At-Home "Tips" for Headache Management: The Use of Self-Trendelenburg to Help Determine the Cause of Worsening Headaches - A Case Series.

Introduction: In-office use of the Trendelenburg position has been shown to be a beneficial clinical tool to help decipher if a CSF pressure/volume component is part of the underlying etiologic process for a patient's persistent headache. Utilizing the Trendelenburg position at home could potentially be an additional diagnostic tool for the treating headache physician. Case Series: Our headache practice has been using at-home self-Trendelenburg for the past 2 years and will present the clinical scenarios in which it seems to be the most helpful utilizing a case series of patients. These include (1) in those who just had a lumbar puncture and call for worsening headaches and do not have an obvious orthostatic component; (2) in those who had a spinal epidural blood patch for a presumed CSF leak and state there was no improvement; (3) in those who are on daily preventive CSF volume-lowering medications and call in with worsening headaches; (4) in those with known CSF pressure-dependent headaches high or low but who are not on daily preventive CSF volume modulatory medications; (5) in those with a history of migraine or other primary headache disorder to see if a new type of headache is possibly from a CSF leak or an abnormal reset of CSF pressure to an elevated state; (6) in those with triggered only headaches like cough or exertional headache. Conclusion: Utilizing at-home self-Trendelenburg can provide valuable information for the treating headache physician on possible underlying headache etiology and can guide specific treatment strategies. Its simplicity and quick declaration of results are very patient pleasing.

Application of novel non-invasive ophthalmic imaging to visualize peripapillary wrinkles, retinal folds and peripapillary hyperreflective ovoid mass-like structures associated with elevated intracranial pressure.

Background: Elevated intracranial pressure (ICP) is a serious and potentially life-threatening condition, for which clinically useful non-invasive measures have been elusive, in some cases due to their inadequate sensitivity and specificity. Our aim was to evaluate novel non-invasive ophthalmic imaging of selected pathological features seen in elevated ICP, namely peripapillary hyperreflective ovoid mass-like structures (PHOMS), peripapillary wrinkles (PPW) and retinal folds (RF) as potential biomarkers of elevated ICP. Methods: This single-center pilot study included subjects with untreated or incompletely treated high ICP. The retinas of these subjects were evaluated with averaged en-face optical coherence tomography (OCT), OCT retinal cross-sections (OCT B-scans), adaptive optics scanning light ophthalmoscopy (AOSLO), and fundus photos. Results: Seven subjects were included in the study. 6 subjects with high ICP (5 idiopathic intracranial hypertension, 1 medication induced, 30.8 ± 8.6 years, 75% female, 5 with papilledema) and 1 control (20-25 years) were included. PHOMS, PPW and RF were present in all subjects with papilledema, but neither in the high ICP subject without papilledema nor in the control subject. Averaged en-face OCT scans and AOSLO were more sensitive for PPW and RF than OCT B-scans and commercial fundus photos. Conclusion: PPW, RF and PHOMS volume have potential as non-invasive biomarkers of ICP. Novel imaging modalities may improve sensitivity. However, lack of automated image acquisition and processing limits current widespread adoption in clinical settings. Further research is needed to validate these structures as biomarkers for elevated ICP and improve clinical utility.

Is foramen magnum decompression for acquired Chiari I malformation like putting a finger in the dyke? - A simplistic overview of artificial intelligence in assessing critical upstream and downstream etiologies.

