Fifth ventricle: an unusual cystic lesion of the conus medullaris

The Physiological Occlusion of the Central Canal May Be a Prerequisite for Syringomyelia Formation

OBJECTIVE

Syringomyelia is a common central nervous system disease characterized by the dilation of the central canal (CC). Regarding the pathogenesis of syringomyelia, cerebrospinal fluid (CSF) circulation obstruction in the subarachnoid space (SAS) of the spinal cord has been widely accepted. However, clinical and animal studies on obstructing the CSF in SAS failed to form syringomyelia, challenging the theory of SAS obstruction. The precise pathogenesis remains unknown.

METHODS

We utilized an extradural compression rat model to investigate the pathogenesis underlying syringomyelia. Magnetic resonance imaging enabled detection of syringomyelia formation. To assess CSF flow within the SAS, Evans blue was infused into the cisterna magna. Histological analysis allowed morphological examination of the CC. Furthermore, CSF flow through the CC was traced using Ovalbumin Alexa-Flour 647 conjugate (OAF-647). Scanning electron microscopy (SEM) enabled visualization of ependymal cilia.

RESULTS

The findings showed that the dura mater below the compression segment exhibited lighter coloration relative to the region above the compression, indicative of partial obstruction within the SAS. However, the degree of SAS occlusion did not significantly differ between syringomyelia (SM-Y group) and those without (SM-N group). Intriguingly, hematoxylin and eosin staining and CSF tracing revealed occlusion of the CC accompanied by reduced CSF flow in the SM-Y group compared to SM-N and control groups. SEM images uncovered impairment of ependymal cilia inside the syringomyelia.

CONCLUSION

CC occlusion may represent a physiological prerequisite for syringomyelia formation, while SAS obstruction serves to initiate disease onset. The impairment of ependymal cilia appears to facilitate progression of syringomyelia.

Cystic Dilatation of the Ventriculus Terminalis: Examining the Relevance of the Revised Operative Classification Through a Systematic Review of the Literature, 2011-2021

The literature features limited evidence on the natural history of the cystic dilatation of the ventriculus terminalis (CDVT) and its response to treatment. The goal of this study is to ascertain which impact the revised operative classification of CDVT had on the management of patients diagnosed over the past 10 years.Ten new clinical articles presenting a total of 30 cases of CDVT were identified and included for qualitative analysis. Two take-home messages can be identified: (1) Adequate consideration should be given to designing national pathways for referral to tertiary centers with relevant expertise in the management of lesions of the conus medullaris, and (2) we suggest that type Ia should be, at least initially, treated conservatively, whereas we reckon that the signs and symptoms described in types Ib, II, and III seem to benefit, although in some patients only partially, from surgical decompression in the form of cystic fenestration, cyst-subarachnoid shunting, or both.While the level of evidence gathered in this systematic review remains low because the literature on CDVT consists only of retrospective studies based on single-center series (level of evidence 4 according to the Oxford Centre for Evidence-Based Medicine (OCEBM)), the strength of recommendation for adopting the revised operative classification of CDVT is moderate.

Recurrent terminal ventricle cyst: a case report

The terminal ventricle (TV) of Krause is a rare cystic dilation of the conus' central canal. Due to limited understanding surrounding its pathophysiology, optimal management remains controversial. We report a 25-year-old female presenting with acute paraparesis. Magnetic resonance imaging spine revealed a cystic conus medullaris lesion in keeping with an incidental TV cyst. However, the patient experienced a rapid resolution of symptoms. We hypothesize that the TV cyst spontaneously ruptured and auto-decompressed. To our knowledge, this is the first reported case of an enlarging symptomatic TV cyst with spontaneous rupture and resolution of symptoms, highlighting the variable natural history of this condition.

Enlarging Ventriculus Terminalis in a Patient With Polyarteritis Nodosa

Ventriculus terminalis (VT) is a cystic embryological remnant within the conus medullaris that normally regresses after birth. In rare cases, it may persist into adulthood and give rise to neurologic symptoms. The pathogenesis remains unclear but is thought to be related to failed embryonic regression with other proposed possible etiologies including vascular disturbances. We present an intriguing case of a slow-growing VT in a woman with progressive neurologic symptoms who experiences symptomatic relief following thoracic laminectomy and fenestration. Our case is the first to present a unique association with polyarteritis nodosa and only the third to report a case of documented enlargement of the VT over time successfully treated with surgical fenestration.

