Efficacy and Safety of Timely Urgent Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Surgery in Patients with Acute Ischemic Stroke: A Single-Institutional Prospective Study and a Pooled Analysis.

BACKGROUND: Clinical outcome in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is not satisfactory if reperfusion treatment fails or is not tried. AIMS: We aimed to assess the efficacy and safety of urgent superficial temporal-to-middle cerebral artery (STA-MCA) bypass surgery in selected patients. METHODS: Patients who were diagnosed with LVO-induced AIS in the anterior circulation but had a failed intra-arterial thrombectomy (IAT) or were not tried due to IAT contraindications were prospectively enrolled. Timely urgent STA-MCA bypass surgery was performed if they showed perfusion-diffusion mismatch or symptom-diffusion mismatch in the acute phase of disease. Clinical and radiological data of these patients were assessed to demonstrate the safety and efficacy of urgent bypass procedures. A pooled analysis of published data on urgent bypass surgery in acute stroke patients was conducted and analyzed. RESULTS: In 18 patients who underwent timely bypass, the National Institutes of Health Stroke Scale (NIHSS) score improved from 12.11 ± 4.84 to 9.89 ± 6.52, 1 week after surgery. Three-month and long-term (9.72 ± 5.00 months) favorable outcomes (modified Rankin Scale [mRS] scores 0-2) were achieved in 50 and 75% of the patients, respectively. The pooled analysis (117 patients from 10 articles, including ours) identified favorable mRS scores in 71.79% patients at 3 months. A significant NIHSS score improvement from 11.51 ± 4.89 to 7.59 ± 5.50 was observed after surgery with significance. Major complications occurred in 3 patients (2.6%, 3/117) without mortality. CONCLUSIONS: Urgent STA-MCA bypass surgery can be regarded as a safe optional treatment to prevent cerebral infarct expansion and to improve clinical and radiological outcomes in highly selected patients.

Altered trigeminothalamic spontaneous low-frequency oscillations in migraine without aura: a resting-state fMRI study.

BACKGROUND: Recent resting-state fMRI studies demonstrated functional dysconnectivity within the central pain matrix in migraineurs. This study aimed to investigate the spatial distribution and amplitude of low-frequency oscillations (LFOs) using fractional amplitude of low-frequency fluctuation (fALFF) analysis in migraine patients without aura, and to examine relationships between regional LFOs and clinical variables. METHODS: Resting-state fMRI data were obtained and preprocessed in 44 migraine patients without aura and 31 matched controls. fALFF was computed according to the original method, z-transformed for standardization, and compared between migraineurs and controls. Correlation analysis between regional fALFF and clinical variables was performed in migraineurs as well. RESULTS: Compared with controls, migraineurs had significant fALFF increases in bilateral ventral posteromedial (VPM) thalamus and brainstem encompassing rostral ventromedial medulla (RVM) and trigeminocervical complex (TCC). Regional fALFF values of bilateral VPM thalamus and brainstem positively correlated with disease duration, but not with migraine attack frequency or Migraine Disability Assessment Scale score. CONCLUSIONS: We have provided evidence for abnormal LFOs in the brainstem including RVM/TCC and thalamic VPM nucleus in migraine without aura, implicating trigeminothalamic network oscillations in migraine pathophysiology. Our results suggest that enhanced LFO activity may underpin the interictal trigeminothalamic dysrhythmia that could contribute to the impairments of pain transmission and modulation in migraine. Given our finding of increasing fALFF in relation to increasing disease duration, the observed trigeminothalamic dysrhythmia may indicate either an inherent pathology leading to migraine headaches or a consequence of repeated attacks on the brain.

Alteration of cerebello-thalamocortical spontaneous low-frequency oscillations in juvenile myoclonic epilepsy.

