Object Scarce morphometric data exist on the developing skull base as a corridor for endonasal endoscopic approaches (EEAs). Furthermore, the impact of skull base lesions on its development has not been assessed. The authors describe a novel set of anatomical parameters characterizing the developmental process as well as the utility of these parameters in preoperative planning and a feasibility assessment of EEAs for neurosurgical treatment of skull base lesions in children. Methods Based on specific MRI sequences in 107 pediatric patients (2–16 years of age) without skull base lesions (referred to here as the normal population), 3 sets of anatomical parameters were analyzed according to age group and sex: drilling distance, restriction sites, and working distance parameters. A separate set of patients undergoing EEAs was analyzed in similar fashion to address the impact of skull base lesions on the developmental process. Results The volume of the sphenoid sinus significantly increases with age, reaching 6866.4 mm3 in the 14–16 years age group, and directly correlates with the pneumatization type (r = 0.533, p = 0.0001). The pneumatization process progresses slowly in a temporal-posterior direction, as demonstrated by the growth trend of the sellar width (r = 0.428, p = 0.0001). Nasal restriction sites do not change significantly with age, with little impact on EEAs. The intercarotid distance is significantly different only in the extreme age groups (3.9 mm, p = 0.038), and has an important impact on the transsphenoidal angle and the intracranial dissection limits (r = 0.443, p < 0.0001). The 14.9° transsphenoidal angle at 2–4 years has a 37.6% significant increase in the 11–13 years age group (p = 0.001) and is highly dependent on pneumatization type. Age-dependent differences between working parameters are mostly noted for the extreme age groups, such as the 8.6-mm increase in nare-vomer distance (p = 0.025). The nare-sellar distance is the only parameter with significant differences based on sex. Skull base lesions induce a high degree of variance in skull base measurements, delaying development and decreasing parameter values. Skull base parameters are interdependent. Nare-sellar distance can be used to assess global skull base development because it highly correlates with the intercarotid distance in both the normal population and in patients harboring skull base lesions. Conclusions Skull base development is a slow, gradual, age-dependent, sex-independent process significantly altering endonasal endoscopic corridors. Preoperative MRI measurements of the pediatric skull base are thus a useful adjunct in choosing the appropriate corridor and in assessing working angles and limits during dissection or reparative surgery. Skull base lesions can significantly impact normal skull base development and age-dependent growth patterns.

Object Accessing intra- and extradural tumors via an endonasal approach requires working safely in a relatively narrow area with unobstructed visibility. The authors describe their experience to highlight the utility of a side-cutting aspiration device for endoscopic endonasal resection of skull base tumors. Methods The authors used this device in 13 nonconsecutive endoscopic endonasal procedures for different skull base tumors (8 pituitary macroadenomas, 2 craniopharyngiomas, 1 chordoma, 1 recurrent ependymoma, and 1 lymphoma). Illustrative cases and video are presented to demonstrate its use. Results The instrument was easy to use and effective in the removal of the lesions presented in this series. In 10 patients (77%), gross-total resection was possible; in the other 3 patients (23%), more than 80% of the tumor was resected. No collateral tissue damage or any other complication resulted from device-related debulking or aspiration. Conclusions The side-cutting tissue resector is a safe, easy to use, and effective tool for internal debulking and extracapsular dissection of nonvascularized tumors that are too firm for bimanual suction or blunt ring curette dissection. It is particularly useful when working through a deep and narrow corridor such as is encountered in endoscopic endonasal skull base surgery.

Background: Patients with epilepsy have a higher risk of skeletal injuries, and some of these fractures occur in the spine during a seizure. Seizure-induced spinal fractures (SISF) are unusual injuries that typically occur in the thoracolumbar spine. Because these skeletal injuries are not well described in the literature, this article aims to analyze the characteristics of this uncommon clinical entity.Methods: A PubMed and Scopus search adhering to preferred reporting items for systematic reviews and meta-analyses guidelines was performed to include studies reporting patients with SISF. The data gathered from this review were analyzed to characterize this condition.Results: The search yielded 34 articles with a total of 38 patients with SISF. All studies were case reports (level 5 evidence). Most fractures occurred in the thoracic and lumbar spine, and the most common injuries were type A1 and A4 fractures according to the AO spine classification system. Different characteristics of SISF are described including demographics, clinical findings, imaging, and treatment.Conclusions: SISF should be ruled out in patients who have a recent history of seizures and who report persistent dorsolumbar pain or neurological deficit. SISF usually occurs in the thoracolumbar spine and less frequently in the cervical spine. This review shows that different patterns of neurological deficits, some of them severe, may occur in approximately a quarter of patients with SISF.Clinical Relevance: This study provides awareness of an uncommon spine condition. Physicians should suspect SISF in patients with persistent dorsolumbar pain after a seizure.

PURPOSE: This study was performed to evaluate the incidence of seizures with its implications on disease progression and the diagnostic value of post-ictal magnetic resonance images (MRI) during the management of highgrade gliomas (HGGs). PATIENTS AND METHODS: A total of 406 consecutive patients with newly diagnosed HGGs were retrospectively reviewed. The incidence of seizure attacks during the management was investigated. In patients who experienced a seizure, the causality between seizures and disease progression was assessed by pre-ictal, post-ictal (,1 month), and follow-up (,3 months) MRI. RESULTS: After a mean follow-up of 21.9 months (range, 0.1 -88.3), seizure attacks developed in 127 patients (31%). Of the 127 patients, radiological progression at the post-ictal MRI was found in 83 patients (65%) and the follow-up MRI confirmed progression in 79 patients (62%). However, other 4 patients (3%) were shown to be progression-free. Among those without radiological progression at the post-ictal MRI, the follow-up MRI confirmed progression-free in 31 patients (24%); however, 13 patients (10%) revealed eventual progression. In the patients with a seizure, absence of preoperative seizure (p ¼ 0.003), , 95% tumor resection (p ¼ 0.001), and pre-ictal Karnofski Performance Scale score ≤ 70 (p ¼ 0.025) were significantly associated with disease progression. CONCLUSION: During the management of HGG, 31% of patients experienced seizures; of these patients, 72% harbored progressive disease. The post-ictal MRI is useful for detecting disease progression; however, there are pitfalls. Clinical settings should be considered together for diagnosing disease progression in patients with seizures.

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