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We retrospectively analyzed data from 15 patients, with a normal pre-operative cognitive performance, undergoing awake surgery for left fronto-temporal low-grade glioma. We combined a pre-surgical measure (fMRI maps of motor- and language-related centers) with intra-surgical measures (MNI-registered cortical sites data obtained during intra-operative direct electrical stimulation, DES, while they performed the two most common language tasks: number counting and picture naming). Selective DES effects along the precentral gyrus/inferior frontal gyrus (and/or the connected speech articulation network) were obtained. DES of the precentral gyrus evoked the motor speech arrest, i.e., anarthria (with apparent mentalis muscle movements). We calculated the number of shared voxels between the lip-tongue and overt counting related- and silent naming-related fMRI maps and the Volumes of Interest (VOIs) obtained by merging together the MNI sites at which a given speech disturbance was observed, normalized on their mean the values (i.e., Z score). Both tongue- and lips-related movements fMRI maps maximally overlapped (Z = 1.05 and Z = 0.94 for lips and tongue vs. 0.16 and -1.003 for counting and naming) with the motor speech arrest seed. DES of the inferior frontal gyrus, pars opercularis and the rolandic operculum induced speech arrest proper (without apparent mentalis muscle movements). This area maximally overlapped with overt counting-related fMRI map (Z = -0.11 and Z = 0.09 for lips and tongue vs. 0.9 and 0.0006 for counting and naming). Interestingly, our fMRI maps indicated reduced Broca's area activity during silent speech compared to overt speech. Lastly, DES of the inferior frontal gyrus, pars opercularis and triangularis evoked variations of the output, i.e., dysarthria, a motor speech disorder occurring when patients cannot control the muscles used to produce articulated sounds (phonemes). Silent object naming-related fMRI map maximally overlapped (Z = -0.93 and Z = -1.04 for lips and tongue vs. -1.07 and 0.99 for counting and naming) with this seed. Speech disturbances evoked by DES may be thought of as selective interferences with specific recruitment of left inferior frontal gyrus and precentral cortex which are differentiable in terms of the specific interference induced., Competing Interests: Declaration of competing interest None of the authors has any conflict of interest to disclose., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Incidentally discovered low-grade gliomas (iLGGs) represent a rare neurological condition, which is associated with a good clinical status and usually preserved - or borderline - cognitive functions; only recently, knowledge has increased on their development and clinical features. Better understanding these aspects is fundamental to set up the most appropriate clinical protocol., Methods: We used fMRI to conduct an exploratory investigation of the effects of iLGG growth on the brain and the potential occurrence of early rearrangement in the functional network associated with object naming. We compared this group of 13 patients with an iLGG in the left hemisphere (maximum lesion overlap in the left inferior frontal gyrus and median tumor volume 12 cm 3 ) and with preserved naming skills with that of a healthy control group., Results: No significant differences were observed in the functional activations between the two groups, but a cluster in the controls vs. patients contrast mainly located in the right lateral visual cortex. As this region is unspecific for object naming and no significant changes emerged when checking for covariates, we concluded that iLGG growth did not affect the functional network and plasticity-related reorganization did not occur yet. We attributed this finding to iLGG features, such as small tumor size at the diagnosis and lack or minimal infiltration., Conclusions: These findings are preliminary, and we recommend future investigation to replicate them and test generalizability to other functional networks. Understanding the potential functional effects of iLGG growth is fundamental for the choice of the most appropriate treatment.

We explored the functional outcome following awake surgery and Real-Time Neuropsychological Testing (RTNT) in the left insula. We carried out a longitudinal investigation by comparing the patients' language profile, and, in particular, the object-naming skills and the associated fMRI network, of pre-surgery and follow-up (i.e., a few months after surgery) in a group of 23 patients harboring a left-sided low grade glioma centered to the insulo-temporal area. Tumor resection, performed while continuously monitoring patients' performance by RNTN, was high (median = 92 %). From the neuropsychological viewpoint, almost all patients displayed preserved naming and language skills in general, both before surgery and at follow-up, when they recovered from a transient impairment recorded immediately after surgery. From the functional imaging viewpoint, the naming networks of the two assessment times were almost equivalent, with non-parametric analyses showing brain remodeling involving perilesional areas preoperatively and the contralesional, healthy, insula at follow-up. We discussed the anatomo-functional mechanisms that contributed to the preservation of the functional and cognitive pattern as observed in this longitudinal study, with a particular focus on the promising plasticity potential of the left insular area. In particular, we commented that, at least in our patient series and by applying an optimized surgical procedure, surgery in the insula was safe and generally contributed to the preservation of the language functions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

We report a case of paraganglioma of the cauda equina and review the MRI features in 11 previously published cases with MRI description. On T1-weighted images, paraganglioma is isointense relative to spinal cord and shows moderate to intense enhancement after Gd-DTPA application, usually with heterogeneous texture. On T2-weighted images, different findings were found. MRI features do not allow to distinguish paraganglioma of the cauda equina from majority of other tumors in this region.

