'Choroid bar': easy-to-seek marker of normal posterior fossa at 12-14 weeks' gestation.

OBJECTIVES: Our objectives were: (1) to assess the visualization rate of the choroid bar in a consecutive series of 306 first-trimester scans; (2) to verify, in this cohort of fetuses, the normality of the posterior fossa later in pregnancy; and (3) to confirm the non-visualization of the choroid bar in a retrospective series of fetuses with posterior fossa malformations. METHODS: This study included a prospective and a retrospective series. The former comprised 306 fetuses undergoing routine obstetric ultrasound at our unit in both the first and second trimesters over a 6-month period, while the latter comprised 12 cases of posterior fossa malformations. In the prospective study, the presence of the choroid bar, which is defined as a visually continuous, homogeneously hyperechogenic, thick structure bridging the cisterna magna from side to side, was evaluated at the end of the first-trimester nuchal translucency scan. In the retrospective study, previously acquired three-dimensional volume datasets were processed in order to assess whether the choroid bar could be visualized in cases of open spinal dysraphisms and vermian cystic anomalies. In the prospective study, confirmation of a normal posterior fossa was based on the sonographic features of this anatomical region at the time of the second-trimester anomaly scan at 19-21 weeks' gestation, while, in the retrospective study, it was based on autopsy results, when available, or further direct imaging of the defect later in pregnancy. RESULTS: In the prospective study, the choroid bar could be visualized in all 306 fetuses, on transabdominal ultrasound in 287 (93.8%) cases and on transvaginal ultrasound in 19 (6.2%) cases. The choroid bar was displayed with a ventral/dorsal approach in 67 (21.9%) cases, with a lateral approach in 56 (18.3%) cases and with both in 183 (59.8%) cases. All 306 cases were confirmed to have a sonographically normal posterior fossa at 19-21 weeks. On the other hand, in the retrospective study, it was not possible to visualize the choroid bar in any of the fetuses with posterior fossa malformations. CONCLUSIONS: We have described a new sign, the choroid bar, consistent with a normal posterior fossa at 12-14 weeks' gestation. The choroid bar provides the option of screening for major abnormalities of the posterior fossa, since its absence raises suspicion of both open spinal dysraphisms and posterior fossa cystic malformations. At the same time, it is easy to visualize, as it can be seen with all lines of insonation. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

PENG block associated with dexmedetomidine sedation for intramedullary femoral fixation in high-risk elderly patients: a case series and review of the literature.

BACKGROUND: Hip fracture is a major cause of hospitalization among the elderly population. The standard surgical treatment involves early repair to reduce mortality and morbidity. One type of treatment in the case of intertrochanteric and subtrochanteric fractures is intramedullary nailing, as it decreases soft tissue damage and permits early weight bearing. The most common anesthesia technique combines spinal anesthesia with a peripheral block. In cases where spinal anesthesia is contraindicated, general anesthesia is preferred. However, both techniques can lead to significant complications, especially in patients with multiple comorbidities. Pain management after hip surgery, particularly in elderly and frail individuals, poses a challenge. The pericapsular nerve group block (PENG) targets the innervation of the anterior portion of the hip joint and is increasingly used for pain management related to hip surgery. CASE SERIES: This paper presents a case series of three elderly patients who underwent pericapsular nerve group block (PENG) block combined with dexmedetomidine sedation for intramedullary femoral fixation. CONCLUSIONS: The PENG block can be effectively used as the sole anesthetic technique for managing elderly patients undergoing intramedullary femoral fixation while on antiplatelet drugs. This procedure effectively controlled pain during both the surgical and postoperative periods. The addition of dexmedetomidine for sedation enables comfortable and safe procedures, minimizing the risk of perioperative neurocognitive dysfunctions and without adverse effects on cardiorespiratory function.

Degenerative cervical myelopathy: Neuroradiological, neurophysiological and clinical correlations in 27 consecutive cases.

•New insight into prognostic factors for recovery of clinical function following posterior decompression for degenerative cervical myelopathy.•An increase of IOM amplitude of at least 50% coupled with preoperative T2-only and diffuse T2 signal changes on MRI is a positive prognostic factors for clinical improvement 6 months after surgery.•Clinical improvement at 6 months follow-up can be expected in patients with T1 hypo intensity if a diffuse border of the lesion on T2 images is present.

