Occipital Research Articles

Geometric Morphometric Study on Distinguishing Metopic Craniosynostosis from Metopic Ridging.

Craniosynostosis, a common congenital anomaly, results from premature fusion of the cranial sutures. One of the forms of craniosynostosis is premature fusion of the metopic suture, referred to as trigonocephaly, but the diagnosis of metopic suture synostosis remains controversial. The purpose of this study was to clarify, using geometric morphometric analysis, if a metopic ridge alone observed in cases of mild trigonocephaly represents a pathological phenomenon. Three different cranial morphologies were compared among patients up to 2 years old who were categorized into the true group, the mild group, and the normal group, based on the presence or absence of specific symptoms, history of cranioplasty for trigonocephaly, or lack of any abnormality on computed tomography. Using the obtained computed tomography images, 235 anatomical landmarks and semi-landmarks were plotted on the entire cranial surface for analysis of neurocranial morphology, and the cranial shapes represented by landmarks were analyzed using geometric morphometrics. Principal components of shape variations among specimens were then computed, based on the variance-covariance matrix of the Procrustes residuals of all specimens, and statistically analyzed. The principal component analyses of the variations in endocranial shape, frontal bone shape, and occipital bone shape did not show any significant differences in cranial morphology between mild trigonocephaly and normal skulls; however, true trigonocephaly was found to differ significantly from mild trigonocephaly and normal skulls. These findings suggest that in assessments of cranial morphology, the presence of a ridge alone cannot be diagnosed as fundamentally pathological, and may represent normal morphology.

DETERMINATION OF THE POSSIBILITY OF A LETHAL BULLET INJURY TO THE HEAD DUE TO A PROJECTILE RICOCHET TAKING INTO ACCOUNT THE ANALYSIS OF MORPHOLOGICAL CHARACTERISTICS OF EXPERIMENTALLY FIRED BULLETS

Gunshot wounds always occupy one of the leading places in the structure of violent mortality, however, there is not enough information in the specialised literature that highlights the distinct individual characteristics of projectiles (bullets) that were removed from a biological object and became the instrument of death, and when they ricochet (collide with an obstacle) after a series of experimental shots. Aim: To determine the possibility of causing a fatal bullet injury to the head after the ricochet of a projectile from the road surface, taking into account the analysis of the morphological characteristics of experimentally fired bullets. Material and methods. The archival material of the SSI "Main Bureau of Forensic Medical Examination of the Ministry of Health of Ukraine" ("Expert conclusion") was used. The objects of the study were: bones of the skull of the victim gr. K, gunshot wounds on the head (entrance, exit hole, wound channel), as well as bullets up to 9 mm cartridges of the "Makarov" pistol, namely 1) one bullet removed from the cranial cavity after an autopsy and 2) 6 bullets removed after an experimental series of shots into the road surface. Their characteristics were studied using standard methods generally accepted in forensic medicine and standard methods of variational statistics. Results. During arrest by a law enforcement officer, the man received a fatal gunshot wound to the head with a 9 mm bullet. There was an entrance hole in the occipital bone, a wound channel in the cranial cavity at an angle of approximately 130° to the midline of the body, and a depressed fracture of the frontal bone. A series of experimental shots with 9mm bullets revealed the remains (fragments) of the asphalt coating and their marked deformation, which was not the case with the bullet that caused the fatal wound. Ballistic analysis showed that the angle of movement of the bullet in the cranial cavity was 30°. Conclusion. According to the circumstances contained in the criminal case materials and established during the forensic examination, the bullet wound could not have been caused by the ricochet of the bullet from the asphalt pavement, since no remains (fragments) of the obstacle with which the bullet collided were found, and its deformation does not correspond to the results of the forensic shooting and ballistic examination.

