Harvey Cushing's early management of hydrocephalus: An historical picture of the conundrum of hydrocephalus until modern shunts after WWII

Purpose

Throughout his early career, Cushing proposed a variety of methods for temporary and permanent drainage and diversion of CSF in his patients, and acknowledged that certain techniques were more suited to particular subsets of hydrocephalus.

Methods

Following IRB approval, and through the courtesy of the Alan Mason Chesney Archives, the surgical records of the Johns Hopkins Hospital, from 1896 to 1912, were reviewed. Patients operated upon by Harvey Cushing were selected for further analysis. Within this cohort, we recovered all available records for a single patient with hydrocephalus and spina bifida, who was treated with a ventriculosubgaleal shunt prior to repair of the spina bifida.

Results

A 3 month-old infant presented with hydrocephalus associated with spina bifida. Cushing performed serial lumbar and ventricular punctures. Following this, Cushing took the patient to the operating room for placement of a ventriculosubgaleal shunt. The patient subsequently underwent excision of the myelomeningocele sac, with post-operative mortality due to unspecified causes.

Conclusions

Cushing's publications document a preference for translumbar-peritoneal drainage in patients with congenital hydrocephalus, particularly those with spina bifida. Although the placement of ventriculosubgaleal shunts has become an accepted practice for contemporary neurosurgeons, this case illustrates the challenges that early neurosurgeons faced in developing operative approaches for the treatment of congenital hydrocephalus.     

Treatment of traumatic acute subdural hematoma in adult hydrocephalus patients with cerebrospinal fluid shunt

Objective

The presence of a cerebrospinal fluid (CSF) shunt is a predisposing factor for the development of subdural hematoma (SDH) in patients with hydrocephalus. However, few reports have addressed how patients with a CSF shunt should be treated in the event of traumatic acute SDH. The purpose of this study was to show how post-traumatic management of CSF shunt affects acute SDH in adult patients with hydrocephalus.

Methods

Twelve patients were studied retrospectively. Pressure settings of shunt valve prior to head injury (HI), severity of HI, treatment on admission, changes in SDH thickness and subsequent hydrocephalus were mainly analyzed.

Results

Ten patients experienced mild HI, with nine showing neurological deterioration until admission. Five patients needed surgical hematoma removal soon after admission. SDH recurred in four cases where shunt pressure levels were kept relatively low. Shunt ligation or raising the pressure level in the programmable valve proved effective for controlling postoperative SDH in such cases. Six of the remaining seven patients underwent only shunt ligation or readjustment of pressure level in the programmable valve on admission. SDH thickness was reduced as ventricles dilated without major neurological complications. Four patients showed delayed development of SDH even though shunts were kept ligated.

Conclusions

Hematoma removal alone may result in hematoma recurrence and require a second treatment comprising shunt management to effectively control hematoma. Using shunt management as the only initial treatment can reduce hematoma volume, but some patients may suffer delayed SDH development and require surgery.     

The microsurgical treatment of cranio-orbital tumors assisted by intraoperative electrophysiologic monitoring and neuronavigation

Objective

Total resection of cranio-orbital tumors without any major complications is still a challenge for neurosurgeons. Intraoperative electrophysiologic monitoring and neuronavigational system have been widely used in microneurosurgery, but their effects during microsurgical treatment of cranio-orbital tumors warrant further investigation.

Methods

Thirty-eight patients with cranio-orbital tumors admitted to our hospital underwent microsurgery assisted by intraoperative electrophysiologic monitoring. We also simultaneously performed intraoperative neuronavigation in 20 patients. A retrospective review of clinical notes, operation records and prognoses of all patients was performed.

Results

Gross total resection was achieved in 29 patients (76%), near total resection in 5 (13%), subtotal resection in 3 (8%) and partial resection in 1 (3%). With the helps of electromyogram (EMG) monitoring of levator palpebrae superioris (LPS) muscle and navigation system, no surgical damages to the oculomotor nerve and other important structures occurred. A follow-up study showed that 31 patients (82%) resumed normal lives (Glasgow Outcome Scale (GOS) score 5), 5 patients (13%) had independent lives (GOS score 4), and 2 patients (5%) were unable to live independently (GOS score 3).

