Shunt, endoscopic, and microsurgical management of trapped temporal horn following resection of lateral ventricle trigonal or peritrigonal tumors: A retrospective multicenter study.

OBJECTIVE: To investigate the surgical management and outcomes of trapped temporal horn (TTH) following resection of lateral ventricle trigonal or peritrigonal tumors. METHODS: Patients who underwent surgical treatment for TTH in three different tertiary centers between 2012 and 2022 were retrospectively studied. The primary outcome was reoperation rate. RESULTS: Thirty-one patients were included for analysis. The underlying pathology was meningioma in 17 patients, central neurocytoma in 7, glioma in 4, ependymoma in 2, and cavernous malformation in 1. The median KPS score was 50 (range 10-90) and the mean volume of TTH was 53.1 ± 29.9 cm³ (range 14.8-118.6). Six patients (19.3 %) required multiple operations. A total of 39 procedures were performed, including 28 CSF shunting, 2 endoscopic septostomy, 3 microsurgical fenestration or temporal tip lobectomy via craniotomy, 2 decompressive craniectomy (DC), and 4 shunt revisions. Reoperation rates according to procedure were as follows: 10.7 % (3/28) for CSF shunting, 50 % (1/2) for endoscopic septostomy, 100 % (2/2) for DC, and 0 (0/3) for microsurgical fenestration or temporal tip lobectomy. CSF shunting tended to have a lower reoperation rate compared to other surgical approaches (p = 0.079). The reoperation rate was significantly higher for DC than for other surgical techniques (p = 0.025). CONCLUSION: CSF shunting was the most frequently used technique with a relatively low revision rate. Long-term patency can be achieved through endoscopic septostomy in selected patients. Microsurgical fenestration or temporal tip lobectomy should be reserved for refractory cases. DC has limited effectiveness and should not be recommended.

Management of entrapped temporal horn: Literature review and operative technique for endoscopic fenestration.

CONTEXT: Entrapment of the temporal horn (TH) is rare condition that can lead to increased intracranial pressure, but there is no consensus on a standard treatment. The aim of this study was to conduct a systematic literature review of the reported cases of TH entrapment and describe our operative technique for endoscopic fenestrations of the lateral ventricle into the basal cisterns. METHODS: We searched the databases Pubmed and Google scholar to find all studies reporting cases of entrapped TH and the subsequent treatment. Additionally, we report two illustrative cases of endoscopic fenestration with a step-by-step description of our surgical technique. RESULTS: Twenty-nine studies with a total of 67 patients were included in the analysis. The mean age was 36.5 years (SD± 21.9), and the female-to-male ratio was 1.5. The most frequent cause of TH entrapment was post-surgical scarring after tumor surgery (n= 30), and the most commonly reported treatment modality was endoscopic fenestration of the TH (n = 14). We observed an increasing use of endoscopic fenestration over time. CONCLUSION: Entrapped TH is a rare condition often requiring surgical treatment. Neuronavigation-guided endoscopic fenestration of the ventricle into the basal cisterns appears to be a safe, efficient, and device-free technique that has gained importance over the past years.

Intraventricular Shunt as a Treatment for Entrapped Temporal Horn After Removal of Ventricular Meningioma: A Report of Two Cases.

Entrapped temporal horn (ETH) is a complication following resection of ventricular trigone tumors. It is a special localized hydrocephalus. Obstruction of cerebrospinal fluid outflow following resection of ventricular trigone tumors leads to dilation of the temporal horn and the production of the local space-occupying effect. This article presents two cases of ETH following the resection of ventricular trigone tumors. Our Intraventricular shunt is an effective treatment that uses a T-connector to connect a reservoir with two catheters. We presented temporal-frontal horn shunt and trigone-front horn shunt. A patient presented with ETH shunt dependency. Our intraventricular shunt surgery achieved a good prognosis.

Trapped temporal horn: From theory to practice, a systematic review of current understanding and future perspectives.

