensive. Here, we investigated the efficacy of immunohistochemical methods to determine molecular subgroups and prognostic predictions of MB. MATERIAL AND METHODS: ß-catenin, GAB1, YAP1, filamin A and p53 were immunohistochemically stained, and MYC and MYCN fluorescent in situ hybridization (FISH) procedures were applied to 218 cases in our series. RESULTS: Based on the histomorphological characteristics of the cases, 67.9% were deemed classic MB; 15.6% as desmoplastic/nodular medulloblastoma (DNMB); 12.8% as large cell/anaplastic (LC/A) MB; 3.7% as medulloblastoma with extensive nodularity (MBEN). Molecular characteristics revealed that 50.5% had non-WNT/non-SHH; 33.9% had SHH-activated and TP53-wildtype; 8.7% had WNT-activated; 6.9% had SHH-activated and TP53-mutant. According to the survival curves, LC/A MBs or non-WNT/non-SHH tumors showed the worst prognosis, whereas DNMBs and WNT-activated tumors showed the best prognosis. Classic MBs or SHH-activated tumors showed a moderate course. MYCN amplification was found to act as an independent poor prognostic factor in the study. CONCLUSION: The distribution of histological subtypes and molecular subgroups, amplification rates, and prognostic data obtained through immunohistochemical methods in our study were consistent with those reported in the literature. It was therefore hypothesized that the determination of molecular subgroups by immunohistochemical methods can be useful in daily diagnostic practice, especially in centers with limited access to molecular techniques.

Ictal Coprolalia: Three Cases with Nondominat Frontal Lobe Involvement and Review of the Literature.

Objective: Coprolalia is defined as the involuntary use of obscene, socially unacceptable, and derogatory words. Ictal coprolalia is a rare presentation of epilepsy. This study aimed to determine the localizing and lateralizing value and frequency of ictal coprolalia in epilepsy patients. Methods: Medical files, discharge summaries, and electroencephalography (EEG) reports of 2238 patients were reviewed retrospectively. We identified patients who suffered from ictal coprolalia. Electroencephalography reports, neuroimaging [brain magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (FDG-PET), single-photon emission computerized tomography (SPECT)] records, F-18 FDG fused on MRI images, and ictal SPECT fused on MRI images were evaluated. Also, original and review articles were identified through a systematic search of Pubmed, Scopus, and Clarivate Analytics. Results: Ictal coprolalia was detected in 3 male (0.15%) patients. In all patients, ictal semiology was extratemporal-frontal type, and potential/proven epileptic focus was non-dominant hemisphere frontal lobe. Topectomy was done in one of the patients, including the suspected dysplastic area plus the area where the electroencephalographic ictal and interictal changes occur, on the left frontal lobe, and the patient had an Engel's classification class IIA. The data depending on the published cases showed that ictal coprolalia was dominant in the male gender and the responsible epileptic area tended to be located in the non-dominant hemisphere frontotemporal region. Conclusion: The rate of ictal coprolalia in the Turkish population is lower compared to other series. Our results are consistent with previous studies in which reported that male preponderance for ictal coprolalia and involvement of non-dominant frontal lobe.

Predictors of Clinically Important Neuroimaging Findings in Children Presenting Pediatric Emergency Department.

OBJECTIVE: The aim of the study is to evaluate predictors of clinically important neuroimaging results, that is, computed tomography and magnetic resonance imaging in children in an academic pediatric emergency department (PED) from 2015 to 2019. METHODS: This study was conducted in an academic PED. The patient's demographic and clinical characteristics of PED visits and neuroimaging findings requested at the PED were recorded for January 1, 2015, to December 31, 2019. In addition, descriptive statistics and logistic regression analyses were conducted. We described and determined the predictors of clinically important neuroimaging findings in children. RESULTS: Clinically important neuroimaging findings were detected in patients with blurred vision ( P = 0.001), ataxia ( P = 0.003), unilateral weakness ( P = 0.004), and altered level of consciousness ( P = 0.026). Clinically important neuroimaging was found 9.4 times higher in patients with altered level of consciousness, 7.4 times higher in patients with focal weakness, 4.6 times higher in patients with blurred vision, and 3.5 times more in patients presenting with ataxia. CONCLUSIONS: Advanced neuroimaging, especially for selected patients in PED, can improve the quality of health care for patients. On the other hand, irrelevant neuroimaging findings can lead physicians away from prompt diagnosis and accurate management. According to our study, advanced neuroimaging can be performed in the early period for both diagnosis and early treatment, especially in selected patients with ataxia, blurred vision, altered consciousness, and unilateral weakness. In other cases, clinicians may find more supporting evidence.