Conclusion

Microsurgical treatment assisted by intraoperative electrophysiologic monitoring and neuronavigation might be a useful method for resection of cranio-orbital tumors, especially better for protection of the important cranial nerve and structure in the kull base.     

Medial posterior choroidal artery territory infarction associated with tumor removal in the pineal/tectum/thalamus region through the occipital transtentorial approach

Object

Damage to the deep venous system, occipital lobe, and/or corpus callosum is well known to cause complications associated with the occipital transtentorial approach (OTA), but ischemic complications are not well documented. The authors investigated the high incidences of ischemic complications associated with removal of pineal/tectal/thalamic tumors through the OTA.

Methods

Clinical records of 29 patients who underwent 31 surgeries using the OTA from December 2001 to May 2011 were retrospectively studied. Tumor locations were the pineal/tectal/thalamic region for 19, cerebellum for 7, and medial temporal lobe for 3.

Results

Postoperative diffusion-weighted magnetic resonance images obtained within 72 h after surgery detected infarction in the tectal/splenial/thalamic region, presumably representing the medial posterior choroidal artery (MPChA) territory, in 10 patients. All these patients had tumor in the pineal/tectal/thalamic region. Deteriorated or newly developed eye symptoms including vertical gaze palsy tended to persist in these patients compared to those without ischemic complications.

Conclusions

A relatively high incidence of MPChA territory infarction was associated with removal of tumors in the pineal/tectal/thalamic region through the OTA. Eye symptoms often occurred post-surgery and tended to persist in these patients. Neurosurgeons must be aware of the possibility of MPChA territory infarction to further increase the safety of the OTA.     

Role of shunts with antisiphon device in treatment of pediatric hydrocephalus

Objective

The use of ventriculo-peritoneal shunts having antisiphon device has been reported in adult patients, but there is a dearth of experience with such shunts in pediatric age group. This study is being undertaken to compare the effectiveness of these types of shunt for the treatment of congenital hydrocephalus.

Patients and methods

Forty patients with congenital hydrocephalus with or without neural tube were divided randomly into two groups (A and B). Patients in antisiphon group were treated with shunts with differential valve including antisiphon device (Vygon^® shunt) while patients in non-antisiphon group were treated with differential valve shunts (Chhabra shunt and Ceredrain^®). Mann–Whitney test, asymmetric t-test and Chi-square test were used to assess the correlation and the significance.

Results

The mean age was 3.5 months and 3.4 months in antisiphon group and non-antisiphon group, respectively. The M:F ratio was 2.3:1 in antisiphon group while it was 3:1 in non-antisiphon group. The mean decrease in OFC was more in non-antisiphon group than antisiphon group during the follow up from 3 months to 6 months while mean decrease in MEI was more in non-antisiphon group from 0 month to 3 months than antisiphon group. There were two cases of shunt overdrainage in non-antisiphon group. The shunt blockage rate was 20% in antisiphon group and 15% in non-antisiphon group, respectively. There was 20% and 15% shunt infection rate in antisiphon group and non-antisiphon group, respectively. This study demonstrated overdrainage syndrome in two of the patients of differential valve shunts.

Conclusion

Though rare, complication associated with overdrainage is certainly a problem in children. In our study, the patients who received shunts with antisiphon device do not show any overdrainage.     

The neuropsychology of iNPH: findings and evaluation of tests in the European multicentre study

Objective

Neuropsychological dysfunction is common in patients with idiopathic normal pressure hydrocephalus (iNPH). Shunt treatment is beneficial, some patients reaching complete or almost complete recovery, while others show only minor improvement. We aimed to assess the efficacy of a small selection of well characterized and sensitive neuropsychological tests in the context of the European multicentre study on iNPH (Eu-INPH).

Methods

One hundred and forty-two iNPH patients included in Eu-iNPH were tested with the Rey Auditory Verbal Learning Test (RAVLT), the Grooved Pegboard and the Stroop test before and after three and twelve months of treatment with a ventriculoperitoneal shunt. Their performance was compared to that of 108 healthy individuals (HI).