Background: The Entrapped Temporal Horn (ETH) is characterized by localized enlargement of the temporal horn of the lateral ventricle of the brain. This study aimed to investigate the factors, development, prognosis, and effective treatment. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic search was conducted in major research databases. The inclusion criteria included patients of all ages with TTH diagnosis in cohort studies, case series, and case reports. Results: Our study included 160 patients and 49 studies. The major causes of TTH were neoplastic lesions (42.3%), infections (22.3%), and cystic disease (13.08%). Of these cases, 71 were unrelated to cranial surgery, while 89 were unrelated to prior surgeries. Headache was the most common symptom (41.91%), followed by seizures (13.20%), drowsiness (12.50%) and memory loss (11.00%). Surgery was not required in 17 patients. Fenestration of the trapped temporal horn was performed in 24 patients, while VP/VA shunt surgeries were performed in the majority (57 patients) owing to favorable outcomes, lower revision rates, and extensive experience. However, TTH recurred in six of the 21 patients who underwent endoscopic ventriculocisternostomy. Tumors were the main cause, and isolated headache was the most frequent symptom. Ventriculoperitoneal shunts (VPS) are preferred because of their positive outcomes, lower revision rates, and wider expertise. Tumors near the trigonal area pose a higher risk. Conclusion: Although TTH remains a rare condition, VPS continues to be the most widely preferred procedure among surgeons.

Comparison of temporal-to-frontal horn shunt and ventriculo-peritoneal shunt for treatment of trapped temporal horn: a retrospective cohort study.

As a localized hydrocephalus, trapped temporal horn (TTH) can be effectively resolved via cerebrospinal fluid shunting. In addition to conventional ventriculo-peritoneal shunt (VPS), temporal-to-frontal horn shunt (TFHS) has been described as a less complex and invasive procedure with promising results; however, there is limited data comparing VPS to TFHS regarding patient outcomes. This study aims to compare TFHS versus VPS for treatment of TTH. We conducted a comparative cohort study with patients undergoing TFHS or VPS for TTH after surgery of trigonal or peritrigonal tumors between 2012 and 2021. The primary outcome was revision rates at 30-day, 6-month, and 1-year. Secondary outcomes included operative duration, postoperative pain, hospital stay, overdrainage, and cost for shunt placement and revision. A total of 24 patients included, with 13 (54.2%) patients receiving TFHS and 11 (45.8%) receiving VPS. Both cohorts shared similar baseline characteristics. There were no significant differences between TFHS and VPS in 30-day (7.7% vs 9.1%, p > 0.99), 6-month (7.7% vs 18.2%, p = 0.576), or 1-year (8.3% vs 18.2%, p = 0.590) revision rates. There were no significant differences in terms of operative duration (93.5 ± 24.1 vs 90.5 ± 29.6 min, p = 0.744), surgical site pain (0 vs 18.2%, p = 0.199), or postoperative length of stay (4.8 ± 2.6 vs 6.9 ± 4.0 days, p = 0.157) between the two groups. For the TFHS cohort, no patient experienced shunt related overdrainage, and there was a trend towards fewer overdrainage (0% vs 27.3%, p = 0.082) compared with VPS. TFHS offered significant reduction in cost for initial shunt (¥20,417 vs ¥33,314, p = 0.030) and total costs for shunt and revision (¥21,602 vs ¥43,196, p = 0.006) compared to VPS. As a technique of valveless shunt and without abdominal incision, TFHS is cosmetic, cost-effective, and completely free of overdrainage with similar revision rates as compared with VPS.

Trigone ventricular glioblastoma multiforme with trapped temporal horn: A case report.

Background: Intraventricular glioblastoma multiforme (GBM) is extremely rare, especially in the trigone region. This report presents a case of trigone ventricular GBM with trapped temporal horn (TTH). Case presentation: A 59-year-old woman was admitted to our department with a 1-month history of rapidly progressive headache, nausea, and weakness in the right lower extremity. Head non-contrast computed tomography and enhanced magnetic resonance imaging (MRI) revealed a trigone ventricular mass lesion with TTH and heterogeneous enhancement. The lesion was found 18 months ago as a small asymptomatic tumor mimicking ependymoma. This neoplasm was removed subtotally through the right parieto-occipital approach guided by neuroendoscopy. A ventriculoperitoneal shunt was subsequently performed to relieve TTH. The final pathological diagnosis was GBM. Unfortunately, 36 days after the first surgery, the patient died due to her family's decision to refuse therapy. Conclusion: This rare case shows that GBM should be considered in the differential diagnosis of trigonal tumors. In this case, the tumor possibly originated from the neural stem cells in the subventricular zone. Patients with intraventricular GBM have a worse prognosis, and careful follow-up and early surgery for small intraventricular tumors are necessary, even for those with ependymoma-like radiological findings.

