Peritoneal baclofen pump migration: a rare complication of subfascial placement. Illustrative cases.

BACKGROUND: The intrathecal baclofen pump is an effective treatment option for patients with severe spasticity. In children, subfascial pump placement is often preferred given concerns for infection and wound healing. However, this approach is not without risk, and rare complications, such as peritoneal pump migration, can occur. OBSERVATIONS: The authors describe three pediatric cases of peritoneal pump migration at their institution over the past 14 years (3/545, 0.5%). All three patients had low body weight (below the 39th percentile), and two had scoliosis requiring surgery. All pumps had been placed using the subfascial technique. The first case occurred 6 months postplacement, and the pump was not replaced. Cases 2 and 3 occurred at 2 and 3 years postplacement, respectively, and both pumps were replaced. LESSONS: The authors conclude that peritoneal pump migration, although uncommon, can occur in patients with subfascial pump placement, and providers should have a low threshold of suspicion for repeat imaging prior to refilling if the pump's location has migrated. Potential contributing factors to pump migration include a patient's small size, a larger pump size (40-mL pump), and scoliosis. All these factors should be considered during pump placement, and surgeons can consider using a 20-ml pump for smaller patients. https://thejns.org/doi/abs/10.3171/CASE24290.

Treatment of ventral neurenteric cyst at the cervicothoracic junction with the anterior approach in a pediatric patient: illustrative case.

BACKGROUND: Neurenteric cysts are rare congenital lesions from heterotopic endodermal tissue, often presenting with radiculopathy or myelopathy in young adults. Gross-total resection is curative; however, the surgical approach remains widely debated for cervicothoracic cases. While the posterior approach is common, the anterior approach has had success in adults. The authors present the first pediatric case of anterior corpectomy with gross-total resection of a cervicothoracic neurenteric cyst alongside an extensive literature review. OBSERVATIONS: A 10-year-old male, who had undergone a previous cyst resection via a posterior approach at an outside institution, presented with back pain, paraplegia, and urinary incontinence. Magnetic resonance imaging of the spine revealed a ventral hyperintense cyst at C7-T1 consistent with a neurenteric cyst. An anterior approach involving C7 and T1 corpectomies was performed, including intradural exploration leading to complete cyst resection. This was followed by the placement of an expandable cage and anterior and posterior fixation with arthrodesis for stabilization. The patient's symptoms completely resolved after surgery, and there has been no recurrence. LESSONS: The anterior approach is a viable option for cervicothoracic neurenteric cyst resection in the pediatric population and can aid in gross-total resection by providing better lesion visualization. More studies are needed on long-term outcomes of the anterior approach in pediatric populations. https://thejns.org/doi/10.3171/CASE24120.

Pure epidural extraosseous cavernous hemangioma with thoracic myelopathy: case report and review of literature.

INTRODUCTION: Pure epidural spinal cavernous hemangiomas are rare, benign vascular tumors that account for approximately 4% of all spinal epidural tumors. Due to their dumbbell shape and propensity for foraminal invasion, they are often misdiagnosed and inadequately treated. We present a case of a 58-year-old male with extra-osseous cavernous hemangioma to better aid in diagnosis and management of these lesions. CASE PRESENTATION: A 58-year-old male presented with chronic lower back pain, progressive lower extremity weakness, T10 sensory level, absent lower extremity proprioception, hyperreflexia, and an episode of bowel incontinence. Imaging demonstrated T7-T10 homogenous dorsal epidural mass causing cord signal change. He underwent resection with histopathologic exam revealing a pure epidural cavernous hemangioma. CONCLUSION: Spinal epidural cavernous hemangiomas are exceedingly rare lesions that are often misdiagnosed as nerve sheath tumors and meningiomas. Common features include chronic pain and myelopathy as well as T1 isodensity, T2 hyperintensity, and homogenous enhancement. Uniquely, they present as a lobulated, spindled shape with tapered ends in the dorsal epidural space. Both gross and subtotal resection result in favorable neurologic outcomes.

The occipital interhemispheric transtentorial approach in infants and toddlers: efficacy and complications.