Results

INPH patients performed significantly worse than HI on all of the neuropsychological measures at entry. The discriminative capacities of the eight variables were similar, with areas under the curve (AUC; ROC analysis) ranging between .86 (Delayed Recall) and .95 (Grooved Pegboard). The most usable test was RAVLT (Learning and Delayed Recall), administered to ≥90% of the patients at all occasions. However, the Grooved Pegboard and the Stroop test were more sensitive to treatment effects.

Conclusion

The three neuropsychological tests used in the Eu-iNPH are expedient, highly diagnostically discriminative, and well suited to evaluate changes following shunt treatment.     

Endoscopy in the management of intra-ventricular lesions: Preliminary experience in the Middle East

Objectives

The study is aimed at evaluating neuroendoscopic procedures in the management of various intra-cranial intra-ventricular lesions.

Methods

We retrospectively review 24 consecutive patients harboring various intra-ventricular lesions with or without associated hydrocephalus, operated and managed by the authors between December 2002 and December 2007. Depending on the preoperative imaging and working diagnosis, endoscopic biopsy or endoscopic resection/debulking, along with concomitant treatment of hydrocephalus via third ventriculostomy or fenestration of the septum pellucidum and ventriculo-peritoneal shunting, were done.

Results

The single endoscopic procedure was successful in most of the patients (22/24), where the goals of surgery in attaining a diagnostic biopsy or resection, and simultaneous treatment of hydrocephalus, were attained helping guide further therapy. The endoscopic procedure was the only procedure needed in most of the patients.

Conclusions

The endoscopic procedures carried a high success rate in the management of intra-ventricular lesions, and were especially valuable in patients harboring chemo and/or radiosensitive deep seated tumors.     

A Retrospective Analysis of Ventriculoperitoneal Shunt Revision Cases of a Single Institute

Objective

Ventriculoperitoneal (VP) shunt complication is a major obstacle in the management of hydrocephalus. To study the differences of VP shunt complications between children and adults, we analyzed shunt revision surgery performed at our hospital during the past 10 years.

Methods

Patients who had undergone shunt revision surgery from January 2001 to December 2010 were evaluated retrospectively by chart review about age distribution, etiology of hydrocephalus, and causes of revision. Patients were grouped into below and above 20 years old.

Results

Among 528 cases of VP shunt surgery performed in our hospital over 10 years, 146 (27.7%) were revision surgery. Infection and obstruction were the most common causes of revision. Fifty-one patients were operated on within 1 month after original VP shunt surgery. Thirty-six of 46 infection cases were operated before 6 months after the initial VP shunt. Incidence of shunt catheter fracture was higher in younger patients compared to older. Two of 8 fractured catheters in the younger group were due to calcification and degradation of shunt catheters with fibrous adhesion to surrounding tissue.

Conclusion

The complications of VP shunts were different between children and adults. The incidence of shunt catheter fracture was higher in younger patients. Degradation of shunt catheter associated with surrounding tissue calcification could be one of the reasons of the difference in facture rates.     

Predisposing Factors Related to Shunt-Dependent Chronic Hydrocephalus after Aneurysmal Subarachnoid Hemorrhage

Objective

Hydrocephalus is a common sequelae of aneurysmal subarachnoid hemorrhage (SAH) and patients who develop hydrocephalus after SAH typically have a worse prognosis than those who do not. This study was designed to identify factors predictive of shunt-dependent chronic hydrocephalus among patients with aneurysmal SAH, and patients who require permanent cerebrospinal fluid diversion.

Methods

Seven-hundred-and-thirty-four patients with aneurysmal SAH who were treated surgically between 1990 and 2006 were retrospectively studied. Three stages of hydrocephalus have been categorized in this paper, i.e., acute (0-3 days after SAH), subacute (4-13 days after SAH), chronic (≥14 days after SAH). Criteria indicating the occurrence of hydrocephalus were the presence of significantly enlarged temporal horns or ratio of frontal horn to maximal biparietal diameter more than 30% in computerized tomography.

