Computed Tomography Assessment of the Retrolabyrinthine Approach.

Introduction This study aimed to evaluate preoperative radiological assessments of the retrolabyrinthine approach to identify and describe anatomical constraints that may anticipate a more challenging situation for neurosurgeons and otolaryngologists specialized in skull base surgery. Materials and methods The study included 75 adult patients who underwent high-resolution computed tomography angiography scans of the head, with the aim of analyzing the side of the dominance of the sigmoid sinus (SS), the level of pneumatization of the mastoid portion of the temporal bone, and the height of the jugular bulb. Results The results showed that dominant SS and type 2 jugular bulbs were more common on the right side, while smaller type 1 bulbs were significantly more common on the left. Conclusions These findings provide valuable information for neurosurgeons and otolaryngologists in predicting the difficulty of the retrolabyrinthine approach based on preoperative radiological assessments.

Histomorphometry of mast cells in the convexity of human intracranial dura mater.

Mast cells, known as pro-inflammatory effector cells, are immunocytes present in the meninges and may be involved in the pathophysiology of migraine. This study aims to evaluate the histomorphometric parameters of mast cells located in the convexity of the human intracranial dura mater. For this, samples of intracranial dura mater from eight human fresh cadavers were collected between 8- and 24-h post-mortem. The whole samples were fixed and, subsequently, two fragments of 1.5 cm² each were cut from four different areas of the dura mater convexity, containing a segment of the middle meningeal artery, totaling 64 fragments. After histological processing, the fragments were submitted to microtomy (5 and 10 µm), stained with toluidine blue (0.1%), or immunohistochemically labeled for tryptase, and analyzed using optical microscopy. The following histomorphometric parameters were evaluated: distance from mast cells to vessels, the density of mast cells, and percentage of mast cells with degranulation. Histomorphometric analyzes showed a higher density of mast cells in the vicinity of blood vessels (arterial and venous), with distances around 0-150 µm. A greater number of mast cells was detected near venous vessels in the periosteal layer (17.0 ± 10.1 cells/mm²) than in the meningeal layer (14.1 ± 7.0 cells/mm²) (p < 0.05). Mast cells from the region close to the superior sagittal sinus were found in greater quantity close to the venous vessels (16.7 ± 10.1 cells/mm²) than to the arterial vessels (11.2 ± 7.5 cells/mm²) (p < 0.05). In short, in the convexity of the human intracranial dura mater, mast cells are located close to blood vessels, with a greater number of cells next to the venous vessels of the periosteal layer and in the proximal region of the superior sagittal sinus.

Cleidocranial dysplasia, a rare skeletal disorder with failure of the cranial closure: case-based update.

BACKGROUND AND AIM: Cleidocranial dysplasia is a rare disorder of skeletal development that mainly promotes, among other malformations, inadequate development of clavicles and failure in cranial closure. In this affection, the role of neurosurgery in addressing cranial defects is rarely discussed. MATERIAL AND METHODS: We conducted an extensive review of the literature using the PubMed database, giving a greater focus to publications in the field of neurosurgery. Additionally, we report a case of a 2-year-old female child with cleidocranial dysplasia. RESULTS: In our review, we encountered several cases of orthodontic implications but a few cases on cranial defect approach. CONCLUSION: The articles present literature that is unanimous on the recommendation of expectant conduct in children since the cranial block can occur spontaneously, even if the delayed form. In our approach, we opted for an expected strategy concerning the cranial defect, using a helmet made for brain protection. We also made the referral for multidisciplinary monitoring of pediatrics, neuropediatrics, ophthalmology, dentistry, and orthopedics.

Is Basilar Invagination Related with Stenosis of the Hypoglossal Nerve Canal?