Background: Missed diagnosis of evolving or coexisting idiopathic (IIH) and spontaneous intracranial hypotension (SIH) is often the reason for persistent or worsening symptoms after foramen magnum decompression for Chiari malformation (CM) I. We explore the role of artificial intelligence (AI)/convolutional neural networks (CNN) in Chiari I malformation in a combinatorial role for the first time in literature, exploring both upstream and downstream magnetic resonance findings as initial screening profilers in CM-1. We have also put together a review of all existing subtypes of CM and discuss the role of upright (gravity-aided) magnetic resonance imaging (MRI) in evaluating equivocal tonsillar descent on a lying-down MRI. We have formulated a workflow algorithm MaChiP 1.0 (Manjila Chiari Protocol 1.0) using upstream and downstream profilers, that cause de novo or worsening Chiari I malformation, which we plan to implement using AI. Materials and Methods: The PRISMA guidelines were used for "CM and machine learning and CNN" on PubMed database articles, and four articles specific to the topic were encountered. The radiologic criteria for IIH and SIH were applied from neurosurgical literature, and they were applied between primary and secondary (acquired) Chiari I malformations. An upstream etiology such as IIH or SIH and an isolated downstream etiology in the spine were characterized using the existing body of literature. We propose the utility of using four selected criteria for IIH and SIH each, over MRI T2 images of the brain and spine, predominantly sagittal sequences in upstream etiology in the brain and multiplanar MRI in spinal lesions. Results: Using MaChiP 1.0 (patent/ copyright pending) concepts, we have proposed the upstream and downstream profilers implicated in progressive Chiari I malformation. The upstream profilers included findings of brain sagging, slope of the third ventricular floor, pontomesencephalic angle, mamillopontine distance, lateral ventricular angle, internal cerebral vein-vein of Galen angle, and displacement of iter, clivus length, tonsillar descent, etc., suggestive of SIH. The IIH features noted in upstream pathologies were posterior flattening of globe of the eye, partial empty sella, optic nerve sheath distortion, and optic nerve tortuosity in MRI. The downstream etiologies involved spinal cerebrospinal fluid (CSF) leak from dural tear, meningeal diverticula, CSF-venous fistulae, etc. Conclusion: AI would help offer predictive analysis along the spectrum of upstream and downstream etiologies, ensuring safety and efficacy in treating secondary (acquired) Chiari I malformation, especially with coexisting IIH and SIH. The MaChiP 1.0 algorithm can help document worsening of a previously diagnosed CM-1 and find the exact etiology of a secondary CM-I. However, the role of posterior fossa morphometry and cine-flow MRI data for intracranial CSF flow dynamics, along with advanced spinal CSF studies using dynamic myelo-CT scanning in the formation of secondary CM-I is still being evaluated.

Is there evidence for the(sole) use of third ventriculostomy in the treatment of Idiopathic. Intracranial Hypertension: A Literature Review.

BACKGROUND: Idiopathic intracranial hypertension (IIH) remains a poorly understood condition with no standardised treatment. Treatment is therefore generally individualised. Recent isolated reports have begun to describe the use of third ventriculostomy (open or closed) for the treatment of IIH. This review aims to communicate the current evidence for the use of third ventriculostomy in IIH. METHODS: A systemic review, using PubMed, was performed of studies describing the use of third ventriculostomy, either open or closed, for the treatment of idiopathic intracranial hypertension. RESULTS: Only 3 studies for a total of 3 patients were found in which a third ventriculostomy was performed for the treatment of IIH. CONCLUSION: Despite very plausible proposed mechanisms of action, there is currently a paucity of both studies and, therefore, evidence for the use of either endoscopic or open third ventriculostomy for the treatment of IIH. The studies done to date do strongly suggest that further consideration is warranted.

A nomogram to predict intracranial hypertension in moderate traumatic brain injury patients.

OBJECTIVE: Patients with moderate traumatic brain injury (TBI) are under the threat of intracranial hypertension (IHT). However, it is unclear which moderate TBI patient will develop IHT and should receive intracranial pressure (ICP)-lowering treatment or invasive ICP monitoring after admission. The purpose of the present study was to develop and validate a prediction model that estimates the risk of IHT in moderate TBI patients. METHODS: Baseline data collected on admission of 296 moderate TBI patients with Glasgow Coma Scale (GCS) score of 9-11 was collected and analyzed. Multi-variable logistic regression modeling with backward stepwise elimination was used to develop a prediction model for IHT. The discrimination efficacy, calibration efficacy, and clinical utility of the prediction model were evaluated. Finally, the prediction model was validated in a separate cohort of 122 patients from 3 hospitals. RESULTS: Four independent prognostic factors for IHT were identified: GCS score, Marshall head computed tomography score, injury severity score and location of contusion. The C-statistic of the prediction model in internal validation was 84.30% (95% confidence interval [CI]: 0.794-0.892). The area under the curve for the prediction model in external validation was 82.80% (95% CI: 0.747∼0.909). CONCLUSIONS: A prediction model based on baseline parameters was found to be highly sensitive in distinguishing moderate TBI patients with GCS score of 9-11 who would suffer IHT. The high discriminative ability of the prediction model supports its use in identifying moderate TBI patients with GCS score of 9-11 who need ICP-lowering therapy or invasive ICP monitoring.