Results

Overall, 66 of the 734 patients (8.9%) underwent shunting procedures for the treatment of chronic hydrocephalus. Statistically significant associations among the following factors and shunt-dependent chronic hydrocephalus were observed. (1) Increased age (p < 0.05), (2) poor Hunt and Hess grade at admission (p < 0.05), (3) intraventricular hemorrhage (p < 0.05), (4) Fisher grade III, IV at admission (p < 0.05), (5) radiological hydrocephalus at admission (p < 0.05), and (6) post surgery meningitis (p < 0.05) did affect development of chronic hydrocephalus. However the presence of intracerebral hemorrhage, multiple aneurysms, vasospasm, and gender did not influence on the development of shunt-dependent chronic hydrocephalus. In addition, the location of the ruptured aneurysms in posterior cerebral circulation did not correlate with the development of shunt-dependent chronic hydrocephalus.

Conclusion

Hydrocephalus after aneurysmal SAH seems to have a multifactorial etiology. Understanding predisposing factors related to the shunt-dependent chronic hydrocephalus may help to guide neurosurgeons for better treatment outcomes.     

Neuroendoscopic fenestration of the septum pellucidum for monoventricular hydrocephalus

Objectives

Monoventricular hydrocephalus (MH) is a rare condition in which the site of obstruction is located around one of the interventricular foramen. In this paper, the authors offer their experiences in the neuroendoscopic management of this uncommon type of hydrocephalus.

Patients and methods

The authors retrospectively reviewed 12 neuroendoscopic procedures performed between July 2003 and June 2011 with MH. Clinical and radiological charts were reviewed and analysed.

Results

The operative course is a simple and successful procedure, and the postoperative complaints are mild. The postoperative radiological findings showed maintenance of ventricular enlargement in four cases and a significant decrease in enlargement in eight patients. However, upon shifting of the septum pellucidum, the periventricular transudation disappeared in all patients.

Conclusions

Fenestration of the septum pellucidum by neuroendoscope is the best treatment for patients with monoventricular hydrocephalus. The approach for fenestration of the septum pellucidum is based on the experience of the neurosurgeon and the preoperative planning.     

Decompressive craniectomy,interhemispheric hygroma and hydrocephalus: A timeline of events?

Background

Decompressive craniectomy (DC) is a known risk factor for the development of post-traumatic hydrocephalus. The occurrence of subdural hygroma (SH) was also reported in 23–56% of patients after DC and it seemed to precede hydrocephalus in more than 80% of cases. We analyzed the relationship among DC, SH and hydrocephalus.

Methods

From 2007 to 2011, 64 patients underwent DC after head trauma. Variables we analyzed were: intaventricular hemorrhage, age, GCS, distance of craniectomy from the midline, evacuation of a hemorrhagic contusion (HC) and infection. Logistic regression was used to assess the independent contribution of the predictive factors to the development of hydrocephalus.

Results

Nineteen patients (29.7%) developed hydrocephalus. Interhemispheric SH was present in 8/19 patients with hydrocephalus and temporally preceded the occurrence of ventricular enlargement. Moreover, most patients who developed a interhemispheric SH had been undergone DC whose superior margin was close to the midline. Logistic regression analysis showed that craniectomy closer than 25 mm to the midline was the only factor independently associated with the development of hydrocephalus.

Conclusion

Craniectomy close to the midline can predispose patients to the development of hydrocephalus. SH could be generated with the same mechanism, and these three events could be correlated on a timeline.     

松果体区肿瘤导致脑积水的处理

目的 探讨松果体区肿瘤脑积水的治疗.方法 回顾性分析56例经手术病理证实的松果体区肿瘤脑积水的处理.结果 术前行脑室外引流1例,脑室-腹腔分流术2例;术中行侧脑室-枕大池分流35例,未作处理15例,行侧脑室外引流3例;术后因脑积水不能缓解行脑室-腹腔分流术12例.结论 术中行脑室-枕大池分流术对大多数松果体区肿瘤脑积水患者是安全有效的.     

Endoscopic management of hydrocephalus due to neurocysticercosis

Objective

Hydrocephalus due to neurocysticercosis usually shows poor prognosis and shunt failure is a common complication. Neuroendoscopy has been suggested as treatment, but the indications remain unclear.