The terminal ventricle of Saguinus leucopus (Primate)

The terminal ventricle is a dilation of the ventricular system located within the spinal cord, which is enveloped in ependymal cells that are involved in the dynamic of the cerebrospinal liquid. In the present study, four Saguinus leucopus specimens were dissected, two males and two females, whose spinal cords were extracted and histologically processed via hematoxylin and eosin stains of cuts at the conus medullaris. The S. leucopus' terminal ventricle was observed at the conus medullaris, and had an average diameter of 241.38 μm. Thus, the presence of the terminal ventricle in the S. leucopus at the level of the conus medullaris was established.

The cystic dilation of ventriculus terminalis with neurological symptoms: Three case reports and a literature review

CONTEXT

The ventriculus terminalis (VT) is a very small ependymal-lined residual lumen in the conus medullaris. It is normally present in all subjects during fetal development. VT in adults appears as an unusual pathology with an uncertain pathogenesis.

FINDINGS

In this paper, we described three case reports of symptomatic fifth ventricle cystic dilations. All of them were female and their mean age was 59 years. We treated them surgically and all three patients were improved based on clinical and imaging assessments.

CONCLUSION

Our cases suggested that surgical decompression was a safe and effective treatment in symptomatic patients and the neurosurgeons should be aware of such rare situations. A complete list of differential diagnosis about other cystic dilations of the conus medullaris should be emphasized to select the correct clinical approach.

Surgery or not? A case of ventriculus terminalis in an adult patient

The ventriculus terminalis (VT) is an intramedullary cavity containing cerebrospinal fluid (CSF), usually located at the conus, and represents an unsuccessful regression of a normal embryological phase of the development of the neural tube. Symptoms are not univocal and may vary from aspecific signs to sphincter dysfunctions and focal neurological deficits. The correct management of this condition is still an object of debate due to its rarity and its unpredictable behaviour in adult patients. Two different studies have proposed a distinction for patients with cystic dilatation of VT based on their symptoms, suggesting that only those patients with neurological deficits clearly related to the terminal ventricle could benefit from surgery. We describe a case of an adult patient with a progressive dilatation of a diagnosed VT that we treated surgically. A management flowchart for this condition is also proposed based on our experience and a review of the literature.

Cystic dilation of a ventriculus terminalis. Case report and review of the literature

The ventriculus terminalis (VT) is a small ependyma-lined cavity within the conus medullaris that is in direct continuity with the central canal of the spinal cord. Cystic dilatation of the ventriculus terminalis on its own is an extremely rare pathological event in adults whose pathogenesis is uncertain. VT has been described in children as a normal developmental phenomenon. These lesions are often diagnosed incidentally during imaging and are in most cases asymptomatic, especially in children. Symptomatic dilatation of VT in adults is a rare condition with 61cases being reported to date. Symptomatic dilatation of VT in children has not been reported till now. We present a 5 year-old-boy with a sphincteric and walking disorder. The patient was assessed by clinical, electrophysiological and urodynamic investigations as well as magnetic resonance imaging (MRI) of the lumbar-sacral segment with and without gadolinium enhancement. Lumbar-sacral MRI demonstrated the presence of a cystic lesion containing cerebrospinal fluid (CSF), which did not enhance after gadolinium, compatible with the diagnosis of the ventriculus terminalis dilation.The patient underwent laminectomy and the cyst wall was fenestrated with a midline myelotomy. In 6-month of follow-up, urinary problems and gait disturbance improved.

Cystic Dilation of the Ventriculus Terminalis: Report of 6 Surgical Cases Treated with Cyst-Subarachnoid Shunting Using a T-Catheter

BACKGROUND

Cystic dilation of the ventriculus terminalis (CDVT) is a rare anatomic variation that and may become symptomatic. Literature regarding CDVT is limited, and thus the clinical characteristics and management strategy of CDVT are unclear. Here we report 6 cases of CDVT seen in our institution, and provide a review of the current literature.

METHODS

The study cohort comprised 6 patients with CDVT seen at Beijing Tiantan Hospital between September 2010 and June 2015. All 6 patients were managed surgically. Data on age, sex, clinical presentation, radiologic features, operative methods, and surgical outcomes were reviewed retrospectively. We evaluated the clinical outcomes and postoperative radiologic changes of these patients and compared them with findings of similar previous reports.