Intracranial hypertension secondary to unruptured pial arteriovenous malformation. Suitability of isolated endovascular treatment with ethylene vinyl alcohol/dimethyl sulfoxide (Onyx®). Case report and literature review.

A 36-year-old male presented to the Emergency Department with clinical symptoms of blurred vision of progressive onset of two years of evolution. The ophthalmological examination revealed the existence of bilateral papilledema. Using cranial computed tomography and magnetic resonance imaging, the presence of a right occipital pial arteriovenous malformation was certified. Arteriographically, pial arterial contributions dependent on the right middle cerebral artery and the right posterior cerebral artery were identified. Venous drainage was located at the level of the superior sagittal sinus. An associated right transverse sinus stenosis was also identified. The existence of secondary intracranial hypertension was corroborated by monitoring with an intracranial pressure sensor. An interventional procedure was carried out consisting of embolization of the arterial supplies of the lesion using Onyx®. The clinical-radiological findings after the procedure were favorable: the papilledema disappeared and complete exclusion of the malformation was achieved. A new intracranial pressure measurement showed resolution of intracranial hypertension. Subsequent regulated radiological controls showed complete exclusion of the malformation up to 5 years later.

Predictors of Headaches and Quality of Life in Women with Ophthalmologically Resolved Idiopathic Intracranial Hypertension.

Background/objectives: The aim of this study was to evaluate the long-term outcomes of a cohort of ophthalmologically resolved female idiopathic intracranial hypertension (IIH) patients. Methods: Our cross-sectional study included adult females with at least 6 months of ophthalmologically resolved IIH. Patients with papilledema or who underwent IIH-targeted surgical intervention were excluded. Participants completed a questionnaire consisting of medical information, the Migraine Disability Assessment Scale (MIDAS) and the Headache Impact Test (HIT-6). Electronic medical records and the results of imaging upon diagnosis were retrospectively reviewed. Results: One-hundred-and-four participants (mean age 35.5 ± 11.9 years) were included (7.85 ± 7 years post-IIH diagnosis). Patients with moderate-severe disability according to the MIDAS scale (n = 68, 65.4%) were younger (32.4 ± 8.9 vs. 41.5 ± 14.4 year-old, p < 0.001), had a shorter time interval from IIH diagnosis (5.9 ± 5.3 vs. 11.7 ± 8.5 years, p < 0.001), and had lower FARB scores (indicating a more narrowed transverse-sigmoid junction; 1.28 ± 1.82 vs. 2.47 ± 2.3, p = 0.02) in comparison to patients with low-mild disability scores. In multivariate analysis, a lower FARB score (OR 1.28, 95% CI 0.89-1.75, p = 0.12) and younger age (OR 1.09, 95% CI 0.98-1.19, p = 0.13) showed a trend toward an association with a moderate-severe MIDAS score. Moreover, in the sub-analysis of patients with a moderate-severe MIDAS scale score, the 10 patients with the highest MIDAS scores had a low FARB score (1.6 ± 1.1 vs. 2.7 ± 2.4, p = 0.041). Conclusions: High numbers of patients with ophthalmologically resolved IIH continue to suffer from related symptoms. Symptoms may be associated with the length of time from the diagnosis of IIH and a lower FARB score.

Paediatric idiopathic intracranial hypertension: Epidemiology, clinical features and treatment outcomes in a tertiary care centre in Western Australia.

