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Progressive multifocal leukoencephalopathy (PML) is a rare central nervous system disease caused by JC virus (JCV) infection. Human immunodeficiency virus (HIV) infection is the greatest risk factor for PML. Other immunological diseases, including systemic sarcoidosis, have also been reported as risk factors for PML. Herein, we report a case of PML co-occurring with neurosarcoidosis. Early diagnosis using brain biopsy and appropriate therapeutic interventions achieved favorable outcomes. PML in patients with active intracranial neurosarcoidosis is extremely rare. We believe that it is important to perform brain biopsy at an early stage to allow diagnosis, even for central nervous system involvement with a progressive parenchymal lesion in patients with sarcoidosis, if PML is possible. [ABSTRACT FROM AUTHOR]

In this study, a new approach is presented that eliminates stereotactic frameworks and the use of markers, offering an alternative to traditional brain biopsy systems. The classical biopsy operation involves the registration of magnetic resonance (MR) and computed tomography (CT) information taken from the patient at different times. Typically, the surgeon's planning information, which takes an average of 4 h on MR, is transferred to CT, and the surgical operation commences. However, this approach necessitates two separate acquisitions (MR and CT), adversely affecting patient comfort and increasing the workload. In the proposed system, it is recommended to register MR‐Depth camera data instead of MR‐CT registration. To achieve this, a 3D face pattern is obtained from the data received from the depth camera attached to the robot arm and overlapped with the mesh obtained by segmentation of the MR. It was observed that registration with sub‐millimeter precision was achieved using the CMFreg surface registration technique. [ABSTRACT FROM AUTHOR]

Abstract Background Progressive multifocal leukoencephalopathy (PML) is a severe opportunistic brain disease caused by lytic JC polyomavirus (JCPyV) replication in oligodendrocytes. Although JCPyV infection is common in the general population, PML almost exclusively occurs in patients immunocompromised due to untreated HIV/AIDS, haematological malignancies, primary immunodeficiencies, solid organ transplantation, or immunomodulatory treatment of autoimmune diseases. There is no effective antiviral treatment, and recovery depends on immune reconstitution. Paradoxically, initiation of antiretroviral therapy for HIV/AIDS or interruption of immunomodulating treatment can worsen the clinical manifestations due to immune reconstitution inflammatory syndrome (IRIS). Here, we report an unusual case of spontaneous IRIS in a 76-year-old immunocompetent woman, unmasking PML and leading to unexpected recovery. Case presentation The patient was admitted to the hospital due to psychosis, speech impairment, and behavioral changes over the last three months. She had previously been healthy, except for a cerebellar stroke secondary to paroxysmal atrial fibrillation. Magnetic resonance imaging (MRI) revealed multiple contrast-enhancing white matter lesions suspicious of cancer metastases. Due to suspicion of edema, dexamethasone was administered, and the patient was released while waiting for a stereotactic brain biopsy. Eight days later, she suffered tonic seizures and was readmitted. Intravenous levetiracetam gave rapid effect, but the patient was paranoid and non-cooperative, and dexamethasone was unintentionally discontinued. Ten days later, the brain biopsy revealed demyelination, abundant perivascular T cells, macrophages, and scattered JCPyV-infected oligodendrocytes, rendering the diagnosis of PML-IRIS. The cerebrospinal fluid contained low amounts of JCPyV-DNA, and plasma contained high levels of anti-JCPyV immunoglobulin G. Despite extensive immunological testing, no evidence of immunodeficiency was found. The patient gradually recovered clinically and radiologically. More than 19 months after diagnosis, the patient has only a slight impairment in language and behavior. Conclusions An apparently immunocompetent elderly person developed clinically symptomatic PML, which spontaneously resolved with symptoms and signs of IRIS. The atypical MRI lesions with contrast enhancement and the lack of known immunological risk factors for PML delayed the diagnosis, eventually proved by biopsy. PML and PML-IRIS should be considered in the differential diagnosis of patients presenting CNS symptoms and focal lesions with contrast enhancement on MRI.

Isolated tumefactive demyelinating lesions (≥2 cm) may be difficult to distinguish from contrast-enhancing brain tumors, central nervous system infections, and (rarely) tissue dysgenesis, which may all occur with increased signal on T2-weighted images. Establishing an accurate diagnosis is essential for management, and we delineate our single-center experience. We performed a retrospective review of medical records, imaging, and biopsy specimens for patients under 18 years presenting with isolated tumefactive demyelination over a 10-year period. Ten children (eight female) met inclusion criteria, with a median age of 14.1 years. Lesions were most likely to involve the thalamus (six of 10), brainstem (five of 10), basal ganglia (four of 10), or corpus callosum (four of 10). Eighty percent had perilesional edema at presentation, and 60% had midline shift. Biopsies demonstrated demyelination with perivascular lymphocytic infiltration and axonal damage ranging from mild to severe. All patients were initially treated with high-dose corticosteroids, and eight of 10 required additional medical therapies such as intravenous immunoglobulin, plasmapheresis, cyclophosphamide, or rituximab. Increased intracranial pressure was managed aggressively with two of 10 patients requiring decompressive craniectomies. Clinical outcomes varied. Solitary tumefactive demyelinating lesions are rare, and aggressive management of inflammation and increased intracranial pressure is essential. Biopsy is helpful to evaluate for other diagnoses on the differential and maximize therapies. Treatment beyond initial therapy with corticosteroids is often required. Isolated tumefactive demyelinating lesions are uncommon; multicenter natural history studies are needed to better delineate differential diagnoses and optimal therapies. [ABSTRACT FROM AUTHOR]

Purpose: Postoperative management following elective cranial surgery, particularly after biopsy procedures, varies significantly across neurosurgical centres. Routine postoperative head CT scans, traditionally performed to detect complications such as intracranial bleeding or cerebral oedema, lack substantial evidence supporting their necessity. Methods: This study is a retrospective cohort analysis conducted at a regional neurosurgical department of 236 patients who underwent brain biopsies between 2018 and 2022. Patient data, including demographics, surgical details, and postoperative outcomes, were collected and analysed. The outcomes investigated were the incidence and impact of postoperative CT scans on time to discharge, management changes, and the influence of preoperative anticoagulation. Results: Out of 236 patients, 205 (86.86%) underwent postoperative CT scans. There was no significant relationship between postoperative hematoma, as detected on a CT scan, and neurological deficit (p = 0.443), or between preoperative anticoagulation and postoperative bleeding on CT scans (p = 0.464). Patients who had postoperative CT scans had a significantly longer length of stay (LOS) compared to those who did not (p < 0.001). Intraoperative bleeding was a predictor of hematoma on postoperative CT (p = 0.017) but not of postoperative neurological deficit. The routine postoperative CT scan showed limited predictive value for symptomatic deficits, with a positive predictive value of 6.67% and a negative predictive value of 96.88%. Conclusions: Routine postoperative CT scans after brain biopsies do not significantly impact management or improve patient outcomes but are associated with longer hospital stays. CT scans should be reserved for patients showing clinical signs of complications rather than used as a routine procedure after a brain biopsy. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) printed models are used in the medical field. This study aimed to evaluate the feasibility and safety of a 3D-printed guide plate for use in brain biopsy. Twelve patients with intracranial lesions were retrospectively reviewed to determine clinical outcomes and technical procedural operability. These patients underwent brain biopsy assisted with the 3D-printed guide plate. Postoperative computed tomography was performed to assess the accuracy and associated complications of this guide plate. All patients received definite diagnoses assisted by this guide plate. The deviations of the entry and target points were 3.93 ± 0.96 mm and 2.59 ± 0.11 mm, respectively. The angle drift of the puncture path was 5.12° ± 0.14°, and the deviation of the puncture depth was 2.35 ± 1.13 mm. The operation time ranged from 38.5 minutes with local anesthesia to 76.2 minutes with general anesthesia. No patient experienced complications. The 3D-printed guide plate was noninvasive and had acceptable accuracy and the flexibility of frameless systems. The economic and operative benefits of this device supported its status as a powerful tool for brain biopsy in medical facilities in economically disadvantaged areas or institutions without navigation systems. [ABSTRACT FROM AUTHOR]