FORENSIC EVALUATION OF SELF-INFLICTED SUICIDES WITH MULTIPLE GUNSHOT WOUNDS

Suicide is a common cause of premature death and a serious social problem. The use of firearms for suicide is quite common. The infliction of multiple self-inflicted wounds, including a fatal one, is rare among suicides, but it is possible and requires careful investigation. Aim To provide a forensic assessment of the possibility of suicide by multiple gunshot wounds. Methods. Archival material from the Kyiv City Clinical Bureau of Forensic Medicine and the Zhytomyr Regional Bureau of Forensic Medicine (2 "medical examination reports") was used. The objects of the study were: gunshot wounds on the head (wounds, wound channels), elastic bullets up to 9 mm cartridges and 9 mm bullets for pistol "Makarov", shot products, pistol "Makarov-MP 79" converted to shoot elastic bullets. Their characteristics were examined visually and under the stereo microscope. The detection of shot soot layers on skin flaps and gunsmith's grease was carried out in infrared and ultraviolet rays. The study of the elemental composition of shot products in objects of biological and non-biological origin was carried out using the X-ray fluorescence spectrometer "M4 TORNADO". Standard methods of variational statistics were used in the study. Results. The forensic examination of the entry and exit wounds and wounds on the head of the corpses of persons who died as a result of self-inflicted gunshot wounds, as well as of the bullets and weapons that caused bodily injuries, confirmed the possibility of committing suicide by firing double shots from pistols to shoot bullets of the so-called "non-lethal type": elastic bullets up to 9 mm cartridges and 9 mm bullets for pistol "Makarov". It was established that in case No 1 the first injury was non-fatal and the second was fatal, accompanied by damage to the skull and brain. In case No. 2, the first wound was fatal and the second was non-fatal, as it damaged only the soft tissues of the head without damaging the bones of the skull and brain. The wounds were caused by automatic shots due to the poor technical condition of the weapon, i.e. partial damage and wear of the trigger mechanism and the pistol sear. This was facilitated by a one-time partial self-destruction of the weapon, followed by the wedging of the next cartridge with an elastic bullet in the lower part of the barrel. Conclusion. Thus, the cases of double head injuries caused by shots from firearms (pistols) for shooting bullets of the so-called "non-lethal type" (elastic bullets up to 9 mm cartridges and 9 mm bullets for pistol "Makarov") serve as evidence of suicide. In case No. 1, one of the wounds was not fatal, as the wound channel began with an entrance hole in the lower half of the right temporal region, continued on the right through the right mastoid process and the soft tissues of the neck, and ended in the middle with an exit wound in the back of the neck. This wound was the first inflicted. The second wound was final and fatal, as there was damage to the skull and brain, as evidenced by the wound channel which passed through the right temporal cyst, the brain and its membranes, the left occipital bone, and ended with the exit wound in the left occipital region. It was the second in order of entry. In case 2, the first wound was fatal, resulting in damage to the bones of the skull and brain and the presence of an elastic ball in the substance of the brain. The second wound was non-fatal and tangential, injuring only the soft tissues of the head without damaging the bones of the skull and brain. It occurred as a result of automatic (independent) shots due to the poor technical condition of the weapon, namely partial damage and wear of the trigger mechanism and the pistol sear. This was facilitated by a one-time partial self-destruction of the weapon, followed by the wedging of the next cartridge with an elastic bullet in the lower part of the barrel.

Monosymmetros Cephalothoracopagus Tetrabrachius and Tetrapus Piglets with Syndromic Evolution.

Conjoined twins are rare congenital malformations that have been reported in mammals. Two different cases are presented in this study. Case No. 1 features monocephalic, thoracopagus-conjoined twin piglets with anencephaly and palatoschisis of the Pietrain breed, and case No. 2 features monocephalic, thoracopagus conjoined twin piglets with palatoschisis and bifid root tongue of a mixed breed. These cases were examined using post-mortem and computed tomography (CT) examinations. In both cases, the conjoined symmetrical twins had a single head, one neck, and fused thoracic cavities, while the abdominal cavities were separated. Similarly, in both cases, they had four forelimbs and four hindlimbs and duplicated foramen magnum. During CT examination, in case No. 1, severe abnormalities were observed in the skull and vertebral column. In the left twin, occult dysraphism was seen from the C2 vertebra until the end of the vertebral column, and in the right twin, from the C3 vertebra until the end of the state vertebral level. In case No. 2, the oral cavity contained a tongue with a bifid root connected with one hyoid bone, and the soft palate presented a small cleft. During CT examination, the parietal bone and the occipital bones were partially duplicated. This case also presented occult dysraphism, but only in the cervical vertebrae, C1-C6 for the left twin and C1-C5 for the right twin. In both cases, abnormalities of the internal organs were revealed during necropsy. Conjoined twins with multiple congenital anomalies presented here enhance our understanding of the various clinical forms of conjoined cases in veterinary medicine.