Methods

A cohort of patients with clinical/radiological diagnosis of hydrocephalus due to NCC, treated between January 2002 and September 2006, were the subjects of the study. We excluded patients with tumors or those in whom diagnosis was not confirmed (histology/positive ELISA in CSF). Neuroendoscopy was offered as the first line of treatment. Shunt failure rate and Karnofsky index at 12 months were assessed.

Results

Eighty-six patients (47 male) with a median age of 38 (9–79) were included in the study. Of them, 36.1% had a shunt before endoscopy and 97.7% had a Karnofsky index <80. We did not find the parasite in 18.6%, extraction was achieved in 79%, and in 87.2% an endoscopic third ventriculostomy (ETV) was performed. The median follow-up time was 43 months (1–72). Shunt failure was seen in 6.6% of patients with ETV in comparison to 27.2% in those without ETV. A hazard ratio of 0.22 (95% CI, 0.05–0.93) for shunt failure after ETV was calculated. At 12 months, 20.9% had a Karnofsky index <80.

Conclusion

Early extraction of parasite plus ETV might allow improving outcome and reducing shunt failure. Limitation of inflammatory stimulation by parasite antigens and improvement of CSF dynamics could be an explanation for these findings.     

Hydrocephalus following decompressive craniectomy for malignant middle cerebral artery infarction

Objective

The aim of this study was to evaluate the incidence of hydrocephalus and understand the influence of hydrocephalus on the functional outcome of patients undergoing decompressive craniectomy for malignant middle cerebral artery (MCA) infarction.

Methods

We retrospectively analyzed data of consecutive patients who underwent decompressive craniectomy for malignant MCA infarction. Clinical and imaging data were reviewed to confirm the incidence of hydrocephalus and evaluate the impact of hydrocephalus on functional outcome. The functional outcomes of patients were estimated with the Glasgow outcome score at 1 year after stroke onset.

Results

Seventeen patients who received decompressive craniectomy for malignant MCA infarction from January 2003 to December 2006 were enrolled. Persistent hydrocephalus developed in 5 patients. The functional outcomes in these patients were uniformly poor regardless of cerebrospinal fluid diversion surgery. Our data revealed that functional outcome was related to patient age and the duration from infarction to craniectomy.

Conclusions

Persistent hydrocephalus is common in patients who receive decompressive craniectomy for malignant MCA infarction. However, the shunt procedure does not significantly improve the patient's clinical condition. The timing of operation in relation to the functional outcome may be critical.     

Ventriculoperitoneal shunt surgery and the incidence of shunt revision in adult patients with hemorrhage-related hydrocephalus

Objective

Ventriculoperitoneal shunt surgery remains the most widely accepted neurosurgical procedure for the management of hydrocephalus. However, shunt failure and complications are common and may require multiple surgical procedures during a patient's lifetime. The purpose of this study is to evaluate the ventriculoperitoneal shunt surgery and the incidence of shunt revision in adult patients with hemorrhage-related hydrocephalus.

Methods

Adult patients who underwent ventriculoperitoneal shunt placement for hemorrhage-related hydrocephalus from October 1990 to October 2009 were included in this study. Medical charts, operative reports, imaging studies, and clinical follow-up evaluations were reviewed and analyzed retrospectively.

Results

A total of 133 adult patients with the median age of 54.5 years were included. Among patients, 41% were males, and 62% Caucasians. The overall shunt revision rate was 51.9%. The shunt revision rate within the first 6 months after the initial placement of ventriculoperitoneal shunts was 45.1%. The median time to first shunt revision was 0.50 (95% CI, 0.24–9.2) months. No significant association was observed between perioperative variables (gender, ethnicity, hydrocephalus type, or hemorrhage type) and the shunt revision rate in these patients. Major causes of shunt revision include infection (3.6%), overdrainage (7.6%), obstruction (4.8%), proximal shunt complication (7.6%), distal shunt complication (3.6%), old shunt dysfunction (6.8%), valve malfunction (10.0%), externalization (3.6%), shunt complication (12.0%), shunt adjustment/replacement (24.0%) and other (16.4%).