Prophylactic Intraventricular Piping Method Prevents Entrapped Temporal Horn After Removal of Ventricle Trigone Meningioma: Technical Note.

BACKGROUND: An entrapped temporal horn (ETH) is one of the critical complications after tumor removal in the lateral ventricle trigone that sometimes becomes life threatening. OBJECTIVE: We sought to develop a novel intraoperative method of prophylactic intraventricular piping (PIP) just after tumor removal to prevent ETH. METHODS: Three patients with meningiomas in the lateral ventricle trigone were treated by a novel intraoperative method of PIP just after tumor removal to prevent ETH. Silicone catheters normally used as ventricular drainage catheters were cut to 5- to 6-cm length and inserted into the tumor cavity to ensure communication between the temporal horn and the atrium or the body of the lateral ventricle through the piping straddling the trigone. RESULTS: None of our patients developed ETH during the follow-up period without complications caused by the tube placement. CONCLUSIONS: PIP might be beneficial to prevent ETH because constant osmotic pressure and constant cerebrospinal fluid pulse wave transmission are maintained between each compartment of the lateral ventricle.

Risk Factors for and Outcomes of Postoperative Entrapped Temporal Horn in Trigone Meningiomas.

Background: Meningioma in the ventricle triangle area is a benign tumor that can be cured by surgery, but postoperative entrapped temporal horn may seriously affect the patient's quality of life and even require a second operation. Currently, there are few reports on this complication. Objective: The risk factors and prognosis of postoperative ETH in trigone meningiomas were investigated. Material and Methods: A retrospective analysis of the clinical data of 87 patients with trigone meningioma from 2010 to 2018 was performed, and univariate and multivariate analyses were used to assess the risk factors associated with postoperative ETH. The degree of ETH was evaluated using the modified ventriculocranial ratio. Results: The incidence of postoperative ETH in trigone meningioma was 29.9% (26/87). Preoperative ETH [odds ratio (OR): 4.826, 95% confidence interval (CI): 1.820-12.796, P = 0.002] and postoperative meningitis (OR: 12.811, 95%CI: 1.615-101.605, P = 0.016) are independent risk factors for postoperative ETH. Of the 18 patients with ETH syndrome, 12 improved after medical treatment, and finally, a total of 6 patients received ETH surgery. The mean duration from tumor resection to the appearance of ETH syndrome was 3.1 ± 1.9 months (range: 9 days-7 months). Patients with ETH grade II and III are more prone to clinical symptoms. Conclusions: : The incidence of postoperative ETH for trigone meningiomas is high, and clinical symptoms generally appear delayed after surgery. Reducing postoperative infections can reduce the occurrence of postoperative ETH. Patients with symptoms of ETH who have failed medical treatment have clear indications for surgery.

Temporal Horn Enlargements Predict Secondary Hydrocephalus Diagnosis Earlier than Evans' Index.

The aim of this study was to identify early radiological signs of secondary hydrocephalus. We retrieved neuroradiological data from scans performed at various times in patients who underwent surgery for secondary hydrocephalus due to severe traumatic brain injury (TBI), subarachnoid haemorrhage (SAH), or brain tumour (BT). Baseline measurements, performed on the earliest images acquired after the neurological event (T0), included Evans' index, the distance between frontal horns, and the widths of both temporal horns. The next neuroimage that showed an increase in at least one of these four parameters­and that lead the surgeon to act­was selected as an indication of ventricular enlargement (T1). Comparisons of T0 and T1 neuroimages showed increases in Evans' index, in the mean frontal horn distance, and in the mean right and left temporal horn widths. Interestingly, in T1 scans, mean Evans' index scores > 0.30 were only observed in patients with BT. However, the temporal horn widths increased up to ten-fold in most patients, independent of Evans' index scores. In conclusion temporal horn enlargements were the earliest, most sensitive findings in predicting ventricular enlargement secondary to TBI, SAH, or BT. To anticipate a secondary hydrocephalus radiological diagnosis, clinicians should measure both Evans' index and the temporal horn widths, to avoid severe disability and poor outcome related to temporal lobe damage.