AIM: This retrospective study aims to analyse the epidemiology, clinical and neuroimaging features, treatment modalities, and outcomes of paediatric idiopathic intracranial hypertension (IIH) in a tertiary care centre in Australia. METHODS: Using the International Classification of Diseases Diagnostic Criteria for IIH, we identified and analysed a cohort of children diagnosed with IIH over a 5-year period (2017-2022). Data on patient demographics, symptomatology, examination findings, investigative results, treatments and outcomes were collected from medical records and electronic health records. RESULTS: A total of 45 cases were analysed. The pre-pubertal group saw a male predominance and the post-pubertal a female one. Increased body mass index was an associated comorbidity in majority of patients. Headaches (89%) and visual symptoms (56%) were the most common symptoms, with tinnitus also seen in 20% of patients. Papilledema was detected in 91% of the cases examined. The commonest neuroimaging features were optic nerve sheath distention (78%) and empty sella (49%). Acetazolamide was the primary treatment, with most patients responding well. Only a minority required surgical intervention. Long-term resolution of headaches was achieved in 89% of patients. CONCLUSIONS: The incidence of paediatric IIH in the West Australian population appears relatively high. It presents with subtle symptoms, emphasising the need for increased awareness among health-care providers. Younger children may represent a distinct subgroup with unique clinical features. Timely diagnosis and aggressive medical management lead to favourable outcomes. However, weight loss interventions showed limited effectiveness. This study underscores the importance of early recognition and management of paediatric IIH to optimise patient outcomes.

Random forest-based prediction of intracranial hypertension in patients with traumatic brain injury.

BACKGROUND: Treatment and prevention of intracranial hypertension (IH) to minimize secondary brain injury are central to the neurocritical care management of traumatic brain injury (TBI). Predicting the onset of IH in advance allows for a more aggressive prophylactic treatment. This study aimed to develop random forest (RF) models for predicting IH events in TBI patients. METHODS: We analyzed prospectively collected data from patients admitted to the intensive care unit with invasive intracranial pressure (ICP) monitoring. Patients with persistent ICP > 22 mmHg in the early postoperative period (first 6 h) were excluded to focus on IH events that had not yet occurred. ICP-related data from the initial 6 h were used to extract linear (ICP, cerebral perfusion pressure, pressure reactivity index, and cerebrospinal fluid compensatory reserve index) and nonlinear features (complexity of ICP and cerebral perfusion pressure). IH was defined as ICP > 22 mmHg for > 5 min, and severe IH (SIH) as ICP > 22 mmHg for > 1 h during the subsequent ICP monitoring period. RF models were then developed using baseline characteristics (age, sex, and initial Glasgow Coma Scale score) along with linear and nonlinear features. Fivefold cross-validation was performed to avoid overfitting. RESULTS: The study included 69 patients. Forty-three patients (62.3%) experienced an IH event, of whom 30 (43%) progressed to SIH. The median time to IH events was 9.83 h, and to SIH events, it was 11.22 h. The RF model showed acceptable performance in predicting IH with an area under the curve (AUC) of 0.76 and excellent performance in predicting SIH (AUC = 0.84). Cross-validation analysis confirmed the stability of the results. CONCLUSIONS: The presented RF model can forecast subsequent IH events, particularly severe ones, in TBI patients using ICP data from the early postoperative period. It provides researchers and clinicians with a potentially predictive pathway and framework that could help triage patients requiring more intensive neurological treatment at an early stage.

Atypical Presentation of Idiopathic Intracranial Hypertension: A Case Series and Literature Review.