OBJECTIVE: Altered thalamocortical network has been proposed to play a pivotal role in the principal pathophysiology underlying juvenile myoclonic epilepsy (JME). Recently, resting-state fMRI studies have provided converging evidence for thalamocortical dysconnectivity in patients with JME. Herein, we investigated the amplitude and spatial distribution of spontaneous low-frequency oscillations using analysis of fractional amplitude of low-frequency fluctuation (fALFF) in a large group of JME patients in comparison with controls. METHODS: Volumetric MRI and resting-state fMRI were acquired in 75 patients with JME and 62 matched controls. After preprocessing of MRI data, fALFF was computed and then Z-transformed for standardization. fALFF was compared between controls and patients, and correlation analysis between regional fALFF and clinical parameters were performed in patients. RESULTS: Compared with controls, JME patients revealed significant fALFF increases in the bilateral medial thalamus, insular cortex/inferior frontal gyrus, and cerebellum vermis (false discovery rate-corrected P < 0.05). There was no region of fALFF reduction in JME patients relative to controls. No significant correlation was observed between regional fALFF and disease duration or cumulative number of generalized tonic-clonic seizures. CONCLUSIONS: We have shown alterations of low-frequency oscillations in the thalamus, insular cortex/inferior frontal gyrus, and cerebellum in patients with JME, implicating cerebello-thalamocortical network abnormality in the pathophysiology underlying JME. Our results could further support the recent concept that JME is a network epilepsy involving specific cortical and subcortical structures, especially the cerebello-thalamocortical network.

Characterizing Intraorbital Optic Nerve Changes on Diffusion Tensor Imaging in Thyroid Eye Disease Before Dysthyroid Optic Neuropathy.

OBJECTIVE: The aim of this study was to determine whether the optic nerve is affected by thyroid eye disease (TED) before the development of dysthyroid optic neuropathy with diffusion-tensor imaging (DTI). METHODS: Twenty TED patients and 20 controls were included. The mean, axial, and radial diffusivities and fractional anisotropy (FA) value were measured at the optic nerves in DTI. Extraocular muscle diameters were measured on computed tomography. The diffusivities and FA of the optic nerves were compared between TED and controls and between active and inactive stages of TED. The correlations between these DTI parameters and the clinical features were determined. RESULTS: The mean, axial, and radial diffusivities were lower in TED compared with the controls (P < 0.05). In contrast, FA was higher in TED (P = 0.001). Radial diffusivity was lower in the active stage of TED than the inactive stage (P = 0.035). The FA was higher in the TED group than in the control group (P = 0.021) and was positively correlated with clinical activity score (r = 0.364, P = 0.021), modified NOSPECS score (r = 0.469, P = 0.002), and extraocular muscle thickness (r = 0.325, P = 0.041) in the TED group. Radial diffusivity was negatively correlated with modified NOSPECS score (r = -0.384, P = 0.014), and axial diffusivity was positively correlated with exophthalmos degree (r = 0.363, P = 0.025). CONCLUSIONS: The diffusivities and FA reflected changes in the optic nerve before dysthyroid optic neuropathy in TED. The FA, in particular, reflected TED activity and severity.

Clinical Significance of Wall Changes After Recanalization Therapy in Acute Stroke: High-Resolution Vessel Wall Imaging.

BACKGROUND AND PURPOSE: Owing to the excellent recanalization rate of endovascular treatment, new outcome predictors are required for patients with acute stroke, who have sufficient recanalization. In this study, the effects of recanalization therapy on occluded arteries in patients with acute stroke were investigated using high-resolution vessel wall imaging. METHODS: Twenty-nine patients with stroke were included in the study. High-resolution vessel wall imaging was performed on patients with acute stroke and adequate postrecanalization results. We characterized the postrecanalization arterial wall changes as concentric enhancements and plaques and examined the associations of the postrecanalization changes with procedural factors and neurological outcomes. RESULTS: The most frequent high-resolution vessel wall imaging finding was concentric enhancement, which was associated with thrombectomy procedural factors such as the number of procedures and the type of device. Concentric enhancements were associated with hemorrhagic transformation, whereas plaque was not associated with procedural details. CONCLUSIONS: The use of high-resolution vessel wall imaging after successful recanalization can provide information about postrecanalization arterial wall changes and clinical outcomes.

Fractional anisotropy and diffusivity changes in thyroid-associated orbitopathy.

