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Clinical Neurology and Neurosurgery Jun 2024This study aimed to identify clinical and surgical features associated with poor long-term postoperative outcomes in patients diagnosed with Type I Chiari Malformation...
Predictors of poor functional outcomes in adults with type I Chiari Malformation: Clinical and surgical factors assessed with the Chicago Chiari Outcome Scale over long-term follow-up.
OBJECTIVE
This study aimed to identify clinical and surgical features associated with poor long-term postoperative outcomes in patients diagnosed with Type I Chiari Malformation (CMI) treated with posterior fossa decompression with duroplasty (PFDD), with or without tonsillar coagulation.
METHODS
This retrospective, single-center study included 107 adult patients with CMI surgically treated between 2010 and 2021. The surgical technique involved a midline suboccipital craniectomy, C1 laminectomy, durotomy, arachnoid dissection, duroplasty, and tonsillar coagulation until 2014, after which tonsillar coagulation was discontinued. Postoperative outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) at a median follow-up of 35 months. Clinical, surgical, and neuroimaging data were analyzed using the Wilcoxon signed-rank test, Cox regression analysis, and Kaplan-Meier survival curves to identify predictors of poor functional outcomes.
RESULTS
Of the 107 patients (mean age 43.9 years, SD 13), 81 (75.5 %) showed functional improvement, 25 (23.4 %) remained unchanged, and 1 (0.9 %) experienced worsened outcomes. Cephalalgia, bilateral motor weakness, and bilateral paresthesia were the most frequent initial symptoms. Tonsillar coagulation was performed in 31 cases (28.9 %) but was clinically associated with higher rates of unfavorable outcomes. The Wilcoxon signed-rank test indicated that long-term follow-up CCOS was significantly higher than postoperative CCOS (Z = -7.678, p < 0.000). Multivariate Cox analysis identified preoperative bilateral motor weakness (HR 6.1, 95 % CI 1.9-18.9; p = 0.002), hydrocephalus (HR 3.01, 95 % CI 1.3-6.9; p = 0.008), and unilateral motor weakness (HR 2.99, 95 % CI 1.1-8.2; p = 0.033) as significant predictors of poor outcomes on a long-term follow-up.
CONCLUSION
This study highlights the high rate of functional improvement in CMI patients following PFDD. Preoperative motor weakness and hydrocephalus were significant predictors of poor long-term outcomes. Tonsillar coagulation did not demonstrate a clear clinical benefit and may be associated with worse outcomes. Our findings suggest that careful preoperative assessment and selection of surgical techniques are crucial for optimizing patient outcomes.
PubMed: 38945118
DOI: 10.1016/j.clineuro.2024.108392 -
Bioengineering (Basel, Switzerland) Jun 2024This study aimed to investigate the effect of the transverse sinus (TS) stenosis (TSS) position caused by arachnoid granulation on patients with venous pulsatile...
This study aimed to investigate the effect of the transverse sinus (TS) stenosis (TSS) position caused by arachnoid granulation on patients with venous pulsatile tinnitus (VPT) and to further identify the types of TSS that are of therapeutic significance for patients. Multiphysics interaction models of six patients with moderate TSS caused by arachnoid granulation and virtual stent placement in TSS were reconstructed, including three patients with TSS located in the middle segment of the TS (group 1) and three patients with TTS in the middle and proximal involvement segment of the TS (group 2). The transient multiphysics interaction simulation method was applied to elucidate the differences in biomechanical and acoustic parameters between the two groups. The results revealed that the blood flow pattern at the TS and sigmoid sinus junction was significantly changed depending on the stenosis position. Preoperative patients had increased blood flow in the TSS region and TSS downstream where the blood flow impacted the vessel wall. In group 1, the postoperative blood flow pattern, average wall pressure, vessel wall vibration, and sound pressure level of the three patients were comparable to the preoperative state. However, the postoperative blood flow velocity decreased in group 2. The postoperative average wall pressure, vessel wall vibration, and sound pressure level of the three patients were significantly improved compared with the preoperative state. Intravascular intervention therapy should be considered for patients with moderate TSS caused by arachnoid granulations in the middle and proximal involvement segment of the TS. TSS might not be considered the cause of VPT symptoms in patients with moderate TSS caused by arachnoid granulation in the middle segment of the TS.