CT myelography by intrathecal injection of contrast medium though percutaneous administration route visualizes compressed cervical spinal cord in a mouse

BackgroundChronic compressive myelopathy (CCM) is a major cause of spinal cord disorders in the elderly, in which the spinal cord is compressed by bony or soft tissue structures. Although computed tomography myelography (CTM) has been clinically used for the diagnosis of CCM, a method of CTM in rodents remains to be developed. New methodA 50 μl Hamilton syringe attached to a disposable needle was percutaneously inserted into the subarachnoid space (cisterna magna) between the occipital bone and C1 lamina in an anesthetized adult mouse, followed by the injection of contrast medium and CT imaging. ResultsCTM clearly visualized the shape of the spinal cord of intact mice and tiptoe-walking Yoshimura (Twy) mice without any health issues. Comparison with existing method(s)Unlike histology, the current method functions in live mice, directly depicts the compressed spinal cord, and provides clinically related image information. Furthermore, the intrathecal administration of contrast medium through the percutaneous route makes CTM less invasive and takes less time than a conventional intrathecal injection method. ConclusionsThe CTM method used in the present study enables clear visualization of the shape of the dural sac and spinal cord and is useful when conducting experiments on CCM and other spinal diseases in rodents.

Enduring maternal brain changes and their role in mediating motherhood’s impact on well-being

Parenthood, particularly motherhood, is known to impact the structure and function of the brain in the short term, but the long-term effects of parenthood and their impacts on well-being are still poorly understood. This study explores the potential longer-term associations between parenthood and the brain, parenthood and well-being, and the potential role of brain modifications in influencing mothers’ well-being. Using data from the UK Biobank, which includes brain imaging information from individuals aged 45–82 at the MRI scanning, we discovered differences in brain structure between mothers and non-mothers, with mothers exhibiting widely distributed higher gray matter density, particularly strong in frontal and occipital regions. No brain changes were observed in fathers. Parents reported a higher sense of life’s meaning compared to their childless counterparts. Gray matter changes did not mediate the relationship between motherhood and well-being. This suggests that the alterations in gray matter associated with motherhood do not play a deterministic role in shaping long-term changes in well-being.

Changes on Cognition and Brain Network Temporal Variability After Pediatric Neurosurgery.

Pediatric intracranial space-occupying lesions are common, with prognoses improving markedly in recent years, significantly extending survival. As such, there is an imperative to pay increased attention to the postoperative cognitive functions and brain network alterations in these children because these factors significantly influence their quality of life. Temporal variability (TV) analysis of brain networks captures the full extent of resting-state activities, reflecting cognitive functions and rehabilitation potential. However, previous research rarely uses TV analyses and most focus on adults or children after multidisciplinary treatments, not reflecting the combined effect caused by neurosurgery only and self-repair. This study gives our insights into this field from a holistic perspective. We studied 35 children with intracranial space-occupying lesions, analyzing pre- and postsurgery MRI and cognitive tests. We used TV analysis to assess changes and correlated imaging indicators with cognitive performance. We observed a tendency for cognitive recovery after about 3 months postsurgery, primarily in the domains of social cognition and nonverbal reasoning. TV analysis of brain networks indicated increased nodal variability within systems such as the visual and sensorimotor networks, which are integral to external interactions. Correlative analysis showed that alterations in certain occipital regions were associated with changes in social cognition and nonverbal reasoning. These findings suggest significant intrinsic repair in cognitive functions and brain networks at around 3 months postneurosurgery in children. This study not only enriches our comprehension of postoperative cognitive and brain network self-repair processes in children but also furnishes potential therapeutic targets for rehabilitation interventions and establishes a theoretical foundation for proactive surgical interventions.

Comparison of Skull Morphometric Characteristics of Simmental and Holstein Cattle Breeds.