INTRODUCTION: To investigate the extraocular muscle (EOM) changes in thyroid-associated orbitopathy (TAO) on DTI and the correlations between DTI parameters and clinical features. METHODS: Twenty TAO patients and 20 age- and sex-matched controls provided informed consent and were enrolled. Ten-directional DTI was acquired in orbit. Fractional anisotropy (FA), mean, axial, and radial diffusivities were obtained at medial and lateral EOMs in both orbits. EOM thickness was measured in patients using axial CT images. FA and diffusivities were compared between patients and controls. The relationships between DTI values and muscle thickness and exophthalmos were evaluated. DTI values compared between patients in active and inactive phases by clinical activity score of TAO. DTI values were also compared between acute and chronic stages by the duration of disease. RESULTS: In medial EOM, FA was significantly lower in patients (p < 0.001) and negatively correlated with muscle thickness (r = -0.604, p < 0.001). Radial diffusivity was significantly higher in patients (p = 0.010) and correlated with muscle thickness (r = 0.349, p = 0.027). In lateral EOM, DTI values did not differ between patients and controls. In the acute stage, the diffusivities of the medial rectus EOM were increased compared with the chronic stage. DTI values of the medial and lateral rectus EOM did not differ significantly between active and inactive phases. CONCLUSION: DTI can be used to diagnose TAO with FA and radial diffusivity change in EOM. Diffusivities can be used to differentiate acute and chronic stage of TAO. However, DTI values showed limitation in reflecting TAO activity according to the CAS.

Intracranial Stenting as a Rescue Therapy in Patients with Stroke-in-Evolution.

BACKGROUND: The feasibility and efficacy of intracranial stenting were evaluated for patients with a stroke-in-evolution after the time window for thrombolysis. METHODS: Patients with symptomatic intracranial steno-occlusive disease with progressive or fluctuating symptoms were treated using intracranial stenting after the time window for hyperacute thrombolysis. RESULTS: Within the study period, we identified 10 patients (7 men, 62.5 ± 11.3 years old) who were eligible for inclusion. The median onset-to-arrival time was 5.8 hours (range: .6-144 hours), and the median onset-to-procedure time was 33 hours (range: 8-346 hours). Only 1 patient previously received intravenous thrombolysis using alteplase. The symptomatic occlusive artery was the right middle cerebral artery, left middle cerebral artery, and basilar artery in 3, 1, and 6 patients, respectively. The median initial National Institutes of Health Stroke Scale (NIHSS) score was 4 (range: 0-6), and the median NIHSS score measured immediately before the procedure was 8 (range: 4-26). All but 1 patient underwent successful angioplasty and stenting using a Wingspan stent. Reocclusion of the stented artery occurred in 1 patient, and his neurological status deteriorated to coma. A favorable outcome (modified Rankin Scale ≤2) at 3 months was noted in 7 patients (70%). CONCLUSION: Intracranial stenting could be considered an alternative strategy for treating patients with medically intractable stroke-in-evolution.

Acyanotic tetralogy of Fallot in a Persian cat.

An 8-year-old, intact male Persian cat was presented with a prominent heart murmur, exercise intolerance, anorexia, and periodontitis. There was no cyanosis and no laboratory evidence for systemic hypoxemia. Echocardiography showed a dextropositioned aorta, moderate pulmonic stenosis (maximal velocity 4.06 m/s), ventricular septal defect, and right ventricular hypertrophy. The shunt direction was predominantly left-to-right in systole and minimally right-to-left in diastole. The cat was diagnosed with acyanotic (pink) tetralogy of Fallot and was managed medically with atenolol.

Tétralogie de Fallot acyanotique chez un chat Persan. Un chat Persan mâle intact âgé de 8 ans a été présenté avec un souffle cardiaque évident, une intolérance à l'effort, de l'anorexie et une parodontite. Il n'y avait pas de cyanose ni de résultats de laboratoire indiquant l'hypoxémie systémique. L'échocardiographie a montré une aorte en dextroposition, une sténose pulmonaire modérée (vélocité maximale de 4,06 m/s), une malformation septale ventriculaire et une hypertrophie ventriculaire droite. La direction du shunt était principalement de gauche à droite en systole et minimalement de droite à gauche en diastole. Un diagnostic de tétralogie de Fallot acyanotique (rose) a été posé et a été géré médicalement à l'aide d'aténolol.(Traduit par Isabelle Vallières).