Visualization, navigation, augmentation. The ever-changing perspective of the neurosurgeon.

Introduction: The evolution of neurosurgery coincides with the evolution of visualization and navigation. Augmented reality technologies, with their ability to bring digital information into the real environment, have the potential to provide a new, revolutionary perspective to the neurosurgeon. Research question: To provide an overview on the historical and technical aspects of visualization and navigation in neurosurgery, and to provide a systematic review on augmented reality (AR) applications in neurosurgery. Material and methods: We provided an overview on the main historical milestones and technical features of visualization and navigation tools in neurosurgery. We systematically searched PubMed and Scopus databases for AR applications in neurosurgery and specifically discussed their relationship with current visualization and navigation systems, as well as main limitations. Results: The evolution of visualization in neurosurgery is embodied by four magnification systems: surgical loupes, endoscope, surgical microscope and more recently the exoscope, each presenting independent features in terms of magnification capabilities, eye-hand coordination and the possibility to implement additional functions. In regard to navigation, two independent systems have been developed: the frame-based and the frame-less systems. The most frequent application setting for AR is brain surgery (71.6%), specifically neuro-oncology (36.2%) and microscope-based (29.2%), even though in the majority of cases AR applications presented their own visualization supports (66%). Discussion and conclusions: The evolution of visualization and navigation in neurosurgery allowed for the development of more precise instruments; the development and clinical validation of AR applications, have the potential to be the next breakthrough, making surgeries safer, as well as improving surgical experience and reducing costs.

Cerebellar mutism syndrome: the importance of preoperative language assessment.

Children undergoing surgical removal of tumors in the posterior cranial fossa can encounter a varied and complex constellation of neurological symptoms, called cerebellar mutism, defined as a disturbance in the planning and programming of motor language with preserved understanding, behavioral disorders such as inattention, visual-spatial disorganization, personality change, as well as ataxia and dysmetria. In the last years, several groups have been trying to establish risk factors or even predictive scores in order to be able at least in part to predict the appearance of speech disorders before surgery. We report on a child with pilocytic astrocytoma of the cerebellar vermis who had already been diagnosed with developmental linguistic delay two years earlier. This disorder initially worsened after surgery and later improved in the following 12 months. The aim of this paper is to emphasize the importance of preoperative neuropsychological evaluation. The present case, along with those reported in the literature, suggests that the risk of long-term cerebellar mutism is higher in children with preoperative speech disorders. In these patients a thorough assessment of cognitive and linguistic functions is therefore necessary to better evaluate the risk of cerebellar mutism after surgery.

Recording cortico-cortical evoked potentials of the human arcuate fasciculus under general anaesthesia.

OBJECTIVE: We examined the feasibility of using cortico-cortical evoked potentials (CCEPs) to monitor the major cortical white matter tract involved in language, the arcuate fasciculus (AF), during surgery under general anaesthesia. METHODS: We prospectively recruited nine patients undergoing surgery for lesions in the left peri-sylvian cortex, for whom awake surgery was not indicated. High angular resolution diffusion imaging (HARDI) tractography was used to localise frontal and temporal AF terminations, which guided intraoperative cortical strip placement. RESULTS: CCEPs were successfully evoked in 5/9 patients, showing a positive potential (P1) at 12 ms and a negative component (N1) at 21 ms when stimulating from the frontal lobe and recording in the temporal lobe. CCEP responses peaked in the posterior middle temporal gyrus. No CCEPs were evoked when stimulating temporal sites and recording from frontal contacts. CONCLUSION: For the first time, we show that CCEPs can be evoked from the peri-sylvian cortices also in adult patients who are not candidates for awake procedures. Our results are akin to those described in the awake setting and suggest the recorded activity is conveyed by the arcuate fasciculus. SIGNIFICANCE: This intraoperative approach may have promising implications in reducing deficits in patients that require surgery in language areas under general anesthesia.

Intramedullary spinal cord metastasis from an adenoid cystic carcinoma of the external auditory canal: case report.

