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The post-operative pediatric cerebellar mutism syndrome (CMS) affects about one-third of children and adolescents following surgical removal of a posterior fossa tumor (PFT). According to the Posterior Fossa Society consensus working definition, CMS is characterized by delayed-onset mutism/reduced speech and emotional lability after cerebellar or 4th ventricle tumor surgery in children, and is frequently accompanied by additional features such as hypotonia and oropharyngeal dysfunction/dysphagia. The main objective of this work was to develop a diagnostic scale to grade CMS duration and severity. Thirty consecutively referred subjects, aged 1–17 years (median 8 years, IQR 3–10), were evaluated with the proposed Post-Operative Pediatric CMS Survey after surgical resection of a PFT and, in case of CMS, for 30 days after the onset (T0) or until symptom remission. At day 30 (T1), CMS was classified into mild, moderate, or severe according to the proposed scale. CMS occurred in 13 patients (43%, 95% C.I.: 25.5–62.6%), with mild severity in 4 cases (31%), moderate in 4 (31%), and severe in 5 (38%). At T1, longer symptom persistence was associated with greater severity (p = 0.01). Greater severity at T0 predicted greater severity at T1 (p = 0.0001). Children with a midline tumor location and those aged under 5 years at diagnosis were at higher risk of CMS (p = 0.025 and p = 0.008, respectively). In conclusion, the proposed scale is a simple and applicable tool for estimating the severity of CMS at its onset, monitoring its course over time, and providing an early prognostic stratification to guide treatment decisions. What is Known:• Post-operative pediatric Cerebellar Mutism Syndrome (CMS) is a complex phenomenon with a wide spectrum of symptoms that may manifest in children undergoing the resection of a posterior fossa tumor (PFT) and that can result into long-term impairment. What is New:• This study developed and pilot-tested an easily applicable diagnostic and severity scale to grade the duration and the severity of symptoms of the CMS.• The proposed scale was found to be a sensitive instrument to identify even mild CMS presentations.• By scoring not only the duration but also the severity of symptoms the scale allows a more accurate prognostic stratification for an optimal planning of clinical and rehabilitative interventions.

Syringomyelia and Chiari malformation are classified as rare diseases on Orphanet, but international guidelines on diagnostic criteria and case definition are missing. Aim of the study: to reach a consensus among international experts on controversial issues in diagnosis and treatment of Chiari 1 malformation and syringomyelia in adults. A multidisciplinary panel of the Chiari and Syringomyelia Consortium (4 neurosurgeons, 2 neurologists, 1 neuroradiologist, 1 pediatric neurologist) appointed an international Jury of experts to elaborate a consensus document. After an evidence-based review and further discussions, 63 draft statements grouped in 4 domains (definition and classification/planning/surgery/isolated syringomyelia) were formulated. A Jury of 32 experts in the field of diagnosis and treatment of Chiari and syringomyelia and patient representatives were invited to take part in a three-round Delphi process. The Jury received a structured questionnaire containing the 63 statements, each to be voted on a 4-point Likert-type scale and commented. Statements with agreement

In anticipation of the “Chiari and Syringomyelia Consensus Conference” held in Milan in 2019, we performed a systematic literature review on the management of Chiari malformation type 1 (CM1) and syringomyelia (Syr) in children. We aimed to summarize the available evidence and identify areas where consensus has not been reached and further research is needed. In accordance with PRISMA guidelines, we formulated seven questions in Patients-Interventions-Comparators-Outcomes (PICO) format. Six PICOs concerned CM1 children with/without additional structural anomalies (Syr, craniosynostosis, hydrocephalus, tethered cord, and cranio-vertebral junction anomalies), and one PICO Syr without CM1. We searched Medline, Embase, Cochrane, and NICE databases from January 1, 1999, to May 29, 2019. Cohort studies, controlled and randomized clinical trials (CCTs, RCTs), and systematic reviews were included, all pertinent only to patients ≤ 18 years of age. For CM1, 3787 records were found, 460 full texts were assessed and 49 studies (46 cohort studies, one RCT, and two systematic reviews) were finally included. For Syr, 376 records were found, 59 full texts were assessed, and five studies (one RCT and four cohort studies) were included. Data on each PICO were synthetized narratively due to heterogeneity in the inclusion criteria, outcome measures, and length of follow-up of the included studies. Despite decades of experience on CM1 and Syr management in children, the available evidence remains limited. Specifically, there is an urgent need for collaborative initiatives focusing on the adoption of shared inclusion criteria and outcome measures, as well as rigorous prospective designs, particularly RCTs.