OBJECTIVE: To analyze the association between basilar invagination (BI) and stenosis in the hypoglossal canal (HC). METHODS: A case-control study with magnetic resonance images (MRIs) of the head from a local database was performed. The study used MRIs of 31 patients with BI (type B) and 36 controls, both groups over 18 years of age and without sex distinction. The internal (ID) and external (ED) diameters of the HC were measured on the coronal plane using the Osirix in its free version 3.9.2 (Mac-Apple platform). We used the Kolmogorov-Smirnov test (with Lilliefors adjustment) to evaluate the normality of the variables, the Levine test to verify the homogeneity of the variances, and Student's t test to verify differences between groups. All analyses were within the 95% confidence interval. RESULTS: Control group presented right and left ED values of 4.7 ± 0.8 mm and 4.6 ± 0.9 mm, respectively, while the right and left ID showed 4.4 ± 0.9 mm and 4.3 ± 0.8 mm, respectively. The group with BI showed right and left ED values of 3.3 ± 0.9 mm and 3.1 ± 0.9 mm, and the right and left ID had values of 2.8 ± 0.7 mm and 2.7 ± 0.7 mm, respectively. Both ED and ID were smaller in the group with BI (P < 0.001). CONCLUSIONS: Patients with BI of type B presented the narrowing of HC when compared with control participants.

Current understanding of pineal gland structure and function in headache.

PURPOSE: The pineal gland plays an important role in biological rhythms, circadian and circannual variations, which are key aspects in several headache disorders. OVERVIEW: Melatonin, the main pineal secreting hormone, has been extensively studied in primary and secondary headache disorders. Altered melatonin secretion occurs in many headache syndromes. Experimental data show pineal gland and melatonin both interfere in headache animal models, decreasing trigeminal activation. Melatonin has been shown to regulate CGRP and control its release. DISCUSSION: Melatonin has been used successfully as a treatment for migraine, cluster headaches and other headaches. There is a rationale for including the pineal gland as a relevant brain structure in the mechanisms of headache pathophysiology, and melatonin as a treatment option in primary headache.

Transcalvarial brain herniation volume as a predictor of posttraumatic hydrocephalus after decompressive craniectomy.

OBJECTIVES: In patients undergoing decompressive craniectomy for traumatic brain injury(TBI) there has been reported an incidence of hydrocephalus between 0-45%. There are several radiological and clinical features described in association with development of hydrocephalus. For study the influence of these factors we conducted a retrospective observational single-center cohort study in a tertiary care center with special attention to the transcalvarial herniation(TCH) volume after decompressive craniectomy. PATIENTS AND METHODS: We selected 50 patients that underwent decompressive craniectomy after closed head injury between january 2014 and January 2015. Hydrocephalus was defined as a modified frontal horn index greater than 33%, presence of Gudeman CT scan criteria or insertion of ventriculoperitoneal Shunt. Variables analyzed were: age, post-resuscitation Glasgow coma scale (GCS) score, pupil reactivity, Zunkeller index, presence of hygroma, TCH volume, craniectomy diameter and distance of craniectomy from midline. Logistic regression was used with hydrocephalus as the primary outcome measure. RESULTS: 17 patients developed hydrocephalus (34%). TCH volume after decompression(p < 0.01), subdural hygroma (p < 0.01), lower admission Glasgow Coma Scale score (p = 0.015), unilateral pupil reactivity(p = 0.042) and higher Zumkeller index(p = 0.044) were significant risk factors for hydrocephalus. Logistic regression analysis showed that factors independently associated with the development of hydrocephalus was the TCH volume (odds ratio 11.08; 95%CI 2.10, 58.4; p = 0.0046), and presence of hygroma (odds ratio 49.59; 95%IC 4.1, 459; p = 0.002). CONCLUSIONS: There was a clear association between severity of TBI, TCH volume and subdural hygroma with the development of hydrocephalus. Clinicians should follow closely patients with those findings in order to avoid late deterioration.

Chiari 1 Malformation Surgery: Comparing Non-violation of the Arachnoid versus Arachnoid Opening and Thermocoagulation of the Tonsils.

OBJECTIVE: Evidence is lacking concerning the myriad surgical techniques for type 1 Chiari malformation. This study evaluated the impact of arachnoid violation with tonsil thermocoagulation during surgical craniovertebral junction decompression. METHODS: The evaluation included aspects of the neurologic examination and parameters of cerebrospinal fluid flow on magnetic resonance imaging during preoperative and postoperative periods. All patients underwent craniovertebral junction decompression and opening of the dura mater. Patients were divided into 2 study groups. Patients in group 1 did not undergo arachnoid violation. Patients in group 2 underwent tonsil manipulation and systematic opening of the fourth ventricle outlet. RESULTS: There were 16 patients enrolled in each group (total of 32 patients). Regarding clinical improvement, there were no significant differences between groups in the postoperative period. Group 2 had more adverse events (relative risk 2.45, 95% confidence interval 1.55-3.86). In terms of cerebrospinal fluid flow parameter analyses, patients in group 1 achieved better results (P < 0.05). CONCLUSIONS: For treatment of symptomatic type 1 Chiari malformation, craniovertebral junction decompression with arachnoid preservation (i.e., without tonsillar manipulation) seems more suitable than the addition of arachnoid opening and thermocoagulation of the tonsils.