Thalamic involvement in paroxysmal kinesigenic dyskinesia: a combined structural and diffusion tensor MRI analysis.

Alteration of basal ganglia-thalamocortical circuit has been hypothesized to play a role in the pathophysiology underlying paroxysmal kinesigenic dyskinesia (PKD). We investigated macrostructural and microstructural changes in PKD patients using structural and diffusion tensor magnetic resonance imaging (MRI) analyses. Twenty-five patients with idiopathic PKD and 25 control subjects were prospectively studied on a 3T magnetic resonance (MR) scanner. Cortical thickness analysis was used to evaluate cortical gray matter (GM) changes, and automated volumetry and shape analysis were used to assess volume changes and shape deformation of the subcortical GM structures, respectively. Tract-based spatial statistics (TBSS) was used to evaluate white matter integrity changes in a whole-brain manner, and region-of-interest (ROI) analysis of diffusion tensor metrics was performed in subcortical GM structures. Compared to controls, PKD patients exhibited a reduction in volume of bilateral thalami and regional shape deformation mainly localized to the anterior and medial aspects of bilateral thalami. TBSS revealed an increase in fractional anisotropy (FA) of bilateral thalami and right anterior thalamic radiation in patients relative to controls. ROI analysis also showed an increase in FA of bilateral thalami in patients compared to controls. We have shown evidence for thalamic abnormalities of volume reduction, regional shape deformation, and increased FA in patients with PKD. Our novel findings of concomitant macrostructural and microstructural abnormalities in the thalamus lend further support to previous observations indicating causal relationship between a preferential lesion in the thalamus and development of PKD, thus providing neuroanatomical basis for the involvement of thalamus within the basal ganglia-thalamocortical pathway in PKD.

Leptomeningeal enhancement on magnetic resonance imaging as a predictor of hemodynamic insufficiency.

OBJECTIVE: The objective of this study was to evaluate the value of leptomeningeal enhancement on magnetic resonance imaging in relation to relative cerebral blood flow (rCBF) and cerebrovascular reserve. METHODS: A retrospective analysis was performed for 31 patients with internal carotid artery or proximal middle cerebral artery occlusion without primary collateral flow, who underwent enhanced T1-weighted magnetic resonance imaging and acetazolamide-challenged perfusion computed tomography. They were graded into 3 groups in leptomeningeal enhancement on T1-weighted imaging. The rCBF and the percentage change of cerebral blood flow were obtained in the ipsilateral middle cerebral artery territory. RESULTS: The mean percentage changes of CBF were -13.7%, 6.9%, and 23.8% in prominent (n = 11), mild (n = 11), and equivalent (n = 9) increased enhancements, respectively. The degree of leptomeningeal enhancement was significantly reverse-correlated with percentage change of CBF (P < 0.001), whereas the rCBFs were not significantly different. CONCLUSIONS: The reverse correlation between leptomeningeal enhancement and cerebrovascular reserve suggests that increased enhancement may indicate impaired primary collaterals and hemodynamic insufficiency. Therefore, leptomeningeal enhancement degree can be used as an indicator of hemodynamic state in stroke.

Altered thalamocortical functional connectivity in idiopathic generalized epilepsy.