Objective To assess the audiological profile in a cohort of children affected by syndromic craniosynostosis. Methods Eleven children with Apert syndrome ( n = 4), Saethre-Chotzen syndrome ( n = 3), Muenke syndrome ( n = 2), Crouzon syndrome ( n = 1) and Pfeiffer syndrome type 1 ( n = 1) were submitted to a complete audiologic evaluation including otoscopy, pure-tone audiometry, tympanometry and acoustic reflex testing, ABR, otoacustic emissions, temporal bone High Resolution CT (HRCT) scan. The main outcome measures were prevalence, type and severity of hearing loss, prevalence of chronic otitis media, correlation with the time of first surgical correction. Results Seven of 11 patients (64%) presented hearing loss (HL), conductive in 3/7 patients (43%) and mixed in 4/7 (57%). No patients showed a purely sensorineural HL. All hearing impaired patients displayed middle ear disorders: the patients with conductive HL had otitis media with effusion (OME) and 3/4 patients with mixed HL showed tympanic alterations or cholesteatoma. A bilateral vestibular aqueduct enlargement was detected by HRCT scan in one normal hearing patient. The ABRs resulted normal in all cases. Conclusion Our study confirms the high prevalence of otologic diseases in such patients. In contrast with previous studies, middle ear disorders were responsible for the hearing impairment also in patients with mixed HL due to secondary inner ear damage. These findings restate the necessity of a close audiologic follow-up. We did not detect the specific ABR abnormalities previously reported, possibly because of an early correction of the cranial vault malformations.

Purpose: The aims of patients’ radiological surveillance are to: ascertain relapse; apply second-line therapy; accrue patients in phase 1/2 protocols if second-line therapy is not standardized/curative; and assess/treat iatrogenic effects. To lessen the emotional and socioeconomic burdens for patients and families, we ideally need to establish whether scheduled radiological surveillance gives patients a better outcome than waiting for symptoms and signs to appear. Methods: We analyzed a prospective series of 160 newly-diagnosed and treated pediatric/adolescent patients with intracranial ependymoma, comparing patients with recurrent disease identified on scheduled MRI (the RECPT group; 34 cases) with those showing signs/symptoms of recurrent disease (the SYMPPT group; 16 cases). The median follow-up was 67 months. Results: No significant differences emerged between the two groups in terms of gender, age, tumor grade/site, shunting, residual disease, or type of relapse (local, distant, or concomitant). The time to relapse (median 19 months; range 5–104) and the MRI follow-up intervals did not differ between the SYMPPT and RECPT groups. The presence of signs/symptoms was an unfavorable factor for overall survival (OS) after recurrence (5-year OS: 8% vs. 37%, p = 0.001). On multivariable analysis, an adjusted model confirmed a significantly worse OS in the SYMPPT than in the RECPT patients. Conclusions: Symptomatic relapses carried a significantly worse survival for ependymoma patients than recurrences detected by MRI alone. It would therefore be desirable to identify recurrences before symptoms develop. Radiological follow-up should be retained in ependymoma patient surveillance because there is a chance of salvage treatment for relapses found on MRI

One of the treatment option to reduce spasticity in cerebral palsy children is selective dorsal rhizotomy. Several studies have demonstrated short and long term improvements in gait and other activities after rhizotomy but this surgery still remains a controversial procedure and patient outcome indicators measures are not uniform.To describe our assessment and outcome evaluation protocol and to verify by this protocol short term results of rhizotomy.We recruited 9 cerebral palsy children (mean age 7.9 years ± 3.2) affected by mild to moderate spastic diplegia and operated by rhizotomy. Patients were studied preoperatively and at 12 months after surgery by the following clinical and instrumental measures correlated to the International Classification of Functioning: modified Ashworth Scale, passive Range of Motion, Medical Research Council Scale, Selective Motor Control Scale, 3D-motion analysis and energy cost of locomotion measurements (indicators of "body functions"); Gross Motor Functional Measure and Motor Functional Independence Measure (indicators of "activities and participation").Our data showed, after rhizotomy, reduction of spasticity specially in plantarflexors muscles (p 0.01), increase of strength of knee flexors/extensors and foot plantar/dorsiflexion muscles (p 0.01), improvement of selective motor control (p 0.05), more similar spatio-temporal parameters of gait analysis to healthy subjects, reduced equinus foot and knees hyperflexion as energy cost.The complementary use of multiple indicators may improve the evaluation of the results of dorsal rhizotomy. A beneficial outcome measured by these indicators has been found in our spastic diplegic children one year after rhizotomy.

