Medical management for cerebellar mutism syndrome following posterior fossa surgery: A systematic review.

INTRODUCTION: Cerebellar mutism syndrome (CMS) is a serious complication of posterior fossa surgeries affecting mainly pediatric age group. The pathophysiology is still not fully understood. It adversely affects the recovery of patients. There is no definitive and standardized management for CMS. However pharmacological therapy has been used in reported cases with variable effectiveness. We aim through this review to summarize the available evidence on pharmacological agents used to treat CMS. METHOD: A thorough systematic review until December 2022, was conducted using PubMed Central, Embase, and Web of Science, databases to identify case reports and case series of CMS patients who underwent posterior fossa surgery and received pharmacological treatment. Patients with pathologies other than posterior fossa lesions were excluded from the study. RESULTS: Of 592 initial studies, 8 studies met our eligibility criteria for inclusion, with 3 more studies were added through manual search; reporting on 13 patients. The median age of 13 years (Standard deviation SD=10.60). The most frequent agent used was Bromocriptine. Other agents were fluoxetine, midazolam, zolpidem, and arpiprazole. Most patients recovered within 48 hours of initiating medical therapy. The median follow-up period was 4 months (SD=13.8). All patients showed complete recovery at the end of follow-up period. CONCLUSION: Cerebellar mutism syndrome is reported after posterior fossa surgeries, despite attempts to identify risk factors, pathophysiology, and management of CMS, it remains a challenging condition with significant morbidity. Different Pharmacological treatments have been proposed with promising results. Further studies and formalized clinical trials are needed to evaluate available options and their effectiveness.

Predictors of Acute Cerebellar Bulge Prior to Posterior Fossa Lesion Resection.

OBJECTIVE: A cerebellar bulge prior to posterior fossa resection is an emergency condition during surgery. Intraoperative cerebellar bulging not only increases the difficulty of lesion resection but also brings additional postoperative complications. Currently, there are few systematic reports on this topic. The predictors of cerebellar bulge and how to effectively prevent intraoperative cerebellar bulge are discussed in this article. METHODS: The clinical and imaging data of 527 patients with posterior fossa lesions who underwent resection at our hospital were retrospectively collected and analyzed. Perioperative clinical and imaging data were assessed. Variables were analyzed using univariate and multivariate regression analyses. RESULTS: Overall, 10.4% (55/527) of patients had intraoperative acute bulges. Multivariate analysis revealed that age <60 years, body mass index ≥24, lesion size ≥30 (mm), cerebellar tonsillar herniation and/or hydrocephalus, and perilesional edema (moderate-severe) were predictors of cerebellar bulging. Relief of the cerebellar bulge can be accomplished by excising the lesion, releasing cerebrospinal fluid, and removing the cerebellum (the outer one-third). Obvious cerebellar-related complications occurred in 4 patients postoperatively, and the symptoms disappeared after 6 months of follow-up. CONCLUSIONS: Cerebellar bulging during intraoperative posterior fossa resection deserves attention. Through the analysis of multiple factors related to cerebellar bulge, comprehensive evaluation and early intervention during the perioperative period are necessary. The incidence of cerebellar bulges can be reduced, and surgical complications related to cerebellar bulges can be avoided.

Catatonia associated with pediatric postoperative cerebellar mutism syndrome.

OBJECTIVE: To ascertain the presence of catatonia in cases of pediatric postoperative cerebellar mutism syndrome (PPCMS). METHOD: A systematic review of PPCMS case reports of patients aged 0-17 years with sufficient clinical information to extract catatonic phenomena was undertaken following PRISMA guidelines. Standardized catatonia rating scales were applied to selected cases retrospectively to ascertain whether diagnostic criteria for catatonia were met. A case known to the authors is also presented. RESULTS: Two hundred twenty-one suitable full-text articles were identified. Following screening and application of inclusion criteria, 51 articles were selected plus seven more from their references, reporting on 119 subjects. All cases met Bush and Francis (BF) diagnostic criteria for catatonia, 92.5% Pediatric Catatonia Rating Scale (PCRS), 52.9% ICD-11, and 44.5% DSM-5. All patients presented with mutism. The next most frequent signs were immobility/stupor (77.3%), withdrawal (35.3%), mannerisms (23.5%), and excitement/agitation (18.5%). Most cases presented with stuporous catatonia (75.6%). Catatonia most frequently occurred following resection of medulloblastoma (64.7%). Preoperative hydrocephalus occurred in 89 patients (74.8%). CONCLUSION: Catatonia was frequent in this PPCMS sample, with a predominant stuporous variant; it should be considered in patients with PPCMS and assessed with reliable and validated instruments for prompt diagnosis and management.

