Comparison of 2 Robotic Systems for Pediatric Stereoelectroencephalography Implantation.

BACKGROUND: Stereoelectroencephalography (SEEG) remains critical in guiding epilepsy surgery. Robot-assisted techniques have shown promise in improving SEEG implantation outcomes but have not been directly compared. In this single-institution series, we compared ROSA and Stealth AutoGuide robots in pediatric SEEG implantation. METHODS: We retrospectively reviewed 21 sequential pediatric SEEG implantations consisting of 6 ROSA and 15 AutoGuide procedures. We determined mean operative time, time per electrode, root mean square (RMS) registration error, and surgical complications. Three-dimensional radial distances were calculated between each electrode's measured entry and target points with respective errors from the planned trajectory line. RESULTS: Mean overall/per electrode operating time was 73.5/7.5 minutes for ROSA and 126.1/10.9 minutes for AutoGuide (P = 0.030 overall, P = 0.082 per electrode). Mean RMS registration error was 0.77 mm (0.55-0.93 mm) for ROSA and 0.6 mm (0.2-1.0 mm) for AutoGuide (P = 0.26). No procedures experienced complications. The mean radial (entry point error was 1.23 ± 0.11 mm for ROSA and 2.65 ± 0.12 mm for AutoGuide (P < 0.001), while the mean radial target point error was 1.86 ± 0.15 mm for ROSA and 3.25 ± 0.16 mm for AutoGuide (P < 0.001). CONCLUSIONS: Overall operative time was greater for AutoGuide procedures, although there was no statistically significant difference in time per electrode. Both systems are highly accurate with no significant RMS error difference. While the ROSA robot yielded significantly lower entry and target point errors, both robots are safe and reliable for deep electrode insertion in pediatric epilepsy.

An Ecchordosis Physaliphora, a Rare Entity, Involving the Central Nervous System: A Systematic Review of the Literature.

Ecchordosis physaliphora (EP) is a benign notochordal remnant, which is often an incidental finding; however, it can rarely present with neurological symptoms. We performed a systematic review of the literature for cases of symptomatic EP published in PubMed, Web of Science and Embase from January 1982 to May 2023. This is the largest review to date and revealed 60 cases including ours. Headache (55%) and CSF rhinorrhea (32%) were the most frequent clinical manifestations. The majority of symptomatic EP lesions were located in the prepontine region (77%) and required surgical resection (75%). EP should be considered in patients with neurologic symptoms in the setting of prepontine or posterior sphenoid sinus lesions. While symptomatic patients often require surgical intervention, rare cases may respond to oral corticosteroids.

Autoimmune and paraneoplastic neurological disorders: A review of relevant neuroimaging findings.

INTRODUCTION: Paraneoplastic neurologic syndromes (PNS) and autoimmune encephalitis (AIE) are immune-mediated disorders. PNS is linked to cancer, while AIE may not Their clinical manifestations and imaging patterns need further elucidation. OBJECTIVE/AIMS: To investigate the clinical profiles, antibody associations, neuroimaging patterns, treatments, and outcomes of PNS and AIE. METHODS: A systematic review of 379 articles published between 2014 and 2023 was conducted. Of the 55 studies screened, 333 patients were diagnosed with either PNS or AIE and tested positive for novel antibodies. Data on demographics, symptoms, imaging, antibodies, cancer associations, treatment, and outcomes were extracted. RESULTS: The study included 333 patients (mean age 54 years, 67% males) with PNS and AIE positive for various novel antibodies. 84% had central nervous system issues like cognitive impairment (53%), rhombencephalitis (17%), and cerebellar disorders (24%). Neuroimaging revealed distinct patterns with high-risk antibodies associated with brainstem lesions in 98%, cerebellar in 91%, hippocampal in 98%, basal ganglia in 75%, and spinal cord in 91%, while low/intermediate-risk antibodies were associated with medial temporal lobe lesions in 71% and other cortical/subcortical lesions in 55%. High-risk antibodies were associated with younger males, deep brain lesions, and increased mortality of 61%, while low/intermediate-risk antibodies were associated with females, cortical/subcortical lesions, and better outcomes with 39% mortality. Associated cancers included seminomas (23%), lung (19%), ovarian (2%), and breast (2%). Treatments included IVIG, chemotherapy, and plasmapheresis. Overall mortality was 25% in this cohort. CONCLUSION: PNS and AIE have distinct clinical and radiological patterns based on antibody profiles. High-risk antibodies are associated with increased mortality while low/intermediate-risk antibodies are associated with improved outcomes. Appropriate imaging and antibody testing are critical for accurate diagnosis.