Diagnosis of intracranial tuberculoma remains a challenge due to its rarity, non-specific clinical presentation, and radiological findings. Herein, we describe a case of intracranial tuberculomas in a male diabetic patient who presented headache and vomiting on admission. Neuroimaging findings indicated multiple ring contrast-enhanced lesions with extensive perilesional edema. However, a cerebrospinal fluid (CSF) examination was normal. When a biopsy of brain lesions was performed, pathological characteristics of tuberculosis were absent and acid-fast staining was negative. A tuberculosis diagnosis was subsequently obtained from an Xpert MTB/RIF Ultra assay of formalin-fixed paraffin-embedded brain tissue. The patient was treated with an optimized anti-tuberculosis regimen which included high-dose intravenous administration of rifampicin and isoniazid, and oral administration of linezolid. The patient recovered well and exhibited marked clinical improvement. This case report demonstrates that when CSF analysis does not indicate the presence of intracranial tuberculomas, analysis of formalin-fixed paraffin-embedded brain tissue specimens with the Xpert MTB/RIF Ultra assay may be able to confirm a diagnosis. Furthermore, a high dose of rifampicin and isoniazid plus linezolid may improve patient outcome.

Abstract Post-malaria neurological syndrome (PMNS) is a rare, self-limiting condition that presents with a wide range of neurological manifestations after clearance of malarial infection, especially 𝘗𝘭𝘢𝘴𝘮𝘰𝘥𝘪𝘶𝘮 f𝘢𝘭𝘤𝘪𝘱𝘢𝘳𝘶𝘮, most patients recover without residual deficits. Here we present a case of a 29-year-old, male with a recent history of malaria treated successfully, who presented due to a generalized tonic-clonic seizure, without any other neurological symptoms, the examination and labs were unremarkable, he underwent a computer tomography (CT) scan and Magnetic resonant imaging (MRI) which both showed two areas of vasogenic edema involving the subcortical white matter of left frontal and right posterior parasagittal regions, all autoimmune screens, infection workup from blood and CSF were negative, he underwent a brain biopsy that showed intense perivascular inflammation with neuronal loss and gliosis, findings are nonspecific and can be seen in a variety of condition. The patient’s condition improved, and he was discharged without any complications.

The objective of this study was to evaluate the accuracy of a CT-based, 3D-printed, patient-specific brain biopsy guide (3D-psBBG) through the application of a transfrontal approach in canine cadavers. A total of ten canine cadavers, with weights ranging from 4.36 to 14.4 kg, were subjected to preoperative CT scans to generate 3D skull models. Customized biopsy guides were created based on these models and manufactured using 3D printing technology. Twenty spinal needle insertions were performed, and the accuracy of needle placement was evaluated through both CT and 3D volume-rendering techniques. The mean needle placement error was 2.1 mm, with no significant differences observed between insertions targeting the fronto-olfactory and piriform lobes. The 3D volume-rendering method demonstrated superior accuracy compared to the CT method, with statistically significant differences in placement errors for both targets. The average time required for the design and manufacture of the guides was 249 min. These findings indicate the high accuracy and potential clinical application of CT-based 3D-psBBG for improving diagnostic outcomes in veterinary neurology.

The use of stereotactic frames is a common practice in neurosurgical interventions such as brain biopsy and deep brain stimulation. However, conventional stereotactic frames have been shown to require modification and adaptation regarding patient and surgeon comfort as well as the increasing demand for individualized medical treatment. To meet these requirements for carrying out state-of-the-art neurosurgery, a 3D print-based, patient-specific stereotactic system was developed and examined for technical accuracy. Sixteen patient-specific frames, each with two target points, were additively manufactured from PA12 using the Multi Jet Fusion process. The 32 target points aim to maximize the variability of biopsy targets and depths for tissue sample retrieval in the brain. Following manufacturing, the frames were measured three-dimensionally using an optical scanner. The frames underwent an autoclave sterilization process prior to rescanning. The scan-generated models were compared with the planned CAD models and the deviation of the planned target points in the XY-plane, Z-direction and in the resulting direction were determined. Significantly lower (p < 0.01) deviations were observed when comparing CAD vs. print and print vs. sterile in the Z-direction (0.17 mm and 0.06 mm, respectively) than in the XY-plane (0.46 mm and 0.16 mm, respectively). The resulting target point deviation (0.51 mm) and the XY-plane (0.46 mm) are significantly higher (p < 0.01) in the CAD vs. print comparison than in the print vs. sterile comparison (0.18 mm and 0.16 mm, respectively). On average, the results from the 32 target positions examined exceeded the clinically required accuracy for a brain biopsy (2 mm) by more than four times. The patient-specific stereotaxic frames meet the requirements of modern neurosurgical navigation and make no compromises when it comes to accuracy. In addition, the material is suitable for autoclave sterilization due to resistance to distortion. [ABSTRACT FROM AUTHOR]

Objective: Multiple ring-enhancing lesions of the brain are enigmatic neuroimaging abnormality. In this systematic review, we evaluated the etiological spectrum of these lesions. Methods: This systematic review adhered to the PRISMA guidelines. We searched PubMed, Embase, Scopus, and Google Scholar up until 15 June 2023. We included case reports and case series. Quality evaluation of each case was based on selection, ascertainment, causality, and reporting. The extracted information included demographic characteristics, clinical features, type and number of multiple enhancing brain lesions, diagnostic procedures, final diagnoses, treatments, and patient outcomes. Protocol Registration: PROSPERO CRD42023437081. Results: We analyzed 156 records representing 161 patients, 60 of whom were immunocompromised. The mean age was 42.6 years, and 67% of patients experienced symptoms for up to 1 month. A higher proportion of immunocompromised patients (42% vs. 30%) exhibited encephalopathy. Chest or CT thorax abnormalities were reported in 27.3% of patients, while CSF abnormalities were found in 31.7%, more frequently among the immunocompromised. Definitive diagnoses were established via brain biopsy, aspiration, or autopsy in 60% of cases, and through CSF examination or other ancillary tests in 40% of cases. Immunocompromised patients had a higher incidence of Toxoplasma gondii infection and CNS lymphoma, while immunocompetent patients had a higher incidence of Mycobacterium tuberculosis infection and immune-mediated and demyelinating disorders. The improvement rate was 74% in immunocompetent patients compared to 52% in the immunocompromised group. Conclusion: Multiple ring-enhancing lesions of the brain in immunocompromised patients are more frequently caused by Toxoplasma gondii infections and CNS lymphoma. Conversely, among immunocompetent patients, Mycobacterium tuberculosis infection and immune-related demyelinating conditions are common. [ABSTRACT FROM AUTHOR]