Background This prospective study stratified patients by surgical resection (complete = NED vs incomplete = ED) and centrally reviewed histology (World Health Organization [WHO] grade II vs III). Methods WHO grade II/NED patients received focal radiotherapy (RT) up to 59.4 Gy with 1.8 Gy/day. Grade III/NED received 4 courses of VEC (vincristine, etoposide, cyclophosphamide) after RT. ED patients received 1-4 VEC courses, second-look surgery, and 59.4 Gy followed by an 8-Gy boost in 2 fractions on still measurable residue. NED children aged 1-3 years with grade II tumors could receive 6 VEC courses alone. Results From January 2002 to December 2014, one hundred sixty consecutive children entered the protocol (median age, 4.9 y; males, 100). Follow-up was a median of 67 months. An infratentorial origin was identified in 110 cases. After surgery, 110 patients were NED, and 84 had grade III disease. Multiple resections were performed in 46/160 children (28.8%). A boost was given to 24/40 ED patients achieving progression-free survival (PFS) and overall survival (OS) rates of 58.1% and 68.7%, respectively, in this poor prognosis subgroup. For the whole series, 5-year PFS and OS rates were 65.4% and 81.1%, with no toxic deaths. On multivariable analysis, NED status and grade II were favorable for OS, and for PFS grade II remained favorable. Conclusions In a multicenter collaboration, this trial accrued the highest number of patients published so far, and results are comparable to the best single-institution series. The RT boost, when feasible, seemed effective in improving prognosis. Even after multiple procedures, complete resection confirmed its prognostic strength, along with tumor grade. Biological parameters emerging in this series will be the object of future correlatives and reports.

The combined recordings of epidural-(D wave) and muscle motor evoked potentials (m-MEPs) have been proposed in many studies in intramedullary spinal cord tumour (IMSCT) surgery, although not all agree. Furthermore, the usefulness of the intraoperative monitoring of motor systems using these methods in other types of spine surgery has not yet been clearly confirmed. The aim of this study is to test the impact of intraoperative D wave on the monitorability and motor outcome in spine surgery.Intraoperative recording of posterior tibial nerve somatosensory potentials, lower limb m-MEPs (LLm-MEPs) and epidurally recorded D wave caudally to the surgical level was attempted in a total of 103 spine and spinal cord surgeries (23 IMSCT, 55 extramedullary spinal cord tumours and 25 myelopathies).There was a 97.1 %, overall monitorability where at least 1 of the 3 modalities was applicable in 100 surgical procedures. Baseline LLm-MEPs were recorded bilaterally in 85 cases and unilaterally in 11. A caudal D wave was recorded in 97 cases. Transient, or persistent intraoperative modifications occurred in 14/23 IMSCT, 5/55 extramedullary spinal cord tumours and in 2/25 myelopathies. The presence of a persistent stable caudal D wave was predictive of a good motor outcome even when the LL-MEPs were absent and/or when lost during surgery.Not only is intraoperative D wave recording to be considered mandatory in IMSCT surgery but it should also be attempted in other types of spine/spinal cord surgeries.

Background: This prospective surveillance study was designed to estimate the incidence of healthcare-associated infections (HAIs) and to analyze the risk factors for their development in a pediatric neurosurgical unit. Methods: The study was performed in an Italian teaching hospital from October 2008 through March 2010. All children (0–18 years) undergoing neurosurgery were included and monitored daily for the development of HAIs. Results: The study included 260 patients, with a mean age of 4.3 ± 4.7 years. Thirty-six HAIs were detected in 25 patients; catheter-related infections were the most frequent. Etiological identification was available in 22 cases; Gram-negative bacteria were the most commonly isolated pathogens. The incidence density was 11.0/1,000 patient days, and the incidence rate was 13.8/100 patients. The crude mortality was 0%. The risk of developing HAIs was related to the length of hospital stay, while the higher the age of the patients, the lower the risk of developing HAIs. Conclusion: To our knowledge, this survey is the first study to evaluate the overall incidence of HAIs and to explore the risk factors implicated in their development in neurosurgical pediatric patients. The most effective strategies to prevent these infections are reduction of the length of the hospital stay and improvement in device management.