Histopathologic "Evolution" in Pediatric Primary Intracranial High-Grade Sarcoma - a Key that Unlocked the Correct Diagnosis.

Central nervous system (CNS) tumors are the second most common in the pediatric age group, accounting for 3.5% of overall mortality. The 2021 World Health Organization (WHO) classification of pediatric CNS tumors has given insight into their molecular biology. Correct diagnosis of high-grade intracranial sarcomas is a well-known challenge because of their histopathological variation, presence of heterologous elements, and haphazard pattern of growth. We present a case of a 13-year-old female with a right-sided frontal hemorrhagic mass. Pathological work-up revealed an intra-cranial high-grade sarcoma, not otherwise specified (NOS). Despite receiving chemo-radiation, the lesion recurred after 9 months. This time, the sarcoma had evolved, showing distinct focal rhabdomyoblastic differentiation. Next-generation sequencing (NGS) based assay revealed variants p.E1705V, p.Y1417Ter in DICER1, and other mutations in KRAS and TP53 genes. The lesion was then diagnosed as spindle cell sarcoma with rhabdomyosarcoma-like features, DICER1 mutant. We propose that upfront molecular studies in pediatric undifferentiated high-grade sarcomas are indicated for precise diagnosis and classification.

Idiopathic Hypertrophic Spinal Pachymeningitis.

Hypertrophic pachymeningitis (HP) is a rare presentation with duramater thickening and fibrosis which can result in cranial or spinal compressive disease. Most cases of spinal HP require surgical management. We present an uncommon case of idiopathic hypertrophic spinal pachymeningitis (IHSP) in a 40-year-old male who showed complete improvement to steroids without any further relapses. The patient presented with bilateral upper limb weakness with magnetic resonance imaging (MRI) spine showing diffuse dural thickening of the entire spine with cervical cord compression. He had an extensive workup for underlying etiology and worsening symptoms until he was diagnosed with IHSP. Later, he was started on high-dose steroids with good response and no relapse after 2 years. A descriptive analysis of IHSP cases since 2009 including ours showed that it usually occurs after 50s with female preponderance. Weakness and sensory loss are the most common complaints with 50% patients showing clinical signs of myelopathy like hyperreflexia, clonus, Babinski sign and sensory level. Cerebrospinal fluid (CSF) and inflammatory markers like erythrocytic sedimentation rate (ESR) and C-reactive protein (CRP) can be used to assess disease progression and prognosis. Surgical removal of HP followed by steroids is the best line of management while steroids alone can be tried in cases where clinical signs of myelopathy are absent.

Vascularity Outcomes of Lingual Artery Ligation in Transoral Robotic Base of Tongue Resections.

To explore the effect of lingual artery ligation on tongue vascularity, we performed an analysis of 25 patients who underwent transoral robotic surgery for base of tongue cancers (May 2011 to December 2019). Hounsfield units of the intrinsic muscles (IMs) and genioglossus muscles (GGs) were measured in postoperative imaging (mean 4 months) as a surrogate for vascularity. In ligated patients (n = 15), the values from the ligated/resected side of the tongue were compared with the contralateral side and the nonligated side of resection. Individually, IMs and GGs on the ligated side demonstrated no significant difference to the contralateral side (P = .662 and .618, respectively). Ligation produced a significant decrease in IM measurements but no difference between GG values vs nonligated patients (P = .050 and .818, respectively). No difference was appreciated in mean values for combined IMs and GGs between cohorts (P = .212). No gross tongue atrophy or complications were incurred. Future studies are warranted to delineate long-term effects.

Bone remineralization of lytic lesions in multiple myeloma - The Arkansas experience.

Multiple myeloma (MM) patients frequently present with extensive osteolytic bone lesions. However, the impact of myeloma treatment on focal lytic lesion remineralization has not been extensively studied. In this study, the effect of anti-myeloma treatment on the extent of bone remineralization was examined and potential mediators identified. Newly diagnosed MM patients enrolled in the Total Therapy 4 and 5 (TT4; n = 231, TT5; n = 64) protocols were longitudinally evaluated for changes in radiological parameters for a median of 6.1 years. Bone remineralization was defined as a sclerotic CT change within the lytic lesion and quantified as a percentage of remineralization, using the initial lesion size as a reference. Such changes were correlated to clinical and biochemical parameters, and the gene expression profile of bone marrow biopsy. Overall, remineralization occurred in 72% of patients (213/295). Of those patients that experienced remineralization, 36% (107/295) achieved at least 25% of bone remineralization. Patients with high-risk disease defined by gene expression profile signature (GEP70 ≥ 0.66) experienced significant remineralization compared to low-risk MM. Female patients were also more likely to experience bone remineralization and in a shorter median time (2.0 vs. 3.3 y). Factors such as serum alkaline phosphatase along with high levels of RUNX2 and SOX4 gene expression correlated with increasing extent of bone remineralization. This analysis demonstrated significant remineralization of lytic lesions in MM patients treated on TT clinical trials. While the underlying mechanism remains elusive these findings support the hypothesis that patient baseline bone-related factors play a fundamental role in the skeletal repair of bone lesions in MM that provide new opportunities for improving patient outcomes.