Conclusion

Although ventriculoperitoneal shunting remains to be the treatment of choice for adult patients with post hemorrhage-related hydrocephalus, a thorough understanding of predisposing factors related to the shunt failure is necessary to improve treatment outcomes.     

Factors predicting the development of new onset post-operative Hydrocephalus following trans-sphenoidal surgery for pituitary adenoma

Background

The aim of this retrospective study was to identify the factors which can predict the development of new onset post-operative Hydrocephalus following transsphenoidal surgery for pituitary adenomas.

Methods

A total of 224 patients with the diagnosis of pituitary adenoma and without preoperative Hydrocephalus were identified from 1995 to 2012. Age, gender, tumor volumes, prior craniotomy and irradiation, outcome, hospital stay, CSF leak, infection and functional status of the tumor were included in the model for analysis.

Results

A total of 13 patients (5.8%) developed new onset post-operative Hydrocephalus. Intraoperative and post-operative CSF leaks were noted in 19 (8.5%) and 17 (7.6%) patients respectively. CSF infection was seen in only 7 (3.1%) patients. Age of the patient (p = 0.010), length of hospital stay (p = 0.012), intraoperative CSF leak (p = 0.000), post-operative CSF leak (p = 0.000) and CSF infection (p = 0.000) had shown significant correlation with the de novo onset of postoperative HC. The independent predictors of post-operative HC were post-operative CSF leak [p = 0.002, OR 27.898, 95% CI 3.350–232.311] and intra-operative CSF leak [p = 0.050, OR 7.687, 95% CI 1.003–58.924].

Conclusion

Age of the patient, intra-operative and post-operative CSF leak, CSF infection and duration of hospital stay were correlated with the development of HC. Post-operative and intra-operative CSF leaks were the independent predictors of new onset HC.     

Post-traumatic hydrocephalus is a contraindication for endoscopic third-ventriculostomy: Isn’t it?

Objectives

Post-traumatic hydrocephalus (PTH) is commonly considered as a relative contraindication for endoscopic third-ventriculostomy (ETV). However, few studies are available on this topic.

Methods

An analysis of the papers published in the last ten years has been performed, in order to assess the level of evidence on which the current indication for ETV for PTH is based.References were identified by PubMed searches of clinical articles relating to both PTH and ETV. Laboratory investigations were excluded.

Results

Only 5 articles were selected, for a total of 15 patients with PTH treated with ETV. All these patients were described by the authors to have a communicating hydrocephalus. No complications of surgery were reported.Outcome data were not available for one patient. Thirteen out of the remaining 14 patients had a clinical improvement after the surgical procedure (93%). Direct or indirect information on pre-operative ICP was available for 11 cases. Eight of them had an elevated ICP and presented a clinical improvement after ETV.

Conclusions

There is no current evidence to support that PTH is a contraindication for ETV. Our data suggest that we could reconsider ETV for the treatment of PTH, especially for patients with elevated ICP. Prospective clinical trials (involving several centers, due to the difficulty of recruiting patients with PTH) are needed.     

Low field intraoperative MRI-guided surgery of gliomas: A single center experience

Introduction

The aim of this article is to report on our experience in using a low field intraoperative MRI (iMRI) system in glioma surgery and to summarize the hitherto use and benefits of iMRI in glioma surgery.

Patients and methods

Between July 2004 and May 2009, a total of 103 patients harboring gliomas underwent tumor resection with the use of a mobile low field iMRI in our institution. Surgeries were performed as standard micro-neurosurgical procedures using regular instrumentarium. All patients underwent early postoperative high field MRI to determine the extent of resection. Adjuvant treatment was conducted according to histopathological grading and standard of care.

Results

All tumors could be reliably visualized on intraoperative imaging. Intraoperative imaging revealed residual tumor tissue in 51 patients (49.5%), leading to further tumor resection in 31 patients (30.1%). Extended resection did not translate into a higher rate of neurological deficits. When analyzing survival of patients with glioblastoma, patients undergoing complete tumor resection did significantly better than patients with residual tumor (50% survival rate at 57.8 weeks vs. 33.8 weeks, log rank test p = 0.003), while younger age did not influence survival (p = 0.12).