RESULTS

All 6 patients were female, with a median age of 50.0 years (interquartile range [IQR], 25.8-54.0 years). Surgical management of cyst-subarachnoid shunting using T-catheter after myelotomy was successfully performed in all patients. During an average follow-up of 41 months, relief of clinical symptoms, especially low-back pain and sciatica, were observed in all 6 patients. No patients experienced symptom recurrence during follow-up, and postoperative magnetic resonance imaging revealed no regrowth of the lesion. Patients with focal neurologic deficits and sphincter disorders also achieved symptom relief from the procedure.

CONCLUSIONS

CDVT is an extremely rare cause of conus medullaris syndrome with an unclear treatment strategy. Our successful surgical management of 6 cases through cystic-subarachnoid shunting using a T-catheter for CDVT drainage provides a potential option for treating CDVT.

The Slowly Enlarging Ventriculus Terminalis

Background

A cerebral spinal fluid (CSF) cavity within the conus medullaris has been described by the term ventriculus terminalis (VT) or the fifth ventricle. The finding of a VT on MRI imaging of the lumbar spine is often incidental but may be found in patients with low back pain or neuromuscular deficits. These lesions, when identified, are thought to regress or remain stable in terms of size, although some have been described to enlarge in the presence of post-traumatic meningeal hemorrhages or deformities of the vertebral canal.

Case Report

We describe a case of a slowly growing VT in a patient with progressing lower limb weakness without any history or imaging findings of trauma or spinal canal abnormalities.

Conclusions

We present an intriguing case of a slowly growing VT in a woman with progressive neurological symptoms. Surgical fenestration provided complete symptomatic relief and follow-up imaging two years after surgery demonstrated no evidence of recurrence. This, to our knowledge, is the first described case of a slowly enlarging VT independent of any other imaging findings.

The Ventricular System of the Brain: Anatomy and Normal Variations

The cerebral ventricular system is intimately associated with the forebrain and brainstem. The ventricular system functions to produce and circulate cerebrospinal fluid, which plays an important role in mechanical protection and regulation of homeostasis in the central nervous system. This article discusses anatomy and neuroimaging of the ventricular system and highlights normal anatomical variations that may be mistaken for pathology. Applied surgical anatomy is reviewed with emphasis on operative approach and potential risk to adjacent central nervous system structures.

Microsurgical fenestration of idiopathic intramedullary cysts in adult patients

PURPOSE

The aim of this study is to describe the findings in one of the largest series of microsurgically treated intramedullary cysts investigated by magnetic resonance imaging (MRI), focusing on the peri- and intraoperative setup including detailed neurological and radiological outcome analyses.

METHODS

Retrospective analysis of patients with intramedullary cyst who had undergone microsurgical fenestration at our department between 2006 and 2011. Preoperative three-dimensional constructive interference of steady-state MRI was conducted to optimize surgical planning. Intraoperative electrophysiological monitoring included motor-evoked potentials, somatosensory-evoked potentials, and electromyogram. Clinical outcome as well as pre-, postoperative and long-term MRI scans were evaluated.

RESULTS

Eight female patients (median age 58.0 years, range 32-72 years) with a median clinical follow-up of 48.0 months (range 2-69 months) were included. Seven cysts were located in the conus medullaris, one in the cervical spine. Overall, 25.0% (2/8) showed complete remission of preoperative symptoms, 62.5% (5/8) improved, and 12.5% (1/8) asymptomatic patients remained unchanged. Pain syndromes (4/4) as well as motor deficits (2/2) improved in all affected patients and bladder dysfunction (3/4) displayed a high tendency for improvement. Postoperative MRI scans showed permanently decreased cyst volumes by ~80%.

CONCLUSION

Microsurgical fenestration of intramedullary cysts using preoperative high-resolution imaging and intraoperative electrophysiological monitoring is a safe and effective treatment option for symptomatic patients.