Post-malaria neurological syndrome (PMNS) is a rare, self-limiting condition that presents with a wide range of neurological manifestations after clearance of malarial infection, especially 혗혭혢혴혮혰혥혪혶혮 f혢혭혤혪혱혢혳혶혮, most patients recover without residual deficits. Here we present a case of a 29-year-old, male with a recent history of malaria treated successfully, who presented due to a generalized tonic-clonic seizure, without any other neurological symptoms, the examination and labs were unremarkable, he underwent a computer tomography (CT) scan and Magnetic resonant imaging (MRI) which both showed two areas of vasogenic edema involving the subcortical white matter of left frontal and right posterior parasagittal regions, all autoimmune screens, infection workup from blood and CSF were negative, he underwent a brain biopsy that showed intense perivascular inflammation with neuronal loss and gliosis, findings are nonspecific and can be seen in a variety of condition. The patient's condition improved, and he was discharged without any complications. [ABSTRACT FROM AUTHOR]

Abstract Background Cerebral Amyloid Angiopathy-related inflammation (CAA-ri) is a distinct but rare subset of CAA. The greater availability of high resolution Magnetic Resonance Imaging (MRI) has currently allowed the increasing recognition and diagnosis of this entity, without the risk of a brain biopsy. However, in rare cases with typical clinical characteristics but uncommon neuroimaging findings at presentation, the brain-biopsy is required for an early and reliable diagnosis. Case description A 71-year-old man with arterial hypertension presented due to 1-week history of headache, vomiting, disorientation and impaired consciousness. Brain MRI revealed multiple acute cortical/subcortical microinfarcts, scarce microbleeds, extensive right parietooccipital and left frontotemporal leptomeningeal enhancement. After an extensive diagnostic work-up, excluding infectious, neoplastic and autoimmune etiologies, the patient underwent brain-biopsy. Histology disclosed amyloid deposition in an arteriolar wall and the patient fulfilled diagnostic criteria for probable CAA-ri with supporting pathology. He received intravenous methylprednisolone, followed by oral tapering with steroids showing clinical and radiological improvement with complete resolution of gadolinium enhancement. Follow-up MRI revealed an increase of cerebral microbleeds and the patient fulfilled CAA-ri neuroimaging criteria. Conclusions This case highlights the importance of continuous vigilance from clinical neurologists to detect CAA-ri diagnosis and the diagnostic value of brain-biopsy in CAA-ri patients with atypical neuroimaging presentation, such as acute microinfarcts. The early diagnosis and the prompt treatment initiation can improve the prognosis and the evolution of this rare disorder.

Acute hemorrhagic leukoencephalitis (AHLE), is a rare inflammatory demyelinating disorder, variant of acute disseminated encephalomyelitis. The diagnosis of AHLE remains challenging due to the rarity of the disease and the lack of a reliable biomarker. We report here a case of a 73-year-old male patient with a progressive, low-grade febrile confusional syndrome 20 days after receiving the first dose of BNT162b2 vaccine against SARS-CoV-2. Evidence indicative of the underlying condition by an extensive panel of imaging (brain magnetic resonance imaging, computed tomography and digital subtraction angiography), laboratory (complete blood count, biochemistry, coagulation, tests for autoimmune or infectious disorders, tumor markers, hormonal levels, cerebrospinal fluid analysis) and electrodiagnostic tests were scarce, and mainly non-specific. Sequential neuroimaging revealed the appearance of extensive T2 lesions (signs of gliosis) along with multiple hemorrhagic lesions at various cortical sites. The patient was treated with corticosteroids, discontinued due to severe adverse effects, and subsequently with sessions of plasmapheresis and monthly intravenous administration of cyclophosphamide. Considering the rapid aggravation of the patient's neurological status, the MRI findings of cortical lesions and the lack of response to any treatment, a biopsy of a frontal lobe lesion was conducted, confirming the presence of confluent, inflammatory-edematous lesions with scattered areas of necrosis and hemorrhage, and ultimately areas of demyelination, thus confirming the diagnosis of AHLE. After more than 5 months of hospitalization the patient was transferred in a primary care facility and remained in a permanent vegetative state until his death, more than 2 years later.

IntroductionPrimary angiitis of the central nervous system (PACNS) is an uncommon inflammatory condition that exclusively affects blood vessels within the brain parenchyma, leptomeninges, and spinal cord. Due to its infrequency and the variability in its clinical presentation and imaging findings, diagnosing PACNS can be challenging.Case descriptionIn this study, we present the case of a teenager who initially presented with headaches and epilepsy. Comprehensive laboratory tests yield normal results. A series of brain magnetic resonance imaging (MRI) revealed a progression of changes, starting from localized cerebral atrophy and culminating in the development of a contrast-enhanced mass with vasogenic edema. Immune-associated encephalitis and mitochondrial encephalopathy were suspected, but immunologic investigations, mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) sequencing using biopsied muscle, and muscle pathologies were all negative. Ultimately, a diagnosis of PACNS was confirmed through a stereotactic brain biopsy, which took place 3.5 years after the onset of symptoms. The patient responded favorably to treatment with glucocorticoids and cyclophosphamide.ConclusionIn summary, we have described a case of PACNS characterized by localized cerebral atrophy and tumor-like MRI findings, who was misdiagnosed as immune-associated encephalitis or mitochondrial encephalopathy for 3.5 years. We emphasize the importance of dynamic observation of MRI changes, as well as brain biopsy.