Isolated primary neurolymphomatosis with cranial multineuritis: a case presentation.

BACKGROUND: Isolated primary neurolymphomatosis (NL) of cranial multineuritis is a very rare condition that refers to the lymphomatous invasion of cranial nerves only. There are sparse cases of isolated cranial nerves NL reported worldwide. CASE PRESENTATION: We present magnetic resonance imaging (MRI) and cerebrospinal fluid (CSF) findings of a 63-year-old female patient suffering from isolated neurolymphomatosis of cranial multineuritis with a wide constellation of syndromes including binocular diplopia, left facial paralysis and pain, syncope episodes, and progressive dysphagia. A contrasted MRI brain showed multiple cranial nerves enhancement. Extensive workup for infectious, autoimmune, neoplastic, paraneoplastic, or inflammatory etiologies had been unrevealing except CSF cytology revealed large atypical monotypic B cells that were suspicious for non-Hodgkin lymphoma on the third large volume tap. The decision of biopsy was deferred after the risks and benefits discussion. Following the four cycles of empiric methotrexate-based induction chemotherapy, the patient's symptoms resolved, and a complete radiographic response was achieved without whole-brain radiation or autologous hematopoietic cell transplantation. In the latest follow-up, she is independent with her daily activities and remains in clinical and radiographic remission more than 3 years since initial chemotherapy. CONCLUSION: Isolated NL of cranial nerves can present diagnostic and management pitfalls for the neurologist, neurosurgeons, and oncologists. Since current diagnostic modalities have modest sensitivity and a pathological diagnosis is often difficult, empiric treatment once other possibilities are ruled out can carry a good prognosis.

Trends in Neuroradiology Fellowship Match in the United States: Analysis of the 13-Year National Resident Matching Program Data.

The neuroradiology fellowship match is conducted by the National Resident Matching Program (NRMP) every year. The purpose of this study is to report the trends in neuroradiology match results from 2008 to 2020 in the United States (US) using data available from the NRMP. The fellowship match data was obtained from the NRMP archives. Data specific to programs (number of programs and filled positions) were obtained. Using the NRMP's "Charting Outcomes in the Match: Specialty Matching Service'' report, a detailed analysis of applicant characteristics broken down for each specialty, was also obtained for neuroradiology for the year 2018. Neuroradiology programs in the NRMP Match increased from 71 to 77 and the number of positions increased from 158 to 270 between 2008 and 2020. The fill rate of fellowship spots has remained steady at 75.9% in 2008 and 74.4% in 2020. The proportion of US allopathic medical graduates (US MD) amongst the filled spots decreased from 79.2% (2008) to 64.2% (2020), while the proportion of international medical graduates (IMGs) increased from 11.7% to 25.4%. US MD and IMG fill trends did not reach statistical significance (P = 0.78 and P = 0.92, respectively). US MDs had a higher number of research experiences and publications (23.2 and 26, respectively) when compared to US IMGs (5 and 7) and non-US IMGs (6.8 and 14.2). To conclude, over the last 13 years, the neuroradiology fellowship programs in the US have increased in number and expanded in size, with an almost stable fill rate of around 75%.

Analysis of Demographic and Educational Backgrounds of Interventional Neuroradiology Fellowship Program Director Workforce in North America.