Post-traumatic syringomyelia: CSF hydrodynamic changes following spinal cord injury are the driving force in the development of PTSM

Post-traumatic syringomyelia (PTSM) is a disorder that occurs infrequently following spinal cord injury (SCI), characterized by progressive neurological deterioration resulting from syrinx expansion originating in proximity to the traumatic epicenter. Several pathogenetic factors are associated with this disorder, however, the precise mechanism of the development of PTSM is controversial. Combined anatomical alterations and molecular changes following trauma to the spinal cord and arachnoid participate in the development of this condition. These factors include narrowing or obstruction of the subarachnoid space (SAS), central canal occlusion, myelomalacia, and alterations in intramedullary water permeability. If a patient sustains a SCI with delayed progressive deterioration in neurological function, in association with the MRI appearance of syringomyelia (SM), the diagnosis of PTSM is straightforward. The treatment of PTSM has not undergone any significant changes recently. The surgical treatment of PTSM consists of reconstructing the SAS or shunting fluid away from the syrinx to other locations. The advantages and disadvantages of each procedure will be discussed. With greater understanding of the mechanisms contributing to the development of SM, including advanced diagnostic methods and further advances in the development of artificial dural and shunting tubing, future therapies of PTSM will be more effective and long-lasting. Incorporation of alterations of AQP4 expression provides an intriguing possibility for future treatment of PTSM.

Massive cystic dilatation within a tethered filum terminale causing cauda equina compression and mimicking syringomyelia in a young adult patient

BACKGROUND

The ventriculus terminalis (VT) is formed during early embryonic development of the spinal cord and can only be identified histologically in both children and adults. Cystic dilatation of the VT can be seen in young children, but it rarely persists through adulthood.

CLINICAL CASE

We describe a 27-year-old female with paraparesis secondary to a massive and tethered cystic dilatation of the VT mimicking syringomyelia. Symptoms appearing in early childhood were ignored, probably leading to the much prominent presentation in early adulthood. The preoperative presentation and surgical treatment are discussed in relation to childhood history.

CONCLUSIONS

Although extremely rare, symptomatic dilatation of the VT can be seen in young adults, usually with previous manifestations in early childhood. This entity should be considered while treating tethered cord spectrum.

Ventriculus terminalis in adults: unusual magnetic resonance imaging features and review of the literature

OBJECTIVE

The ventriculus terminalis (VT) in adults is a rare pathology. We report various MR imaging features of the adult VT.

MATERIALS AND METHODS

Ten patients were included in this retrospective review.. All patients had undergone magnetic resonance (MR imaging with a surface coil that used two different 1.5T MR systems. All patients had undergone initial and follow-up MR imaging with contrast enhancement using gadopentate dimeglumine. Three patients underwent additional MR imaging using the echocardiogram-gated spatial modulation of magnetization (SPAMM) technique. If a shift in tagging band during the systolic phase was less than half of the band space, it was defined as a "non-pulsatile fluid". Two neuroradiologists independently reviewed these images, while clinical symptoms and outcomes were statistically analyzed between the treated and non-treated group.

RESULTS

All cases presented an intramedullary cystic lesion in the conus medullaris and showed the same signal intensity as CSF. Three VTs had intracystic septation and cord edema, which were pathologically confirmed after surgery; two of these were associated with kyphotic deformity and spinal arteriovenous malformation. SPAMM-MRI of 3 patients demonstrated non-pulsatile fluid motion within the VT. In the treated group, clinical symptoms improved better than the non-treated group.

CONCLUSION

The adult VT shows some unusual imaging features, including septation, cord edema, and coexistence of a spinal AVM, as well as the typical findings. Surgical maneuvers may be considered as a treatment option in adult VT with progressive neurological symptoms.

Cystic dilation of the ventriculus terminalis

Object

The ventriculus terminalis, an embryological remnant consisting of the ependymal-lined space of the conus medullaris, can occasionally become symptomatic after cystic dilation. In the existing literature, consisting of 32 cases, the preferred type of management (conservative vs surgical) is still debated. The object of this study was to report the surgical results in a consecutive series of 10 adult patients with cystic dilation of the ventriculus terminalis (CDVT), to match them with data retrieved from the relevant literature, and specifically to validate a new recent clinical classification.

Methods

The authors reported 13 new cases of CDVT treated in the Department of Neurosurgery at University Hospital in Verona, Italy. Treatment modalities and clinical and radiological outcomes, both early and at follow-up, were analyzed and compared with a preoperative classification of clinical presentation, as established by de Moura Batista and colleagues (2008).