Primary CNS vasculitis (CNSV) is a rare, idiopathic autoimmune disease that, if untreated, can cause significant morbidity and mortality. It is a challenging diagnosis due to multiple mimics that can be difficult to differentiate, given that the CNS is an immunologically privileged and structurally isolated space. As such, diagnosis requires comprehensive multimodal investigations. Usually, a brain biopsy is required to confirm the diagnosis. Treatment of CNSV involves aggressive immunosuppression, but relapses and morbidity remain common. This expert review provides the reader with a deeper understanding of presentations of CNSV and the multiple parallel diagnostic pathways that are required to diagnose CNSV (and recognize its mimics), highlights the important knowledge gaps that exist in the disease and also highlights how we might be able to care for these patients better in the future. [ABSTRACT FROM AUTHOR]

Connectomics allows mapping of cells and their circuits at the nanometer scale in volumes of approximately 1 mm3. Given that the human cerebral cortex can be 3 mm in thickness, larger volumes are required. Larger-volume circuit reconstructions of human brain are limited by 1) the availability of fresh biopsies; 2) the need for excellent preservation of ultrastructure, including extracellular space; and 3) the requirement of uniform staining throughout the sample, among other technical challenges. Cerebral cortical samples from neurosurgical patients are available owing to lead placement for deep brain stimulation. Described here is an immersion fixation, heavy metal staining, and tissue processing method that consistently provides excellent ultrastructure throughout human and rodent surgical brain samples of volumes 2 × 2 × 2 mm3 and up to 37 mm3 with one dimension ≤2 mm. This method should allow synapse-level circuit analysis in samples from patients with psychiatric and neurologic disorders. [ABSTRACT FROM AUTHOR]

Introduction: This study was performed to examine whether there is a link between the application of three types of robot-guided stereotactic biopsy techniques and the diagnostic rate of intracranial lesion biopsy. Methods: The study involved 407 patients who underwent robot-guided stereotactic intracranial lesion biopsy at Xuanwu Hospital of Capital Medical University from January 2019 to December 2021. Age, sex, lesion characteristics, lesion distribution, surgical method, and target path depth were assessed for their impact on the biopsy diagnostic rate. Results: The patients' mean age was 42.1 years (range, 6 months-82 years). All patients underwent robot-assisted stereotactic brain biopsy using one of three different systems: a ROSA robotic system (n=35), the CAS-R-2 (n=65), or the REMEBOT domestic robotic system (n=307). No significant difference was found in the diagnostic rate of positive histopathological findings or the mean time of surgery among the three biopsy modalities. The diagnostic rate was 93.86%. Multiple linear regression analysis showed that age, sex, and biopsy modality did not affect the diagnostic rate n>0.05), whereas enhancing lesions and smallervolume lesions (=l cm3) were significantly correlated with the diagnostic rate (p = 0.01). Lesions located in the suprasellar and pineal regions were significantly associated with the negative diagnostic rate (p<0.05). Conclusion: The presence of enhancing lesions, lesion location, and lesion volume significantly affected the diagnostic rate of brain biopsy. Age, sex, lesion depth, and biopsy modality did not significantly affect the diagnostic rate. All three procedures had high safety and effectiveness. [ABSTRACT FROM AUTHOR]

Background: Cerebral Amyloid Angiopathy-related inflammation (CAA-ri) is a distinct but rare subset of CAA. The greater availability of high resolution Magnetic Resonance Imaging (MRI) has currently allowed the increasing recognition and diagnosis of this entity, without the risk of a brain biopsy. However, in rare cases with typical clinical characteristics but uncommon neuroimaging findings at presentation, the brain-biopsy is required for an early and reliable diagnosis. Case description: A 71-year-old man with arterial hypertension presented due to 1-week history of headache, vomiting, disorientation and impaired consciousness. Brain MRI revealed multiple acute cortical/subcortical microinfarcts, scarce microbleeds, extensive right parietooccipital and left frontotemporal leptomeningeal enhancement. After an extensive diagnostic work-up, excluding infectious, neoplastic and autoimmune etiologies, the patient underwent brain-biopsy. Histology disclosed amyloid deposition in an arteriolar wall and the patient fulfilled diagnostic criteria for probable CAA-ri with supporting pathology. He received intravenous methylprednisolone, followed by oral tapering with steroids showing clinical and radiological improvement with complete resolution of gadolinium enhancement. Follow-up MRI revealed an increase of cerebral microbleeds and the patient fulfilled CAA-ri neuroimaging criteria. Conclusions: This case highlights the importance of continuous vigilance from clinical neurologists to detect CAA-ri diagnosis and the diagnostic value of brain-biopsy in CAA-ri patients with atypical neuroimaging presentation, such as acute microinfarcts. The early diagnosis and the prompt treatment initiation can improve the prognosis and the evolution of this rare disorder. [ABSTRACT FROM AUTHOR]

To evaluate the diagnostic performance of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) metrics for glioma grading on a point-to-point basis. Forty patients with treatment-naïve glioma underwent DCE-MR examination and stereotactic biopsy. DCE-derived parameters including endothelial transfer constant (K trans ), volume of extravascular-extracellular space (v e), fractional plasma volume (f p v), and reflux transfer rate (k ep) were measured within ROIs on DCE maps accurately matched with biopsies used for histologic grades diagnosis. Differences in parameters between grades were evaluated by Kruskal-Wallis tests. Diagnostic accuracy of each parameter and their combination was assessed using receiver operating characteristic curve. Eighty-four independent biopsy samples from 40 patients were analyzed in our study. Significant statistical differences in K trans and v e were observed between grades except v e between grade 2 and 3. K trans showed good to excellent accuracy in discriminating grade 2 from 3, 3 from 4, and 2 from 4 (area under the curve = 0.802, 0.801 and 0.971, respectively). V e indicated good accuracy in discriminating grade 3 from 4 and 2 from 4 (AUC = 0.874 and 0.899, respectively). The combined parameter demonstrated fair to excellent accuracy in discriminating grade 2 from 3, 3 from 4, and 2 from 4 (AUC = 0.794, 0.899 and 0.982, respectively). Our study had identified K trans , v e and the combination of parameters to be an accurate predictor for grading glioma. [ABSTRACT FROM AUTHOR]

Abstract Background Small vessel childhood primary angiitis of the central nervous system (SV-cPACNS) is a rare disease characterized by inflammation within small vessels such as arterioles or capillaries. Case presentation We report a case of SV-cPACNS in an 8-year-old boy confirmed by brain biopsy. This patient was also incidentally found to have anti-glial fibrillary acidic protein (GFAP) antibodies in the cerebrospinal fluid (CSF) but had no evidence of antibody-mediated disease on brain biopsy. A literature review highlighted the rarity of SV-cPACNS and found no prior reports of CSF GFAP-associated SV-cPACNS in the pediatric age group. Conclusion We present the first case of biopsy proven SV-cPACNS vasculitis associated with an incidental finding of CSF GFAP antibodies. The GFAP antibodies are likely a clinically insignificant bystander in this case and possibly in other diseases with CNS inflammation. Further research is needed to determine the clinical significance of newer CSF autoantibodies such as anti-GFAP before they are used for medical decision-making in pediatrics.