Conclusion

Low field iMRI is a helpful tool in modern neurosurgery and facilitates brain tumor resection to a maximum safe extent. Its use translates into a better prognosis for these patients with devastating tumors. Future studies covering the use of iMRI will need to be conducted in a prospective, randomized fashion to prove the true benefit of iMRI in glioma surgery.     

Unusual radiologic findings and pathologic growth patterns on choroid plexus papillomas

Objective

Choroid plexus papillomas (CPPs) are generally regarded as benign tumors with typical radiologic and pathologic findings. However, they sometimes have unusual findings. We have analyzed radiologic findings and pathologic growth patterns on CPPs.

Methods

The study group included 5 male and 5 female patients (age range, 3 months to 58 years : median, 29 years). The study group included 3 pediatric and 7 adult patients. All patients underwent surgery; 9 patients had a gross total resection and 1 patient had a subtotal resection. We analyzed the radiologic findings (location, size, mottle-like appearance, enhancement, calcifications, and hydrocephalus) and pathologic growth patterns (typical papillary, papillary and solid, and papillary and tubular).

Results

The median follow-up duration was 21.3 months (range, 4-47.8 months). There were no recurrences after initial treatment. All patients had benign CPPs. Pediatric CPPs were 3.2 cm masses (range, 2.7-4 cm) with homogeneous enhancement and a mottle-like appearance, which pathologically showed the papillary growth pattern. Hydrocephalus was present in all pediatric patients. Postoperatively, subdural hygroma had occurred in two patients. In adults, CPPs were located in the fourth ventricle in 6 patients and suprasellar area in 1 patient. The size varied from 0.5-4.2 cm. Hydrocephalus and calcifications occurred in 3 and 4 patients, respectively. Three patients showed the heterogeneous enhancement without a mottle-like appearance and pathologically showed combined papillary and solid growth in 2 patients and papillary and tubular growth in one. Postoperatively, two patients with large masses had injuries of the brainstem and underwent shunt procedures for aggravation of hydrocephalus.

Conclusion

CPPs may show unusual radiologic findings, which preoperatively give the difficulty to be differentiated from other tumors. CPPs with unusual radiologic findings showed the combined pathologic growth patterns.     

Clinical features and pathophysiological mechanism of the hemianoptic complication after the occipital transtentorial approach

Objective

To obtain detailed insight into neuro-ophthalmological characteristics and pathophysiology of hemianoptic complications after occipital transtentorial surgery.

Methods

We reviewed the cases of 14 patients surgically treated by the occipital transtentorial approach. Treated lesions included 6 posterior third ventricle tumors, including pineal and tectal lesions, 3 falco-tentorial meningiomas, and 5 superior cerebellar lesions. The surgeries were performed by the unilateral occipital transtentorial approach with patients in the prone position.

Results

Visual functions were preoperatively normal in all patients. After surgery, 11 patients (79%) showed hemianoptic complications detected by a confrontation test in the immediate postoperative period. The condition began to improve in the early postoperative days. The visual field recovered completely in 6 patients within 10 days, 2 patients recovered within 3 months, and 3 patients complained of permanent visual field defects. Optometric neuro-ophthalmic evaluation in the early postoperative period failed to detect complete homonymous hemianopsia, but homonymous inferior quadrantanopia and scotomatous defects were observed in 6 patients. These visual field defects were permanent in 3 patients. Postoperative MRI showed no morphological abnormality except these three patients. Atrophic change of the occipital lobe with preservation of striate cortex was associated with persistent visual field defects in two patients. Cerebral blood flow evaluation by single photon emission computed tomography suggested that temporary local hyperperfusion of the retracted occipital region when visual field defect was present.

Conclusion

Hemianoptic visual field defects can recover via inferior quadrantanopia or scotomatous defect. All of these defects are attributable to injury to the optic radiation as well to the occipital lobe. Hyperperfusion of the retracted occipital region may underlie the pathophysiology of hemianoptic complications after the occipital transtentorial approach.