OBJECTIVE: Aberrant thalamocortical network has been hypothesized to play a crucial role in the fundamental pathogenesis underlying idiopathic generalized epilepsy (IGE). We aimed to investigate alterations of thalamocortical functional network in patients with IGE using thalamic seed-based functional connectivity (FC) analysis, and their relationships with frontal cognitive functions and clinical characteristics. METHODS: Forty-nine IGE patients (31 with juvenile myoclonic epilepsy, 17 with IGE with generalized tonic-clonic seizures only, one with juvenile absence epilepsy) and 42 control subjects were prospectively recruited. Voxel-based morphometry (VBM) was first performed to detect thalamic region of gray matter (GM) reduction in patients compared to controls. Between-group comparison of thalamocortical FC was then carried out using resting-state functional magnetic resonance imaging (MRI) analysis seeding at thalamic region of volume difference. In addition, thalamocortical FC was correlated with frontal cognitive performance and clinical variables. RESULTS: Neuropsychological assessment revealed that patients with IGE had poorer performance than controls on most of the frontal cognitive functions. VBM detected a reduction in GM in the anteromedial thalamus in patients relative to controls. FC analysis seeding at the anteromedial thalamus revealed a reduction of thalamocortical FC in the bilateral medial prefrontal cortex and precuneus/posterior cingulate cortex in patients with IGE compared to controls. Thalamocortical FC strength of bilateral medial prefrontal cortex correlated negatively with disease duration, but did not correlate with seizure frequency or frontal cognitive functions in patients with IGE. SIGNIFICANCE: Our results indicate that IGE is associated with decreased thalamocortical FC between anteromedial thalamus and medial prefrontal cortex and precuneus/posterior cingulate cortex. Our finding of greater reduction of medial prefrontal FC in relation to increasing disease duration suggests that thalamoprefrontal network abnormality, the proposed pathophysiologic mechanism underlying IGE, may be the consequence of the long-standing burden of the disease.

Thickening of the somatosensory cortex in migraine without aura.

OBJECTIVE: We aimed to explore cortical thickness abnormalities in a homogeneous group of patients with migraine without aura and to delineate possible relationships between cortical thickness changes and clinical variables. METHODS: Fifty-six female migraine patients without aura and T2-visible white matter hyperintensities and 34 female controls were scanned on a 3T magnetic resonance imager. Cortical thickness was estimated and compared between patients and controls using a whole-brain vertex-by-vertex analysis. Correlation analysis was conducted between cortical thickness of significant clusters and clinical variables. RESULTS: Compared to controls, migraine patients had cortical thickening in left rostral middle frontal gyrus and bilateral post-central gyri. Region-of-interest analysis revealed cortical thickening of bilateral post-central gyri in migraine patients relative to controls. The average thickness of bilateral post-central gyri positively correlated with disease duration as well as estimated lifetime headache frequency. CONCLUSIONS: We have provided evidence for interictal cortical abnormalities of thickened prefrontal cortex and somatosensory cortex in female migraine patients without aura. Our findings of greater thickening of the somatosensory cortex in relation to increasing disease duration and increasing headache frequency suggest that repeated migraine attacks over time may lead to structural changes of the somatosensory cortex through increased noxious afferent input within the trigemino-thalamo-cortical pathway in migraine.

Respiratory syncytial virus-related encephalitis: magnetic resonance imaging findings with diffusion-weighted study.

INTRODUCTION: Respiratory syncytial virus (RSV) is a common pathogen causing acute respiratory infection in children. Herein, we describe the incidence and clinical and magnetic resonance imaging (MRI) findings of RSV-related encephalitis, a major neurological complication of RSV infection. METHODS: We retrospectively reviewed the medical records and imaging findings of the patients over the past 7 years who are admitted to our medical center and are tested positive for RSV-RNA by reverse transcriptase PCR. In total, 3,856 patients were diagnosed with RSV bronchiolitis, and 28 of them underwent brain MRI for the evaluation of neurologic symptoms; 8 of these 28 patients had positive imaging findings. Five of these 8 patients were excluded because of non-RSV-related pathologies, such as subdural hemorrhage, brain volume loss due to status epilepticus, periventricular leukomalacia, preexisting ventriculomegaly, and hypoxic brain injury. RESULTS: The incidence of RSV-related encephalitis was as follows: 3/3,856 (0.08 %) of the patients are positive for RSV RNA, 3/28 (10.7 %) of the patient underwent brain MRI for neurological symptom, and 3/8 (37.5 %) of patients revealed abnormal MR findings. The imaging findings were suggestive of patterns of rhombenmesencephalitis, encephalitis with acute disseminated encephalomyelitis, and limbic encephalitis. They demonstrated no diffusion abnormality on diffusion-weighted image and symptom improvement on the follow-up study. CONCLUSION: Encephalitis with RSV bronchiolitis occurs rarely. However, on brain MRI performed upon suspicion of neurologic involvement, RSV encephalitis is not infrequently observed among the abnormal MR findings and may mimic other viral and limbic encephalitis. Physicians should be aware of this entity to ensure proper diagnosis and neurologic care of RSV-positive patients.