BACKGROUND AND IMPORTANCE: Intramedullary spinal cord metastases (ISCMs) are rare and no cases of ISCM from an adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) have been reported. CLINICAL PRESENTATION: We report a 54-year old man complaining backpain and worsening myelopathy. He had an ACC of the EAC resected years prior. A spinal MRI demonstrated a contrast-enhancing intramedullary lesion within the conus medullaris. The histopathological diagnosis of the patient was consistent with the patient's primary cancer. At 3 months follow-up, the neurological condition of the patient was unchanged. CONCLUSIONS: This is the first reported case of ISCM from a primary ACC of the EAC.

Combined circular external fixation and flexible intramedullary nailing for pediatric bilateral open tibia fractures in blast injury.

Management of blast injuries with open fractures and extensive soft tissue damage in pediatric patients is a challenging task even in experienced hands. This article reports the case of an 8-year-old boy with bilateral open tibia fractures and soft tissue loss due to the accidental explosion of a skyrocket. After the emergency procedures with lavage, debridement and temporary bone stabilization, we performed the definitive reconstruction surgery using a combined circular external fixation and flexible intramedullary nailing technique on both legs. This technique allowed easy access to the wounds for plastic surgery procedures and early bilateral weight bearing. All implants were removed within 6 months, the fractures healed with good axial alignment and the patient returned to his preinjury activities one year after the trauma. In this case, the combined use of circular external fixation and flexible intramedullary nailing ensured optimal fractures stabilization, minimizing the damage to the soft tissues and the obstruction for plastic surgeons. We believe that this technique should be considered in pediatric patients with open fractures of the lower limbs and extensive soft tissue injuries.

A snapshot of European neurosurgery December 2019 vs. March 2020: just before and during the Covid-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. METHODS: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. RESULTS: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. CONCLUSION: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent European countries.

Recommendations of the International Society of Intraoperative Neurophysiology for intraoperative somatosensory evoked potentials.

Intraoperative somatosensory evoked potentials (SEPs) provide dorsal somatosensory system functional and localizing information, and complement motor evoked potentials. Correct application and interpretation require in-depth knowledge of relevant anatomy, electrophysiology, and techniques. It is advisable to facilitate cortical SEPs with total intravenous propofol-opioid or similarly favorable anesthesia. Moreover, SEP optimization is recommended to enhance surgical feedback speed and accuracy by maximizing signal-to-noise ratio (SNR); it consists of selecting highest-SNR peripheral and cortical derivations while omitting low-SNR channels. Confounding factors causing non-surgical SEP reduction should be excluded before issuing a warning. It is advisable to facilitate their identification with peripheral SEP controls and cortical SEP systemic controls whenever possible. Warning criteria should adjust for baseline drift and reproducibility. The recommended adaptive warning criterion is visually obvious amplitude reduction from recent pre-change values and clearly exceeding trial-to-trial variability, particularly when abrupt and focal. Acquisition and interpretation should be done by qualified technical and professional level personnel. Indications for SEP monitoring include intracranial, posterior fossa, and spinal neurosurgery, as well as orthopedic spine, cerebrovascular, and descending aortic surgery. Indications for SEP mapping include sensorimotor cortex and dorsal column midline identification. Future advances could modify current recommendations.

Evaluation of Levothyroxine Bioavailability after Oral Administration of a Fixed Combination of Soy Isoflavones in Post-menopausal Female Volunteers.