This study aimed to reveal the morphological characteristics of pure Holstein and Simmental skulls and to obtain reference values for morphometric analysis. Moreover, 54 skulls from 12- to 14-month-old male Holstein (n = 25) and Simmental (n = 29) cattle were collected from Turkey's Southeastern Anatolia Region between 2023 and 2024. Linear measurements indicated that Holsteins had longer skulls compared to Simmentals. Holsteins exhibited significantly higher values for the greatest length of nasals and the shortest skull length. The facial breadth was wider in Holsteins and statistically distinctive between the breeds. Holsteins had a more oval orbital bony roof, while Simmentals exhibited a wider orbital structure. The orbital index was higher in Holsteins, distinguishing between the two breeds. It was observed that Simmental cattle had a wider occipital region. This difference is likely due to the larger lateral appearance of the Simmental skull, which has more body weight and provides a larger surface area for muscle attachment. These differences not only aid in breed identification but also offer insights into the functional adaptations of each breed. Future research should explore the genetic and environmental factors contributing to these morphological traits, further enriching our knowledge of cattle morphology and its implications for breeding and conservation efforts.

Surgical treatment of a teenager with an extensive wound defect of soft tissues against the background of severe combined injury

Extensive posttraumatic wounds, affecting functionally active areas and complicated by a purulent–necrotic process, are a serious problem in the acute period of injury due to a critical condition and in reconstructive surgical treatment. This study presents the case of a 16-year-old victim of a transport accident on a ferry who underwent a surgical treatment. Due to a truck collision, the girl was crushed against the metal structure of the ship and received a severe combined injury: closed craniocerebral injury, moderate brain contusion, linear fracture of the occipital bone on the right, closed chest injury, fracture of 9–11 ribs on the right, closed abdominal injury, rupture of the right kidney, damage to the bladder, retroperitoneal hematoma on the right, closed spinal injury, fracture of the spinous processes of the L4–L5 vertebrae, open fractures of the pelvic bones, and extensive posttraumatic wounds of the right half of the pelvic girdle and hip joints. During the initial hospitalization, the following were performed within 2 days: laparotomy, nephrectomy of a crushed kidney on the right, suturing of the bladder, primary surgical treatment of the wound in the sacrogluteofemoral region on the right and the wound of the left thigh with their primary suturing, and external osteosynthesis of the pelvic bones with a rod-based external fixation device. The early postoperative period was complicated by necrosis of injured soft tissues and a new surgical infection (polyantibiotic-resistant strains of microorganisms), which led to an increase in the size of the wound defect and loss of soft tissues due to their purulent melting. Complex surgical treatment aimed at eliminating surgical infection and transferring the wound process to the regeneration phase included repeated surgical treatments and the use of modern dressings and negative pressure therapy. An extensive wound defect of soft tissues caused by and injury or surgical treatment for purulent–necrotic complication was found in the functionally active zone of the hip joint and in the sacral region, which required the restoration of the skin of these areas. A strategy for surgical repair of a soft tissue wound defect is presented. Nonfree (rotated) blood-supply flaps were used: fasciocutaneous muscle flap based on the musculus tensor fascia lata from the right thigh and gluteal fasciocutaneous flap from the left gluteal region. After multistage surgical treatment, it was possible to replace an extensive wound defect of soft tissues and restore full skin in the hip joint and sacrogluteal region, which enabled avoiding trophic disorders and joint contractures and ensured a satisfactory cosmetic and functional result during 5-year followup.

Mercedes Benz pattern craniosynostosis associated with Chiari malformation type 1: A case report of a rare condition

Introduction: Craniosynostosis results from the premature fusion of cranial sutures and is classified as complex when it affects multiple sutures. The abnormal and rare fusion of the sagittal and bilateral lambdoid sutures is known as the Mercedes-Benz (CMB) pattern responsible for up to 0.7% of craniosynostoses. It's characterized by flattening of the occipital bone and sub-lambdoid depression. Additionally, the Arnold-Chiari malformation, one of the anomalies associated, occurs due to the junction of deformities in the posterior fossa and rhombencephalon. Type 1 (CM1) is the most incident and less severe, represented by the pointed shape of the cerebellar tonsils. Objective: The objective of this article is to report a rare case presentation of Mercedes Benz pattern Craniosynostosis associated with Arnold Chiari malformation Case presentation: Male patient, 11 months old, diagnosed with CMB associated with CM1, presenting with anterior turribrachycephaly and occipital brachycephaly. The diagnosis was made after the 10th month of life, with typical findings on computed tomography and cerebellar tonsil herniation (CTH) on magnetic resonance imaging (MRI). No signs of neurodevelopmental delay were observed, and there is no history of cranial malformations in the family. At 11 months, the patient underwent neurosurgery involving cranial parietal remodeling to correct craniosynostosis, along with posterior fossa decompression to address CM1. Conclusion: Neurosurgical techniques like parietal remodeling and posterior decompression, despite their complexity, play a central role in addressing CMB. It's crucial to discuss this rare condition to ensure early diagnosis and treatment, facilitating an efficient approach and preventing potential later consequences.