One model to unite them all: Personalized federated learning of multi-contrast MRI synthesis.

Curation of large, diverse MRI datasets via multi-institutional collaborations can help improve learning of generalizable synthesis models that reliably translate source- onto target-contrast images. To facilitate collaborations, federated learning (FL) adopts decentralized model training while mitigating privacy concerns by avoiding sharing of imaging data. However, conventional FL methods can be impaired by the inherent heterogeneity in the data distribution, with domain shifts evident within and across imaging sites. Here we introduce the first personalized FL method for MRI Synthesis (pFLSynth) that improves reliability against data heterogeneity via model specialization to individual sites and synthesis tasks (i.e., source-target contrasts). To do this, pFLSynth leverages an adversarial model equipped with novel personalization blocks that control the statistics of generated feature maps across the spatial/channel dimensions, given latent variables specific to sites and tasks. To further promote communication efficiency and site specialization, partial network aggregation is employed over later generator stages while earlier generator stages and the discriminator are trained locally. As such, pFLSynth enables multi-task training of multi-site synthesis models with high generalization performance across sites and tasks. Comprehensive experiments demonstrate the superior performance and reliability of pFLSynth in MRI synthesis against prior federated methods.

Neural correlates of distorted body images in adolescent girls with anorexia nervosa: How is it different from major depressive disorder?

Body image disturbance is closely linked to eating disorders including anorexia nervosa (AN). Distorted body image perception, dissatisfaction and preoccupation with weight and shape are often key factors in the development and maintenance of these disorders. Although the pathophysiological mechanism of body image disorder is not yet fully understood, aberrant biological processes may interfere with perceptive, cognitive and emotional aspects of body image. This study focuses on the neurobiological aspects of body image disturbance. The sample consisted of 12 adolescent girls diagnosed with AN, nine girls with major depressive disorder (MDD) and 10 without psychiatric diagnoses (HC, the healthy control group). We applied a block-design task in functional magnetic resonance imaging using participants' original and distorted overweight and underweight images. After imaging, the participants scored the images for resemblance, satisfaction and anxiety levels. The findings of this study demonstrate that overweight images elicited dissatisfaction and increased occipitotemporal activations across all participants. However, no difference was found between the groups. Furthermore, the MDD and HC groups showed increased activations in the prefrontal cortex and insula in response to underweight images compared to their original counterparts, whereas the AN group exhibited increased activations in the parietal cortex, cingulate gyrus and parahippocampal cortex in response to the same stimuli.

The effect of SARS-CoV-2 virus on resting-state functional connectivity during adolescence: Investigating brain correlates of psychotic-like experiences and SARS-CoV-2 related inflammation response.

We first aimed to investigate resting-state functional connectivity (rs-FC) differences between adolescents exposed to SARS-CoV-2 and healthy controls. Secondly, the moderator effect of PLEs on group differences in rs-FC was examined. Thirdly, brain correlates of inflammation response during acute SARS-CoV-2 infection were investigated. Eighty-two participants aged between 14 and 24 years (SARS-CoV-2 (n = 35), controls (n = 47)) were examined using rs-fMRI. Seed-based rs-FC analysis was performed. The positive subscale of Community Assessment of Psychotic Experiences-42 (CAPE-Pos) was used to measure PLEs. The SARS-CoV-2 group had a lesser rs-FC within sensorimotor network (SMN), central executive network (CEN) and language network (LN), but an increased rs-FC within visual network (VN) compared to controls. No significant differences were detected between the groups regarding CAPE-Pos-score. However, including CAPE-Pos as a covariate, we found increased rs-FC within CEN and SN in SARS-CoV-2 compared to controls. Among the SARS-CoV-2 group, neutrophil/lymphocyte and thrombocyte*neutrophil/lymphocyte ratio was correlated with decreased/increased FC within DMN and SN, and increased FC within CEN. Our results showed rs-FC alterations within the SMN, CEN, LN, and VN among adolescents exposed to SARS-CoV-2. Moreover, changes in rs-FC associated with PLEs existed in these adolescents despite the absence of clinical changes. Furthermore, inflammation response was correlated with alterations in FC within the triple network system.