Objective: To describe postoperative CT and MRI findings and their time course in uncomplicated cases after stereotactic volumetric resections of brain lesions., Materials and Methods: One-hundred twenty-eight imaging studies (CT, 86; MRI, 42), performed 6 h to 2 years after 52 stereotactic operations, were retrospectively reviewed and analyzed in relation to time of surgery in cases without complications., Results: The extent of resection bed did not change during the first week after operation; reduction of size then began and continued up to 3-6 months. Mass effect and edema showed no changed during the first 4 days, then later regressed gradually. Pneumocephalus was found in 58% of cases in the first 3 weeks, but never later. Benign, surgically-induced enhancement appeared at the margins of encephalotomy and retractor at the end of the first postoperative week, became more prominent during the following weeks, and lasted up to 3-5 months. In the majority of cases enhancement prevented recognition of the residual tumor. Dural enhancement was observed at the craniotomy site very early after the operation and persisted up to 1 year. Meningeal enhancement over convexities was found in 44% of MRI studies., Conclusion: Extent of the resection bed, mass effect, edema, and pneumocephalus show, in uncomplicated cases, a regular regression during the postoperative period. The time course of enhancement is complex and can be a source of diagnostic misinterpretation.

Since 1990 112 patients have undergone stereotactic resection of intra-axial tumoural lesions with volumetric reconstruction, using the Kelly-Goerss system. Stereotactic integration of CT, angiographic and particularly MRI information, together with three-dimensional information of the lesion, provide an innovative evaluation of the most appropriate surgical approach, even for each single patient. The main limitation of this surgical method is in cases where the infiltrating part of the tumour is pre-eminent, while it can allow "macroscopically complete resection" of well circumscribed lesions, almost independently of their location and volume. Some technical aspects of stereotactic resection of brain tumours are discussed in the light of our experience.

One of the possible causes of the so-called "essential" trigeminal neuralgia is a neurovascular compression of the fifth cranial nerve root at the pons. The demonstration of this hypothesis could orientate the surgical treatment to microvascular decompression. In order to evaluate the role of MRI in the diagnosis of trigeminal neuralgia due to neurovascular compression, the authors present the results of a prospective evaluation of the cranial MR studies of 18 neuralgic patients in comparison with a retrospective evaluation of the cranial MR studies of 50 healthy control subjects. The results show that neurovascular compression can be demonstrated in 83.3% of the neurological patients. In all cases a good correlation between the clinical symptoms, the side of positive MR findings and the surgical findings, when available, was demonstrated. On the other hand, neurovascular compression was demonstrated in 28% of the healthy control subjects. The authors conclude that neurovascular compression can be demonstrated in a high percentage of patients with the so-called "essential" trigeminal neuralgia. Compared with the other imaging modalities (angiography, Computed Tomography) MRI is the best technique in the diagnosis of this disease. In fact, MRI is not only able to differentiate the symptomatic from the essential type of neuralgia, but is also very sensitive in the identification of trigeminal neuralgia due to neurovascular compression. This diagnosis could direct the surgical treatment to microvascular decompression.

Between January 2007 and March 2008, we prospectively studied all patients operated on for intracranial tumours in our Department of Neurosurgery. Preoperatively, all patients were interviewed by a neurologist to collect headache characteristics. Measurements of tumour and oedema volume were made using dedicated software for magnetic resonance imaging studies. Tumour histopathology was established by histological examination postoperatively. If headache improved postoperatively, a diagnosis of ‘headache attributed to intracranial neoplasm’ was made, according to the 2004 International Classification of Headache Disorders (ICHD-II). A multivariate logistic regression model was used to evaluate the association of headache with potential risk factors. We studied 206 subjects. The prevalence of tumour headache was 47.6%. Intracranial tumour headache was non-specific and in most cases could not be classified by current ICHD-II diagnostic criteria for primary headache syndromes. Its prevalence varied depending on volume, location and type of tumour, as well as on the patient's previous headache history. [ABSTRACT FROM AUTHOR]

Thunderclap headache is well known to be a presenting feature of a variety of causal events. Indeed, a primary form is considered in the International Classification of Headache Disorders-II, but such diagnosis must be made only after exclusion of a possible secondary cause. We report a case of late-onset idiopathic aqueductal stenosis presenting with thunderclap headache, in the absence of abnormal neurological findings or indirect signs of raised intracranial pressure. The patient recovered completely after endoscopic third ventriculostomy. This case indicates primary aqueduct stenosis as a possible, never previously reported, cause of thunderclap headache. [ABSTRACT FROM AUTHOR]