Diagnostic accuracy of classical radiological measurements for basilar invagination of type B at MRI.

OBJECTIVE: To evaluate the diagnostic accuracy of classical measurements for basilar invagination (BI) of type B at MRI. METHODS: This study used head MRIs from 31 participants with BI type B and 96 controls. The radiological criterion for BI was the odontoid process invagination using the obex as reference. It based on the independent prospective reading of two neuroradiologists. Concordance between the two neuroradiologists was analysed through the KAPPA index, and the discrepancy was resolved in a consensus meeting. A third examiner measured in two occasions (double blind) the distance of the odontoid apex to Chamberlain's line (DOCL) and McGregor's line (DOMG), clivus canal angle (CCA), Welcker's basal angle (WBA), and Boogaard's angle (BOA). Intra-examiner reproducibility of the measurements was evaluated with the intraclass correlation coefficient and the diagnostic accuracy by ROC curve. All analyses were at 95% confidence interval. RESULTS: Agreement between the two neuroradiologists was statistically relevant (KAPPA = .91; P = .0001). The intra-examiner reproducibilities were .98 (DOCL), .97 (DOMG), .96 (CCA), .94 (WBA), and .95 (BOA) (P < .05). The areas under the ROC curve were .963 (DOCL), .940 (DOMG), .880 (CCA), .867 (WBA), and .951 (BOA) (P < .05). The cut-off criteria were ≥ 7 mm (DOCL), ≥ 8 mm (DOMG), ≤ 145° (CCA), ≥ 142° (WBA), and ≥ 136° (BOA). The diagnostic accuracies were .904 (DOCL), .870 (DOMG), .844 (CCA), .810 (WBA), and .899 (BOA). CONCLUSION: The DOCL and BOA presented the highest diagnostic accuracy for BI type B. These slides can be retrieved under Electronic Supplementary Material.

Correction: Krymchantowski, A.V.; et al. Medication-Overuse Headache: Differences between Daily and Near-Daily Headache Patients; Brain Sciences 2016, 6, 30.

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Medication-Overuse Headache: Differences between Daily and Near-Daily Headache Patients.

UNLABELLED: Medication-overuse headache (MOH) is a challenging neurological disease, which brings frustration for sufferers and treating physicians. The patient's lack of adherence and limited treatment evidence are frequent. The aim of this study was to compare the outcome and treatment strategies between consecutive MOH patients with daily and near-daily headache from a tertiary center. METHODS: Every consecutive patient seen between January and December 2014 with the diagnosis of MOH was included. Psychiatric comorbidities, inability to inform baseline headache frequency, current or previous two-month use of preventive medications, and refusal to sign informed consent were exclusion criteria. The patients were evaluated in thorough initial consultations and divided in two groups based on their baseline headache frequency. The diagnosis and treatment strategies were clearly explained. The filling out of a detailed headache diary was requested from all patients. Endpoints compared headache frequency and adherence after two, four, and eight months between the two study groups. RESULTS: One-hundred sixty-eight patients (31 male, 137 female) met the inclusion criteria. Nineteen patients (11.3%) were excluded. All patients had migraine or chronic migraine as primary headaches. Eighty had daily (DH), and 69 near-daily headache (NDH), at baseline consultation. Mean baseline frequency was 24.8 headache days/month (18.9 days/month for the near-daily group), average headache history was 20.6 years and mean time with >15 headache days/month was 4.8 years. Outpatient withdrawal, starting prevention, and enforcing the correct use of rescue therapy was carried out with all patients. After two months, 88% of the DH and 71% of the NDH groups adhered to treatment (p = 0.0002). The HF decreased to 12 and 9 headache days/month, respectively in DH and NDH groups (p > 0.05, non-significant) (Intention-to-treat (ITT) 14 DH; 12 NDH; p > 0.05). After four and eight months, 86.3% and 83.7% of the DH patients, and 59.4% and 55% of the NDH patients were still under treatment (p = 0.0003 and p = 0.0001). The HF decreased, respectively, to nine and nine headache days/month in the DH patients compared to 6 and 7 headache days/month in the NDH group (p > 0.05) (ITT, 12; 12; DH; 10; 11; NDH; p > 0.05). CONCLUSIONS: Although open studies provide limited conclusions, withdrawing overused medications and starting prevention may have helped the favorable outcomes. However, daily headache patients had a significantly higher adherence and lower relapse rates than near-daily headache patients, despite a considerable reduced headache frequency in both groups. Additionally, real-world patient studies are scarce and the comparison between these two subsets of patients may be useful to guide clinicians in approaching their patients. Controlled studies are necessary to confirm these observations.