Idiopathic intracranial hypertension (IIH) is a condition in which intracranial pressure (ICP) increases without an apparent cause. Typically, patients present with headaches, dizziness, pulsatile tinnitus, visual disturbances, blurred vision, diplopia, photophobia, visual field defects, and papilledema on fundoscopy. The association between IIH, spontaneous cerebrospinal fluid (CSF) rhinorrhea, and arachnoid cysts has been discussed in the literature; however, there is no clear explanation for this association. We aimed to present a series of four patients with a confirmed diagnosis of IIH with atypical presentations, discuss the management of each case, and provide an explanation for this association to alert clinicians to the atypical presentation of IIH and facilitate early diagnosis and proper treatment of this condition by CSF diversion. This was a retrospective case series of all patients who were diagnosed with IIH and showed improvement after ventriculoperitoneal shunt insertion after failure of at least one operative intervention resulting from primary radiological and clinical findings in 2001 to 2022. Data on demographics, clinical presentation, radiological findings, surgical management, and diagnostic criteria for IIH were recorded. We identified four patients with a confirmed diagnosis of IIH who presented with atypical presentations as follows: intracranial arachnoid cyst, cervical spine arachnoid cyst, giant Virchow perivascular space, and spontaneous CSF (CSF) rhinorrhea. All patients responded to CSF diversion after failure of surgical treatment targeting the primary pathology. IIH should be suspected after the failure of primary surgical treatment in cases of spontaneous CSF rhinorrhea, spinal and cranial arachnoid cysts, and symptomatic ventriculoperitoneal shunt. Treatment in such situations should be directed toward IIH with CSF diversion.

Clinical characteristics and surgical outcomes of epilepsy associated with temporal encephalocele: A systematic review.

Temporal encephaloceles (TE) are an under-identified, potentially intervenable cause of epilepsy. This systematic review consolidates the current data to identify the major clinical, neuroimaging, and EEG features and surgical outcomes of epilepsy associated with TE. Literature searches were carried out using MEDLINE, Embase, PsycINFO, Scopus, and Cochrane Library databases from inception to December 7, 2023. Studies were included if they described clinical, neuroimaging, EEG, or surgical data in ≥5 patients with TE and epilepsy. Of 562 studies identified in the search, 24 met the eligibility criteria, reporting 423 unique patients with both epilepsy and TE. Compared to epilepsy patients without TE, those with TE had a higher mean age of seizure onset and were less likely to have a history of febrile seizures. Seizure semiologies were variable, but primarily mirrored temporal lobe onset patterns. Epilepsy patients with TE had a higher likelihood of having clinical or radiographic features of idiopathic intracranial hypertension (IIH) than those without. Brain MRI may show ipsilateral mesial temporal sclerosis (16 %). CT scans of the skull base usually revealed bony defects near the TE (90 %). Brain PET scans primarily showed ipsilateral temporal lobe hypometabolism (80 %), mostly in the anterior temporal lobe (67 %). Scalp EEG mostly lateralized ipsilateral to the implicated TE (92 % seizure onset) and localized to the temporal lobe (96 %). Intracranial EEG revealed seizure onset near the TE (11 of 12 cases including TE-adjacent electrodes) with variable timing of spread to the ipsilateral hippocampus. After surgical treatment of the TE, the rate of Engel I or ILAE 1 outcomes at one year was 75 % for lesionectomy, 85 % for anterior temporal lobectomy (ATL), and 80 % for ATL with amygdalohippocampectomy. Further studies are needed to better elucidate the relationship between IIH, TE, and epilepsy, improve the identification of TE, and optimize surgical interventions.

[Clinical diagnosis and treatment analysis of spontaneous cerebrospinal fluid otorrhoea].