Neural correlates for word-frequency effect in Chinese natural reading.

Word frequency effect has always been of interest for reading research because of its critical role in exploring mental processing underlying reading behaviors. Access to word frequency information has long been considered an indicator of the beginning of lexical processing and the most sensitive marker for studying when the brain begins to extract semantic information Sereno & Rayner, Brain and Cognition, 42, 78-81, (2000), Trends in Cognitive Sciences, 7, 489-493, (2003). While the word frequency effect has been extensively studied in numerous eye-tracking and traditional EEG research using the RSVP paradigm, there is a lack of corresponding evidence in studies of natural reading. To find the neural correlates of the word frequency effect, we conducted a study of Chinese natural reading using EEG and eye-tracking coregistration to examine the time course of lexical processing. Our results reliably showed that the word frequency effect first appeared in the N200 time window and the bilateral occipitotemporal regions. Additionally, the word frequency effect was reflected in the N400 time window, spreading from the occipital region to the central parietal and frontal regions. Our current study provides the first neural correlates for word-frequency effect in natural Chinese reading so far, shedding new light on understanding lexical processing in natural reading and could serve as an important basis for further reading study when considering neural correlates in a realistic manner.

Changes in slow-wave sleep characteristics in Parkinson's disease patients with mild-moderate depression

IntroductionDepression and sleep disturbances are commonly seen non-motor symptoms in patients with Parkinson's disease (PD). This study used polysomnography to examine the relationship between mild-moderate depression in PD and sleep characteristics, particularly slow wave activities (SWA). Methods59 PD patients were split into two groups: nd-PD (n = 27) (patients with PD without depression) and d-PD (n = 32) (patients with PD with mild-moderate depression). Their clinical features, polysomnography parameters, and demographics were evaluated. Early and late sleep SWA spectrum densities and overnight SWA decline in different brain regions were particularly analyzed. ResultsNon-rapid eye movement 3 (N3) sleep duration and percentage were greater in the d-PD group. N3 percentage was linked to depression (p = 0.014). During late sleep, higher SWA (0.5–4Hz) in the frontal and central regions, higher low-SWA (0.5–2Hz) in the whole brain, central and occipital regions, and higher high-SWA (2–4Hz) in the frontal region was observed in the d-PD group. During early sleep, there was also higher low-SWA (0.5–2Hz) in the occipital region. Patients in d-PD group exhibited reduced overnight high-SWA (2–4Hz) decline (Δhigh-SWA) in the whole brain and occipital regions. Δhigh-SWA(2–4Hz) in the occipital region were associated with depression (p = 0.049). ConclusionPD patients with mild-moderate depression have impaired slow wave sleep, exhibiting as increased N3 sleep, SWA, and reduced overnight SWA decline. This implies that synaptic strength reduction during sleep and impaired synaptic homeostasis regulation may be associated with depression in PD. Reduced overnight high-SWA decline in the occipital region may serve as a novel electrophysiological biomarker for indicating depression in PD.

ОСОБЕННОСТИ СТРОЕНИЯ СКЕЛЕТА ГОЛОВЫ АЗИАТСКОГО (БЕЛОХВОСТОГО) ДИКОБРАЗА (HYSTRICIDAE LEVICURA)