PubMed: 38927848
DOI: 10.3390/bioengineering11060612 -
Anatomical Record (Hoboken, N.J. : 2007) Jun 2024The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate... (Review)
Review
The existence of a previously unrecognized subarachnoid lymphatic-like membrane (SLYM) was reported in a recent study. SLYM is described as an intermediate leptomeningeal layer between the arachnoid and pia mater in mouse and human brains, which divides the subarachnoid space (SAS) into two functional compartments. Being a macroscopic structure, having missed detection in previous studies is surprising. We systematically reviewed the published reports in animals and humans to explore whether prior descriptions of this meningeal layer were reported in some way. A comprehensive search was conducted in PubMed/Medline, EMBASE, Google Scholar, Science Direct, and Web of Science databases using combinations of MeSH terms and keywords with Boolean operators from inception until 31 December 2023. We found at least eight studies that provided structural evidence of an intermediate leptomeningeal layer in the brain or spinal cord. However, unequivocal descriptions for this layer all along the central nervous system were scarce. Obscure names like the epipial, intermediate meningeal, outer pial layers, or intermediate lamella were used to describe it. Its microscopic/ultrastructural details closely resemble the recently reported SLYM. We further examined the counterarguments in current literature that are skeptical of the existence of this layer. The potential physiological and clinical implications of this new meningeal layer are significant, underscoring the urgent need for further exploration of its structural and functional details.
PubMed: 38924700
DOI: 10.1002/ar.25524 -
Current Protocols Jun 2024This article describes a step-by-step process of lumbar intrathecal injection of Evans blue dye and AAV9-EGFP in adult (2-month-old) and neonatal (postnatal day 10)...
This article describes a step-by-step process of lumbar intrathecal injection of Evans blue dye and AAV9-EGFP in adult (2-month-old) and neonatal (postnatal day 10) mice. Intrathecal injection is a clinically translatable technique that has already been extensively applied in humans. In mice, intrathecal injection is considered a challenging procedure that requires a trained and experienced researcher. For both adult and neonatal mice, lumbar intrathecal injection is directed into the L5-L6 intervertebral space. Intrathecally injected material enters the cerebrospinal fluid (CSF) within the intrathecal space from where it can directly access the central nervous system (CNS) parenchyma. Simultaneously, intrathecally injected material exits the CSF with pressure gradient and enters the endoneurial fluid and ultimately the peripheral nerves. While in the CSF, the injectable material also enters the bloodstream and systemic circulation through the arachnoid villi. A successful lumbar intrathecal injection results in adequate biodistribution of the injectable material in the CNS, PNS, and peripheral organs. When correctly applied, this technique is considered as minimally invasive and non-disruptive and can be used for the lumbar delivery of any solute. © 2024 Wiley Periodicals LLC. Basic Protocol 1: C57BL/6 adult and P10 mice lumbar intrathecal injection Basic Protocol 2: Tissue collection and preparation for evaluating Evans blue dye diffusion Basic Protocol 3: Tissue collection and preparation for immunohistochemistry staining Basic Protocol 4: Tissue collection and vector genome copy number analysis.
Topics: Animals; Injections, Spinal; Mice; Animals, Newborn; Mice, Inbred C57BL; Evans Blue; Green Fluorescent Proteins; Dependovirus; Genetic Vectors
PubMed: 38923413
DOI: 10.1002/cpz1.1091 -
Headache Jun 2024The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with...
OBJECTIVE
The aim of this study was to investigate whether the relative narrowing of the dural venous sinuses by arachnoid granulations (AGs) is more pronounced in patients with idiopathic intracranial hypertension (IIH) compared to healthy controls.
BACKGROUND
IIH is characterized by increased intracranial pressure, which is associated with symptoms such as headache and visual disturbances. The role of cerebral venous drainage obstruction in IIH is the subject of ongoing research.
MATERIALS AND METHODS
In this retrospective case-control study, 3D contrast-enhanced magnetic resonance images of a cohort of 43 patients with IIH were evaluated for (1) the number of AGs per venous sinus and (2) the diameters of the dural venous sinuses at the site of an AG and at standardized measurement points. In addition, the minimum width of the transverse/sigmoid sinus was measured. All data were compared to the same data from a cohort of 43 control participants.
RESULTS
Patients with IIH showed less relative sinus narrowing by AG compared to controls (median: 7%, interquartile range [IQR] 10% vs. 11%, IQR 9% in controls; p = 0.009). In patients with IIH, sinus diameter was larger at the site of an AG (70 ± 25 mm) compared to its diameter at the standardized measurement point (48 ± 23 mm; p = 0.010). In the superior sagittal sinus (SSS), patients with IIH had smaller AGs (median: 3 mm, IQR 2 mm vs. 5 mm, IQR 3 mm in controls; p = 0.023) while the respective sinus segment was larger (median: 69 mm; IQR 21 mm vs. 52 mm, IQR 26 mm in controls; p = 0.002). The right transverse sinus was narrower in patients with IIH (41 ± 21 mm vs. 57 ± 20 mm in controls; p < 0.001).