The Presence of the Temporal Horn Exacerbates the Vulnerability of Hippocampus During Head Impacts.

Hippocampal injury is common in traumatic brain injury (TBI) patients, but the underlying pathogenesis remains elusive. In this study, we hypothesize that the presence of the adjacent fluid-containing temporal horn exacerbates the biomechanical vulnerability of the hippocampus. Two finite element models of the human head were used to investigate this hypothesis, one with and one without the temporal horn, and both including a detailed hippocampal subfield delineation. A fluid-structure interaction coupling approach was used to simulate the brain-ventricle interface, in which the intraventricular cerebrospinal fluid was represented by an arbitrary Lagrangian-Eulerian multi-material formation to account for its fluid behavior. By comparing the response of these two models under identical loadings, the model that included the temporal horn predicted increased magnitudes of strain and strain rate in the hippocampus with respect to its counterpart without the temporal horn. This specifically affected cornu ammonis (CA) 1 (CA1), CA2/3, hippocampal tail, subiculum, and the adjacent amygdala and ventral diencephalon. These computational results suggest that the presence of the temporal horn exacerbate the vulnerability of the hippocampus, highlighting the mechanobiological dependency of the hippocampus on the temporal horn.

A novel endoscopic ventriculocisternostomy and stenting technique with a transparent acryl puncture needle for a trapped temporal horn: a technical report and literature review.

Trapped temporal horn is a rare type of noncommunicating focal hydrocephalus, and no standard treatment has been established yet for trapped temporal horn. Recent studies have shown the efficacy of endoscopic ventriculocisternostomy by opening the choroidal fissure; however, some surgical complications were reported during the procedure. Thus, we aimed to report a novel endoscopic ventriculocisternostomy and stenting technique for trapped temporal horn. In this technique, a 5.8-mm transparent acryl puncture needle with a 2.7-mm 0° rigid endoscope was used to open the choroidal fissure. It can fenestrate the choroidal fissure under real-time endoscopic observation of the critical neurovascular structures over the choroidal fissure. Moreover, the dull tip of the needle is less likely to injure the critical neurovascular structures, resulting in safer ventriculocisternostomy than the previously reported technique. Then, a stent is placed along the tract to prevent future obstruction of the stoma. Six trapped temporal horns in four patients were treated using the technique. All the patients showed improved symptoms with no surgical complications. None of the patients showed recurrence of trapped temporal horn during the mean follow-up period of 39.3 months. The combination of endoscopic ventriculocisternostomy and stenting with a transparent acryl puncture needle is a safe and effective treatment option for trapped temporal horn.

Refined Temporal-to-Frontal Horn Shunt for Treatment of Trapped Temporal Horn After Surgery of Peri- or Intraventricular Tumor: A Case Series Study.