The purpose of research is to study the structural features of the head skeleton of the Asian (white-tailed) porcupine. The object of the study is the skeleton of the head of an Asian (white-tailed) porcupine at the age of 12 years. To make the porcupine skeleton, a biological method of processing the material was used. The study of the bones was accompanied by measuring their length and width using an electronic caliper with an accuracy of 0.1 mm, describing and photographing. The head skeleton of the Asian (white-tailed) porcupine is divided into cerebral and facial sections, the size of which is related to the size of the brain and the development of the masticatory apparatus. The brain region is represented by unpaired (occipital, sphenoid, interparietal, ethmoid) and paired (temporal, frontal, parietal, alar) bones. The facial region is represented by the maxillary, incisive, palatine, zygomatic, lacrimal and nasal bones. The rostral edge of the orbit serves as the boundary between the facial and brain regions. The facial section reaches the greatest development, occupying 59.8 % of the length of the brain. The configuration of the skull and the presence of a large number of processes make it possible to attach well-developed masticatory muscles to it. The caudal part of the skull is represented by the occipital bone, and the cranial part by the ethmoid bones. The body of the occipital bone is connected to the sphenoid bone, which participates in the formation of the foramen lacerum. The body of the sphenoid bone is trapezoidal in shape, from which the orbital and temporal wings branch. There are six foramina on the orbital wing: optic, orbital fissure, round, caudal alar, oval and carotid. The temporal wing is involved in the formation of the foramen lacerum with the oval, spinous and carotid notches. On the facial surface of the maxillary bone there is a facial ridge; between its facial and nasal surfaces there is an extensive maxillary sinus. The mandibular bone is paired, represented by two bones connected to each other by a ligament. The massive, triangular-shaped lower jaw has two processes: the condylar and the coronoid. The condylar process is convex, oval-elongated. The coronoid process is low with a bifurcated apex. The pterygoid and chewing fossae are deep and triangular in shape.

Clinical phenotype and genetic analysis of a child with Intellectual developmental disorder and epilepsy due to variant of CLTC gene

To explore the clinical features and genetic basis for a child with Intellectual developmental disorder (IDD) and epilepsy. A child who was admitted to the Children's Medical Center of the Affiliated Hospital of Guangdong Medical University in February 2021 was selected as the study subject. Clinical data of the child was collected. Peripheral blood samples of the child and her parents were collected and subjected to whole exome sequencing (WES). Candidate variant was verified by Sanger sequencing. The patient, a 3-month-and-27-day female infant, had developed the symptoms in the neonatal period, which included severe developmental delay, respiratory difficulties and pauses, increased muscle tone of four limbs, feeding difficulty, and seizures. Cerebral MRI revealed bilateral cerebellar hypoplasia, and video EEG showed slightly increased sharp waves emanating predominantly from the right parietal, occipital, and posterior temporal regions. WES revealed that she has harbored a missense c.3196G>A (p.Glu1066Lys) variant of the CLTC gene, which was confirmed to be de novo by Sanger sequencing. Based on the guideline from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as likely pathogenic (PS2+PM2_Supporting+PP3). The c.3196G>A (p.Glu1066Lys) missense variant of the CLTC gene probably underlay the pathogenesis in this child. Above finding has facilitated her diagnosis and treatment.

Functional MRI-based biomarkers of insomnia with objective short sleep duration phenotype

BackgroundInsomnia disorder with objective short sleep duration (ISS) phenotype is a more serious biological subtype than insomnia with objective normal sleep duration (INS) phenotype, and the neuroimaging data is helpful to understand the pathophysiology of the ISS phenotype. This study was to compare the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) between the ISS phenotype and the INS phenotype. MethodsIn this cross-sectional study, 55 patients with insomnia disorder were recruited, and 22 of them were defined as the ISS phenotype by the objective cardiopulmonary coupling (CPC) technique. The blood oxygen level-dependent (BOLD) sequences of all participants were obtained using the 3.0 T magnetic resonance imaging system. We analyzed and compared the ALFF, ReHo, and FC between the ISS phenotype and the INS phenotype. We also conducted Pearson's correlation analysis between significant neuroimaging biomarkers and the CPC parameters. ResultsThe differences were not significant in ALFF (PFWE-corr＞0.05) or ReHo (PFWE-corr＞0.05) between the ISS phenotype and the INS phenotype. For the FC analysis, the ISS phenotype had a Hub-node of the left inferior occipital gyrus (IOG.L), with significantly decreased connections (p＜0.001) in the bilateral occipital, parietal, and temporal regions. The significant FCs were closely related to sleep parameters. ConclusionThe left inferior occipital gyrus (IOG.L), as a Hub-node with decreased functional connections, may be a potential fMRI-based biomarker of the ISS phenotype.

