Cisternal, vascular, and parenchymal landmarks in amygdalohippocampectomy for mesial temporal sclerosis: an index case with learnings from 820 resections.

Cortico-amygdalo-hippocampectomy is the most common epilepsy surgery resection in adults and offers excellent outcomes. Seizure outcome benefits range from 75% to 88% with a 2%-4% adverse event rate. The safety profile and outcomes could be enhanced further by clearly defining key surgical landmarks that could also aid tumoral resections in the mesial temporal lobe and selective mesial resections. The authors present their learnings of intraoperative landmarks (cisternal, parenchymal, and vascular) and surgical substeps through an index case of cortico-amygdalo-hippocampectomy with lessons from 820 resections. The video can be found here: https://stream.cadmore.media/r10.3171/2024.4.FOCVID2428.

Do we have to continue antiseizure medications post surgery in long-term epilepsy associated tumors (LEATs)?

OBJECTIVE: To identify the rate of successful antiseizure medication (ASM) withdrawal after resective surgery in patients with long-term epilepsy-associated tumors (LEATs). METHODS: A retrospective analysis (from our prospectively archived data) on the post-operative ASM profile of 123 consecutive patients who completed a minimum of 2 years after resection of LEATs for ASM-resistant epilepsy. A comparison between recurred and non-recurred groups in terms of seizure recurrence was used to identify the potential predictors of seizure recurrence whose attributes were further analyzed using univariate and multiple logistic regression analysis. Kaplan-Meier survival curves were used to study the probability of ASM freedom following surgery. RESULTS: We attempted ASM withdrawal in 102 (82.9 %) patients. Forty-eight (47.1 %) had seizure recurrence while reducing ASM, of which 22 (21.6 %) continued to have seizures even after ASM optimisation. On univariate analysis, presence of pre-operative secondary generalized seizure(s) was the only factor associated with seizure recurrence. At a mean follow-up of 6.1 years, 72 (58.5 %) patients were seizure-free and aura-free at terminal follow-up (53 patients were off any ASM). The cumulative probability of achieving complete ASM-free status was 29 % at fourth year, 42 % at sixth year, 55 % at eighth year, and 59 % at 10th year after surgery. CONCLUSIONS: Following resective surgery for LEATs, ASM(s) could be successfully discontinued in half of the patients. About one-third of the patients may have recurrent seizures on follow-up. Presence of secondary generalized seizure(s) prior to surgery predicts seizure recurrence, whereas MRI defined completeness of resection will not. This information will help in rationalising decisions on ASM management post-resection.

Lumbar vertebral diskitis-osteomyelitis with mycotic abdominal aortic aneurysm caused by Streptococcus mitis.

Vertebral osteomyelitis is a well-documented disease entity in literature with various known etiologies. However, vertebral diskitis-osteomyelitis secondary to an infected aortic aneurysm is an uncommon and life-threatening complication. We present the case of a 65-year-old male patient who presented with chronic low back pain that acutely worsened for 1 to 1.5 months and was diagnosed with vertebral diskitis-osteomyelitis secondary to a contiguous infection from an adjacent mycotic aortic aneurysm. To our knowledge, this is one of the few cases reported of vertebral diskitis-osteomyelitis secondary to mycotic aortic aneurysm. We discuss the findings on CT and MRI, as well as the value of imaging in guiding management.

Review of the demographic and educational profiles of abdominal imaging fellowship program directors in the United States.

PURPOSE: To evaluate demographics, academic backgrounds, and scholarly activities of Program Directors (PDs) in Abdominal Imaging Fellowships in the United States (US), emphasizing gender representation, international origins, and academic milestones. METHODS: A list of Fellowships in Abdominal Imaging programs in the US was obtained from the Society of Abdominal Radiology. The search was expanded using the Fellowship and Residency Electronic Interactive Database. Data for PDs were sourced from program websites, Healthgrades, Doximity, and Elsevier's Scopus. Metrics such as age, gender, education, academic rank, additional qualifications, prior leadership roles, publications, and h-indices were analyzed using R software. A two-tailed unpaired t-test was used to calculate the difference in means of scholarly activity between male and female PDs. RESULTS: 113 programs were identified: South (36.28%), Northeast (25.66%), Mid-West (20.35%), West (17.69%). Of 107 PDs, 54% male, 41% female, and average age 48 ± 9.4 years. 66.6% were US graduates, 29.2% were international graduates. Most were Assistant Professors (36.28%). 19.46% had degrees like M.P.H. or M.B.A. 45% had prior leadership roles. Average year of residency graduation was 2007. Mean publication count was 54.16, and mean h-index was 14.663. Male PDs had higher publication counts and h-indices than female PDs (p= 0.009 and p= 0.0019 respectively). CONCLUSION: In Abdominal Imaging Fellowship programs in the US, there is an increasing representation of females in Program Director roles. However, research led by female PDs remains less prevalent. The field of Abdominal Imaging values contributions from international graduates and insights from Assistant Professors.