BACKGROUND: Trapped temporal horn (TTH) is a localized hydrocephalus that can be treated with cerebrospinal fluid diversion. Refined temporal-to-frontal horn shunt (RTFHS) through the parieto-occipital approach is rarely reported in the literature and its effectiveness remains unclear. The aim of the present study is to investigate the efficacy and outcome of RTFHS for treatment of TTH. MATERIALS AND METHODS: We consecutively enrolled 10 patients who underwent RTFHS for TTH after surgical resection of peri- or intraventricular tumors from February 2018 to March 2021. Clinical, radiological, and follow-up data were collected and analyzed. The most common underlying pathology was meningioma (n=4), followed by central neurocytoma (n=3), thalamic glioblastoma (n=2), and anaplastic ependymoma (n=1). RESULTS: The mean Karnofsky performance scale (KPS) score and TTH volume at onset were 54.0 ± 15.1 (range 40-80) and 71.3 ± 33.2cm3 (range 31.7-118.6cm3), respectively. All patients (10/10, 100.0%) presented with periventricular brain edema (PVBE), while midline shift was observed in 9 patients (9/10, 90.0%). RTFHSs were implanted using valveless shunting catheters. No patients developed acute intracranial hemorrhage or new neurological deficit postoperatively. During the follow-up of 17.2 ± 13.7 months (range 3-39 months), all patients showed clinical and radiological improvement. The mean KPS score at the last follow-up was significantly increased to 88.0 ± 10.3 (range 70-100, p<0.0001). RTFHS resulted in significant complete remission in PVBE and midline shift in 8 (80.0%, p=0.0007) and 9 (100.0%, p=0.0001) patients, respectively. As the postoperative follow-up duration prolonged, the mean TTH volume decreased in a consistent, linear trend (p<0.0001). At last follow-up, the mean TTH volume was significantly reduced to 15.4 ± 11.5 cm3 (range 5.6-44.1 cm3, p=0.0003), resulting in a mean relative reduction of 77.2 ± 13.1% compared with the volume of TTH at onset. Over drainage was not observed during the follow-up. No patient suffered from proximal or distal shunt obstruction or shunt related infection, and the revision rate was 0%. CONCLUSION: RTFHS seems to be safe and effective for the treatment of TTH with favorable outcomes. Advantages of this technique could be technically less complex and invasive, cost-effective, avoidance of various intraperitoneal complications, and maintaining a near-physiological CSF pathway.

Can Medial Temporal Impairment Be an Imaging Red Flag for Neurodegeneration in Disproportionately Enlarged Subarachnoid Space Hydrocephalus?

BACKGROUND: The differentiation of idiopathic normal pressure hydrocephalus (iNPH) from neurodegenerative diseases such as Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) is often challenging because of their non-specific symptoms. Therefore, various neuroradiological markers other than ventriculomegaly have been proposed. Despite the utility of disproportionately enlarged subarachnoid-space hydrocephalus (DESH) for the appropriate selection of shunt surgery candidates, the specificity and neuropathology of this finding have not been sufficiently evaluated. OBJECTIVE: Investigation of the clinicopathological features and comparison of the neuroradiological findings between DESH with postmortem neuropathological diagnoses (pDESH) and clinically-diagnosed iNPH (ciNPH) patients are the main purposes of this study. METHOD: In addition to the retrospective evaluation of clinicopathological information, quantitative, semiquantitative, and qualitative magnetic resonance imaging (MRI) indices were compared between pathologically-investigated 10 patients with pDESH and 10 patients with ciNPHResults:Excluding one patient with multiple cerebral infarctions, the postmortem neuropathological diagnoses of the pathologically-investigated patients were mainly neurodegenerative diseases (five AD, one DLB with AD pathologies, one DLB, one argyrophilic grain disease, and one Huntington's disease). In addition to the common neuroradiological featuresConclusion:Hippocampal atrophy and deformation with temporal horn enlargement seem to be characteristic neuroradiological findings of long-standing severely demented patients with DESH and neurodegenerative diseases, mainly advanced-stage AD.

Intraoperative Temporal Horn Ventriculostomy for Brain Relaxation During Aneurysm Surgeries in Pterional Approaches.

BACKGROUND: Achieving optimal brain relaxation is paramount in aneurysm surgery. Despite proper positioning and the use of newer anesthetic drugs and the administration of decongestants, it is often not possible to achieve satisfactory relaxation, which can lead to neurological deficits owing to excessive brain retraction. The present study aimed to provide detailed surgical notes regarding the novel technique of temporal horn tapping for intraoperative ventriculostomy. METHODS: The hospital records of anterior circulation aneurysm surgery performed during the previous 5 years were retrieved. Only those cases in which we had used temporal horn tapping were included. Ventriculostomy was performed only in those cases in which the brain was tense despite the administration of decongestants. A small corticectomy was performed over the middle temporal gyrus and deepened to access the temporal horn. RESULTS: This technique was used in 84 surgical cases. The mean patient age was 52.8 years. The male/female ratio was 1:1.4. Anterior communicating artery aneurysms were the most common. Adequate brain relaxation was satisfactorily achieved in all cases. Two patients had developed a small temporal hematoma attributable to the temporal corticectomy, both managed conservatively. CONCLUSIONS: We believe that this new trajectory through the middle temporal gyrus to access the temporal horn is very safe because of the lack of proximity to any blood vessel or critical structures. We recommend the use of this technique during pterional approaches for acute aneurysmal surgery in the tight, bulging brain to achieve relaxation and avoid secondary complications such as retraction contusions and resultant cerebral edema.