INTRODUCTION: Outcomes for pineal region and superior cerebellar tumors in young children often hinge on extent of microsurgical resection, and thus choosing an approach that provides adequate visualization of pathology is essential. The occipital interhemispheric transtentorial (OITT) approach provides excellent exposure while minimizing cerebellar retraction. However, this approach has not been widely accepted as a viable option for very young children due to concerns for potential blood loss when incising the tentorium. The aim of this paper is to characterize our recent institutional experience with the occipital interhemispheric transtentorial approach (OITT) for tumor resection in infants and toddlers. METHODS: A retrospective study was performed between 2016 and 2023 of pediatric patients less than 36 months of age who underwent OITT for tumor resection at a high-volume referral center. Patients with at least 3 months of postoperative follow-up and postoperative MRI were included. Primary outcomes included extent of resection, intraoperative and postoperative complications, and neurologic outcome. Secondary outcomes included length of stay and estimated blood loss. RESULTS: Eight patients, five male, were included. The median age at the time of surgery was 10 months (range 5-36 months). Presenting symptoms included macrocephaly, nausea/vomiting, strabismus, gait instability, or milestone regression. Hydrocephalus was present preoperatively in all patients. Average tumor volume was 38.6 cm3, ranging from 1.3 to 71.9 cm3. All patients underwent an OITT approach for tumor resection with stereotactic guidance. No intraoperative complications occurred, and no permanent neurologic deficits developed postoperatively. Gross total resection was achieved in all cases per postoperative MRI report, and no instances of new cerebellar, brainstem, or occipital lobe ischemia were noted. CONCLUSIONS: OITT approach for tumor resection in very young children (≤ 36 months) is an effective strategy with an acceptable safety profile. In our series, no significant intraoperative or postoperative complications occurred. To our knowledge, this is the first report describing this technique specifically in patients less than 36 months of age.

Adult neuromuscular choristoma, a rare peripheral nerve pathology: illustrative case.

BACKGROUND: Neuromuscular choristomas (NMCs) are rare tumors involving aberrant intercalation of muscle fibers into peripheral nerves, most commonly the sciatic nerve. Although benign, these lesions risk developing into NMCs with desmoid-type fibrosis (NMC-DTFs), aggressive lesions potentially requiring amputation. Currently, information on NMCs and the link between NMCs and NMC-DTFs is limited in adults, with the majority of cases reported in children. We present the case of a 66-year-old male with a sciatic NMC alongside a Preferred Reporting Items for Systematic Reviews and Meta-Analyses-based systematic review of similar cases to better characterize this lesion in the adult population. OBSERVATIONS: A male presented with 10 years of progressive left lower-extremity weakness and paresthesia, and a mildly enlarged proximal sciatic nerve was discovered on magnetic resonance imaging. He underwent left sciatic fascicular nerve biopsy, with histopathological examination identifying the lesion as an NMC. The literature review revealed that our case, alongside other cases of adults with NMCs, shared characteristics similar to NMCs in the pediatric population. LESSONS: More comprehensive studies of adults with NMCs are needed, as the current literature contains limited information concerning disease course, diagnostic characteristics, and treatment. Furthermore, NMCs in adults should be handled with care because of the increased likelihood of transformation to NMC-DTF after surgical intervention.

The Role and Therapeutic Implications of Inflammation in the Pathogenesis of Brain Arteriovenous Malformations.

Brain arteriovenous malformations (bAVMs) are focal vascular lesions composed of abnormal vascular channels without an intervening capillary network. As a result, high-pressure arterial blood shunts directly into the venous outflow system. These high-flow, low-resistance shunts are composed of dilated, tortuous, and fragile vessels, which are prone to rupture. BAVMs are a leading cause of hemorrhagic stroke in children and young adults. Current treatments for bAVMs are limited to surgery, embolization, and radiosurgery, although even these options are not viable for ~20% of AVM patients due to excessive risk. Critically, inflammation has been suggested to contribute to lesion progression. Here we summarize the current literature discussing the role of the immune system in bAVM pathogenesis and lesion progression, as well as the potential for targeting inflammation to prevent bAVM rupture and intracranial hemorrhage. We conclude by proposing that a dysfunctional endothelium, which harbors the somatic mutations that have been shown to give rise to sporadic bAVMs, may drive disease development and progression by altering the immune status of the brain.

Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms.

Harmful algal blooms (HABs) are increasing in magnitude, frequency, and duration caused by anthropogenic factors such as eutrophication and altered climatic regimes. While the concentrations and ratios of nitrogen (N) and phosphorus are correlated with bloom biomass and cyanotoxin production, there is less known about how N forms and micronutrients (MN) interact to regulate HABs and cyanotoxin production. Here, we used two separate approaches to examine how N and MN supply affects cyanobacteria biomass and cyanotoxin production. First, we used a Microcystis laboratory culture to examine how N and MN concentration and N form affected the biomass, particulate N, and microcystin-LR concentration and cell quotas. Then, we monitored the N, iron, molybdenum, and total microcystin concentrations from a hypereutrophic reservoir. From this hypereutrophic reservoir, we performed a community HAB bioassay to examine how N and MN addition affected the biomass, particulate N, and microcystin concentration. Microcystis laboratory cultures grown in high urea and MN conditions produced more biomass, particulate N, and had similar C:N stoichiometry, but lower microcystin-LR concentrations and cell quotas when compared to high nitrate and MN conditions. Our community HAB bioassay revealed no interactions between N concentration and MN addition caused by non-limiting MN background concentrations. Biomass, particulate N, and microcystin concentration increased with N addition. The community HAB amended with MN resulted in greater microcystin-LA concentration compared to non-MN amended community HABs. Our results highlight the complexity of how abiotic variables control biomass and cyanotoxin production in both laboratory cultures of Microcystis and community HABs.