Parallel-stream fusion of scan-specific and scan-general priors for learning deep MRI reconstruction in low-data regimes.

Magnetic resonance imaging (MRI) is an essential diagnostic tool that suffers from prolonged scan times. Reconstruction methods can alleviate this limitation by recovering clinically usable images from accelerated acquisitions. In particular, learning-based methods promise performance leaps by employing deep neural networks as data-driven priors. A powerful approach uses scan-specific (SS) priors that leverage information regarding the underlying physical signal model for reconstruction. SS priors are learned on each individual test scan without the need for a training dataset, albeit they suffer from computationally burdening inference with nonlinear networks. An alternative approach uses scan-general (SG) priors that instead leverage information regarding the latent features of MRI images for reconstruction. SG priors are frozen at test time for efficiency, albeit they require learning from a large training dataset. Here, we introduce a novel parallel-stream fusion model (PSFNet) that synergistically fuses SS and SG priors for performant MRI reconstruction in low-data regimes, while maintaining competitive inference times to SG methods. PSFNet implements its SG prior based on a nonlinear network, yet it forms its SS prior based on a linear network to maintain efficiency. A pervasive framework for combining multiple priors in MRI reconstruction is algorithmic unrolling that uses serially alternated projections, causing error propagation under low-data regimes. To alleviate error propagation, PSFNet combines its SS and SG priors via a novel parallel-stream architecture with learnable fusion parameters. Demonstrations are performed on multi-coil brain MRI for varying amounts of training data. PSFNet outperforms SG methods in low-data regimes, and surpasses SS methods with few tens of training samples. On average across tasks, PSFNet achieves 3.1 dB higher PSNR, 2.8% higher SSIM, and 0.3 × lower RMSE than baselines. Furthermore, in both supervised and unsupervised setups, PSFNet requires an order of magnitude lower samples compared to SG methods, and enables an order of magnitude faster inference compared to SS methods. Thus, the proposed model improves deep MRI reconstruction with elevated learning and computational efficiency.

ORAI1 defect in a patient with disseminated CMV infection and severe hypotonia.

BACKGROUND: A clinical presentation similar to severe combined immunodeficiency (SCID) with defective T cell activation but normal lymphocyte development occurs due to certain molecule defects including ORAI1- and STIM1. CASE: A four-month-old girl sufferd from fever, restlessness, diarrhea, and poor weight gain following the neonatal period. There was consanguinity and a positive family history. She had hypotonia and spontaneous opisthotonic posture. Refractory and extensive CMV infections were detected; immunological investigations revealed normal quantitative immunoglobulins and low numbers of CD3+, CD4+, and CD8+ cells. The next generation sequencing analysis revealed a mutation in the ORAI1 gene. CONCLUSIONS: The present patient`s history of refractory and widespread CMV infections shows a clinically substantial reduction in resistance against opportunistic microorganisms. This case emphasizes the importance of considering STIM1 and ORAI1 defects in patients with SCID phenotype and neurologic involvement, such as hypotonia.

Extracellular-Vesicle-Based Cancer Panels Diagnose Glioblastomas with High Sensitivity and Specificity.

Glioblastoma is one of the most devastating neoplasms of the central nervous system. This study focused on the development of serum extracellular vesicle (EV)-based glioblastoma tumor marker panels that can be used in a clinic to diagnose glioblastomas and to monitor tumor burden, progression, and regression in response to treatment. RNA sequencing studies were performed using RNA isolated from serum EVs from both patients (n = 85) and control donors (n = 31). RNA sequencing results for preoperative glioblastoma EVs compared to control EVs revealed 569 differentially expressed genes (DEGs, 2XFC, FDR < 0.05). By using these DEGs, we developed serum-EV-based biomarker panels for the following glioblastomas: wild-type IDH1 (96% sensitivity/80% specificity), MGMT promoter methylation (91% sensitivity/73% specificity), p53 gene mutation (100% sensitivity/89% specificity), and TERT promoter mutation (89% sensitivity/100% specificity). This is the first study showing that serum-EV-based biomarker panels can be used to diagnose glioblastomas with a high sensitivity and specificity.