MRI-based Neuropathy Score Reporting And Data System (NS-RADS): multi-institutional wider-experience usability study of peripheral neuropathy conditions among 32 radiology readers.

OBJECTIVE: To determine the inter-reader reliability and diagnostic performance of classification and severity scales of Neuropathy Score Reporting And Data System (NS-RADS) among readers of differing experience levels after limited teaching of the scoring system. METHODS: This is a multi-institutional, cross-sectional, retrospective study of MRI cases of proven peripheral neuropathy (PN) conditions. Thirty-two radiology readers with varying experience levels were recruited from different institutions. Each reader attended and received a structured presentation that described the NS-RADS classification system containing examples and reviewed published articles on this subject. The readers were then asked to perform NS-RADS scoring with recording of category, subcategory, and most likely diagnosis. Inter-reader agreements were evaluated by Conger's kappa and diagnostic accuracy was calculated for each reader as percent correct diagnosis. A linear mixed model was used to estimate and compare accuracy between trainees and attendings. RESULTS: Across all readers, agreement was good for NS-RADS category and moderate for subcategory. Inter-reader agreement of trainees was comparable to attendings (0.65 vs 0.65). Reader accuracy for attendings was 75% (95% CI 73%, 77%), slightly higher than for trainees (71% (69%, 72%), p = 0.0006) for nerves and comparable for muscles (attendings, 87.5% (95% CI 86.1-88.8%) and trainees, 86.6% (95% CI 85.2-87.9%), p = 0.4). NS-RADS accuracy was also higher than average accuracy for the most plausible diagnosis for attending radiologists at 67% (95% CI 63%, 71%) and for trainees at 65% (95% CI 60%, 69%) (p = 0.036). CONCLUSION: Non-expert radiologists interpreted PN conditions with good accuracy and moderate-to-good inter-reader reliability using the NS-RADS scoring system. CLINICAL RELEVANCE STATEMENT: The Neuropathy Score Reporting And Data System (NS-RADS) is an accurate and reliable MRI-based image scoring system for practical use for the diagnosis and grading of severity of peripheral neuromuscular disorders by both experienced and general radiologists. KEY POINTS: • The Neuropathy Score Reporting And Data System (NS-RADS) can be used effectively by non-expert radiologists to categorize peripheral neuropathy. • Across 32 different experience-level readers, the agreement was good for NS-RADS category and moderate for NS-RADS subcategory. • NS-RADS accuracy was higher than the average accuracy for the most plausible diagnosis for both attending radiologists and trainees (at 75%, 71% and 65%, 65%, respectively).

Compressive lesions of the head and neck: Common and uncommon must-know entities.

There are many lesions that cause compression of nerves and vessels in the head and neck, and they can often be overlooked in the absence of adequate history or if not suspected by the radiologist. Many of these lesions require a high index of suspicion and optimal positioning for imaging. While a multimodality approach is critical in the evaluation of compressive lesions, an MRI utilizing high-resolution (heavily weighted) T2-weighted sequence is extremely useful as a starting point. In this review, we aim to discuss the radiological features of the common and uncommon compressive lesions of the head and neck which are broadly categorized into vascular, osseous, and miscellaneous etiologies.

CT perfusion in stroke: Comparing conventional and RAPID automated software.

CT perfusion (CTP) imaging is increasingly used for routine evaluation of acute ischemic stroke. Knowledge about the different types of CTP software, imaging acquisition and post-processing, and interpretation is crucial for appropriate patient selection for reperfusion therapy. Conventional vendor-provided CTP software differentiates between ischemic penumbra and core infarct using the tiebreaker of critically reduced cerebral blood volume (CBV) values within brain regions showing abnormally elevated time parameters like mean transit time (MTT) or time to peak (TTP). On the other hand, RAPID automated software differentiates between ischemic penumbra and core infarct using the tiebreaker of critically reduced cerebral blood flow (CBF) values within brain regions showing abnormally elevated time to maximum (Tmax). Additionally, RAPID calculates certain indices that confer prognostic value, such as the hypoperfusion and CBV index. In this review, we aim to familiarize the reader with the technical principles of CTP imaging, compare CTP maps generated by conventional and RAPID software, and discuss important thresholds for reperfusion and prognostic indices. Lastly, we discuss common pitfalls to help with the accurate interpretation of CTP imaging.