BACKGROUND: Post-menopausal women under treatment with levothyroxine for their medical conditions may take concomitantly dietary supplements containing soy isoflavones in combination to treat their post-menopausal symptoms. The aim of this study was to investigate the effect of a fixed combination of soy isoflavones on the oral bioavailability of levothyroxine in post-menopausal female volunteers. METHODS: 12 healthy post-menopausal female, who were on stable oral levothyroxine as replacement/supplementation therapy for hypothyroidism, received a single recommended oral dose of a food supplement containing 60 mg of soy isoflavones (>19% genistin and daidzin) concomitantly with (test) and 6 h later (reference) the administration of levothyroxine in a randomized, open label, crossover fashion. Plasma concentrations of levothyroxine and soy isoflavones (daidzin, daidzein, genistin, genistein, S-equol) were determined by LC-MS/MS. Pharmacokinetic (PK) parameters were determined by non-compartmental analysis. No effect of soy isoflavones was assumed if the 90% confidence intervals (CIs) for the estimated ratio test/reference was included in the acceptance limits 0.80-1.25 for PK parameters Cmax and AUCt. RESULTS: The test/reference ratios Cmax and AUCt of levothyroxine were very close to unity (1.02 and 0.99, respectively) and the corresponding 90% CIs (0.99-1.04 and 0.88-1.12, respectively) fell entirely within the acceptance bioequivalence limits. CONCLUSION: The combination of soy isoflavones used in the present investigation does not affect the rate and extent of levothyroxine absorption when administered concomitantly in post-menopausal women.

Intraoperative neurophysiological monitoring for the resection of brain tumors in pediatric patients.

Intraoperative neurophysiology (ION) is the gold standard to map and monitor brain functions during supratentorial surgery in critical areas. This is of great value for the surgery of brain gliomas in adults, but the same ION techniques can be used in the pediatric population with respect to both epilepsy and brain tumor surgery. While the principles of most ION techniques are the same for adults and children, the developing nervous system has peculiar characteristics in terms of anatomical and physiological maturation of afferent and efferent pathways within the brain and the spinal cord. Accordingly, some adjustments, particularly with regards to stimulation parameters, are needed in younger children. This paper will review current ION techniques to assist during the resection of brain tumors in children, focusing on the aspects peculiar to mapping and monitoring of sensori-motor functions in the pediatric population. On the other hand, awake surgery, of common use in adult patients when aiming to identify cortical and subcortical cognitive functions, is of very limited use in children and will not be discussed here.

The Italian validation of the Anosognosia Questionnaire for Dementia in Alzheimer's disease.

Although the Anosognosia Questionnaire-Dementia (AQ-D) is one of the main instruments for assessing awareness in Alzheimer's disease (AD), the normative data were until now limited to people from Argentina and Japan. This study aims to validate this instrument in an European context, in particular in an Italian sample. In a multicenter project (Verona, Padova, and Trapani), 130 patients with AD and their caregivers participated in the study. Psychometric characteristics of AQ-D are confirmed indicating that the scale permits the early identification of anosognosia and the correct care management of patients. Indeed, anosognosia results to be present also in patients with very mild AD (moderate: 44.44%; mild: 47.17%; and very mild: 23.73%). Moreover, the results indicate that deficits in awareness may vary in severity and that different types of anosognosia may be identified.

Intraoperative mapping and monitoring in supratentorial tumor surgery.

With the increasing strive for complete resections of supratentorial low or high-grade gliomas, the necessity for intraoperative electrical stimulation methods to map and monitor functional important cortical or subcortical brain areas increased. While many brain functions can be assessed during awake surgery using electrical stimulation, motor function as well as visual function can be mapped and monitored in the asleep patient, as well. Several different methods reviewed in this article are available which lead to an improved functional outcome while increasing the extent of tumor resection and thereby potentially the oncological outcome of the patient.

Trigeminal laser-evoked potentials: a neurophysiological tool to detect post-surgical outcome in trigeminovascular contact neuralgia.

BACKGROUND: The aim of this study was to explore the nociceptive system of patients affected by trigeminal neuralgia (TN) secondary to documented vascular contact who underwent microvascular decompression. For that purpose, we used the classical trigeminal reflexes and the trigeminal laser-evoked potentials (tLEPs) before and after surgery, in order to verify any possible change after decompression and determine if there was any correlation between the neurophysiological parameters and the clinical outcome. METHODS: Eleven patients affected by TN caused by trigeminovascular contact and 10 age-matched controls underwent conventional trigeminal reflexes (bilateral Blink Reflex/BR and Masseter Inhibitory Reflex stimulating infraorbital and mental nerves/MIR V2 and V3) and tLEPs. Patients repeated neurophysiological tests one week after surgery. RESULTS: Short-latency BR and MIR were normal in all patients before surgery and there was no statistical difference before and after surgery. Conversely, in patients before surgery, tLEPs' amplitudes were significantly lower in the affected than in the healthy side (p = 0.017 for V2 and 0.037 for V3 branches). After surgery, on the affected side, tLEP amplitude increased and the pre/post-operative difference was significant (p = 0.017 for V2 and 0.028 for V3 divisions). Nine patients referred satisfactory pain relief and the favourable clinical outcome correlated with the neurophysiological recovery. CONCLUSIONS: This study demonstrates that TN caused by trigeminovascular compression may be related to Aδ fibres impairment, and tLEPs are more sensitive than conventional trigeminal reflexes to reveal small fibre dysfunction and to monitor the post-surgical outcome in these patients.