Rhombencephalitis and longitudinal extensive myelitis associated with dinutuximab use in high-risk neuroblastoma.

BACKGROUND: Dinutuximab is a monoclonal antibody that targets the GD2 antigen used in the treatment of high-risk neuroblastoma. Dinutuximab-associated rhombencephalitis and myelitis is a rare, steroid-responsive, serious, but reversible pathology. To date, three transverse myelitis cases and one rhombencephalitis case due to dinutuximab have already been reported. Moreover, a recently published article identified five inflammatory CNS demyelination cases (four myelitis and one rhombencephalitis). We present a 5-year-old patient with rhombencephalitis and myelitis following dinutuximab-beta treatment. CASE: A 5-year-old patient with a left-sided retroperitoneal mass infiltrating the left kidney and multiple lytic bone lesions was diagnosed with neuroblastoma with a percutaneous biopsy from the abdominal mass. Surgery was performed after a prominent treatment response was detected on the abdominal CT. Radiotherapy was applied to the abdomen. While she was still undergoing maintenance treatment with 13-cis retinoic acid, a metaiodobenzylguanidine (MIBG) scan detected new bone lesions, and brain MRG identified pachymeningeal involvement. A new chemotherapy regimen was started and decreased MIBG uptake was seen in all previous bone lesions. However, newly developed eighth rib metastasis was seen in the following MIBG scan. Autologous stem cell transplantation was done. Soon after, dinutuximab-beta, together with temozolomide and irinotecan, was initiated. Following the third cycle hypotension, somnolence, paraparesis, and unilateral fixed dilated pupil were developed. Afterward, hemiballismus-like irregular limb movements were observed. Work-up studies were unremarkable, except for hypodensity in the brain stem on the brain CT. MRI revealed T2 hyperintensity of the brainstem and spinal cord extending from the cervicomedullary junction to the T7 level. Moreover, incomplete contrast enhancement and facilitated diffusion were observed. Imaging findings suggested demyelination. Steroids and intravenous immune globulin (IVIG) treatment were initiated. Both imaging abnormalities and clinical symptoms resolved partially at one month and disappeared at six months. CONCLUSIONS: Awareness of the radiological findings of dinutuximab toxicity will lead to prompt diagnosis and treatment.

IgG4-related pachymeningitis-Long term follow up and outcome of six patients.

OBJECTIVE: Our understanding of IgG4-RD and pachymeningitis has grown substantially, but the optimal approach for diagnosis, management, and long-term outcomes is still an area of uncertainty. METHODS: HUVAC is a database for IgG4-RD patients, this database was retrospectively evaluated for pachymeningeal disease. Demographic, clinical, serological, imaging, histopathological data, and treatment details were re-interpreted in patients with pachymeningitis. RESULTS: Among 97 patients with IgG4-RD, 6 (6.2%) had pachymeningitis. None of these patients had extracranial features, and also, in most of the patients, serum IgG4 levels were normal. Tentorium cerebelli and transverse sinus dura were the most commonly involved in the posterior fossa. During 18 months of median follow-up on steroid+-rituximab, none of them relapsed as pachymeningitis. CONCLUSION: Our patients were mainly older males with sole neurological involvement. Non-specific headache was the most common manifestation, and serum IgG4 levels were not useful for diagnosis. Typical radiology and tentorial thickening should suggest IgG4-RD and prompt an early biopsy. Moreover, accompanying hypophysitis could also be a clue. With steroids+ rituximab treatment, no relapse related to meningeal involvement was seen in long-term follow-up.

Flocculus Herniation into the Internal Acoustic Canal in Incomplete Partition Type I: A Case Report.