Rate of abnormalities in quantitative MR neuroimaging of persons with chronic traumatic brain injury

BackgroundMild traumatic brain injury (mTBI) can result in lasting brain damage that is often too subtle to detect by qualitative visual inspection on conventional MR imaging. Although a number of FDA-cleared MR neuroimaging tools have demonstrated changes associated with mTBI, they are still under-utilized in clinical practice.MethodsWe investigated a group of 65 individuals with predominantly mTBI (60 mTBI, 48 due to motor-vehicle collision, mean age 47 ± 13 years, 27 men and 38 women) with MR neuroimaging performed in a median of 37 months post-injury. We evaluated abnormalities in brain volumetry including analysis of left-right asymmetry by quantitative volumetric analysis, cerebral perfusion by pseudo-continuous arterial spin labeling (PCASL), white matter microstructure by diffusion tensor imaging (DTI), and neurometabolites via magnetic resonance spectroscopy (MRS).ResultsAll participants demonstrated atrophy in at least one lobar structure or increased lateral ventricular volume. The globus pallidi and cerebellar grey matter were most likely to demonstrate atrophy and asymmetry. Perfusion imaging revealed significant reductions of cerebral blood flow in both occipital and right frontoparietal regions. Diffusion abnormalities were relatively less common though a subset analysis of participants with higher resolution DTI demonstrated additional abnormalities. All participants showed abnormal levels on at least one brain metabolite, most commonly in choline and N-acetylaspartate.ConclusionWe demonstrate the presence of coup-contrecoup perfusion injury patterns, widespread atrophy, regional brain volume asymmetry, and metabolic aberrations as sensitive markers of chronic mTBI sequelae. Our findings expand the historic focus on quantitative imaging of mTBI with DTI by highlighting the complementary importance of volumetry, arterial spin labeling perfusion and magnetic resonance spectroscopy neurometabolite analyses in the evaluation of chronic mTBI.

YAP1∷KMT2A fusion-positive sarcoma: An emerging soft tissue tumor entity with morphological features resembling a sclerosing epithelioid fibrosarcoma.

Sclerosing epithelioid fibrosarcoma (SEF) and low-grade fibromyxoid sarcoma (LGFMS) constitute a morphological continuum with certain overlapping histopathological features and MUC 4 immunopositivity. SEF is characterized by EWSR1 gene rearrangement, is relatively more aggressive and shows a limited response to chemotherapy. Lately, a subset of tumors with morphological features of SEF, but lacking MUC4 immunostaining and EWSR1 gene rearrangement have been observed. We report the first case of YAP1∷KMT2A-positive sarcoma from the Indian subcontinent along with a review of similar tumors reported previously. A case of 31-year-old male presented with a 3 cm painful lump in the right suboccipital region. Histopathological examination of the excised specimen revealed a cellular tumor composed of atypical spindle and epithelioid cells, exhibiting moderate nuclear pleomorphism, arranged in cords, embedded in a dense collagenous/hyalinized stroma. By immunohistochemistry, the tumor cells were diffusely positive for cyclin D1 and negative for MUC4, desmin, myogenin, β-catenin, STAT6, myoD1, SMA, and S100P. By fluorescence in-situ hybridization, EWSR1 gene rearrangement was negative. Next-generation sequencing (NGS) revealed YAP1exon5∷KMT2Aexon4 fusion. Given a positive resection margin, he underwent a revision surgery involving wide local excision of the lesion including the outer table of the occipital bone followed by image-guided radiation therapy. Over 2 years of his follow-up, the patient is alive with no evidence of recurrence. Thus, YAP1∷KMT2A positive sarcomas have distinct molecular and overlapping histopathological features with SEF, with relatively less aggressive disease course. Documentation of additional similar tumors with long-term follow-up is required.

Changes of brain functional network in Alzheimer’s disease and frontotemporal dementia: a graph-theoretic analysis