Evaluation of safety of fluoxetine for cerebellar mutism syndrome in children after posterior fossa surgery.

BACKGROUND: Cerebellar mutism syndrome (CMS) occurs in 8-29 % of children undergoing posterior fossa tumor surgery. Its main symptoms are mutism and emotional lability. Although it is always transient, recovery time can be lengthy with long-term cognitive sequelae. There is no approved drug treatment for CMS, but some drugs are used in everyday medical practice. One of these is fluoxetine, which has been used for many years in our institution. The main objective of this study was to establish the safety profile of fluoxetine in this condition. MATERIALS AND METHODS: The records of patients admitted to the pediatric intensive care unit after brain surgery at Angers University Hospital from 2010 to 2020 were reviewed. Children aged 2 years and older who underwent a posterior fossa tumor surgery and were diagnosed with CMS were included. Data on patient characteristics, prescription of fluoxetine treatment, side effects if any, and complete mutism duration were collected. RESULTS: Among 246 patients admitted to the pediatric intensive care unit for brain surgery during the study period, 23 had CMS and eight were prescribed fluoxetine. No serious adverse event related to fluoxetine was reported. Complete mutism duration did not differ significantly between the fluoxetine group and the non-fluoxetine group(p = 0.22). However, the treatment was initiated after recovery from complete mutism in half of the treated patients. CONCLUSION: This study suggests a positive safety profile of fluoxetine used in postoperative CMS. It does not answer the question of whether the treatment is effective for this indication. A randomized controlled trial based on a syndrome severity scale should be conducted to provide a more reliable assessment of the efficacy and safety of fluoxetine.

Surgical evacuation of spontaneous cerebellar hemorrhage: Comparison of safety and efficacy of suboccipital craniotomy and robotic-assisted stereotactic hematoma drainage.

OBJECTIVE: This study compared the efficacies of robotic-assisted stereotactic hematoma drainage and suboccipital craniotomy (SC) in patients with spontaneous cerebellar hemorrhage (SCH). METHODS: This retrospective study included 138 non-comatose patients with SCH (Glasgow Coma Scale score [GCS] >8), divided into the SC and Robotic Stereotactic Assistance (ROSA) groups. The study recorded and analyzed complications and prognoses 90 days after ictus. RESULTS: The inclusion criteria were met by 138 patients: 61 in the SC and 77 in the ROSA group, with no significant differences in sex, age, GCS score, hematoma volume, and the time from ictus to operation. The time of operation was greater in the SC group (287.53±87.57) than in the ROSA group (60.54±20.03). The evacuation rate (ER) was greater in the SC group (93.20±1.58) than in the ROSA group (89.13±2.75). The incidence of pneumonia and stress ulcers, as well as the length or costs of medical services, were lower in the ROSA group than in the SC group. Ninety days after ictus, the modified Rankin Scale (mRS), Glasgow Prognostic Scale (GOS), and Karnofsky Performance Scale (KPS) scores significantly differed between the groups. The rate of good prognosis in the ROSA group was significantly higher compared with that in the SC group. The incidence of balance disorders was lower in the ROSA group than in the SC group; no statistically significant difference was found in the incidence of dysarthria and swallowing disorders. CONCLUSION: Robotic-assisted stereotactic hematoma drainage may be suitable for non-comatose and stable condition patients with SCH. This procedure improves prognosis 90 days after ictus, lowers the incidence of pneumonia and stress ulcers, and reduces the length and costs of medical services.

Indications for surgical evacuation of cerebellar intracerebral hemorrhage: consensus guidelines from the French Society of Neurosurgery (SFNC) and the French Society of Vascular Neurology (SFNV).