Objective:To investigate the clinical features, imaging findings, surgical methods， diagnostic and treatment experience of spontaneous cerebrospinal fluid otorrhoea. Methods:The clinical data of 11 patients with spontaneous cerebrospinal fluid otorrhoea treated surgically at our hospital from May 2018 to May 2023 were retrospectively analyzed. The medical data included medical history, imaging data, leak location, surgical repair method, treatment effect and postoperative follow-up. Results:Among the 11 surgical patients, 4 patients were initially diagnosed with secretory otitis media, 1 was initially diagnosed with purulent otitis media, and 5 patients had a history of meningitis or presented because meningitis as the initial diagnosis. There were 2 cases of cerebrospinal fluid leakage repaired through the ear canal pathway and 9 cases of cerebrospinal fluid leakage repaired through the mastoid pathway. During the operation, leaks were located in the stapes floor plate in 4 cases, sinus meningeal angle in 1 case, posterior cranial fossa combined with middle cranial fossa in 1 case, middle cranial fossa in 4 cases, and labyrinthine segment of the internal auditory canal and facial nerve canal in 1 case. Ten patient was successfully repaired, and another patient developed intracranial hypertension after surgery, with symptoms alleviated by a lateral ventriculoperitoneal shunt. Postoperative follow-up ranged from 6 months to 4 years, and there was no CSF otorrhoea and meningitis recurrence. Conclusion:The incidence of spontaneous cerebrospinal fluid otorrhea is low, the clinical symptoms are atypical, and the rate of delayed diagnosis or missed diagnosis and misdiagnosis is high. Surgery is currently the preferred treatment for spontaneous cerebrospinal fluid otorrhoea, and satisfactory results are usually achieved; During diagnosis and treatment, it is crucial to be vigilant for intracranial hypertension to prevent serious complications and irreversible damage.

Regulation of brain fluid volumes and pressures: basic principles, intracranial hypertension, ventriculomegaly and hydrocephalus.

The principles of cerebrospinal fluid (CSF) production, circulation and outflow and regulation of fluid volumes and pressures in the normal brain are summarised. Abnormalities in these aspects in intracranial hypertension, ventriculomegaly and hydrocephalus are discussed. The brain parenchyma has a cellular framework with interstitial fluid (ISF) in the intervening spaces. Framework stress and interstitial fluid pressure (ISFP) combined provide the total stress which, after allowing for gravity, normally equals intracerebral pressure (ICP) with gradients of total stress too small to measure. Fluid pressure may differ from ICP in the parenchyma and collapsed subarachnoid spaces when the parenchyma presses against the meninges. Fluid pressure gradients determine fluid movements. In adults, restricting CSF outflow from subarachnoid spaces produces intracranial hypertension which, when CSF volumes change very little, is called idiopathic intracranial hypertension (iIH). Raised ICP in iIH is accompanied by increased venous sinus pressure, though which is cause and which effect is unclear. In infants with growing skulls, restriction in outflow leads to increased head and CSF volumes. In adults, ventriculomegaly can arise due to cerebral atrophy or, in hydrocephalus, to obstructions to intracranial CSF flow. In non-communicating hydrocephalus, flow through or out of the ventricles is somehow obstructed, whereas in communicating hydrocephalus, the obstruction is somewhere between the cisterna magna and cranial sites of outflow. When normal outflow routes are obstructed, continued CSF production in the ventricles may be partially balanced by outflow through the parenchyma via an oedematous periventricular layer and perivascular spaces. In adults, secondary hydrocephalus with raised ICP results from obvious obstructions to flow. By contrast, with the more subtly obstructed flow seen in normal pressure hydrocephalus (NPH), fluid pressure must be reduced elsewhere, e.g. in some subarachnoid spaces. In idiopathic NPH, where ventriculomegaly is accompanied by gait disturbance, dementia and/or urinary incontinence, the functional deficits can sometimes be reversed by shunting or third ventriculostomy. Parenchymal shrinkage is irreversible in late stage hydrocephalus with cellular framework loss but may not occur in early stages, whether by exclusion of fluid or otherwise. Further studies that are needed to explain the development of hydrocephalus are outlined.

Idiopathic Intracranial Hypertension in an Adolescent With Recent Human Immunodeficiency Virus (HIV) Diagnosis: A Challenging Etiological Dilemma.

Idiopathic intracranial hypertension (IIH) or benign intracranial hypertension affects the neuro-ophthalmological system and leads to elevated intracranial pressure. Elevated opening pressure during lumbar puncture is diagnostic of IIH. Here in, we present an interesting case of a 15-year-old girl, recently immigrated and with a high BMI, presenting with recurrent fever, abdominal issues, weight loss, and other symptoms, leading to a diagnosis of pelvic inflammatory disease (PID) and HIV infection. After treatment with antibiotics (doxycycline) and antiretroviral therapy, she developed IIH, manifesting as sudden-onset headache and vision problems. MRI and lumbar puncture confirmed the diagnosis. She responded well to acetazolamide and was discharged with continued medication and follow-up appointments. This case underscores the complexity of IIH development, especially in the setting of acute HIV infection and antibiotic treatment, highlighting the need for a comprehensive diagnostic approach and multidisciplinary management.

