Midbrain, Pons, and Medulla: Anatomy and Syndromes.

The anatomy of the brainstem is complex. It contains numerous cranial nerve nuclei and is traversed by multiple tracts between the brain and spinal cord. Improved MRI resolution now allows the radiologist to identify a higher level of anatomic detail, but an understanding of functional anatomy is crucial for correct interpretation of disease. Brainstem syndromes are most commonly due to occlusion of the posterior circulation or mass effect from intrinsic space-occupying lesions. These syndromes can have subtle imaging findings that may be missed by a radiologist unfamiliar with the anatomy or typical manifesting features. This article presents the developmental anatomy of the brainstem and discusses associated pathologic syndromes. Congenital and acquired syndromes are described and correlated with anatomic locations at imaging, with diagrams to provide a reference to aid in radiologic interpretation. ©RSNA, 2019.

Rosai-Dorfman disease with spinal cord compression: a diagnostic challenge.

PURPOSE: Rosai-Dorfman disease (RDD) is an uncommon benign histiocytic proliferative disorder commonly involving the cervical lymph nodes and less frequently extranodal sites, including, rarely, the central nervous system, mainly intracranially. Spinal involvement is unusual. RDD is characterized by pathognomonic histopathological features, which are decisive in the definitive diagnosis. We present the case of a 75-year-old lady who presented with an isolated thoracic vertebral lesion. She underwent 3 CT-guided biopsies, all not confirmative for a definite diagnosis, and 2 open biopsies and debulking of the lesion. METHODS: The clinical notes, operation notes, investigations and clinic letters of the patient were reviewed. A literature search was performed using PubMed, with the keywords "Rosai-Dorfman disease", "sinus histiocytosis with massive lymphadenopathy", "histiocytic proliferative disorder". RESULTS: Only the histopathology after the last procedure was diagnostic for Rosai-Dorfman disease. The patient was treated with steroids with marked improvement in her clinical condition. CONCLUSIONS: This case demonstrates the challenge in making a diagnosis. RDD should be considered as a differential diagnosis in case of spinal lesion and non-diagnostic biopsy, especially in steroid sensitive lesions. The implications of the case are discussed.

Rechargeable occipital nerve stimulator systems: a patient satisfaction study.

INTRODUCTION: Cluster headache is a disabling severe headache syndrome, with a prevalence of 0.12%. Occipital nerve stimulation (ONS) is a recognized treatment for medically intractable cluster headache, composed of two electrodes in contact with the greater occipital nerves and connected to an Implantable Pulse Generator (IPG). The battery can be non-rechargeable or rechargeable, which has a longer total lifespan. This is, to our knowledge, the largest patient survey to examine the level of satisfaction with rechargeable batteries. METHODOLOGY: Using the ONS database at the National Hospital for Neurology and Neurosurgery, London we identified 100 patients who have had rechargeable systems implanted. We used a patient satisfaction questionnaire, developed with some questions adapted from McAuley et al. regarding rechargeable IPGs for spinal cord stimulation. RESULTS: Ninety-two out of the 100 patients consented to participate. Of them, 68 patients (74%) found recharging the battery convenient and 81 (88%) found that the amount of inconvenience associated with recharging worth the benefit they receive from the stimulation. Of 48 patients who had a non-rechargeable battery before the current rechargeable one, 37 (84%) stated preferring the current rechargeable. DISCUSSION: The results indicate a positive general outcome of ONS with rechargeable battery. We believe that this survey gives a reliable estimation of the outcome considering the large size of the sample and the very high rate of patients' compliance to answer our questionnaire. CONCLUSIONS: These data suggest that ONS with rechargeable IPG may be considered the system of choice for patients undergoing ONS implant.

Early Outcomes of the Pipeline Vantage Flow Diverter : A Multicentre Study.

PURPOSE: The recently introduced Pipeline Vantage Embolization Device with Shield Technology is the fourth generation of Pipeline flow diverter devices. Due to the relatively high rate of intraprocedural technical complications, modifications were subsequently made to the device after a limited release of the device in 2020. This study aimed to evaluate the safety and efficacy of the modified version of this device. METHODS: This was a multicentre retrospective series. The primary efficacy endpoint was aneurysm occlusion in the absence of retreatment. The primary safety endpoint was any neurological morbidity or death. Ruptured and unruptured aneurysms were included in the study. RESULTS: A total of 52 procedures were performed for 60 target aneurysms. Treatment was performed on 5 patients with ruptured aneurysms. The technical success rate was 98%. The mean clinical follow-up time was 5.5 months. In patients presenting with unruptured aneurysms there were no deaths, 3 (6.4%) major complications and 7 (13%) minor complications. In the five patients presenting with subarachnoid haemorrhage there were 2 (40%) major complications with 1 (20%) of these resulting in death, and 1 (20%) minor complication. Of the patients 29 (56%) had undergone 6­monthly postprocedural angiographic imaging with a mean time of 6.6 months demonstrating that 83% of patients had achieved adequate occlusion (RROC1/2) of the aneurysm. CONCLUSIONS: In this non-industry-sponsored study, the occlusion rates and safety outcomes were similar to those seen in previously published studies with flow diverter devices and earlier generation Pipeline devices. Modifications to the device appear to have improved ease of deployment.

Outcome study of the Pipeline Vantage Embolization Device (second version) in unruptured (and ruptured) aneurysms (PEDVU(R) study).