BACKGROUND: Cerebellar intracerebral hemorrhage (ICH) is associated with poor functional prognosis and high mortality. Surgical evacuation has been proposed to improve outcome. The purpose of this review was to determine the benefit of surgical evacuation of cerebellar ICH and to establish guidelines for when it should be performed. METHOD: The writing committee comprised 9 members of the SFNV and the SFNC. Recommendations were established based on a literature review using the PICO questions. The American Heart Association (AHA) classification was used to define recommendation level. In case of insufficient evidence, expert opinions were provided. RESULTS: Levels of evidence were low to moderate, precluding definitive recommendations. Based on available data, surgical hematoma evacuation is not recommended to improve functional outcome (Class III; Level B NR). However, based on subgroup analysis, surgical evacuation may be considered in strictly selected patients (Class IIb; Level C-EO): hematoma volume 15-25 cm3, GCS 6-10, and no oral anticoagulation or antiplatelet therapy. Moreover, surgical evacuation is recommended to decrease risk of death (Class IIa; Level B NR) in patients with a hematoma volume >15 cm3 and GCS score <10. CONCLUSION: These guidelines were based on observational studies, limiting the level of evidence. However, except for strictly selected patients, surgical evacuation of cerebellar ICH was not associated with improved functional outcome, limiting indications. Data from RCTs are needed in this field.

Necrosectomy Versus Stand-Alone Suboccipital Decompressive Craniectomy for the Management of Space-Occupying Cerebellar Infarctions-A Retrospective Multicenter Study.

BACKGROUND AND OBJECTIVES: Space-occupying cerebellar stroke (SOCS) when coupled with neurological deterioration represents a neurosurgical emergency. Although current evidence supports surgical intervention in such patients with SOCS and rapid neurological deterioration, the optimal surgical methods/techniques to be applied remain a matter of debate. METHODS: We conducted a retrospective, multicenter study of patients undergoing surgery for SOCS. Patients were stratified according to the type of surgery as (1) suboccipital decompressive craniectomy (SDC) or (2) suboccipital craniotomy with concurrent necrosectomy. The primary end point examined was functional outcome using the modified Rankin Scale (mRS) at discharge and at 3 months (mRS 0-3 defined as favorable and mRS 4-6 as unfavorable outcome). Secondary end points included the analysis of in-house postoperative complications, mortality, and length of hospitalization. RESULTS: Ninety-two patients were included in the final analysis: 49 underwent necrosectomy and 43 underwent SDC. Those with necrosectomy displayed significantly higher rate of favorable outcome at discharge as compared with those who underwent SDC alone: 65.3% vs 27.9%, respectively ( P < .001, odds ratios 4.9, 95% CI 2.0-11.8). This difference was also observed at 3 months: 65.3% vs 41.7% ( P = .030, odds ratios 2.7, 95% CI 1.1-6.7). No significant differences were observed in mortality and/or postoperative complications, such as hemorrhagic transformation, infection, and/or the development of cerebrospinal fluid leaks/fistulas. CONCLUSION: In the setting of SOCS, patients treated with necrosectomy displayed better functional outcomes than those patients who underwent SDC alone. Ultimately, prospective, randomized studies will be needed to confirm this finding.

Neuronavigation-assisted neuroendoscopy versus conventional craniotomy for hypertensive cerebellar hemorrhage: A comparative analysis of efficacy and outcomes.

OBJECTIVE: Hypertensive cerebellar hemorrhage is a severe condition in neurosurgery, associated with high disability and mortality rates. The present study compares the efficacy and outcomes of neuronavigation-assisted neuroendoscopy versus conventional microscope (craniotomy) in treating patients with hypertensive cerebellar hemorrhage. METHODS: A retrospective study was conducted by analyzing medical records of patients with hypertensive cerebellar hemorrhage treated at Wuhan No.1 Hospital between February 2015 and February 2019. The study included 65 patients who underwent either neuronavigation-assisted neuroendoscopy (n = 35) or conventional microscopy treatment (n = 30). All patients underwent standard neurological and clinical examinations, as well as routine laboratory tests upon admission. The diagnosis of hypertensive cerebellar hemorrhage was based on computed tomography (CT) findings. Basic parameters, clinical status on admission, imaging results, management, and outcome measures were evaluated and compared between the two groups. RESULTS: Neuronavigation-assisted neuroendoscopy showed advantages over craniotomy in terms of surgical procedure time and intraoperative blood loss ((81.91 ± 17.77) min vs (195.20 ± 31.97) min, (63.66 ± 12.42) ml vs (335.00 ± 104.26) ml, P < 0.01). The hematoma evacuation rate was higher in neuroendoscopy group ((94.37 ± 5.174)% compared to the craniotomy group ((90.80 ± 5.404)%, P < 0.01). Additionally, the time of ventricular drainage was shorter in the neuroendoscopy group ((4.83 ± 1.671) days) than in the craniotomy group ((7.70 ± 1.878) days, P < 0.01). Neuroendoscopy group also resulted in fewer surgical complications and a shorter hospital stay (P < 0.05). There was no significant difference in the risk of rebleeding and mortality between the neuroendoscopy and craniotomy group (P > 0.05). CONCLUSION: Neuronavigation-assisted neuroendoscopy is a rapid, safe, and effective minimally invasive technique for the treatment of hypertensive cerebellar hemorrhage. It offers potential benefits in reducing surgical complications and hospital stay compared to conventional craniotomy.