Is intraoperative electrocorticography (ECoG) for long-term epilepsy-associated tumors (LEATs) more useful in children?-A Randomized Controlled Trial.

OBJECTIVES: The utility of intraoperative electrocorticography (ECoG)-guided resective surgery for pediatric long-term epilepsy-associated tumors (LEATs) with antiseizure medication (ASM) resistant epilepsy is not supported by robust evidence. As epilepsy networks and their ramifications are different in children from those in adults, the impact of intraoperative ECoG-based tailored resections in predicting prognosis and influencing outcomes may also differ. We evaluated this hypothesis by comparing the outcomes of resections with and without the use of ECoG in children and adults by a randomized study. METHODS: From June 2020 to January 2022, 42 patients (17 children and 25 adults) with LEATs and antiseizure medication (ASM)-resistant epilepsy were randomly assigned to one of the 2 groups (ECoG or no ECoG), prior to surgical resection. The 'no ECoG' arm underwent gross total lesion resection (GTR) without ECoG guidance and the ECoG arm underwent GTR with ECoG guidance and further additional tailored resections, as necessary. Factors evaluated were tumor location, size, lateralization, seizure duration, preoperative antiepileptic drug therapy, pre- and postresection ECoG patterns and tumor histology. Postoperative Engel score and adverse event rates were compared in the pediatric and adult groups of both arms. Eloquent cortex lesions and re-explorations were excluded to avoid confounders. RESULTS: Forty-two patients were included in the study of which 17 patients were in the pediatric cohort (age < 18 years) and 25 in the adult cohort. The mean age in the pediatric group was 11.11 years (SD 4.72) and in the adult group was 29.56 years (SD 9.29). The mean duration of epilepsy was 9.7 years (SD 4.8) in the pediatric group and 10.96 (SD 8.8) in the adult group. The ECoG arm of LEAT resections had 23 patients (9 children and 14 adults) and the non-ECoG arm had 19 patients (8 children and 11 adults). Three children and 3 adults from the ECoG group further underwent ECoG-guided tailored resections (average 1.33 additional tailored resections/per patient.).The histology of the tailored resection specimen was unremarkable in 3/6 (50%).Overall, the commonest histology in both groups was ganglioglioma and the temporal lobe, the commonest site of the lesion. 88.23% of pediatric cases (n = 15/17) had an excellent outcome (Engel Ia) following resection, compared to 84% of adult cases (n = 21/25) at a mean duration of follow-up of 25.76 months in children and 26.72 months in adults (p = 0.405).There was no significant difference in seizure outcomes between the ECoG and no ECoG groups both in children and adults, respectively (p > 0.05). Additional tailored resection did not offer any seizure outcome benefit when compared to the non-tailored resections. CONCLUSIONS: The use of intraoperative electrocorticography in LEATs did not contribute to postoperative seizure outcome benefit in children and adults. No additional advantage or utility was offered by ECoG in children when compared to its use in adults. ECoG-guided additional tailored resections did not offer any additional seizure outcome benefit both in children and adults.

Recurrent sporadic malignant triton tumor in the carotid sheath in the absence of neurofibromatosis.

Malignant Triton Tumors (MTTs) are a rare and aggressive subtype of malignant peripheral nerve sheath tumors (MPNSTs), often associated with neurofibromatosis type 1. This case report describes a unique instance of recurrent sporadic MTT within the carotid sheath in a 33-year-old male without any personal or familial history of neurofibromatosis. The patient initially presented with a biopsy-confirmed MTT in the right neck, involving the carotid body and brachial plexus, and underwent partial resection, radiation therapy, and chemotherapy. Six months later, the patient presented with recurrent MTT, and subsequently underwent radical tumor resection, segmental right carotid artery resection, and deep femoral vein interposition. Recovery was complicated by hematoma formation, and the patient developed vocal fold paralysis and a left vocal fold cyst, necessitating further surgeries. Yearly follow-ups for 8 years revealed no recurrence. This case emphasizes the importance of comprehensive patient evaluation, including clinical history, imaging, and biopsy findings, for accurate diagnosis and prompt surgical intervention in managing such rare and aggressive tumors. Further research is needed to identify novel therapies and improve survival rates for patients with MTTs.

Cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion (CHANTER) syndrome in the setting of opioid and phencyclidine use.