Object Interhemispheric arachnoid cysts are very rare, and they are often associated with complex brain malformations such as corpus callosum agenesis and hydrocephalus. Debate remains concerning the proper management of these lesions. Placement of shunts and microsurgical marsupialization of the cyst are the traditional options. Using endoscopic methods to create areas of communication between the cyst, the ventricular system, and/or the subarachnoid space is an attractive alternative to the use of shunts and microsurgery. Methods Between 2000 and 2005, seven consecutive pediatric patients with interhemispheric arachnoid cysts underwent neuroendoscopic treatment involving cystoventriculostomy in two patients, cystocisternostomy in two, and cystoventriculocisternostomy in three. There were three cases of associated hydrocephalus, six cases of corpus callosum agenesis, and one case of corpus callosum hypogenesis. The follow-up period ranged from 12 to 49 months (mean 31.6 months). Endoscopic procedures were completely successful in all but two patients. In one of the remaining two patients, a repeated endoscopic cystocisternostomy was performed with success because of closure of the previous stoma. In the other, a subcutaneous collection of cerebrospinal fluid (CSF) was managed by insertion of a lumboperitoneal shunt. A subdural collection of CSF developed in three patients; it was treated with insertion of a subduroperitoneal shunt in one patient and managed conservatively in the other two patients, resolving spontaneously without further treatment. Neurodevelopmental evaluation performed in six patients showed normal intelligence (total intelligence quotient [IQ] > 80) in three patients, mild developmental delay (total IQ 50–80) in two, and severe developmental delay (total IQ < 50) in one. Conclusions Endoscopic treatment of interhemispheric cysts can be considered a useful alternative to traditional treatments, even if some complications are to be expected, such as subdural or subcutaneous CSF collections and CSF leaks due to thinness of cerebral mantle and to the often-associated multifactorial hydrocephalus.

The management of children with cancer during the end-of-life (EOL) period is often difficult and requires skilled medical professionals. Patients with tumors of the central nervous system (CNS) with relapse or disease progression might have additional needs because of the presence of unique issues, such as neurological impairment and altered consciousness. Very few reports specifically concerning the EOL period in pediatric neuro-oncology are available.Among all patients followed at our center during the EOL, we retrospectively analyzed data from 39 children and adolescents with brain tumors, in order to point out on their peculiar needs.Patients were followed-up for a median time of 20.1 months. Eighty-two percent were receiving only palliative therapy before death. Almost half the patients (44%) died at home, while 56% died in a hospital. Palliative sedation with midazolam was performed in 58% of cases; morphine was administered in 51.6% of cases. No patient had uncontrolled pain.The EOL in children with advanced CNS cancer is a period of active medical care. Patients may develop complex neurological symptoms and often require long hospitalization. We organized a network-based collaboration among the reference pediatric oncology center, other pediatric hospitals and domiciliary care personnel, with the aim to ameliorate the quality of care during the EOL period. In our cohort, palliative sedation was widely used while no patients died with uncontrolled pain. A precise process of data collection and a better sharing of knowledge are necessary in order to improve the management of such patients.

The authors studied the role of the sole posterior fossa bony decompression in the management of symptomatic children affected by Chiari type I anomalies. The series in the pediatric literature of this subject were reviewed and compared with that presented in this article. From May 1994 to December 1998, 53 patients (3 months to 26 years) were observed. They were divided into: asymptomatic patients (27), who received no surgical treatment and were only subject to clinical observation; symptomatic patients (brain stem compression 16, syringomyelia 10, including 7 with holocord). All the symptomatic patients were treated with the same surgical approach: bony decompression of posterior fossa with removal of the posterior arch of C-1 and the outer layer of the dura without dural opening. In all 16 (100%) of the 16 patients with brain stem compression the symptoms resolved or improved; in patients with syringomyelia the symptoms were resolved or improved in 94.4% of cases. Two children required further surgery after 13 and 24 months, respectively. This series seems to demonstrate that even a simple extradural surgical approach, with a lower rate of postoperative complications and short stay in hospital, is sufficient to arrest the disease and to improve the symptomatology in a high percentage of cases (97.2%), which is comparable to that achieved with other, more aggressive, procedures.