Cerebellar Abscess Induced by Cochlear Fistula due to Chronic Suppurative Otitis Media.

Cochlear fistulas with cholesteatoma as the primary disease have been reported frequently in the relevant literature. However, there are no reports of cochlear fistula without cholesteatoma due to chronic suppurative otitis media with intracranial complications. We report a case of cochlear fistula due to chronic otitis media that was diagnosed after the onset of a cerebellar abscess. The patient was a 25-year-old man with severe autism. He was admitted to our hospital with otorrhea from his left ear, emesis, and impaired consciousness. Computed tomography (CT) of the head showed left suppurative otitis media, left cerebellar abscess, and brainstem compression due to hydrocephalus. Right extra-ventricular drainage and brain abscess drainage were urgently performed. The next day, foramen magnum decompression and abscess drainage with partial resection of the swollen cerebellum were performed for decompression purposes. He was subsequently treated with antimicrobial therapy, but magnetic resonance imaging of the head showed an increase in the size of the cerebellar abscess. Re-examination of the temporal bone CT scans revealed a bony defect in the left cochlear promontory angle. We assumed that the cochlear fistula was responsible for the otogenic brain abscess. Thus, the patient underwent surgical closure of the cochlear fistula. After the operation, the cerebellar abscess lesion gradually shrank, and his general condition stabilized. Cochlear fistula should be considered in the management of patients with inflammatory middle ear disease associated with otogenic intracranial complications in the middle ear.

Microsurgical Resection of Tonsillar Arteriovenous Malformation: Operative Video.

Cerebellar arteriovenous malformation (AVM) comprises 10%-15% of intracranial AVMs.1 Rupture often leads to devastating brainstem compression, with mortality reported as high as 67%.2 AVM can be a challenging disease, especially when large in size.3 AVMs can be treated by 1 or a combination of treatment modalities, namely embolization, radiosurgery, or microsurgical resection.4,5 Arterial adhesions to tonsilobulbar and telovelonsilar segments of posterior inferior cerebellar artery (PICA) can be a challenge, increasing bleeding and ischemic risk.6 We present a 2-dimensional video case of a tonsillar AVM. The patient, a previously healthy female in her 20s, presented with a chronic headache. She had no medical history. Initial magnetic resonance imaging revealed a tonsillar AVM classified as Spetzler-Martin grade II. It received its supply from the tonsilobulbar and telovelotonsilar segments of the PICA and drained directly into the precentral vein, transverse sinus, and sigmoid sinus. An angiogram revealed severe venous engorgement-the source of the patient's headache. The AVM was partially embolized 1 month preoperatively. A medial suboccipital telovelar approach was chosen to reduce the working distance and afford a wider corridor to expose the suboccipital surface of the cerebellum.7,8 Complete resection of the AVM was achieved with no additional morbidity. Microsurgery in experienced hands offers the best chance of cure for AVMs. In Video 1, we demonstrate the relationships among the tonsila, biventral lobule, vallecula cerebelli, PICA, and cerebellomedullary fissure as an important anatomic landmark in a safe total resection of a tonsillar AVM.

Structural damage burden and hypertrophic olivary degeneration in pediatric postoperative cerebellar mutism syndrome.