Neurophysiological assessment of the injured spinal cord: an intraoperative approach.

STUDY DESIGN: Prospective, observational study. OBJECTIVES: To assess the spinal cord function intraoperatively in subjects during spine stabilization for spinal cord trauma, by recording muscular (m-MEPs) and epidural motor evoked potentials (e-MEPs, D wave) along with cortical and epidural somatosensory evoked potentials (e-SEPs) and predicting the outcome of spinal cord injury (SCI). SETTING: Regional Trauma Center, Torino, Italy. METHODS: Fifty-five patients were intraoperatively studied during posterior spine stabilization surgery for traumatic SCI. In all, 21 of these had complete SCI, 14 an incomplete SCI-6 of them with central cord syndrome and 1 with central cord plus Brown Sequard syndrome-and 20 patients were neurologically uncompromised. RESULTS: The neurophysiologic profile of the complete SCI was the absence of both m-MEPs and e-MEPs caudally to the lesion site, associated with a lack of cortical and e-SEPs cranially to the lesion site. None of these patients recovered motor function in the follow-up. A clearly detectable caudal D wave was associated with motor recovery even in deeply paraparetic patients. In one neurologically incomplete patient a reversible deterioration of m-MEPs and e-MEPs was observed during the compression-distraction manoeuvre. CONCLUSION: Intraoperative neurophysiological evaluation of SCI patients can provide information about spinal cord function that is not retrievable by other clinical means and can correctly predict neurological outcome. Intraoperative testing during early stabilization of the spine of deeply paraparetic SCI patients provides additional information about their neurological profile.

Wave Function and Density Functional Theory Studies of Dihydrogen Complexes.

We performed a benchmark study on a series of dihydrogen bond complexes and constructed a set of reference bond distances and interaction energies. The test set was employed to assess the performance of several wave function correlated and density functional theory methods. We found that second-order correlation methods describe relatively well the dihydrogen complexes. However, for high accuracy inclusion of triple contributions is important. On the other hand, none of the considered density functional methods can simultaneously yield accurate bond lengths and interaction energies. However, we found that improved results can be obtained by the inclusion of nonlocal exchange contributions.

Awareness of cognitive deficits and clinical competence in mild to moderate Alzheimer's disease: their relevance in clinical practice.

Awareness of cognitive deficits and clinical competence were investigated in 79 mild to moderate Alzheimer's disease patients. Awareness was assessed by the anosognosia questionnaire for dementia, and clinical competence by specific neuropsychological tests such as trail making test-A, Babcock story recall test, semantic and phonemic verbal fluency. The findings show that 66 % of the patients were aware of memory deficits, while the 34 % were unaware. Deficit in awareness correlated with lower scores on the Mini Mental State Examination test that, in the score range from 24.51 to 30 and from 19.50 to 24.50, appeared to be a significant predictor of level of awareness. None of the AD patients had fully preserved clinical competence, only 7 patients (9 %) had partially preserved clinical competence and 72 patients (91 %) had completely lost clinical competence. All the patients with partially preserved clinical competence (9 %) were aware of their memory deficit. The study indicates that neuropsychological tests used for the assessment of executive functions are not suitable for investigating clinical competence. Therefore, additional and specific tools for the evaluation of clinical competence are necessary. Indeed, these might allow clinicians to identify AD patients who, despite their deficits in selected functions, retain their autonomy of choice as well as recognize those patients who should proceed to the nomination of a legal representative.