CONCLUSIONS
In contrast to our hypothesis, patients with IIH showed less pronounced relative sinus narrowing by AG compared to controls, especially within the SSS, where AGs were smaller and the corresponding sinus segment wider. Smaller AGs could result in lower cerebrospinal fluid resorption, favoring the development of IIH. Conversely, the smaller AGs could also be a consequence of IIH due to backpressure in the SSS because of the narrower transverse/sigmoid sinus, which widens the SSS and compresses the AG.
PubMed: 38922856
DOI: 10.1111/head.14776 -
Frontiers in Endocrinology 2024Acromegaly is a rare endocrine disorder caused by hypersecretion of growth hormone (GH) from a pituitary adenoma. Elevated GH levels stimulate excess production of...
UNLABELLED
Acromegaly is a rare endocrine disorder caused by hypersecretion of growth hormone (GH) from a pituitary adenoma. Elevated GH levels stimulate excess production of insulin-like growth factor 1 (IGF-1) which leads to the insidious onset of clinical manifestations. The most common primary central nervous system (CNS) tumors, meningiomas originate from the arachnoid layer of the meninges and are typically benign and slow-growing. Meningiomas are over twice as common in women as in men, with age-adjusted incidence (per 100,000 individuals) of 10.66 and 4.75, respectively. Several reports describe co-occurrence of meningiomas and acromegaly. We aimed to determine whether patients with acromegaly are at elevated risk for meningioma. Investigation of the literature showed that co-occurrence of a pituitary adenoma and a meningioma is a rare phenomenon, and the majority of cases involve GH-secreting adenomas. To the best of our knowledge, a systematic review examining the association between meningiomas and elevated GH levels (due to GH-secreting adenomas in acromegaly or exposure to exogenous GH) has never been conducted. The nature of the observed coexistence between acromegaly and meningioma -whether it reflects causation or mere co-association -is unclear, as is the pathophysiologic etiology.
SYSTEMATIC REVIEW REGISTRATION
https://www.crd.york.ac.uk/prospero/, identifier CRD42022376998.
Topics: Humans; Meningioma; Acromegaly; Meningeal Neoplasms; Human Growth Hormone; Risk Factors; Adenoma
PubMed: 38919490
DOI: 10.3389/fendo.2024.1407615 -
Journal of Neurosurgery. Case Lessons Jun 2024Spinal extradural arachnoid cysts (SEACs) communicate with the subarachnoid space through small communicating dural holes. The precise preoperative detection of all...
Successful detection of multiple communicating holes in multiple spinal extradural arachnoid cysts by using time-spatial labeling inversion pulse magnetic resonance imaging: illustrative case.
BACKGROUND
Spinal extradural arachnoid cysts (SEACs) communicate with the subarachnoid space through small communicating dural holes. The precise preoperative detection of all communicating holes, followed by minimally invasive dural closure, is the ideal treatment to prevent postoperative spinal deformities, especially in cases of multiple SEACs. However, standard imaging methods often fail to detect communicating hole locations. Although a few cases of successful single-hole detection via cinematic magnetic resonance imaging (MRI) have been reported, this modality's ability to detect multiple holes has not been demonstrated.
OBSERVATIONS
The authors describe the case of a 14-year-old male with myelopathy due to multiple SEACs at T5-8 and T8-12. Myelography revealed a complete block at the T8 level; no cephalic cyst or communicating holes were identified. Time-spatial labeling inversion pulse (T-SLIP) MRI revealed cerebrospinal fluid flow into the cyst at T10 and T7. A limited laminectomy or hemilaminectomy was performed at T7 and T10, and two dural holes were closed without a total cystectomy. The patient's gait disturbance and rectal disorder disappeared. The cysts were confirmed to have completely disappeared on conventional MRI at 1 year postoperatively.
LESSONS
T-SLIP MRI, a cinematic MRI, is useful for detecting multiple communicating holes in SEACs.
PubMed: 38914022
DOI: 10.3171/CASE24200 -
The Journal of Infectious Diseases Jun 2024Central nervous system (CNS) compartmentalization provides opportunity for HIV persistence and resistance development. Differences between cerebrospinal fluid (CSF) and...
BACKGROUND
Central nervous system (CNS) compartmentalization provides opportunity for HIV persistence and resistance development. Differences between cerebrospinal fluid (CSF) and cerebral matter regarding HIV persistence are well described. However, CSF is often used as surrogate for CNS drug exposure, and knowledge from solid brain tissue is rare.
METHODS
Dolutegravir, tenofovir, lamivudine and efavirenz concentrations were measured across 13 CNS regions plus plasma in samples collected during autopsy in 49 Ugandan decedents. Median time from death to autopsy was 8 (IQR 5,15) hours. To evaluate postmortem redistribution, a time course study was performed in a mouse model.