We present the case of a 6-year-old male affected by an infratentorial tumor. Histological diagnosis was melanotic medulloblastoma. Immunohistochemistry showed in the melanin rich areas positive cells for HMB45. We performed a proteomic study to compare protein profiles in melanotic versus non-melanotic areas. Protein profiles of different areas of the tumor displayed similarity, with the exception of seven proteins. In accordance with the hypothesis that melanotic medulloblastomas produce oculo-cutaneous melanin, proteomic analysis showed melanocytic-associated antigens and epidermal autoantigen 450K in the pigmented nodule; both these proteins have a significant role as markers of melanotic elements.

OBJECTIVE: To evaluate retrospectively the operative findings and long-term results of a repeat endoscopic third ventriculostomy (ETV) in pediatric hydrocephalic patients readmitted after the first procedure with symptoms and/or signs of intracranial hypertension and/or radiological evidence of increased ventricular dilation and/or occluded stoma on follow-up radiological examinations. METHODS: We analyzed a series of 482 ETVs in pediatric patients from 2 Italian departments of pediatric neurosurgery. The clinical charts of 40 patients undergoing a second ETV were selected and reviewed retrospectively. The pre- and postoperative radiological findings and operative films were analyzed retrospectively. RESULTS: Forty patients underwent a total of 82 ETVs. Thirty-eight patients were operated on twice and 2 were operated on 3 times. During the second procedure, the stoma was found to be closed in 28 patients without underlying adhesions, to be open but with significant arachnoid adhesions in the prepontine cistern in 8 patients, to be open without adhesions in 2 patients, to have a pinhole orifice in 1 patient, and to be closed with underlying adhesions in 1 patient. The second procedure allowed reopening of the stoma or lysis of the arachnoid adhesions in 35 patients and was abandoned in 3 patients because of extensive arachnoid adhesions or because the stoma was found to be wide open (2 patients). In 30 patients (75%), the second ETV was effective, and the 2 patients who underwent a third ETV remained shunt free. In 10 patients (25%), a ventriculoperitoneal shunt was eventually placed. Age younger than 2 years at the time of the first procedure and arachnoid adhesions in the subarachnoid cisterns observed during the second procedure are the main negative prognostic factors for the success of a second ETV. CONCLUSION: A second ETV can be performed with a reasonable chance of restoring patency of the stoma and avoiding placement of an extrathecal shunt. Every effort should be made to detect subarachnoid adhesions in the cistern on preoperative imaging study to select potential candidates and avoid unnecessary procedures.

The authors describe the clinical and radiological findings in a case of brainstem arteriovenous malformation (AVM) associated with a hepatic patent ductus venosus (PDV) in a 12-year-old child. The AVM was discovered on magnetic resonance (MR) imaging performed because of slight mental retardation and headache. The malformation was otherwise asymptomatic and no treatment was proposed. An abdominal ultrasonography study performed 1 year later because of hyperammonemia revealed a PDV, which was surgically ligated. One year later, MR images and angiograms showed complete resolution of the brainstem AVM. This report is the first documentation of an association between these two entities in the same patient, and the possible pathophysiological interactions between them are discussed.

Brainstem tumors (BSTs) are usually gliomas and are divided into diffuse BSTs (DBSTs) and focal BSTs (FBSTs). The aim of this study is to investigate the different outcomes of these two entities.Thirty-one patients with BSTs were admitted to our institution from 1995 to 2003. Patients with DBSTs were treated with locoregional radiotherapy (1.8 Gy/day for 54 Gy) and weekly vincristine for radiosensitization (1.5 mg/sm for six total doses). Patients with FBSTs underwent surgical resection. Chemotherapy and/or radiotherapy were considered in progression.Fourteen patients were diagnosed as having DBSTs. The responses to treatment were ten cases of partial response, three of stable disease, and one of progressive disease. General and/or neurological symptoms improved in more than 80% of patients. The median time from diagnosis to progression and to death were, nonetheless, 8 (range of 3-13) and 13 (range of 4-25) months, respectively, with a 2-year overall survival rate of 12.3% [standard error (SE) 11.2]. Seventeen patients were diagnosed as having FBSTs. Gross total removal was achieved in 4/17 cases, subtotal removal in 7/17, and partial removal in 6/17. There was one surgery-related death. Eight out of 17 patients had adjuvant chemo- and/or radiotherapy after progression: 6/8 are without neurological symptoms and 2/8 have died due to tumor progression. The 4-year overall and disease-free survival rates are 87.4 (SE 8.4) and 58.8% (SE 11.9), respectively, the extent of resection being the most important prognostic factor (p=0.012). DBSTs continue to carry a dismal prognosis, thus demanding new treatment modalities; FBSTs can be treated surgically and patients benefit from a better prognosis.