Postoperative delayed trapped temporal horn in patients with lateral ventricular trigone meningioma: Risk factors, surgical management, and literature review.

OBJECT: To assess the risk factors for and surgical treatment of delayed trapped temporal horn (dTTH) in patients who had undergone removal of lateral ventricular trigone meningioma. METHOD: Patients with lateral ventricular trigone meningioma treated at our institution from 2011 to 2015 were identified. Predictors for dTTH were determined using logistic regression. Literature review and pooled analysis were also conducted to evaluate the comparative effectiveness of surgical treatment for dTTH. RESULTS: A total of 110 cases were included in the analysis. Thirteen (11.8%) cases developed dTTH following surgery. Multivariable logistic regression demonstrated an association of longer operative duration with higher incidence of dTTH (OR, 1.34; 95% CI, 1.00-1.80; p = 0.049). As surgical duration prolonged from less than 3 hours to 5 hours or more, the incidence of dTTH increased in a consistent, linear fashion from 7.7% to 13.9% (p = 0.03). Six cases (46.2%, 6/13) of dTTH underwent surgical treatment for their life-threatening symptoms. Seven studies including 13 cases of dTTH in the literature were identified. Literature data, including the current series, revealed a total of 24 procedures were performed in 19 cases. Endoscopic fenestration trended toward fewer complications than shunt (7.7% vs 25.0%, p = 0.530). There were no significant differences in failure rates between the two groups (23.1% vs 25.0%, p = 1.000). CONCLUSION: Patients with prolonged operative duration may be at higher risk of dTTH. Endoscopic fenestration is considered in preference to shunt placement, since it possesses equivalent success rates with fewer complications and avoids the need for a permanent implant.

Zygomatic-Meatal Perpendicular Projection Lines: Bony Landmarks for Early Identification of the Temporal Horn of the Lateral Ventricle.

OBJECTIVE: Localization of the temporal horn of the lateral ventricle (TH) may be required during temporal lobe and ambient cistern surgery. Most available anatomic landmarks for TH localization are based on adjacent cortical landmarks that are inherently variable or subtle. This study aimed to localize the anterior tip of the TH relative to adjacent bony landmarks. METHODS: The TH was exposed on 21 sides of 11 cadaveric heads via removal of the middle temporal gyrus. Two lines were defined: (1) a perpendicular line to the zygomatic arch projected from the anterior concavity of the posterior zygomatic root (line A), and (2) a parallel line passing through the anterosuperior corner of the external auditory canal (line B). Sagittal distances from lines A and B to a parallel line passing through the anterior recess of the TH (line H) were measured. RESULTS: Mean (standard deviation) distances from lines A and B to line H were 13.3 (2.5) mm and 11.9 (2.2) mm, respectively. Line H was at 53% (8%) of the line A-line B interval measured from line A. The best way to search for the TH was to start approximately 15 mm posterior to line A and progress posteriorly such that a more posteriorly located TH tip would not be missed. CONCLUSIONS: The zygomatic-meatal landmark is a reliable tool to localize TH during various approaches. It is independent from the approach trajectory. This landmark may be used as an ancillary tool in conjunction with other cortical landmarks and image guidance.

Application of Sonography in the Diagnosis and Follow-Up of Trapped Temporal Horn of Lateral Ventricle: Two Case Reports.