Cerebellar mutism syndrome (CMS) occurs in one out of four children after posterior fossa tumor surgery, with open questions regarding risk factors, pathophysiology, and prevention strategies. Because of similarities between several cerebellar syndromes, a common pathophysiology with damage to the dentato-thalamo-cortical and dentato-rubro-olivary pathways has been proposed. Hypertrophic olivary degeneration (HOD) is an imaging correlate of cerebellar injury observed for instance in stroke patients. Aim of this study was to investigate whether the occurrence and severity of CMS correlates with the extent of damage to the relevant anatomical structures and whether HOD is a time-dependent postoperative neuroimaging correlate of CMS. We performed a retrospective single center study of CMS patients compared with matched non-CMS controls. CMS occurred in 10 children (13% of the overall cohort) with a median age of 8 years. Dentate nucleus (DN) injury significantly correlated with CMS, and superior cerebellar peduncle (SCP) injury was associated by tendency. HOD was observed as a dynamic neuroimaging phenomenon in the postoperative course and its presence significantly correlated with CMS and DN injury. Children who later developed HOD had an earlier onset and tended to have longer persistence of CMS. These findings can guide surgical measures to protect the DN and SCP during posterior fossa tumor resections and to avoid a high damage burden (i.e., bilateral damage). Development of intraoperative neuromonitoring of the cerebellar efferent pathways as well as improved preoperative risk stratification could help to establish a patient-specific strategy with optimal balance between degree of resection and functional integrity.

Cerebellar mutism syndrome: the importance of preoperative language assessment.

Children undergoing surgical removal of tumors in the posterior cranial fossa can encounter a varied and complex constellation of neurological symptoms, called cerebellar mutism, defined as a disturbance in the planning and programming of motor language with preserved understanding, behavioral disorders such as inattention, visual-spatial disorganization, personality change, as well as ataxia and dysmetria. In the last years, several groups have been trying to establish risk factors or even predictive scores in order to be able at least in part to predict the appearance of speech disorders before surgery. We report on a child with pilocytic astrocytoma of the cerebellar vermis who had already been diagnosed with developmental linguistic delay two years earlier. This disorder initially worsened after surgery and later improved in the following 12 months. The aim of this paper is to emphasize the importance of preoperative neuropsychological evaluation. The present case, along with those reported in the literature, suggests that the risk of long-term cerebellar mutism is higher in children with preoperative speech disorders. In these patients a thorough assessment of cognitive and linguistic functions is therefore necessary to better evaluate the risk of cerebellar mutism after surgery.

Long-term surgical outcome of Chiari type-I malformation-related syringomyelia: an experience of tertiary referral hospital.

OBJECTIVE: Syringomyelia is a common condition seen in patients with Chiari type-I malformation (CM1). The purpose of this retrospective study was to evaluate the long-term clinical and radiological outcomes of posterior fossa decompression with duraplasty (PFDD) with coagulation of tonsillar ectopia in consecutive surgically treated adult patients with CM1-related syringomyelia (CRS). METHODS: Over 9 years' duration (1993-2001), medical charts of diagnosed patient with CM1 at our neurosurgical center were reviewed retrospectively. This study included adult patients with CM1 who had syringomyelia and underwent PFDD with coagulation of tonsillar ectopia surgery. The differences between the pre- and postoperative syrinx/cord ratio (S/C), the syrinx length, and the regression of herniated cerebellar tonsils on coronal and midsagittal MRIs were evaluated. RESULTS: A total of 87 surgical procedures (46 primary operations, 7 ventriculoperitoneal shunts, and 34 additional operations) for CRS were performed on 24 males and 22 females. The mean preoperative S/C was 0.59 ± 0.12. The means of regression in herniated cerebellar tonsils on mid-sagittal and coronal images were 11.8 ± 2.3 mm and 10.2 ± 2.2 mm (p < 0.0001), respectively. 35 (76.1%) patients were discharged after showing signs of recovery or improvement. Different complications occurred in 16 (34.8%) patients. Negative correlations were noticed between postoperative recovery/improvement and the long symptoms' duration, the herniated tonsils' extent, S/C, and the persistence of the herniated tonsils on the coronal images. CONCLUSION: Early diagnosis of patients with CRS can improve surgical outcomes. Due to its efficacy in resolving clinical symptoms and syrinx cavities, PFDD is still an optimal surgical approach for CRS.

Secondary Hematoma Evacuation and Outcome After Initial Conservative Approach for Patients with Cerebellar Hematoma Larger than 3 cm.