Cerebellar, hippocampal, and basal nuclei transient edema with restricted diffusion (CHANTER) syndrome is a constellation of specific imaging findings characterized by cytotoxic edema in the bilateral hippocampi, cerebellar cortices, and basal ganglia in patients presenting with altered mental status in the setting of substance intoxication. Previous case reports have demonstrated a strong correlation between CHANTER syndrome and polysubstance abuse, particularly with opioid intoxication. The patient we present in this case was found unresponsive following opioid use and demonstrated a constellation of findings on initial and follow-up imaging, consistent with CHANTER syndrome. While cases of irreversible brain damage or death during hospitalization have been reported in the literature, our patient demonstrated near-full recovery a few days after admission to the hospital. We aim to highlight the presentation and progression of CHANTER syndrome and alert clinicians and radiologists to include this entity in their diagnostic checklist for patients with polysubstance abuse and altered mental status.

MR imaging differentiating features between lytic and degenerative lumbosacral spondylolisthesis.

Spondylolisthesis is characterized by the displacement of one vertebral body in relation to the adjacent vertebra. It is commonly observed in the lower lumbar region and can be caused by a variety of factors, including spondylolysis (a fracture in the pars interarticularis) or degenerative disease. Magnetic resonance imaging (MRI) is becoming increasingly popular as the primary modality for evaluation of low back pain and is often used in the absence of radiographs or Computed Tomography. However, it can be challenging for radiologists to differentiate between the two types of spondylolisthesis based on MRI alone. The goal of this article is to identify key imaging features on MRI that can aid radiologists in differentiating between spondylolysis and degenerative spondylolisthesis on MRI. Five key concepts are discussed: the "step-off" sign, the "wide canal" sign, T2 cortical bone signal on MRI, epidural fat interposition, and fluid in the facet joints. The utility, limitations and potential pitfalls of these concepts are also discussed to provide a comprehensive understanding of their use in differentiating between the two types of spondylolisthesis on MRI.

Utility of balanced steady-state field precession sequence in the evaluation of retinal and subdural hemorrhages in patients with abusive head trauma.

Abusive head trauma is the leading cause of physical child abuse deaths in children under 5 years of age in the United States. To evaluate suspected child abuse, radiologic studies are typically the first to identify hallmark findings of abusive head trauma including intracranial hemorrhage, cerebral edema, and ischemic injury. Prompt evaluation and diagnosis are necessary as findings may change rapidly. Current imaging recommendations include brain magnetic resonance imaging with the addition of a susceptibility weighted imaging (SWI) sequence which can detect additional findings that suggest abusive head trauma including cortical venous injury and retinal hemorrhages. However, SWI is limited due to blooming artifacts and artifacts from the adjacent skull vault or retroorbital fat, which can affect the evaluation of retinal, subdural, and subarachnoid hemorrhages. This work explores the utility of the high-resolution, heavily T2 weighted balanced steady-state field precession (bSSFP) sequence to identify and characterize retinal hemorrhage and cerebral cortical venous injury in children with abusive head trauma. The bSSFP sequence provides distinct anatomical images to improve the identification of retinal hemorrhage and cortical venous injury.

Clinical Reasoning: A Teenager With Chronic Meningitis-Does Occam's Razor Apply?

A 14-year-old girl presented with subacute onset headache, fever, and vomiting and was managed initially with antibiotics for suspected bacterial meningitis. Her symptoms further evolved over the next few weeks with systemic signs and symptoms favoring chronic meningitis with raised intracranial pressure. After the etiologic workup was unrevealing, she was started on empirical antituberculous therapy. After a period of partial improvement, symptoms recurred with a new-onset focal seizure. Her imaging findings evolved from features suggestive of focal leptomeningitis to multifocal heterogeneous enhancing cortical and subcortical lesions with hemorrhagic foci, leading to brain biopsy that confirmed diagnosis. Our case highlights the utility of diagnostic biopsy in patients with "chronic meningitis" in uncertain cases rather than confining the approach to the law of parsimony. The decision to initiate empirical therapy in chronic meningitis should be considered on a case-by-case basis and take into account factors, such as clinical examination findings, immune status, recent exposures, and potential risks of treatment. Atypical MRI features should lower the threshold for meningocortical biopsy when indicated.

Ischemia of the parotid gland and adjacent muscles of mastication following middle meningeal artery embolization.