Objective To explore the application value of intraoperative frozen section analysis in stereotactic biopsy of brain lesions. Methods The clinical data of 44 patients with brain lesions from June 2015 to October 2021 were analyzed retrospectively. Intraoperative frozen pathology analysis was applied in all 46 procedures, immunohistochemical examination was applied if necessary. Regular pathological results were used as the gold standard for diagnosis, and the diagnostic rate, delayed diagnostic rate and misdiagnosis rate of frozen results were judged. The diagnostic positive rate, diagnostic coincidence rate and influencing factors of frozen pathology during operation were analyzed. Results Of the 44 patients who underwent 46 biopsies, 9 patients had negative results in the first intraoperative freezing, and 7 of them had positive results after adjusting the depth of puncture and re-biopsy. 23 patients were diagnosed by intraoperative immunohistochemistry. In the end, 44 patients (96.65%) had positive intraoperative freezing results, and the diagnostic accuracy rate was 91.3% （35 cases were confirmed+7 cases were delayed). The results of puncture biopsy included 27 cases of glioma (6 cases of WHO grade Ⅰ-Ⅱ, 21 cases of WHO grade Ⅲ-Ⅳ12cases of lymphoma, 4 cases of germinoma, and 1 case of amyloidosis. Conclusions Although intraoperative frozen pathology leads to more operation time consuming, it can quickly uncover the pathology of biopsy specimens, avoid excessive sampling improve operation efficiency and reduce surgical complications. Intraoperative frozen pathology can be applied in robot-assisted stereotactic brain lesion biopsy. [ABSTRACT FROM AUTHOR]

Background: Small vessel childhood primary angiitis of the central nervous system (SV-cPACNS) is a rare disease characterized by inflammation within small vessels such as arterioles or capillaries. Case presentation: We report a case of SV-cPACNS in an 8-year-old boy confirmed by brain biopsy. This patient was also incidentally found to have anti-glial fibrillary acidic protein (GFAP) antibodies in the cerebrospinal fluid (CSF) but had no evidence of antibody-mediated disease on brain biopsy. A literature review highlighted the rarity of SV-cPACNS and found no prior reports of CSF GFAP-associated SV-cPACNS in the pediatric age group. Conclusion: We present the first case of biopsy proven SV-cPACNS vasculitis associated with an incidental finding of CSF GFAP antibodies. The GFAP antibodies are likely a clinically insignificant bystander in this case and possibly in other diseases with CNS inflammation. Further research is needed to determine the clinical significance of newer CSF autoantibodies such as anti-GFAP before they are used for medical decision-making in pediatrics. [ABSTRACT FROM AUTHOR]

A nine-year-old boy manifested with headache, progressive mild cognitive decline and hemiparesis, but without clinical epileptic seizures (with abnormal EEG waves). Brain magnetic resonance imaging (MRI) showed bilateral cortical lesions mainly on the right hemisphere, and new lesions developed in frontal, parietal, occipital and temporal lobes around the old lesions presenting as a lace-like or ring-like enhancement in T1 with contrast over a disease course of five years. A suspected diagnosis of primary angiitis of the central nervous system was initially considered. Treated with high-dose corticosteroids, intravenous immunoglobulins and monthly pulse cyclophosphamide, his symptoms worsened with the intracranial lesion progression. Brain biopsy of the right frontal lobe was performed nearly five years after onset; prominent neuronal loss, a microglial nodule, as well as parenchymal and perivascular lymphocytic infiltrate within the cortex were found, which coincided with RE pathology changes. Encouragingly, after a regimen of rituximab, lesions on the follow-up brain MRI tended to be stable. Apparently, it was immune-mediated, but did not strictly fit any known disease entity, although it was similar to RE. We summarize this unique case, including clinical characteristics, imaging and pathology findings. We also discuss the diagnosis and treatment, focusing on comparison to RE as well as other possible neurological diseases. [ABSTRACT FROM AUTHOR]

Introduction: Lymphomatosis cerebri (LC) is a rare variant of primary central nervous system lymphoma that diffusely involves throughout the brain. In recent years, increasingly reported cases have notably broadened the spectrum of clinical and radiological features; however, it remains a great diagnostic challenge.Case Report: We reported an atypical case of LC presented with subacute onset of focal neurological deficits and diffuse T2 hyperintensities without contrast enhancement on magnetic resonance imaging. He was initially considered as inflammatory leukoencephalopathy and received empirical corticosteroids, showing a dramatically clinical response. Three months later, the patient relapsed with deteriorating symptoms and enlarged brain lesions with mass-like enhancement. A diagnosis of LC was finally established according to the radiological and pathological findings.Discussion: Though rare, LC should always be kept as a differential diagnosis of diffuse leukoencephalopathy. Neurologists should be aware of every detailed information about LC to avoid a delay of diagnostic biopsy in clinical practice. [ABSTRACT FROM AUTHOR]

Abstract Background Seizures in the early postoperative period after intracranial surgery may affect outcome in dogs. Objectives To determine the incidence of early postoperative seizures (EPS) in dogs with brain tumors, identify specific risk factors for EPS, and determine if EPS affects outcome. Animals Eighty‐eight dogs that underwent 125 intracranial surgeries for diagnosis and treatment of rostrotentorial brain tumors. Methods Retrospective cohort study. All patients with a diagnosis of rostrotentorial brain tumor from 2006 to 2020 were included. Early postoperative seizures were diagnosed by observation of seizure activity within 14 days of neurosurgery. Previously diagnosed structural epilepsy, perioperative anticonvulsant drug (ACD) use, magnetic resonance imaging (MRI), and tumor characteristics were evaluated. Outcome measures included neurologic and nonneurologic complications, duration of hospitalization, and survival to discharge. Results Dogs with rostrotentorial brain tumors had EPS after 16/125 (12.8%) neurosurgical procedures (95% confidence interval [CI], 7%‐19%). Presence of previous structural epilepsy was not associated with EPS risk (P = 1). Perioperative ACD use also was not associated with EPS (P = .06). Dogs with EPS had longer hospitalization (P

Primary angiitis of the central nervous system (PACNS) is a rare inflammatory disease that affects both small- and medium-sized vessels of the CNS, while myelin oligodendrocyte glycoprotein (MOG) antibody–associated disease (MOGAD) is a novel antibody-mediated inflammatory demyelinating disorder that causes damage to the myelin in CNS. We report a case diagnosed as MOGAD due to a history of recurrent myelitis, brain lesions, and positive anti-MOG, but the brain biopsy showed vasculitis without demyelination. [ABSTRACT FROM AUTHOR]

Introduction: Brain biopsy provides important histopathological diagnostic information for patients with new intracranial lesions. Although a minimally invasive technique, previous studies report an associated morbidity and mortality between 0.6% and 6.8%. We sought to characterise the risk linked to this procedure, and to establish the feasibility of instigating a day-case brain biopsy pathway at our institution. Materials and methods: This single-centre retrospective case series study included neuronavigation guided mini craniotomy and frameless stereotactic brain biopsies carried out between April 2019 and December 2021. Exclusion criteria were interventions performed for non-neoplastic lesions. Demographic data, clinical and radiological presentation, type of biopsy, histology and complications in the post-operative period were recorded. Results: Data from 196 patients with a mean age of 58.7 years (SD+/-14.4 years) was analysed. 79% (n=155) were frameless stereotactic biopsies and 21% (n=41) neuronavigation guided mini craniotomy biopsies. Complications resulting in acute intracerebral haemorrhage and death, or new persistent neurological deficits were observed in 2% of patients (n=4; 2 frameless stereotactic; 2 open). Less severe complications or transient symptoms were noted in 2.5% of cases (n=5). 8 patients had minor haemorrhages in the biopsy tract with no clinical ramifications. Biopsy was non-diagnostic in 2.5% (n=5) of cases. Two cases were subsequently identified as lymphoma. Other reasons included insufficient sampling, necrotic tissue, and target error. Discussion and conclusion: This study demonstrates that brain biopsy is a procedure with an acceptably low rate of severe complications and mortality, in line with previously published literature. This supports the development of day-case pathway allowing improved patient flow, reducing the risk of iatrogenic complications associated with hospital stay, such as infection and thrombosis.