In this study, we present the first case with cerebellar herniation into the internal acoustic canal in incomplete partition type I anomaly. Cerebellar herniation into the internal acoustic canal is very rare with only a few cases reported in the literature. Although it is a rare clinical situation, cerebellar herniation into the internal acoustic canal may be seen in patients with incomplete partition type I. We presented magnetic resonance imaging findings of a 3-year-old girl with a history of meningitis, middle ear effusion, and bilateral congenital sensorineural hearing loss. Magnetic resonance imaging showed bilateral incomplete partition type I malformation and an additional flocculus herniation into the right internal acoustic canal. In the presented case, predisposition to cerebrospinal fluid leak in incomplete partition type I anomaly may be the reason for cerebellar herniation into internal acoustic canal. Also, possible increased intracranial pressure due to meningitis may be a contributing factor.

Imaging Cancer in Neuroradiology.

Neuroimaging plays a pivotal role in the diagnosis, management, and prognostication of brain tumors. Recently, the World Health Organization published the fifth edition of the WHO Classification of Tumors of the Central Nervous System (CNS5), which places greater emphasis on tumor genetics and molecular markers to complement the existing histological and immunohistochemical approaches. Recent advances in computational power allowed modern neuro-oncological imaging to move from a strictly morphology-based discipline to advanced neuroimaging techniques with quantifiable tissue characteristics such as tumor cellularity, microstructural organization, hemodynamic, functional, and metabolic features, providing more precise tumor diagnosis and management. The aim of this review is to highlight the key imaging features of the recently published CNS5, outlining the current imaging standards and summarizing the latest advances in neuro-oncological imaging techniques and their role in complementing traditional brain tumor imaging and management.

Targeted resequencing reveals high-level mosaicism for a novel frameshift variant in WDR45 associated with beta-propeller protein-associated neurodegeneration.

OBJECTIVES: Beta-propeller protein-associated neurodegeneration (BPAN) is a rare X-linked dominant neurodegenerative disease, which is characterized by iron accumulation in the basal ganglia. BPAN is associated with pathogenic variation in WDR45, which has been reported almost exclusively in females most probably due to male lethality in the hemizygous state. METHODS: Whole exome sequencing (WES) and targeted deep sequencing were performed for a male with a clinical diagnosis of BPAN at the age of 37. RESULTS: The novel frameshift variant in WDR45 detected by WES was further analyzed with targeted resequencing to detect a mosaic variant with a level of 85.5% in the blood sample of the proband. DISCUSSION: Although the main role of WDR45 remains elusive, recent studies show that WDR45 may contribute to neurodegeneration through defects in autophagy, iron storage and ferritin metabolism, mitochondria organization, and endoplasmic reticulum homeostasis. The extend of spatiotemporal haploinsufficiency of WDR45 frameshifting variants caused by mosaicism in males may lead to variable clinical severity, which may be hard to elaborate clinically. Promising genetic analysis strategies using targeted deep sequencing may help determine the clinical outcome of somatic mosaicism in neurological disorders including BPAN. Additionally, we suggest that deep sequencing should be conducted in cerebrospinal fluid samples to provide more reliable results in terms of reflecting the mosaicism level in the brain for future studies.

Clinically important intracranial abnormalities in children presenting with first focal seizure.

BACKGROUND: Management of pediatric patients presenting with first seizure is challenging, especially with regards to emergent neuroimaging. The rate of abnormal neuroimaging findings is known to be higher in focal seizures than in generalized seizures, but those intracranial abnormalities are not always clinically emergent. In this study, we aimed to determine the rate and indicators for clinically important intracranial abnormalities that change acute management in children presenting with a first focal seizure to the pediatric emergency department (PED). METHODS: This study was conducted retrospectively in the PED at a University Children`s Hospital setting. The study population consisted of patients aged between 30 days and 18 years with first focal seizure and who had emergent neuroimaging at the PED between the years 2001 and 2012. RESULTS: There were 65 eligible patients meeting the study criteria. Clinically important intracranial abnormalities requiring emergent neurosurgical or medical intervention were detected in 18 patients (27.7%) at the PED. Four patients (6.1%) underwent emergent surgical procedures. Seizure recurrence and the need for acute seizure treatment in the PED were significantly associated with clinically important intracranial abnormalities. CONCLUSIONS: Neuroimaging study yielding of 27.7% shows that first focal seizure must be evaluated meticulously. From the emergency department`s point of view; we suggest that first focal seizures in children should be evaluated with emergent neuroimaging, if possible with magnetic resonance imaging. Especially patients with recurrent seizures at presentation requires more careful evaluation.