Trapped temporal horn of lateral ventricle (TTHLV) is a rare condition of isolated focal hydrocephalus. We report two cases with different presentations, etiologies, and surgical managements. The first case involved an extremely preterm male baby with a history of ventriculitis and intraventricular hemorrhage; he received external ventricle drainage twice due to obstructive hydrocephalus. TTHLV was detected by sonography. He received a ventriculoperitoneal shunt involving two catheters to bypass the adhesion site. There was no ventricular dilatation during 2 years of follow-up. The second case involved a term baby with an enlarged head; brain sonography revealed left focal hydrocephalus with TTHLV and mild midline shift. Neuroendoscopic cystoventriculostomy with fenestration from the left trigone to the frontal horn was performed and serial follow-up brain sonography for 3 months showed decreased ventricle size. The suitable surgical techniques for the management of TTHLV should be adjusted according to the patients' condition to obtain more favorable outcomes. Brain sonography can be a useful tool for the diagnosis and for following up the surgical outcomes in infants with TTHLV.

Entrapment of the temporal horn secondary to postoperative gamma-knife radiosurgery in intraventricular meningioma: A case report.

BACKGROUND: Entrapment of the temporal horn (ETH) is a rare pathologic condition. It is a kind of focal hydrocephalus caused by obstruction of flow pathway of cerebrospinal fluid. It is caused by various conditions, but ETH secondary to postoperative gamma-knife radiosurgery (GKS) is extremely rare. CASE SUMMARY: A 52-year old previously healthy woman underwent resection of a large intraventricular meningioma. A small fragment of residual tumor with no obvious enlargement of the temporal horn was observed 3 mo after surgery, and she was referred for GKS. Two months after GKS, she complained of headache and progressive paralysis of the left limb. Magnetic resonance imaging revealed enlargement of the temporal horn. There was a second procedure to resect the residual tumor 8 mo after GKS. After the second procedure, she recovered smoothly. As of the date of this writing, she has remained in good condition. CONCLUSION: This case reminds us that ETH should be considered in the treatment of intraventricular meningiomas, especially before GKS.

Temporal Horn Choroid Plexus Papilloma Presenting with Seizures in Adulthood: Clinical Case Report and Review of the Literature.

BACKGROUND: Choroid plexus papillomas (CPPs) are benign World Health Organization grade I tumors that comprise 2%-4% of all brain tumors among children and less than 1% of brain tumors in adults. Most adult cases occur in the fourth ventricle, with only 1 previous report describing an adult patient with a temporal horn CPP. CASE DESCRIPTION: We report a rare case of a temporal horn CPP presenting in an adult with seizures. We performed a minimally invasive subtemporal approach for gross total resection of the lesion. CONCLUSIONS: CPP presenting in the temporal horn is rare among adults. We discuss the surgical nuances of the subtemporal approach for resection and review the literature regarding adult presentation of CPP and the treatment strategies for adult CPP.

Utility of Radiologic Variables to Predict the Result of Lumbar Infusion Test in the Diagnosis of Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Diagnosis of idiopathic normal pressure hydrocephalus is based in clinical data, radiologic variables, and invasive cerebrospinal fluid (CSF) testing, such as the lumbar infusion test. Several neuroimaging findings are inconclusively related to improvement after CSF shunt surgery. CSF tests are invasive and have complications. The aim of this study was to select radiologic variables related to a positive lumbar infusion test so as to avoid this test in patients. METHODS: Patients with possible idiopathic normal pressure hydrocephalus were reviewed. The collected radiologic data were cingulate sulcus sign, disproportionately enlarged subarachnoid space, callosal angle, and width of temporal horns. Two groups were established: group 1, comprising patients with resistance to CSF outflow <12 mm Hg/mL/minute, and group 2, comprising patients with resistance to CSF outflow >12 mm Hg/mL/minute. Negative and positive predictive values were determined. RESULTS: The study included 43 patients in group 1 and 64 patients in group 2. Group 2 significantly showed more acute callosal angle with higher accuracy cutoff value of 90.6°, lower width of temporal horns with higher accuracy cutoff value of 8 mm, and higher percentage of cingulate sulcus sign and disproportionately enlarged subarachnoid space. Matching the radiologic variables, positive predictive values were >80%; however, negative predictive values were low. CONCLUSIONS: Owing to high positive predictive values of matched radiological variables, the lumbar infusion test could be avoided in the diagnosis of idiopathic normal pressure hydrocephalus. However, when 1 or 2 of the variables are negative, this invasive test should be performed.