RESULTS
Regions with the highest penetration ratios were choroid plexus/arachnoid (dolutegravir and tenofovir), CSF (lamivudine), and cervical spinal cord/meninges (efavirenz); the lowest were corpus callosum (dolutegravir and tenofovir), frontal lobe (lamivudine), and parietal lobe (efavirenz). On average, brain concentrations were 84%, 87%, and 76% of CSF for dolutegravir, tenofovir, and lamivudine respectively. Postmortem redistribution was observed in the mouse model, with tenofovir and lamivudine concentration increased by 350% and efavirenz concentration decreased by 24% at 24-hours post-mortem.
CONCLUSION
Analysis of postmortem tissue provides a unique opportunity to investigate CNS antiretroviral penetration. Regional differences were observed paving the way to identify mechanisms of viral compartmentalization and/or neurotoxicity.
PubMed: 38900910
DOI: 10.1093/infdis/jiae325 -
Operative Neurosurgery (Hagerstown, Md.) Jun 2024The extended translabyrinthine approach to acoustic neuroma (AN) was created to allow improved visualization and access to larger tumors.1,2 The dural opening, however,...
The extended translabyrinthine approach to acoustic neuroma (AN) was created to allow improved visualization and access to larger tumors.1,2 The dural opening, however, remained confined to the presigmoid space. Other authors have introduced modifications to increase the dura exposure around the internal auditory canal (IAC).3-5 The extra-extended translabyrinthine approach was conceptualized by the senior author (CC) to maximize AN exposure and early cranial nerve identification. The tentorial peeling was added to allow extradural mobilization of the temporal lobe.6 This allows further safe bone removal around the IAC and petrous apex and consistent opening of the facial canal at IAC fundus. This modification creates 280-to-360-degree dura exposure at the IAC. The dural opening extends to the petrous apex superiorly and the prepontine arachnoid cistern inferiorly and includes resection of a tentorium dural flap created by the tentorial peeling.6 This exposure allows for near circumferential exposure of the tumor and early identification of the glossopharyngeal nerve in the cochlear aqueduct area, the trigeminal nerve at the porus trigeminal, and the facial nerve (FN) at IAC fundus. In addition, this ample exposure permits identification of the FN trajectory in the tumor capsule before any tumor dissection. We present a detailed video of extra-extended translabyrinthine approach technique in a patient with a large left AN (Hannover classification T4B).7 This video does not involve any human research projects not requiring Institutional Review Board/ethic committee approval. The patient consented to the procedure and to the publication of his image. Complete resection was obtained. The FN function was House-Brackman I/VI.
PubMed: 38888316
DOI: 10.1227/ons.0000000000001223 -
Neurosurgical Review Jun 2024Aim of the present study was to conduct a comprehensive review of surgical strategies that can be offered to patients with trigeminal neuralgia undergoing microvascular... (Review)
Review
A systematic review on the efficacy of adjunctive surgical strategies during microvascular decompression for trigeminal neuralgia without intraoperative evidence of neurovascular conflict.
Aim of the present study was to conduct a comprehensive review of surgical strategies that can be offered to patients with trigeminal neuralgia undergoing microvascular decompression (MVD) surgery and without intraoperative evidence of neurovascular conflict, with a high pre-operative suspicion of conflict lacking intraoperative confirmation, or individuals experiencing recurrence after previous treatment. This systematic review followed established guidelines (PRISMA) to identify and critically appraise relevant studies. The review question was formulated according to the PICO (P: patients; I: intervention; C: comparison; O: outcomes) framework as follows. For patients with trigeminal neuralgia (P) undergoing MVD surgery (I) without demonstrable preoperative neurovascular conflict, high suspicion of conflict but no intraoperative confirmation or recurrence after previous treatment (C), do additional surgical techniques (nerve combing, neurapraxia, arachnoid lysis) (O) improve pain relief outcomes (O)? The search of the literature yielded a total of 221 results. Duplicate records were then removed (n = [76]). A total of 143 papers was screened, and 117 records were excluded via title and abstract screening; 26 studies were found to be relevant to our research question and were assessed for eligibility. Upon full-text review, 17 articles were included in the review, describing the following techniques; (1) internal neurolysis (n = 6) (2) arachnoid lysis/adhesiolysis (n = 2) (3) neurapraxia (n = 3) (4) partial rhizotomy of the sensory root (n = 4) (5) pontine descending tractotomy (n = 2). The risk of bias was assessed using the ROBINS-I (Risk of Bias in Non-randomized Studies - of Interventions) assessment tool. While the described techniques hold promise, further research is warranted to establish standardized protocols, refine surgical approaches, and comprehensively evaluate long-term outcomes.
Topics: Trigeminal Neuralgia; Humans; Microvascular Decompression Surgery; Treatment Outcome
PubMed: 38884812
DOI: 10.1007/s10143-024-02498-7