BACKGROUND: The Pipeline Vantage Embolization Device (PEDV) is the fourth-generation pipeline flow diverter for intracranial aneurysm treatment. There are no outcome studies for the second PEDV version. We aimed to evaluate safety and efficacy outcomes. Primary and secondary objectives were to determine outcomes for unruptured and ruptured cohorts, respectively. METHODS: In this multicenter retrospective and prospective study, we analyzed outcome data from eight centers using core laboratory assessments. We determined 30-day and ≥3-month mortality and morbidity rates, and 6- and 18-month radiographic aneurysm occlusion rates for procedures performed during the period July 2021-March 2023. RESULTS: We included 121 consecutive patients with 131 aneurysms. The adequate occlusion rate for the unruptured cohort at short-term and medium-term follow up, and also for the ruptured cohort at short-term follow up, was >90%. Two aneurysms (1.5%) underwent retreatment. When mortality attributed to a palliative case in the unruptured cohort, or subarachnoid hemorrhage in the ruptured cohort, was excluded then the overall major adverse event rate in respective cohorts was 7.5% and 23.5%, with 0% mortality rates for each. When all event causes were included on an intention-to-treat basis, the major adverse event rates in respective cohorts were 8.3% and 40.9%, with 0.9% and 22.7% mortality rates. CONCLUSIONS: For unruptured aneurysm treatment, the second PEDV version appears to have a superior efficacy and similar safety profile to previous-generation PEDs. These are acceptable outcomes in this pragmatic and non-industry-sponsored study. Analysis of ruptured aneurysm outcomes is limited by cohort size. Further prospective studies, particularly for ruptured aneurysms, are needed.

Safety and Efficacy of the Neuroform Atlas Stent for Treatment of Intracranial Aneurysms : A Systematic Review and Meta-Analysis.

OBJECTIVE: The Neuroform Atlas (Stryker Neurovascular, Fremont, CA, USA) is a low-profile laser cut self-expanding nitinol stent designed to provide coil support and wall apposition during aneurysm embolisation. In this study, we performed a meta-analysis of outcomes after treatment with the Neuroform Atlas stent for the purpose of coil embolisation. METHODS: The primary objectives of this meta-analysis were to define the safety (treatment-related complications, neurologic outcomes, mortality rate) and the efficacy (aneurysm occlusion rate) of the treatment of intracranial aneurysms with the Neuroform Atlas stent. A systematic review and meta-analysis was performed by searching PubMed, EMBASE, and the Cochrane CENTRAL Library for all published studies on the treatment of intracranial aneurysms with the Neuroform Atlas device up to 6 April 2020. The review was prepared in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS: A total of 14 studies were analysed (577 patients with 593 intracranial aneurysms). The mean age was 58.2 years and 35.6% were male. Technical success of the procedure was 100%. RROC1/RROC2 (Raymond-Roy occlusion classification (RROC) 1/2) (total occlusion/neck remnant) at a mean follow-up of 8.9 months was achieved in 94.8%. RROC3 was 4.9%. All-cause mortality was 1.8% and permanent residual neurological deficit or disability was 2.7%. Overall complications at follow-up were 6.2%. CONCLUSION: Our analysis demonstrated good rates of occlusion at follow-up for aneurysms treated with the Atlas device at follow-up. The safety profile appears similar to other low-profile intracranial stents.

Variations of treatment in selected proximal femur fractures among surgeons with different surgical experience--A survey at an international AO course.

INTRODUCTION: Different modalities of treatment for hip fractures have been discussed in the literature; however, practice may vary between centres. A survey was conducted on participants at an international AO course to assess the current management of pertrochanteric fractures (AO/OTA 31-A2) and displaced, non-impacted, subcapital fractures (AO/OTA 31-B3) in a 35-year-old patient and an 85-year-old patient. METHODS: Surgeons taking part in an international orthopaedic course were invited to participate in a survey and were divided into two groups: inexperienced (one-to-three years since qualification) and experienced (four or more years). A survey was conducted to assess the management modalities used for pertrochanteric fractures (AO/OTA 31-A2) and displaced, non-impacted, subcapital fractures (AO/OTA 31-B3) in a 35-year-old patient and an 85-year-old patient. RESULTS: Fifty-two surgeons participated: 18 were inexperienced and 34 were experienced. The method of operative fixation for the pertrochanteric fracture was gamma-nailing for 95% of the surgeons in the inexperienced group; in the experienced group, 56% opted for gamma-nailing and 38% for dynamic hip screw (DHS). For the displaced subcapital fracture in a 35-year-old, screw fixation was the dominant treatment option for both groups. For the displaced subcapital fracture in an 85-year-old, most of the surgeons in both groups preferred hemiarthroplasty: 59% in the inexperienced group chose cemented bipolar hemiarthroplasty and 12% uncemented, whereas 56% of the experienced group suggested cemented bipolar hemiarthroplasty and 25% uncemented. DISCUSSION: This survey shows that a variety of methods are used to treat femoral neck fractures. A prospective randomised trial has shown the DHS to be the implant of choice for pertrochanteric fractures; however, this was not considered an option in the inexperienced group of surgeons and was the treatment of choice in only 13 out of 34 experienced surgeons. There is a general consensus for femoral head-conserving surgery in young patients with displaced subcapital fractures. Replacement arthroplasty was considered in the 85-year-old with a subcapital fracture. In the inexperienced group, 10 of 17 surgeons would cement the prosthesis, as would 27 of 36 in the experienced group.