A novel agar-based phantom was developed and assessed for ultrasonography (USG)-guided brain biopsy training. The phantom provides visual cues combined with sonologic cues, allowing multimodal training. Impact of multimodal training is evaluated through pretraining and posttraining trials. Twenty-five participants were divided based on experience with USG-based procedures into familiar (≥3 procedures performed in the past) (n = 14) and unfamiliar (<3 procedures performed) (n = 11). Agar phantoms with an opaque top and transparent middle layer were constructed in transparent glass bowls, each having 12 embedded targets. Participants underwent 2 supervised trials of USG-guided biopsy with aluminum foil covering the glass bowls, eliminating visual cues. Between 2 trials, participants underwent unsupervised self-training on a phantom without foil cover, providing visual cues. Performance was measured through insonation efficiency (EfI), biopsy efficiency (EfB), efficiency score (Ef), error score (Er), and performance score (PS). Scores were compared between and within the 2 groups before and after training. Impact of the self-training session on subjective comfort levels with the procedure was assessed through feedback forms. Familiars had better pretraining EfB, Ef, Er, and PS (P < 0.001) compared with unfamiliars. After training, both performed similarly on all metrics. After training, familiars improved only in EfI (P = 0.001), with the unfamiliars showing significance in all metrics except EfI. Simulation and phantom-based models can never supplant training through supervised skill application in vivo but our model supplements training by enabling technical skill acquisition, especially for beginners in USG-guided brain biopsy. [ABSTRACT FROM AUTHOR]

Background: Neurosurgical procedures are complex and require years of training and experience. Traditional training on human cadavers is expensive, requires facilities and planning, and raises ethical concerns. Therefore, the use of anthropomorphic phantoms could be an excellent substitute. The aim of the study was to design and develop a patient-specific 3D-skull and brain model with realistic CT-attenuation suitable for conventional and augmented reality (AR)-navigated neurosurgical simulations. Methods: The radiodensity of materials considered for the skull and brain phantoms were investigated using cone beam CT (CBCT) and compared to the radiodensities of the human skull and brain. The mechanical properties of the materials considered were tested in the laboratory and subsequently evaluated by clinically active neurosurgeons. Optimization of the phantom for the intended purposes was performed in a feedback cycle of tests and improvements. Results: The skull, including a complete representation of the nasal cavity and skull base, was 3D printed using polylactic acid with calcium carbonate. The brain was cast using a mixture of water and coolant, with 4 wt% polyvinyl alcohol and 0.1 wt% barium sulfate, in a mold obtained from segmentation of CBCT and T1 weighted MR images from a cadaver. The experiments revealed that the radiodensities of the skull and brain phantoms were 547 and 38 Hounsfield units (HU), as compared to real skull bone and brain tissues with values of around 1300 and 30 HU, respectively. As for the mechanical properties testing, the brain phantom exhibited a similar elasticity to real brain tissue. The phantom was subsequently evaluated by neurosurgeons in simulations of endonasal skull-base surgery, brain biopsies, and external ventricular drain (EVD) placement and found to fulfill the requirements of a surgical phantom. Conclusions: A realistic and CT-compatible anthropomorphic head phantom was designed and successfully used for simulated augmented reality-led neurosurgical procedures. The anatomic details of the skull base and brain were realistically reproduced. This phantom can easily be manufactured and used for surgical training at a low cost. [ABSTRACT FROM AUTHOR]

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by JC virus (JCV) infection. Although recognized as an AIDS complication in the 1980s, PML has emerged as a serious adverse event of immunosuppressive therapies since 2005, particularly disease-modifying drugs (DMDs) for multiple sclerosis (MS). PML can also occur in patients with collagenous diseases receiving steroid therapy or with age-related immunosuppression. In some cases, the etiology of immunosuppression remains unclear. These cases often present with early manifestations of PML, which, while common, are less well recognized, as PML was identified at more advanced stages in AIDS-related cases. Early diagnosis poses difficulty due to unfamiliar magnetic resonance (MR) images and low viral loads in cerebrospinal fluid (CSF), and brain biopsy may be conducted. This review summarizes the PML pathology identified through biopsy. Early cytopathological changes of JCV-infected cells, with the importance of dot-shaped inclusions associated with promyelocytic leukemia nuclear bodies (PML-NBs), are described. The variability of host immune responses, including PML immune reconstitution inflammatory syndrome (PML-IRIS), is addressed. The potential role of immune checkpoint inhibitors (ICIs), such as pembrolizumab, is also explored. Understanding the pathology of early PML helps to optimize diagnostic strategies and therapeutic interventions, ultimately improving prognosis., (© 2024 The Author(s). Pathology International published by Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.)

The objective of this study was to evaluate the accuracy of a CT-based, 3D-printed, patient-specific brain biopsy guide (3D-psBBG) through the application of a transfrontal approach in canine cadavers. A total of ten canine cadavers, with weights ranging from 4.36 to 14.4 kg, were subjected to preoperative CT scans to generate 3D skull models. Customized biopsy guides were created based on these models and manufactured using 3D printing technology. Twenty spinal needle insertions were performed, and the accuracy of needle placement was evaluated through both CT and 3D volume-rendering techniques. The mean needle placement error was 2.1 mm, with no significant differences observed between insertions targeting the fronto-olfactory and piriform lobes. The 3D volume-rendering method demonstrated superior accuracy compared to the CT method, with statistically significant differences in placement errors for both targets. The average time required for the design and manufacture of the guides was 249 min. These findings indicate the high accuracy and potential clinical application of CT-based 3D-psBBG for improving diagnostic outcomes in veterinary neurology.

Background: Obtaining a definitive pathological diagnosis from brain tissue sampling was challenging due to the small, non-representative sample. This study introduced a novel syringe technique for brain biopsy aimed at enhancing diagnostic accuracy by obtaining core tissue samples that better represent the targeted tissue., Methods: The ten patients with atypical brain lesions underwent the syringe biopsy. After meticulous preoperative planning with neuronavigation, a minimally invasive approach was used: a 3 cm skin incision and a 14 mm burr hole were created. A modified 3-cc syringe was used to create negative pressure and cannulate the brain tissue. The desired sample size (24 cm³) was obtained by controlling the syringe depth and withdrawal. Medical records were reviewed to assess sample analysis results and any complications., Results: The syringe technique successfully yielded adequate tissue samples in 9 out of 10 patients. In one case, the desired tissue could not be retrieved and required a microsurgical approach for removal. In all ten cases, a correct diagnosis was made without significant complications., Conclusion: The preliminary findings suggest that the syringe technique is both safe and effective for obtaining substantial volumes of brain tissue, facilitating accurate pathological evaluation in cases of complex neurological disorders., (Copyright © 2024. Published by Elsevier Inc.)