Lesions on DWI and the Outcome in Hyperacute Posterior Circulation Stroke.

BACKGROUND: few studies have addressed the association between the characteristics of ischemic lesions detected by diffusion-weighted imaging (dWi) and the clinical outcome in patients with hyperacute posterior circulation ischemic stroke. this study demonstrates a relationship between the findings assessed by dWi and the outcome in patients with hyperacute posterior circulation ischemic stroke. METHODS: We reviewed data from 118 patients who had posterior circulation ischemic stroke within six hours from the onset of their symptoms. the clinical outcome included early neurological deterioration (end) and a favorable outcome at three months after the onset of symptoms. using dWi, the lesion volume and the number and location of injured anatomical regions were analyzed to evaluate whether the results correlated with the clinical outcome measures. RESULTS: the number of injured anatomical regions assessed by dWi was associated with the initial and delayed neurological status. Both the total volume and the number of injured anatomical regions associated with end and a favorable outcome. analysis of the location of the injured regions determined that only a pontine lesion independently associated with end. interestingly, four out of five patients who underwent decompressive craniectomy exhibited a large infarction volume but minor symptoms. CONCLUSIONS: in patients with hyperacute posterior circulation ischemic strokes, the lesions assessed by dWi were associated with the clinical outcome, regardless of the initial neurological status. dWi is an effective initial imaging tool for assessing the extent of lesions and clinical outcomes in patients with hyperacute posterior circulation ischemic stroke.

Deep Learning-Based Automatic Classification of Ischemic Stroke Subtype Using Diffusion-Weighted Images.

BACKGROUND AND PURPOSE: Accurate classification of ischemic stroke subtype is important for effective secondary prevention of stroke. We used diffusion-weighted image (DWI) and atrial fibrillation (AF) data to train a deep learning algorithm to classify stroke subtype. METHODS: Model development was done in 2,988 patients with ischemic stroke from three centers by using U-net for infarct segmentation and EfficientNetV2 for subtype classification. Experienced neurologists (n=5) determined subtypes for external test datasets, while establishing a consensus for clinical trial datasets. Automatically segmented infarcts were fed into the model (DWI-only algorithm). Subsequently, another model was trained, with AF included as a categorical variable (DWI+AF algorithm). These models were tested: (1) internally against the opinion of the labeling experts, (2) against fresh external DWI data, and (3) against clinical trial dataset. RESULTS: In the training-and-validation datasets, the mean (±standard deviation) age was 68.0±12.5 (61.1% male). In internal testing, compared with the experts, the DWI-only and the DWI+AF algorithms respectively achieved moderate (65.3%) and near-strong (79.1%) agreement. In external testing, both algorithms again showed good agreements (59.3%-60.7% and 73.7%-74.0%, respectively). In the clinical trial dataset, compared with the expert consensus, percentage agreements and Cohen's kappa were respectively 58.1% and 0.34 for the DWI-only vs. 72.9% and 0.57 for the DWI+AF algorithms. The corresponding values between experts were comparable (76.0% and 0.61) to the DWI+AF algorithm. CONCLUSION: Our model trained on a large dataset of DWI (both with or without AF information) was able to classify ischemic stroke subtypes comparable to a consensus of stroke experts.

Study of intrathyroid fat-containing lesions using CT imaging with literature review.