PURPOSE: To analyse the demographics, academic background, and scholarly activity of Interventional Neuroradiology (INR)/Endovascular Surgical Neuroradiology (ESN) program directors (PDs) in the United States (US) and Canada. METHODS: A list of all INR/ESN fellowships was obtained from the Accreditation Council for Graduate Medical Education, the Committee on Advanced Subspecialty Training, maintained by Society of Neurological Surgeons, the NeuroInterventional Training list website maintained by the Society of NeuroInterventional Surgery, and the Neurosurgical Fellowship Training Program Directory website maintained by the American Association of Neurological Surgeons. Online search was performed to identify PDs for these programs. Publicly available sources used to gather information about each PD included the program websites, the HealthGrades and Doximity websites, and Elsevier's Scopus database. Demographic and educational data including age, gender, educational background, subspecialty, appointment age, interval between residency completion and appointment as PD, additional degrees, academic rank, prior leadership positions, and metrics of scholarly activity were recorded. One-way analysis of variance was used to determine differences between the means of different groups. RESULTS: A total of 78 PDs from 72 programs were included, of which 72 (92.3%) were male with the mean age of 49.59 years (SD 7.25). Specialty division of PDs was neurosurgery (40, 51.3%), radiology (26, 33.3%), and neurology (10, 12.8%), whereas 2 PDs were dual board-certified in neurology and radiology. Twenty-five (32.1%) PDs attended an international medical school. All PDs received an MD degree or foreign equivalent, with no PD holding a DO degree. Eleven PDs received a PhD degree and 16 PDs received fellowship from a professional medical society. The mean ± SD publications, citations, and h-indexes of PDs were 111.32 ± 121.18, 2985.0 ± 1459.0 and 22.27 ± 15.45, respectively. There was no statistical difference in scholarly activity among PDs when stratified on the basis of specialty, gender, and US region. CONCLUSION: INR/ESN PDs are predominantly male, with a majority from neurosurgery background, and thirty percent having graduated from international medical schools.

Intractable Scapular Pain Due to Undiagnosed Osteoid Osteoma: A Case Report.

A 36-year-old female patient presented to our stroke neurology clinic for progressively worsening intractable, sharp, shooting interscapular pain radiating to the right shoulder and neck, which she had experienced for 4 years. She had previously seen an orthopedist and was referred to a neurosurgeon for surgical intervention after an MRI of the cervical spine showed the C3-C4 right vertebral artery loop protruding into the right C3-C4 neural foramen and compressing the exiting C4 nerve root. MR neurography showed a stable tortuous right vertebral artery loop, causing a mass effect on the dorsal root ganglion. A neuroforaminal decompression surgery was planned. However, the patient visited our stroke neurology clinic for a second opinion before surgery. An MRI of the thoracic spine showed an enhancing soft tissue mass at the right T4-T5 pedicles and adjacent body. A chest CT with contrast showed a 1 cm radiolucent lesion in the superior articular facet of T5, which represented a nidus. A technetium bone scan showed focal increased uptake within the right T5 pedicle, which is indicative of osteoid osteoma. The patient underwent laminectomy/resection and was pain-free at a 6-month follow-up; biopsy confirmed osteoid osteoma. This case illustrates the importance of neurolocalization during diagnostic testing.

Lack of Spleen Signal on Diffusion Weighted MRI is associated with High Tumor Burden and Poor Prognosis in Multiple Myeloma: A Link to Extramedullary Hematopoiesis?

Due to the low frequency of abnormalities affecting the spleen, this organ is often overlooked during radiological examinations. Here, we report on the unexpected finding, that the spleen signal on diffusion-weighted MRI (DW-MRI) is associated with clinical parameters in patients with plasma cell dyscrasias. Methods: We investigated the spleen signal on DW-MRI together with clinical and molecular parameters in 295 transplant-eligible newly diagnosed Multiple Myeloma (NDMM) patients and in 72 cases with monoclonal gammopathy of undetermined significance (MGUS). Results: Usually, the spleen is the abdominal organ with the highest intensities on DW-MRI. Yet, significant signal loss on DW-MRI images was seen in 71 of 295 (24%) NDMM patients. This phenomenon was associated with the level of bone marrow plasmacytosis (P=1x10-10) and International Staging System 3 (P=0.0001) but not with gain(1q), and del(17p) or plasma cell gene signatures. The signal was preserved in 72 individuals with monoclonal gammopathy of undetermined significance and generally re-appeared in MM patients responding to treatment, suggesting that lack of signal reflects increased tumor burden. While absence of spleen signal in MM patients with high risk disease defined a subgroup with very poor outcome, re-appearance of the spleen signal after autologous stem cell transplantation was seen in patients with improved outcome. Our preliminary observation suggests that extramedullary hematopoiesis in the spleen is a factor that modifies the DW-MRI signal of this organ. Conclusions: The DW-MRI spleen signal is a promising marker for tumor load and provides prognostic information in MM.

The presence of large focal lesions is a strong independent prognostic factor in multiple myeloma.