Comparative analysis of freezing of gait in distinct Parkinsonism types by diffusion tensor imaging method and cognitive profiles.

Freezing of gait (FOG) is an episodic gait pattern that is common in advanced Parkinson's disease (PD) and other atypical parkinsonism syndromes. Recently, disturbances in the pedunculopontine nucleus (PPN) and its connections have been suggested to play a critical role in the development of FOG. In this study, we aimed to demonstrate possible disturbances in PPN and its connections by performing the diffusion tensor imaging (DTI) technique. We included 18 patients of PD with FOG [PD-FOG], 13 patients of PD without FOG [PD-nFOG] and 12 healthy subjects as well as a group of patients with progressive supranuclear palsy (PSP), an atypical parkinsonism syndrome which is very often complicated with FOG [6 PSP-FOG, 5 PSP-nFOG]. To determine the specific cognitive parameters that can be related to FOG, deliberate neurophysiological evaluations of all the individuals were performed. The comparative analyses and correlation analyses were performed to reveal the neurophysiological and DTI correlates of FOG in either group. We have found disturbances in values reflecting microstructural integrity of the bilateral superior frontal gyrus (SFG), bilateral fastigial nucleus (FN), left pre-supplementary motor area (SMA) in the PD-FOG group relative to the PD-nFOG group. The analysis of the PSP group also demonstrated disturbance in left pre-SMA values in the PSP-FOG group likewise, while negative correlations were determined between right STN, left PPN values and FOG scores. In neurophysiological assessments, lower performances for visuospatial functions were demonstrated in FOG ( +) individuals for either patient group. The disturbances in the visuospatial abilities may be a critical step for the occurrence of FOG. Together with the results of DTI analyses, it might be suggested that impairment in the connectivity of disturbed frontal areas with disordered basal ganglia, maybe the key factor for the occurrence of FOG in the PD group, whereas left PPN which is a nondopaminergic nucleus may play a more prominent role in the process of FOG in PSP. Moreover, our results support the relationship between right STN, and FOG as mentioned before, as well as introduce the importance of FN as a new structure that may be involved in FOG pathogenesis.

SMART syndrome: a case report.

INTRODUCTION: Stroke-like migraine attacks after radiation therapy (SMART) syndrome, is a late complication of brain radiotherapy (1). Symptoms are commonly subacute in onset and involve migraine type of headache, seizures, focal neurologic deficits (2). Magnetic resonance imaging (MRI) findings are usually unilateral and posterior predominant cortical-subcortical hyperintensity, swelling and prominent gyriform (cortical and leptomeningeal) gadolinium enhancement in the areas of the brain that underwent irradiation with or without diffusion restriction (1). There is no standard treatment protocol for SMART syndrome. Antiepileptics and corticosteroids are commonly used drugs. CASE REPORT: A 65 years old woman was diagnosed with breast cancer with brain metastases and treated with more than 50 Gy brain radiotherapy. The patient presented with acute right-sided weakness and numbness, episodic myoclonic jerking of the right arm and leg, and gait instability five months later. MRI and magnetic resonance angiography of the brain with gadolinium revealed left parietooccipital cortical diffusion restriction and accompanying dilatation of the left posterior cerebral artery as new findings. Computed tomography (CT) perfusion revealed increased perfusion in the affected area. The patient was diagnosed with SMART syndrome. MANAGEMENT AND OUTCOME: The patient was treated with dexamethasone (16 mg/day) and anticonvulsant therapy. Myoclonic seizures had almost completely remitted. However, her cognitive impairment persisted, then the patient was arrested because of aspiration a month later. DISCUSSION: Besides confirming SMART syndrome, diagnostic investigations are also important to exclude other etiologies. Posterior reversible encephalopathy syndrome, post-ictal changes, meningoencephalitis, and cerebrovascular diseases are radiological differential diagnoses considered (3). Proper and early diagnosis of SMART syndrome is significant in preventing unnecessary aggressive approaches and appropriate treatment to avoid lesions of sequela.

The Effects of Respiratory Muscle Training on Resting-State Brain Activity and Thoracic Mobility in Healthy Subjects: A Randomized Controlled Trial.