BACKGROUND: In patients with spontaneous cerebellar intracerebral hemorrhage (ICH) guidelines advocate evacuation when the hematoma diameter is > 3 cm. We studied outcome in patients with cerebellar ICH > 3 cm who did not undergo immediate hematoma evacuation. METHODS: We included consecutive patients with cerebellar ICH > 3 cm at two academic hospitals between 2008 and 2017. Patients who died < 24 h (h) were excluded because of probable confounding by indication. We determined patient characteristics, hematoma volumes, EVD placement, secondary hematoma evacuation, in-hospital and 3-month case-fatality, and functional outcome. RESULTS: Of 130 patients with cerebellar ICH, 98 (77%) had a hematoma > 3 cm of whom 22 (23%) died < 24 h and 28 (29%) underwent hematoma evacuation < 24 h. Thus, 48 patients were initially treated conservatively (mean age 70 ± 13, 24 (50%) female). Of these 48 patients, 7 (15%) underwent secondary hematoma evacuation > 24 h, of whom 1 (14%) had received an EVD < 24 h. Five others also received an EVD < 24 h without subsequent hematoma evacuation. Of the 41 patients without secondary hematoma evacuation, 11 (28%) died and 20 (51%) had a favorable outcome (mRS of 0-3) at 3 months. The 7 patients who underwent secondary hematoma evacuation had a decrease in GCS score of at least two points prior to surgery; two (29%) had deceased at 3 months; and 5 (71%) had a good functional outcome (mRS 0-3). CONCLUSIONS: While cerebellar ICH > 3 cm is often considered an indication for immediate hematoma evacuation, there may be a subgroup of patients in whom surgery can be safely deferred. Further data are needed to assess the optimal timing and indications of surgical treatment in these patients.

Cerebellitis as a neurosurgical disease in pediatrics.

The diagnostic evaluation and role of neurosurgery in the treatment of cerebellitis is unclear. We explore the diagnostic evaluation and subsequent role of neurosurgical intervention in pediatric cerebellitis in a case series, highlighting the diagnostic work up and treatments applied. A retrospective review was conducted of all pediatricpatients diagnosed with cerebellitis for whom neurosurgery was consulted at a single center from June 2008 to February 2019. Nine patients, four males (44.4%) and five females (55.6%) were identified. Common presenting symptoms were headache (n = 6, 66.7%), emesis (n = 5, 55.6%), and altered mental status (n = 4, 44.4%). Six (66.7%) had associated infections. Imaging abnormalities included tonsillar ectopia (n = 8, 88.9%), bilateral cerebellar T2 hyperintensity (n = 6, 66.7%), and obstructive hydrocephalus (n = 6, 66.7%). Management included antibiotics, antivirals, corticosteroids, mannitol, and hypertonic saline. Four (44.4%) required external ventricular drain (EVD) placement for a mean 11 days (SD 6.8, range 4-20) for hydrocephalus; none required additional neurosurgical interventions. Seven patients (77.8%) required ICU care for a mean 11.7 days (SD 14.0 range 1-42). At follow-up (mean 20.8 months, SD 28.7, range 0.6-64.9), two patients (n = 2, 22.2%) recovered completely, and six (66.7%) were functionally dependent (mRS > 2); the most common residual deficit was cognitive impairment (n = 5, 55.6%). Neurosurgical consultation should be considered in pediatric patients with cerebellitis. In our experience, temporary CSF diversion via an EVD is employed nearly half of the time. The presence of hydrocephalus requiring neurosurgical intervention may be a predictor of severe disease and poor outcome.

Resection of cerebellar tumours causes widespread and functionally relevant white matter impairments.

Several diffusion tensor imaging studies reveal that white matter (WM) lesions are common in children suffering from benign cerebellar tumours who are treated with surgery only. The clinical implications of WM alterations that occur as a direct consequence of cerebellar disease have not been thoroughly studied. Here, we analysed structural and diffusion imaging data from cerebellar patients with chronic surgical lesions after resection for benign cerebellar tumours. We aimed to elucidate the impact of focal lesions of the cerebellum on WM integrity across the entire brain, and to investigate whether WM deficits were associated with behavioural impairment in three different motor tasks. Lesion symptom mapping analysis suggested that lesions in critical cerebellar regions were related to deficits in savings during an eyeblink conditioning task, as well as to deficits in motor action timing. Diffusion imaging analysis of cerebellar WM indicated that better behavioural performance was associated with higher fractional anisotropy (FA) in the superior cerebellar peduncle, cerebellum's main outflow path. Moreover, voxel-wise analysis revealed a global pattern of WM deficits in patients within many cerebral WM tracts critical for motor and non-motor function. Finally, we observed a positive correlation between FA and savings within cerebello-thalamo-cortical pathways in patients but not in controls, showing that saving effects partly depend on extracerebellar areas, and may be recruited for compensation. These results confirm that the cerebellum has extended connections with many cerebral areas involved in motor/cognitive functions, and the observed WM changes likely contribute to long-term clinical deficits of posterior fossa tumour survivors.