Spatial intratumor heterogeneity is frequently seen in multiple myeloma (MM) and poses a significant challenge for risk classifiers, which rely on tumor samples from the iliac crest. Because biopsy-based assessment of multiple skeletal sites is difficult, alternative strategies for risk stratification are required. Recently, the size of focal lesions (FLs) was shown to be a surrogate marker for spatial heterogeneity, suggesting that data from medical imaging could be used to improve risk stratification approaches. Here, we investigated the prognostic value of FL size in 404 transplant-eligible, newly diagnosed MM patients. Using diffusion-weighted magnetic resonance imaging with background suppression, we identified the presence of multiple large FLs as a strong prognostic factor. Patients with at least 3 large FLs with a product of the perpendicular diameters >5 cm2 were associated with poor progression-free survival (PFS) and overall survival (OS; median, 2.3 and 3.6 years, respectively). This pattern, seen in 13.8% of patients, was independent of the Revised International Staging System (RISS), gene expression profiling (GEP)-based risk score, gain(1q), or extramedullary disease (hazard ratio, 2.7 and 2.2 for PFS and OS in multivariate analysis, respectively). The number of FLs lost its negative impact on outcome after adjusting for FL size. In conclusion, the presence of at least 3 large FL is a feature of high risk, which can be used to refine the diagnosis of this type of disease behavior and as an entry criterion for risk-stratified trials.

Herniation despite Decompressive Hemicraniectomy in Large Hemispherical Ischemic Strokes.

BACKGROUND: Despite decompressive hemicraniectomy (DHC), progressive herniation resulting in death has been reported following middle cerebral artery (MCA) strokes. We aimed to determine the surgical parameters measured on brain computed tomography (CT) scan that are associated with progressive herniation despite DHC in large MCA strokes. METHODS: Retrospective chart review of medical records of patients with malignant hemispheric infarction who underwent DHC for cerebral edema was performed. Infarct volume was calculated on CT scans obtained within 24 hours of ictus. Radiological parameters of craniectomy bone flap size, brain volume protruding out of the skull, adequate centering of the craniectomy over the stroke bed, and the infarct volume outside the craniectomy bed (volume not centered [VNC]) were measured on the postoperative brain CT. RESULTS: Of 41 patients who underwent DHC, 7 had progressive herniation leading to death. Radiographic parameters significantly associated with progressive herniation included insufficient centering of craniectomy bed on the stroke bed (P = .03), VNC (P = .011), additional anterior cerebral artery infarction (P = .047), and smaller craniectomy length (P = .05). Multivariate logistic regression analysis for progressive herniation using craniectomy length and VNC as independent variables demonstrated that a higher VNC was significantly associated with progressive herniation despite surgery (P = .029). CONCLUSIONS: In large MCA strokes, identification of large infarct volume outside the craniectomy bed was associated with progressive herniation despite surgery. These results will need to be verified in larger prospective studies.

Low expression of hexokinase-2 is associated with false-negative FDG-positron emission tomography in multiple myeloma.

18F-Fluorodeoxyglucose (FDG)-positron emission tomography (PET) and diffusion-weighted magnetic resonance imaging with background signal suppression (DWIBS) are 2 powerful functional imaging modalities in the evaluation of malignant plasma cell (PC) disease multiple myeloma (MM). Preliminary observations have suggested that MM patients with extensive disease according to DWIBS may be reported as being disease-free on FDG-PET ("PET false-negative"). The aim of this study was to describe the proportion of PET false-negativity in a representative set of 227 newly diagnosed MM patients with simultaneous assessment of FDG-PET and DWIBS, and to identify tumor-intrinsic features associated with this pattern. We found the incidence of PET false-negativity to be 11%. Neither tumor load-associated parameters, such as degree of bone marrow PC infiltration, nor the PC proliferation rate were associated with this subset. However, the gene coding for hexokinase-2, which catalyzes the first step of glycolysis, was significantly lower expressed in PET false-negative cases (5.3-fold change, P < .001) which provides a mechanistic explanation for this feature. In conclusion, we demonstrate a relevant number of patients with FDG-PET false-negative MM and a strong association between hexokinase-2 expression and this negativity: a finding which may also be relevant for clinical imaging of other hematological cancers.

PRES and Epilepsy: A Potential Long-Term Consequence of a "Reversible" Syndrome.

Epilepsy is very rarely attributed to posterior reversible encephalopathy syndrome (PRES). We report the case of a previously healthy 21-year-old who developed epilepsy with mesial temporal sclerosis following an episode of PRES related to a complicated Cesarean delivery. Neuroimaging at the time of PRES and 3 months after revealed the development of unilateral hippocampal volume loss following resolution of acute PRES-related brain edema. We discuss the incidence and importance of "non-reversible" sequelae of PRES and their implications for patient care.