The Frequent Unusual Headache Syndromes: A Proposed Classification Based on Lifetime Prevalence.

BACKGROUND: There is no agreement on a single cutoff point or prevalence for regarding a given disease as rare. The concept of what is a rare headache disorder is even less clear and the spectrum from a very frequent, frequent, occasional to rare headache syndrome is yet to be established. OBJECTIVE: An attempt has been made to estimate the lifetime prevalence of each of the headache subtypes classified in the ICHD-II. METHOD: Using the ICHD-II, 199 different headache subtypes were identified. The following classification was made according to the estimated lifetime prevalence of each headache disorder: very frequent (prevalence >10%); frequent (between 1 and 10%); occasional (between 0.07 and 1%); and unusual or rare (<0.07%). RESULTS: One hundred and fifty-four of 199 (77%) were categorized as unusual headache disorders, 7/199 (4%) as very frequent, 9/199 (5%) as frequent, and 29/199 (15%) as occasional forms of headache disorder. CONCLUSION: The unusual headache syndromes do not appear to be as infrequent in clinical practice as has been generally believed. About three-fourths of the classified headache disorders found in the ICHD-II can be considered as rare. This narrative review article may be regarded as an introduction to the concept of unusual headaches and a proposed classification of all headaches (at least those listed in the ICHD-II).

Alice in Wonderland Syndrome, Burning Mouth Syndrome, Cold Stimulus Headache, and HaNDL: Narrative Review.

BACKGROUND: Unusual headache syndromes are not as infrequent in clinical practice as was generally believed. About three fourths of the classified headache disorders found in the ICHD-II can be considered rare. OBJECTIVE: The aim of this narrative review was to perform a literature review of the pathophysiology, clinical presentation, diagnostic criteria, and treatment of the following unusual headache disorders: Alice in Wonderland syndrome, burning mouth syndrome, cold stimulus headache, and the syndrome of transient headache and neurologic deficits with cerebrospinal fluid lymphocytosis. METHOD: A literature review was performed using PubMed for each of the abovementioned headache disorders. CONCLUSION: The unusual headache syndromes as a distinct group of disorders are not as infrequent in clinical practice as was generally believed. Some of them, albeit considered as unusual, may occur with relative frequency, such as cold stimulus headache and burning mouth syndrome.

"Sit back, observe, and wait." Or is there a pharmacologic preventive treatment for cerebral aneurysms?

Intracranial aneurysms (IA) are a relatively frequent vascular abnormality. The prevailing opinion is that cerebral aneurysmal disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall which was acquired by a specific, often unknown, event. Possibly the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/atherosclerosis. In most individuals, an endovascular/microsurgical approach is possible in order to obliterate the IA. However, in a number of patients with an unruptured IA (UIA), the neurosurgeon's decision is to just "sit back, observe, and wait", based on the favorable natural history of some of the UIAs. Furthermore, some individuals need to be kept under close observation since they have a higher chance of developing IA, especially those with at least two affected first-degree relatives with an IA, subjects with polycystic kidney disease, and patients who have undergone an aneurysm intervention. In these examples prophylactic strategies should be adopted, if it is at all possible. The main question is deciding the best option of clinical treatment for these cases, when surgical approach is contraindicated, or for those subjects who are more prone to develop an IA. In the present article, we hypothetically suggest a pharmacologic form of treatment with statins, beta-adrenergic blocker agents, and/or angiotensin-converting-enzyme inhibitor/angiotensin II receptor blockers to inhibit or slow down IA formation, taking into consideration some pathophysiological aspects related to aneurysmal development, such as: hemodynamic stress, arterial wall inflammation, nitric oxide formation, and atheromatous disease.