Rare Case of Hydatid Cyst in the Cerebellopontine Cistern.

Posterior fossa localization of a hydatid cyst is uncommon; in these cases, the cysts usually grow in the cerebellum. Localization within the subarachnoid spaces or the cerebrospinal fluid ventricular system is exceptional. In the present report, which appears to be the sixth in the literature, we describe a case of a hydatid cyst in the cerebellopontine cistern. Magnetic resonance imaging findings revealed a nonneoplastic cystic lesion mimicking an arachnoid cyst. The hydatid nature of the cyst was unexpected preoperatively. The cyst was successfully removed using the puncture, aspiration, irrigation, and resection technique via a retrosigmoid approach. Histopathologic examination confirmed the cysts to be Echinococcus granulosus in nature. Hydatid cyst may be considered in the differential diagnosis of arachnoid cysts of the cerebellopontine cistern to determine which surgical procedure to perform and to avoid unexpected complications.

An Uncommon Case of Neuroenteric Cyst Located at the Lateral Cerebellomedullary Cistern.

We present the case of a 42-year-old woman with a 5-week history of headache, progressive dysphagia, dysphonia, and hoarseness. A brain magnetic resonance imaging revealed an extra-axial cyst of the left lateral cerebellomedullary cistern. The subsequent histopathologic examination diagnosed a neuroenteric cyst. This case sheds light on the pivotal role of histologic identification of neuroenteric cyst, which could be crucial for further diagnostic investigations, especially in pediatric patients.

Orthostatic Enlargement of a Supracerebellar Arachnoid Cyst With Cerebellar Descent Visualized by Upright Computed Tomography.

BACKGROUND: Posterior fossa arachnoid cysts are often asymptomatic, but can rarely cause postural headache, the mechanism of which remains unknown. CASE DESCRIPTION: We present a 40-year-old woman with an asymptomatic supracerebellar arachnoid cyst. Upright computed tomography (CT) showed enlargement of the arachnoid cyst and caudal descent of the cerebellum compared with supine CT with narrowing of the craniocervical junction cerebrospinal fluid space. CONCLUSIONS: This finding aids in understanding the association of posterior fossa arachnoid cysts with orthostatic headache. Clinicians should be aware of possible posture-related changes in intracranial structures.

Cerebellar Necrosectomy Instead of Suboccipital Decompression: A Suitable Alternative for Patients with Space-Occupying Cerebellar Infarction.

OBJECTIVE: Space-occupying cerebellar ischemic strokes (SOCSs) often lead to neurological deterioration and require surgical intervention to release pressure from the posterior fossa. Current guidelines recommend suboccipital decompressive craniectomy (SDC) with dural expansion when medical therapy is not sufficient. However, no good-quality evidence is available to support this surgical practice, and the surgical timing and technique both remain controversial. We have described an alternative to SDC, surgical evacuation of infarcted tissue (necrosectomy) and its clinical outcomes. METHODS: In the present retrospective, single-center study, 34 consecutive patients with SOCS undergoing necrosectomy via osteoplastic craniotomy were included. The patient characteristics and radiological findings were evaluated. To differentiate the effects of age on the functional outcomes, the patients were divided into 2 groups (group I, age ≤60 years; and group II, age >60 years). Functional outcomes were assessed using the Glasgow outcome scale, modified Rankin scale, and Barthel index at discharge and 30 days postoperatively. RESULTS: In our cohort, we observed overall mortality of 21%, with good functional outcomes (Glasgow outcome scale score ≥4) for 76% of the patients. No statistically significant differences in mortality or functional outcomes were observed between the 2 patient groups. Comparing our data with a recent meta-analysis of SDC, the number of adverse events and unfavorable outcome showed equipoise between the 2 treatment modalities. CONCLUSIONS: Necrosectomy appears to be a suitable alternative to SDC for SOCS, achieving comparable mortality and functional outcomes. Further trials are necessary to evaluate which surgical technique is more beneficial in the setting of SOCSs.