Invasive aspergillosis is an uncommon but often lethal complication in immunocompromised patients. Despite the progress obtained with new antifungal drugs, intracranial aspergillosis often requires a combined medical and surgical approach. Most cases previously reported in immunocompromised children were fatal. We describe 4 immunosuppressed children with intracranial aspergillosis successfully treated with surgery and antifungal long-term therapy.

With two study protocols, one retrospective and the other prospective, we evaluated hypothalamo-hypophysial dysfunction (HHD) in paediatric patients treated for traumatic brain injury (TBI) in the neurosurgical or intensive care department at our hospital. The retrospective group comprised 22 patients who had experienced TBI 0.7-7.25 years before the study. The prospective group included 30 patients assessed at TBI (T0), 26 of 30 after 6 months (T6), and 20 of 26 after 12 months (T12). Auxological and hormonal basal parameters of hypothalamo-hypophysial function were evaluated at recall in the retrospective group, and at T0, T6 and T12 in the prospective group. Basal data and standard dynamic tests in selected patients revealed one with precocious puberty, one with total anterior hypopituitarism, one with central hypogonadism, and one with growth hormone (GH) deficiency in the retrospective group; three patients with cerebral salt-wasting syndrome, one with diabetes insipidus and seven with low T3 syndrome at T0 (all transient), one with hypocorticism at T6 confirmed at T12, and one with GH deficiency at T12 in the prospective group. The results of our study show that post-TBI HHD in our paediatric cohort is not uncommon. Of the 48 patients who underwent a complete evaluation (22 retrospective study patients and 26 prospective study patients evaluated at T6) five (10.4%) developed HHD 6 months or more after TBI. HHD was newly diagnosed in one previously normal patient from the prospective group at 12 months after TBI. GH deficiency was the most frequent disorder in our paediatric cohort.

Neuroendoscopic surgery is being used as an alternative to traditional shunt surgery and craniotomy in the management of hydrocephalus and intracranial fluid-filled cavities. In this study, the authors evaluated the incidence and type of complications occurring after neuroendoscopic procedures that were performed in a consecutive series of pediatric patients at a single institution to determine the effectiveness of neuroendoscopy in such patients.Four hundred ninety-five neuroendoscopic procedures were consecutively performed in 450 pediatric patients at one institution over a 10-year period. Charts were retrospectively reviewed. A complication was defined as follows: 1) any postoperative neurological deficit that was not observed before surgery; 2) any event occurring during surgery that resulted in the procedure being aborted; or 3) any adverse event occurring within 7 days postsurgery that resulted in a modification of the normal postoperative care. However, headache, vomiting, and fever without cerebrospinal fluid (CSF) pleocytosis were not considered complications. Complications were observed in 40 (8.1%) of 495 procedures. Two patients had two complications. One patient died of diffuse brain edema following endoscopic biopsy sampling of a basal ganglia tumor (mortality rate 0.2%). Other complications observed were abandonment of the procedure in eight cases, CSF leakage in 11 (with associated wound infection in one), intraventricular hemorrhage in six (with external drainage needed in four), intraparenchymal hemorrhage in three, subdural collection in eight (with subdural-peritoneal shunt placement needed in seven), transient oculomotor palsy in two, and transient hemiparesis in one.Many complications can be avoided by determining the correct diagnosis and using suitable techniques and instruments. Most complications can be managed conservatively and do not produce long-term morbidity. Complex procedures in most patients and simple procedures in patients with preoperative risk factors carry the highest hazard. Every attempt should be made to optimize the surgical technique. The most serious and potentially the most lethal complication remains arterial bleeding from injury to the basilar artery complex.