Neuropathologic changes of Alzheimer disease (AD) including Aβ accumulation and neuroinflammation are frequently observed in the cerebral cortex of patients with idiopathic normal pressure hydrocephalus (iNPH). We created an automated analysis platform to quantify Aβ load and reactive microglia in the vicinity of Aβ plaques and to evaluate their association with cognitive outcome in cortical biopsies of patients with iNPH obtained at the time of shunting. Aiforia Create deep learning software was used on whole slide images of Iba1/4G8 double immunostained frontal cortical biopsies of 120 shunted iNPH patients to identify Iba1-positive microglia somas and Aβ areas, respectively. Dementia, AD clinical syndrome (ACS), and Clinical Dementia Rating Global score (CDR-GS) were evaluated retrospectively after a median follow-up of 4.4 years. Deep learning artificial intelligence yielded excellent (>95%) precision for tissue, Aβ, and microglia somas. Using an age-adjusted model, higher Aβ coverage predicted the development of dementia, the diagnosis of ACS, and more severe memory impairment by CDR-GS whereas measured microglial densities and Aβ-related microglia did not correlate with cognitive outcome in these patients. Therefore, cognitive outcome seems to be hampered by higher Aβ coverage in cortical biopsies in shunted iNPH patients but is not correlated with densities of surrounding microglia., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Association of Neuropathologists, Inc.)

Progressive multifocal leukoencephalopathy (PML) is a rare central nervous system disease caused by JC virus (JCV) infection. Human immunodeficiency virus (HIV) infection is the greatest risk factor for PML. Other immunological diseases, including systemic sarcoidosis, have also been reported as risk factors for PML. Herein, we report a case of PML co-occurring with neurosarcoidosis. Early diagnosis using brain biopsy and appropriate therapeutic interventions achieved favorable outcomes. PML in patients with active intracranial neurosarcoidosis is extremely rare. We believe that it is important to perform brain biopsy at an early stage to allow diagnosis, even for central nervous system involvement with a progressive parenchymal lesion in patients with sarcoidosis, if PML is possible., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Tsuboguchi, Okamoto, Tada, Kakita, Nakamichi, Oishi, Kanazawa and Onodera.)

A definitive diagnosis of brain lesions not amenable to surgery is mainly made by stereotactic needle biopsy. The diagnostic yield and safety of the frameless versus frame-based image-guided stereotactic techniques is unclear. Our objective was to evaluate the safety and accuracy of frameless versus frame-based stereotactic brain biopsy techniques. A total of 278 patients (153 men; mean age: 65.5 years) with intra-axial brain lesions underwent frame-based (n = 148) or frameless image-guided stereotactic brain biopsy (n = 130) using a minimally invasive twist drill technique during 2010–2016 at Sheba Medical Center. Demographic, imaging, and clinical data were retrospectively analyzed. The diagnostic yield (>90%) did not differ significantly between groups. Overall morbidity (6.8% vs. 8.5%), incidence of permanent neurologic deficits (2.1% vs. 1.6%), mortality rate (0.7% vs. 0.8%), and postoperative computed tomography–detected asymptomatic (14.2% vs. 16.1%) and symptomatic (2.0% vs. 1.6%) bleeding also did not differ significantly between the frame-based and frameless cohorts, respectively. The diagnostic yield and complication rates related to the biopsy technique were not significantly associated with sex, age, entry angle to the skull and skull thickness, lesion location or depth, or radiologic characteristics. Diagnostic yield was significantly associated with the mean lesion volume. Smaller lesions were less diagnostic than larger lesions in both techniques (P = 0.043 frame-based and P = 0.048 frameless). The frameless biopsy technique is as efficient as the frame-based brain biopsy technique with a low complication rate. Lesion volume was the only predictive factor of diagnostic yield. The minimally invasive twist drill technique is safe and efficient. [ABSTRACT FROM AUTHOR]

Introduction: Frame-based stereotactic biopsy is well-established to play an essential role in neurosurgery. In recent years, different robotic devices have been introduced in neurosurgery centers. This study aimed to compare the SINO surgical robot-assisted frameless brain biopsy with standard frame-based stereotactic biopsy in terms of efficacy, accuracy and complications. Methods: A retrospective analysis was performed on 151 consecutive patients who underwent stereotactic biopsy at Chongqing Sanbo Jiangling Hospital between August 2017 and December 2021. All patients were divided into the frame-based group (n = 47) and the SINO surgical robot-assisted group (n = 104). The data collected included clinical characteristics, diagnostic yield, operation times, accuracy, and postoperative complications. Results: There was no significant difference in diagnostic yield between the frame-based group and the SINO surgical robot-assisted group (95.74 vs. 98.08%, p > 0.05). The mean operation time in the SINO surgical robot-assisted group was significantly shorter than in the frame-based group (29.36 ± 13.64 vs. 50.57 ± 41.08 min). The entry point error in the frame-based group was significantly higher than in the robot-assisted group [1.33 ± 0.40mm (0.47-2.30) vs. 0.92 ± 0.27 mm (0.35-1.65), P < 0.001]. The target point error in the frame-based group was also significantly higher than in the robot-assisted group [1.63 ± 0.41 mm (0.74-2.65) vs. 1.10 ± 0.30 mm (0.69-2.03), P <0.001]. Finally, there was no significant difference in postoperative complications between the two groups. Conclusion: Robot-assisted brain biopsy becomes an increasingly mainstream tool in the neurosurgical procedure. The SINO surgical robot-assisted platform is as efficient, accurate and safe as standard frame-based stereotactic biopsy and provides a reasonable alternative to stereotactic biopsy in neurosurgery. [ABSTRACT FROM AUTHOR]

Background and purpose: An accurate histopathological examination with minimal neuronal damage is essential for optimizing treatment strategies of central nervous system lesions. We investigated the feasibility and safety of CT and 3-tesla (3 T) MR-guided freehand brain aspiration biopsies with 18/20-gauge coaxial needles in performing a single imaging unit. Materials and methods: We reviewed CT and 3 T-MR guided freehand aspiration biopsies with 18/20-gauge coaxial needles of 33 patients (11-female and 22-male, mean and median ages: 53 years, min–max 21–79 years) in our tertiary hospital within an 8-year-period were included in this retrospective study. Lesion sizes, diagnostic yield, morbidity, and mortality rates of these biopsies without a scalp incision, surgical burr-hole, or stereotactic-instrumentation/neuro-navigation guidance were assessed. All biopsies were performed with local anesthesia and sedation within a single imaging unit of our radiology department. All free-hand biopsies were done as in-patient procedures and the patients were closely observed after the biopsies. Results: The mean diameter of the lesions was 27 mm (median 25; range 15–46 mm). The diagnostic yield of all free-hand brain biopsies was 88% [one inconclusive result (90%) for 3 T-MR; three inconclusive results (87%) for CT]. There was no major hemorrhage or hematoma, no clinical deterioration, or no infection in our patients on early- and late-phase examinations. Postprocedural minor hemorrhage with a ≤ 2 cm diameter was observed in two patients. The morbidity rate of the study population is 6%. There was no procedure-related infection or mortality in the post-procedural 3 weeks. Conclusions: Freehand CT or 3 T-MR guided aspiration biopsy was a safe and feasible method for pathological diagnosis of intracranial lesions. Biopsy workflow was simplified with this technique. It could be considered a valuable alternative for stereotaxic biopsies, especially for centers that do not have stereotaxic equipment or experience. [ABSTRACT FROM AUTHOR]