INTRODUCTION: This study was conducted to estimate the incidence of intrathyroid fat-containing lesions based in the general population on CT imaging. The imaging characteristics of the lesions on CT were also analyzed. METHODS: This retrospective study included data for 1,205 patients who underwent neck CT at our institution from January 2012 to January 2013. Data concerning size, shape, homogeneity of attenuation and location of lesions, and the presence of a fatty band connecting to extrathyroid fat were evaluated. Pathologic specimens were reevaluated when available. A literature review was conducted based on 16 peer-reviewed articles describing intrathyroid fat-containing lesions. RESULTS: Intrathyroid fat-containing lesions were detected in 13 patients (1.2 %). The mean lesion size was 5.7 mm (range, 2.6-10.6 mm). Nodular shape (92 %), homogeneous attenuation (92 %), and the fatty band (77 %) were common CT features. Posterior (85 %), medial (85 %), and upper (92 %) aspects of the thyroid gland were most commonly involved. In four patients who underwent surgery, one had fat-containing nodular hyperplasia, one had ectopic thymic tissue within mature fat, and one had mature fat itself. In 16 previously reported studies, the 41 lesions presented two fat infiltration patterns, diffuse (n = 12) and localized (n = 29), and two lesions showed mature fat tissue itself. CONCLUSION: Intrathyroidal fat-containing lesions were found in 1.2 % of patients presenting for neck CT. Almost all of the lesions occurred in common locations and showed similar features on CT, including nodular shape, homogeneous attenuation, and a fatty band.

Altered Functional Connectivity of the Nucleus Accumbens and Amygdala in Cyber Addiction: A Resting State Functional Magnetic Resonance Imaging Study.

Objective: Cyber addiction, which is more vulnerable in adolescents, is defined as the excessive use of computers and the Internet that causes serious psychological, social, and physical problems. In this study, we investigated the resting-state functional connectivity (rsFC) in adolescents with cyber addiction. Methods: We collected and analyzed resting-state functional neuroimaging data of 20 patients with cyber addiction, aged 13-18 years, and 27 healthy controls. Based on previous studies, the seed regions included the dorsolateral prefrontal cortex, medial orbitofrontal cortex, lateral orbitofrontal cortex, dorsal anterior cingulate cortex, insula, hippocampus, amygdala, nucleus accumbens, and the ventral tegmental area. Seed-to-voxel analyses were performed to investigate the differences between patients and healthy controls. A correlation analysis between rsFC and cyber addiction severity was also performed. Results: Patients with cyber addiction showed the following characteristics: increased positive rsFC between the left insular-right middle temporal gyrus; increased positive rsFC between the right hippocampus-right precentral gyrus; increased positive rsFC between the right amygdala-right precentral gyrus and right parietal operculum cortex; increased negative rsFC between the left nucleus accumbens-right cerebellum crus II and right cerebellum VI. Conclusion: Adolescents with cyber addiction show altered functional connectivity during the resting state. The findings of this study may help us better understand the neuropathology of cyber addiction in adolescents.

Functional connectivity and network analysis in adolescents with major depressive disorder showing suicidal behavior.

BACKGROUND: This study aimed to gather a homogeneous sample of adolescent patients to analyze the differences in functional connectivity and brain network parameters between suicidal and non-suicidal major depressive disorder (MDD) patients using a data-driven whole-brain approach. METHODS: Patients recruited at the psychiatry department of Korea University Guro Hospital from November 2014 to March 2020 were diagnosed with MDD, were 13-18 years old, had IQ scores >80, had no family history of psychotic or personality disorders, had no smoking or alcohol consumption history, and were drug-naïve to psychotropic medication. Depressive symptoms were assessed using the Hamilton Depression Rating Scale and the Children's Depression Inventory. Structural and functional MRI scans were conducted and analyzed using the CONN toolbox. RESULTS: Of 74 enrolled patients, 62 were analyzed. Regions of interest (ROIs) showing higher betweenness centrality in non-suicidal patients were the left superior temporal gyrus and left supramarginal gyrus. ROIs showing higher betweenness centrality in suicidal patients were the right hippocampus, left intracalcarine cortex, right inferior temporal gyrus, and the lateral visual network. Suicidal patients also showed different resting state functional connectivity profiles from non-suicidal patients. LIMITATIONS: Small sample size. CONCLUSION: Suicidal patients may overthink and overvalue future risks while having a more negatively biased autobiographical memory. Social cognition and the ability to overcome egocentricity bias seem to weaken. Such features can disrupt cognitive recovery and resilience, leading to more suicidal behaviors. Therefore, increased suicidality is not acquired, but is an innate trait.