Middle meningeal artery (MMA) embolization is commonly performed as either a first-line or adjunct treatment for chronic subdural hematomas (cSDH). We present the case of a 59 year-old male patient who presented with right hemibody weakness and cognitive impairment and was diagnosed with left-sided cSDH. A left MMA embolization was performed due to the recurrent nature of the chronic subdural hemorrhage and the history of prior craniotomy. On postoperative day 1, the patient developed sudden onset left facial swelling and tenderness, and a contrast computed tomography (CT) of the neck revealed acute ischemia in the left parotid gland, adjacent superior aspect of the left masseter muscle, the left lateral pterygoid, and left temporalis muscles. The patient was treated conservatively with antibiotics, steroids, and analgesics and reported resolution of symptoms on the three-month follow-up. To our knowledge, this is the first reported case of the ipsilateral parotid gland, temporalis muscle, adjacent superior aspect of the masseter muscle, and pterygoid muscle ischemia secondary to non-target particle embolization following MMA embolization in cSDH. Knowledge of normal and variant origin of the MMA and various anastomoses of this vessel with branches of the internal carotid artery (ICA), external carotid artery (ECA), and vertebrobasilar system is crucial to avoid complications during embolization.

Medicolegal Priorities for a Neurosurgeon/Neurologist in the COVID Era.

Vulnerable moments, panic, and uncertainties are the hallmarks of pandemic outbreaks. Medicolegal challenges add further injury to the public health chaos. Although containing the pandemic is of prime concern, medicolegal and ethical uncertainties further complicate ideal standards of medical care. Constraints in the provision of medical care, resource limitations, infectivity risks, burgeoning costs, and pandemic control laws, create extremely precarious medicolegal situations. Ethics and medical negligence laws may, at times, be trampled upon by the overwhelming urgencies of the pandemic. Hence, we attempt to review basic ethical and medicolegal principles that are put to test by pandemic urgencies. We aim to study these vulnerable medicolegal moments in neurosurgeons'/neurologists' clinical and research practices during the COVID-19 times from our own practice and contemporary literature on COVID practices, medicolegal sciences, and pandemic healthcare directives. We also review supportive measures and safeguards to brace these vulnerable moments effectively. We compile medicolegally sound and ideal practice parameters, including the basic principles for a restructured informed surgical consent ensuring a medicolegally and ethically sound practice. Several ethical and medicolegal exigencies are part of medical practice during a pandemic. Special care should be taken to avoid violations of medicolegal and ethical proprieties during the urgencies of medical care and research. Restructuring of contracts like the informed consent would also count as an ideal practice modification in a pandemic.

A 15-Year Analysis of International Medical Graduates Matching Into Diagnostic Radiology Residency Programs in the United States.

RATIONALE AND OBJECTIVES: To analyze the trends in international medical graduates (IMGs) matching into diagnostic radiology residency programs in the United States (US). MATERIALS AND METHODS: The National Resident Match Program data was accessed for years 2005-2020 and diagnostic radiology residency-specific data was extracted for US MD, osteopathic (DO), and IMG applicants. IMGs were categorized into US-citizen IMGs and non-US citizen IMGs per the National Residency Match Program. Variables collected for each year included the number of positions, number of applicants in each group, positions filled/unfilled, and fill rate of each group. Additional data for some years included USMLE Step 1 score, United States Medical Licensing Examination (USMLE) Step 2 clinical knowledge (CK) score, number of research experiences, number of abstracts/publications, and additional degrees obtained. Trends were analyzed using simple linear regression model and p value <0.05 was considered significant. RESULTS: The number of diagnostic radiology residency programs increased from 203 (2006) to 212 (2020). The total number of diagnostic radiology residency positions increased from 1011 (2006) to 1113 (2020), with the peak of 1145 in 2014. The overall "match rate," that is, proportion of positions filled to positions available, increased from 96.4% (2006) to 97.3% (2020), with a brief decline to 86.7% in 2015. Among the filled positions, the proportion filled by US medical school graduates significantly declined from 89.7% (2006) to 69.2% (2020) (p < 0.001), and the proportion of positions filled by osteopathic seniors and graduates significantly increased from 2.2% (2006) to 15.1% (2020; p < 0.001). The proportion of US IMGs increased from 3.2% (2006) to 5.4% (2020), while the proportion of non-US IMGs increased from 4.4% (2006) to 9.4% (2020), with overall IMG match rate increased significantly from 7.6% to 14.9% (p = 0.009). The mean Step 1 scores of US IMGs and non-US IMGs were 238 and 237.3, and the mean Step 2 CK scores were 241.67 and 241, respectively. Cumulatively over the study period, a total of 736 US IMGs and 1051 non-US IMGs have matched into diagnostic radiology residency. CONCLUSION: There is an increasing proportion of IMGs, especially the non-US citizen IMGs, matching into US radiology residency programs in the last decade. Diagnostic radiology remains a competitive specialty evidenced by average USMLE scores higher than national average and research experiences of matched candidates.