Primary diffuse leptomeningeal melanomatosis is an extremely rare variant of primary melanoma of the central nervous system. It is characterized by a variety of nonspecific clinical, radiological, and histopathological features requiring differential diagnosis from a variety of diseases. Here, we aimed to use our own clinical case as an example of the difficulties in the diagnosis of this disease. A 14-year-old boy presented with focal to bilateral tonic-clonic seizures. Brain MRI showed diffuse cortical surface and subcortical lesions, isointense on T1-weighted images and hypointense on T2-weighted images, respectively, with diffuse leptomeningeal gadolinium enhancement. Cytology of the cerebrospinal fluid revealed atypical mononuclear cells, but characteristic melanoma cells were not found. Although we suspected meningeal carcinomatosis, we did not perform a brain biopsy under the tentative diagnosis of Sturge–Weber syndrome. A definitive diagnosis of primary diffuse leptomeningeal melanomatosis was made with a brain biopsy after he developed non-convulsive status epilepticus. Despite treatment, he died of hydrocephalus 1 year and 8 months after onset. Primary diffuse leptomeningeal melanomatosis poses a clinical diagnostic and therapeutic challenge. Leptomeningeal enhancement extending into the cerebral sulci and signal changes in T1/T2 weighted images of cortical and subcortical lesions on MRI are key to an early decision regarding whether to perform a biopsy, even in the pediatric population. [ABSTRACT FROM AUTHOR]

Abstract Background Brain biopsies are crucial diagnostic interventions, providing valuable information for treatment and prognosis, but largely depend on a high accuracy and precision. We hypothesized that through the combination of neuronavigation-based frameless stereotaxy and MRI-guided trajectory planning with intraoperative CT examination using a mobile unit, one can achieve a seamlessly integrated approach yielding optimal target accuracy. Methods We analyzed a total of 7 stereotactic biopsy trajectories for a variety of deep-seated locations and different patient positions. After rigid head fixation, an intraoperative pre-procedural scan using a mobile CT unit was performed for automatic image fusion with the planning MRI images and a peri-procedural scan with the biopsy cannula in situ for verification of the definite target position. We then evaluated the radial trajectory error. Results Intraoperative scanning, surgery, computerized merging of MRI and CT images as well as trajectory planning were feasible without difficulties and safe in all cases. We achieved a radial trajectory deviation of 0.97 ± 0.39 mm at a trajectory length of 60 ± 12.3 mm (mean ± standard deviation). Repositioning of the biopsy cannula due to inaccurate targeting was not required. Conclusion Intraoperative verification using a mobile CT unit in combination with frameless neuronavigation-guided stereotaxy and pre-operative MRI-based trajectory planning was feasible, safe and highly accurate. The setting enabled single-millimeter accuracy for deep-seated brain lesions and direct detection of intraoperative complications, did not depend on a dedicated operating room and was seamlessly integrated into common stereotactic procedures.

ObjectivesTo characterize clinical and imaging features in patients with pathologically confirmed demyelinating lesions.MethodsIn this retrospective chart review, we analyzed clinical-radiological-pathological correlations in patients >15years old who underwent brain biopsy at our institution between 2000 and 2015 and had inflammatory demyelination on neuropathology.ResultsOf 31 patients, the mean age was 42years (range 16 to 69years) and 55% were female. All but one of the biopsied lesions were considered tumefactive demyelinating lesions (TDLs) by imaging criteria, measuring >2cm on contrast-enhanced brain MRI. On clinical follow-up, the final diagnosis was a CNS malignancy in 2 patients (6.5%). In patients without malignant tumor, the TDL was solitary in 12 (41%) and multifocal in 17 (59%), with contrast enhancement in all but one case, primarily in an incomplete rim enhancement pattern (75.9%). Of 16 patients with at least 12months of clinical follow-up, 7 (43.8%) had a clinical relapse. Of patients without a prior neurologic history, relapse occurred in 2/7 (29%) in solitary TDL and 2/6 (33%) in multifocal lesions at initial presentation. Recurrent TDLs occurred in 3 patients, all with initially solitary TDLs. Stratifying by CSF analysis, 4 of 6 patients (67%) with either an elevated IgG Index or >2 oligoclonal bands suffered a clinical relapse compared to 2/8 (25%) with non-inflammatory CSF.ConclusionsPathologically confirmed TDLs call for careful clinical correlation, clinical follow-up and imaging surveillance. Although sometimes clinically monophasic, tumefactive demyelinating lesions carried nearly a 45% risk of near-term clinical relapse in our study, even when presenting initially as a solitary mass lesion.

Amyloid-β-related angiitis (ABRA) is a rare complication of cerebral amyloid angiopathy in which amyloid-β deposition in the leptomeningeal and cortical vessels is associated with vasculitis characterized by transmural lymphohistiocytic, often granulomatous, inflammation. Patients usually present with acute to subacute cognitive dysfunction, headaches, and focal neurologic deficits. We report 2 cases of ABRA with unusual clinical presentations, including one case with fatal cerebral edema leading to herniation and Duret hemorrhages, and another associated with both lobar and deep parenchymal hemorrhages with intraventricular extension as well as hypercoagulability. Both showed extensive vascular amyloid-β deposition associated with granulomatous angiitis and foreign body-type multinucleated giant cells. One of our cases demonstrates the likely effects of ABRA on impairment of fluid regulation leading to severe cerebral edema, which is an uncommon manifestation of ABRA, and may be a result of impaired blood-brain barrier function or malfunction of the neurovascular unit.

Three-dimensional (3D) printing techniques for patient-individual medicine has found its way into veterinary neurosurgery. Because of the high accuracy of 3D printed specific neurosurgical navigation devices, it seems to be a safe and reliable option to use patient-individual constructions for sampling brain tissue. Due to the complexity and vulnerability of the brain a particularly precise and safe procedure is required. In a recent cadaver study a better accuracy for the 3D printed MRI-based patient individual stereotactic brain biopsy device for dogs is determined compared to the accuracies of other biopsy systems which are currently used in veterinary medicine. This case report describes the clinical use of this 3D printed MRI-based patient individual brain biopsy device for brain sampling in three dogs. The system was characterized by a simple handling. Furthermore, it was an effective and reliable tool to gain diagnostic brain biopsy samples in dogs with no significant side effects.