Independent effect of Aß burden on cognitive impairment in patients with small subcortical infarction.

BACKGROUND: The effect of amyloid-ß (Aß) on cognitive impairment in patients with small subcortical infarction remains controversial, although a growing body of evidence shows a substantial overlap between Alzheimer's disease (AD) and subcortical ischemic vascular dementia, another form of cerebral small vessel disease (cSVD). Therefore, we investigated the relationships between Aß positivity and the development of post-stroke cognitive impairment (PSCI) in patients with small subcortical infarction. METHODS: We prospectively recruited 37 patients aged ≥ 50 years, with first-ever small subcortical infarction, who underwent amyloid positron emission tomography, 3 months after stroke at Korea University Guro Hospital. We also enrolled CU participants matched for age and sex with stroke patients for comparison of Aß positivity. Patients were followed up at 3 and 12 months after the stroke to assess cognitive decline. Logistic and linear mixed-effect regression analyses were performed to identify the effect of Aß positivity on PSCI development and long-term cognitive trajectories. RESULTS: At 3 months after stroke, 12/37 (32.4%) patients developed PSCI, and 11/37 (29.7%) patients had Aß deposition. Aß positivity (odds ratio [OR] = 72.2, p = 0.024) was predictive of PSCI development regardless of cSVD burden. Aß positivity (ß = 0.846, p = 0.014) was also associated with poor cognitive trajectory, assessed by the Clinical Dementia Rating-Sum of Box, for 1 year after stroke. CONCLUSIONS: Our findings highlight that Aß positivity is an important predictor for PSCI development and cognitive decline over 1 year. Furthermore, our results provide evidence that anti-AD medications may be a strategy for preventing cognitive decline in patients with small subcortical infarctions.

Microstructural white matter abnormality and frontal cognitive dysfunctions in juvenile myoclonic epilepsy.

PURPOSE: Previous neuroimaging studies provide growing evidence that patients with juvenile myoclonic epilepsy (JME) have both structural and functional abnormalities of the thalamus and frontal lobe gray matter. However, limited data are available regarding the issue of white matter (WM) involvement, making the microstructural WM changes in JME largely unknown. In the present study we investigated changes of WM integrity in patients with JME, and their relationships with cognitive functions and epilepsy-specific clinical factors. METHODS: We performed diffusion tensor imaging (DTI) and neuropsychological assessment in 25 patients with JME and 30 control subjects matched for age, gender, and education level. Between-group comparisons of fractional anisotropy (FA) and mean diffusivity (MD) were carried out in a whole-brain voxel-wise manner by using tract-based spatial statistics (TBSS). In addition, both FA and MD were correlated with cognitive performance and epilepsy-specific clinical variables to investigate the influence of these clinical and cognitive factors on WM integrity changes. KEY FINDINGS: Neuropsychological evaluation revealed that patients with JME had poorer performance than control subjects on most of the frontal function tests. TBSS demonstrated that, compared to controls, patients with JME had significantly reduced FA and increased MD in bilateral anterior and superior corona radiata, genu and body of corpus callosum, and multiple frontal WM tracts. Disease severity, as assessed by the number of generalized tonic-clonic seizures in given years, was negatively correlated with FA and positively correlated with MD extracted from regions of significant differences between patients and controls in TBSS. SIGNIFICANCE: Our findings of widespread disturbance of microstructural WM integrity in the frontal lobe and corpus callosum that interconnects frontal cortices could further support the pathophysiologic hypothesis of thalamofrontal network abnormality in JME. These WM abnormalities may implicate frontal cognitive dysfunctions and disease progression in JME.