A retrospective case-control study evaluating systemic blood pressure and heart rate in dogs with brain herniation under general anesthesia.

OBJECTIVE: To examine whether increased systemic arterial blood pressure (ABP) and decreased heart rate (HR) under inhalant anesthesia were suggestive of the Cushing reflex (CR) in dogs with neurological diseases based on magnetic resonance imaging (MRI) findings. STUDY DESIGN: Retrospective case-control study. ANIMALS: A sample of 137 client-owned dogs admitted to two veterinary teaching hospitals for diagnosis and patient care owing to suspected intracranial disease from 2005 to 2020. All dogs underwent general anesthesia for MRI of the brain. METHODS: Based on MRI study reports, dogs were divided into three study groups: group A, dogs with suspected brain herniation; group B, dogs with an abnormal MRI finding but without suspicion of herniation; and group C, dogs with structurally unremarkable brains (control). Initial evaluation by an anesthesiologist resulted in 58 cases selected for further review based on suspicion of having intracranial hypertension, as indicated by ABP and HR changes under anesthesia. Anesthetic records were randomized and independently reviewed by three board-certified anesthesiologists blinded to MRI diagnosis who allocated each dog into one of three groups: 1) likely to have CR; 2) unlikely to have CR; or 3) insufficient data for determination. RESULTS: Of the 58 cases evaluated, nine were considered likely to have CR and 48 were considered unlikely to have CR. In one case, the anesthesiologists were unable to determine whether CR occurred. Of the nine dogs with likely CR, three had an MRI diagnosis of intracranial herniation. The remaining six dogs suspected of CR belonged to the normal brain group. CONCLUSIONS AND CLINICAL RELEVANCE: The ABP and HR changes associated with CR are not reliably associated with brain herniation in dogs undergoing general anesthesia.

Endolymphatic sac tumor: An urgent case presenting acute intracranial hypertension successfully treated with suboccipital decompressive craniectomy - 8 years of follow-up.

Background: Endolymphatic sac tumor (ELST) is a rare lesion. It may be sporadically or associated with Von Hippel-Lindau syndrome. Progressive audiovestibular symptoms characterize the typical clinical presentation. Here, we report a unique case of ELST with acute intracranial hypertension (IH) due to tumor compression, successfully treated with an urgent suboccipital decompressive craniectomy (SDC). Case Description: A 33-year-old woman previously underwent a biopsy and ventriculoperitoneal shunt. The histopathological finding revealed an ELST. One year later, she developed headache, vomiting, and somnolence due to brainstem compression. An urgent SDC was performed. One month later, preoperative endovascular embolization and partial tumor resection were carried out. After 6 months adjuvant radiotherapy (RT) therapy was administered. She has been under follow-up for 8 years since the last surgical procedure, and the tumor remains stable. Conclusion: ELST generally has a progressive clinical course. This is a unique case with acute IH due to tumor compression. The tumor's high vascularity and the unavailability of endovascular embolization precluded its resection. SDC was an alternative approach. The final treatment included tumor embolization, surgical resection, and RT. No progression was observed for 8 years after the last procedure, and long-term follow-up is warranted.

Permanent Visual Loss as a Complication of Decompressive Surgery for the Treatment of Posterior Fossa Tumours: A Report of Two Cases.

Posterior fossa tumours are one of the most common types of solid neoplasia in paediatric patients. Although impaired vision can occur at presentation, it usually stabilises or improves after decompressive surgery. However, cases of permanent and profound visual loss have been reported following successful tumour resection, despite receiving little attention from the medical community. In this paper, we present two cases of young patients who experienced severe and permanent visual loss following uncomplicated surgery for posterior fossa tumour removal. We discuss the possible mechanism involved in the visual loss and measures to prevent such a dreadful complication.