BACKGROUND: Although inspiratory muscle training (IMT) is an effective intervention for improving breath perception, brain mechanisms have not been studied yet. PURPOSE: To examine the effects of IMT on insula and default mode network (DMN) using resting-state functional MRI (RS-fMRI). STUDY TYPE: Prospective. POPULATION: A total of 26 healthy participants were randomly assigned to two groups as IMT group (n = 14) and sham IMT groups (n = 12). FIELD STRENGTH/SEQUENCE: A 3-T, three-dimensional T2* gradient-echo echo planar imaging sequence for RS-fMRI was obtained. ASSESSMENT: The intervention group received IMT at 60% and sham group received at 15% of maximal inspiratory pressure (MIP) for 8 weeks. Pulmonary and respiratory muscle function, and breathing patterns were measured. Groups underwent RS-fMRI before and after the treatment. STATISTICAL TESTS: Statistical tests were two-tailed P < 0.05 was considered statistically significant. Student's t test was used to compare the groups. One-sample t-test for each group was used to reveal pattern of functional connectivity. A statistical threshold of P < 0.001 uncorrected value was set at voxel level. We used False discovery rate (FDR)-corrected P < 0.05 cluster level. RESULTS: The IMT group showed more prominent alterations in insula and DMN connectivity than sham group. The MIP was significantly different after IMT. Respiratory rate (P = 0.344), inspiratory time (P = 0.222), expiratory time (P = 1.000), and inspiratory time/total breath time (P = 0.572) of respiratory patterns showed no significant change after IMT. All DMN components showed decreased, while insula showed increased activation significantly. DATA CONCLUSION: Differences in brain activity and connectivity may reflect improved ventilatory perception with IMT with a possible role in regulating breathing pattern by processing interoceptive signals. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 4.

Assessment of glymphatic function in narcolepsy using DTI-ALPS index.

INTRODUCTION: Sleep is a modulator of glymphatic activity which is altered in various sleep disorders. Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness (EDS), rapid onset of rapid eye movement (REM) sleep, cataplexy, disturbed night sleep with fragmentation. It is categorized into two types, type 1 (NT1) and type 2 (NT2) depending on the presence of cataplexy and/or absence of orexin. We sought for alterations in glymphatic activity in narcoleptic patients using diffusion tensor imaging (DTI) along perivascular space (ALPS) index on magnetic resonance imaging (MRI). MATERIAL AND METHODS: Adult patients diagnosed with NT1 or NT2 who had polysomnography (PSG) and MRI with DTI were included in the study. Sleep recording included Epworth Sleepiness Scale (ESS) score, sleep latency during multiple sleep latency test (MSLT), sleep efficiency during night PSG, wake after sleep onset (WASO), REM sleep latency during PSG, percentage of non-REM (NREM), REM sleep and wakefulness during night PSG. DTI-ALPS index was calculated for each patient and age-sex matched healthy control(HC)s. RESULTS: The study group was composed of 25 patients [F/M = 15/10, median age = 34 (29.5-44.5)], 14 with NT1 and 11 with NT2 disease. ESS, WASO and percentage of wakefulness were significantly higher in NT1 patients (p < 0.05). Mean DTI-ALPS was not significantly different neither between narcoleptic patients and HCs, nor between NT1 and NT2 patients (all, p > 0.05). However, DTI-ALPS was negatively correlated with WASO (r = -0.745, p = 0.013) and percentage of wakefulness (r = -0.837, p = 0.005) in NT1 patients. DTI-ALPS correlated negatively with percentage of N1 sleep (r = -0.781, p = 0.005) but positively with REM percentage (r = 0.618, p = 0.043) in NT2 patients. CONCLUSION: In this study, DTI-ALPS was not significantly different in narcoleptic patients than the HCs. However, the glymphatic index as assessed by DTI-ALPS correlated with PSG parameters; negatively with WASO, percentage of wakefulness in NT1, percentage of N1 sleep in NT2, and positively with REM sleep in NT2. A tendency for a reduction in DTI-ALPS in NT1 patients compared to both NT2 patients and HCs was also found. These findings might show the first evidence of an alteration of glymphatic activity, especially in NT1 patients, thus warrant further prospective studies in larger size of narcoleptic patient cohorts.