BackgroundAlzheimer’s disease (AD) and frontotemporal dementia (FTD) are the two most common neurodegenerative dementias, presenting with similar clinical features that challenge accurate diagnosis. Despite extensive research, the underlying pathophysiological mechanisms remain unclear, and effective treatments are limited. This study aims to investigate the alterations in brain network connectivity associated with AD and FTD to enhance our understanding of their pathophysiology and establish a scientific foundation for their diagnosis and treatment.MethodsWe analyzed preprocessed electroencephalogram (EEG) data from the OpenNeuro public dataset, comprising 36 patients with AD, 23 patients with FTD, and 29 healthy controls (HC). Participants were in a resting state with eyes closed. We estimated the average functional connectivity using the Phase Lag Index (PLI) for lower frequencies (delta and theta) and the Amplitude Envelope Correlation with leakage correction (AEC-c) for higher frequencies (alpha, beta, and gamma). Graph theory was applied to calculate topological parameters, including mean node degree, clustering coefficient, characteristic path length, global and local efficiency. A permutation test was then utilized to assess changes in brain network connectivity in AD and FTD based on these parameters.ResultsBoth AD and FTD patients showed increased mean PLI values in the theta frequency band, along with increases in average node degree, clustering coefficient, global efficiency, and local efficiency. Conversely, mean AEC-c values in the alpha frequency band were notably diminished, which was accompanied by decreases average node degree, clustering coefficient, global efficiency, and local efficiency. Furthermore, AD patients in the occipital region showed an increase in theta band node degree and decreased alpha band clustering coefficient and local efficiency, a pattern not observed in FTD.ConclusionsOur findings reveal distinct abnormalities in the functional network topology and connectivity in AD and FTD, which may contribute to a better understanding of the pathophysiological mechanisms of these diseases. Specifically, patients with AD demonstrated a more widespread change in functional connectivity, while those with FTD retained connectivity in the occipital lobe. These observations could provide valuable insights for developing electrophysiological markers to differentiate between the two diseases.

Cortical Generators and Connections Underlying Phoneme Perception: A Mismatch Negativity and P300 Investigation.

The cortical generators of the pure tone MMN and P300 have been thoroughly studied. Their nature and interaction with respect to phoneme perception, however, is poorly understood. Accordingly, the cortical sources and functional connections that underlie the MMN and P300 in relation to passive and active speech sound perception were identified.An inattentive and attentive phonemic oddball paradigm, eliciting a MMN and P300 respectively, were administered in 60 healthy adults during simultaneous high-density EEG recording. For both the MMN and P300, eLORETA source reconstruction was performed. The maximal cross-correlation was calculated between ROI-pairs to investigate inter-regional functional connectivity specific to passive and active deviant processing.MMN activation clusters were identified in the temporal (insula, superior temporal gyrus and temporal pole), frontal (rostral middle frontal and pars opercularis) and parietal (postcentral and supramarginal gyrus) cortex. Passive discrimination of deviant phonemes was aided by a network connecting right temporoparietal cortices to left frontal areas. For the P300, clusters with significantly higher activity were found in the frontal (caudal middle frontal and precentral), parietal (precuneus) and cingulate (posterior and isthmus) cortex. Significant intra- and interhemispheric connections between parietal, cingulate and occipital regions constituted the network governing active phonemic target detection. A predominantly bilateral network was found to underly both the MMN and P300.While passive phoneme discrimination is aided by a fronto-temporo-parietal network, active categorization calls on a network entailing fronto-parieto-cingulate cortices. Neural processing of phonemic contrasts, as reflected by the MMN and P300, does not appear to show pronounced lateralization to the language-dominant hemisphere.

Neural underpinnings of memory encoding and retrieval: Validation of a novel ecologically valid fMRI paradigm

Cognitive impairment is prevalent in affective disorders. Currently, there is a lack of effective treatment options, which is partly due to limited insight into their neural underpinnings and poor transfer to everyday life. Integrating neuroimaging measures in cognition trials to identify neurocircuitry biomarkers is crucial for treatment development. We pooled baseline data from two clinical trials to validate a novel functional magnetic resonance imaging (fMRI) paradigm simulating real-life verbal learning and memory tasks. Healthy participants with no psychiatric history (n = 34) underwent fMRI and an ecologically valid virtual reality-based verbal memory task. During fMRI, they performed an ecologically valid paradigm involving encoding and recognition of a grocery shopping list. Whole-brain analyses assessed task-related activation in key neural networks. Neural underpinnings of memory encoding involved the hippocampus, prefrontal, temporal, occipital, and parietal regions, and caudate. Recognition task activation encompassed a network of frontal, parietal, temporal, and occipital regions. Positive associations were found between encoding-related activity in the inferior temporal gyrus and lateral occipital cortex and the number of correctly recalled grocery items. This study introduces and validates a novel fMRI paradigm for assessing real-life verbal learning and memory abilities. The identified neural underpinnings highlight the involvement of diverse brain regions in encoding and recognition processes that may be implemented in future investigations of the neural correlates of memory impairment and improvement.