Results

Surgical treatment seemed to guarantee the resolution of CDVT. Dorsolumbar laminotomy, myelotomy, and cystic drainage were performed in 10 patients. Patients with Type I symptoms (nonspecific complaints) often presented with comorbidities (herniated disc or facet hypertrophy) confusing their clinical status. The surgical treatment of patients with Type I symptoms promoted good results only if the diagnosis of CDVT was definitive and symptoms had rapidly evolved. In patients with Type II (focal neurological deficits) and III (sphincter disturbances) symptoms, surgical treatment sustained improvement even at the late follow-up.

Conclusions

While confirming the usefulness of de Moura Batista and colleagues' classification in its impact on prognosis, the authors propose a revision of the classification with subgroups Type Ia (nonspecific symptoms without clear relation to CDVT), which is best treated conservatively, and Type Ib (rapid onset and invalidating unspecific complaints without comorbidities), which may benefit from surgical evacuation.

Percutaneous aspiration of spinal terminal ventricle cysts using real-time magnetic resonance imaging and navigation

STUDY DESIGN

Clinical case series.

OBJECTIVE

To present a new innovative treatment option for cysts of the terminal ventricle.

SUMMARY OF BACKGROUND DATA

Invasive surgery including laminectomy and cyst fenestration has been the sole reported method of treatment for this rare pathology.

METHODS

Four cases of symptomatic cyst of the terminal ventricle of the spinal cord were treated by percutaneous aspiration using real-time guidance with magnetic resonance imaging (MRI) and optically-tracking navigation.

RESULTS

Three patients were treated successfully by this percutaneous method, and for 1 patient the treatment was converted to conventional surgery after a single unsuccessful trial of percutaneous puncture. All patients were relieved of their symptoms without any complication. Follow-up MRI revealed continued shrinkage of the cysts after both surgery and MRI-guided percutaneous fenestration.

CONCLUSION

MRI-navigated percutaneous aspiration can be a minimally-invasive treatment option for symptomatic cysts of the terminal ventricle, and therefore, can be indicated before more invasive surgery might be scheduled.

Cystic lesion of the ventriculus terminalis: proposal for a new clinical classification

The ventriculus terminalis is a small cavity inside the conus medullaris that is formed during the embryonic development. Previous reports regarding cystic lesion of the ventriculus terminalis (CLVT) in adults have detailed a broad and diversified distribution in terms of clinical symptoms, clinical evolution, neurological findings, and treatment. Therefore, nonstandardized management has led to unsatisfactory outcomes. Thus, the authors propose a new classification system in which the clinical presentation is taken into account to standardize the cases and facilitate the proper management of these lesions. Two more cases are described. The literature was reviewed, dividing the patients into 3 groups by clinical presentation as follows: CLVT Type I, patients with nonspecific neurological symptoms or nonspecific complaints; CLVT Type II, presence of focal neurological deficit; and CLVT Type III, presence of sphincter disturbances (bowel or bladder dysfunction). Two patients were classified as CLVT Type I, 3 as CLVT Type II, and 12 as CLVT Type III. In Type I, no improvement was observed in clinical evaluation after surgery, and stable symptoms were achieved with clinical management. In Type II, 2 patients had total improvement and 1 had subtotal improvement after surgery. Finally, in Type III, 92% of the patients improved postoperatively; among these 33% presented with total improvement. Only 1 case in this group was handled conservatively and no improvement was documented. This new classification is useful to group the patients into 3 clinical types to provide guidance as to the best management options. Treatment for the Type I lesion seems to be best conducted conservatively, whereas Types II and III seem to be best handled surgically.

Cystic dilation of the ventriculus terminalis in adults

✓The ventriculus terminalis (VT) is a small ependyma-lined cavity within the conus medullaris that is in direct continuity with the central canal of the anterior portion of the spinal cord. Normally, such a cavity is identifiable only histologically in children and adults and can be visualized using common neuroradiological techniques only after dilation. Currently, the mechanisms of isolated dilation are not documented. The present work describes 2 cases of VT in elderly patients. Data from a histological and ultrastructural study of a case of VT dilation are reported, and the results are compared with those obtained from the VT of 5 fetuses to explain the nosological aspects of nontumoral VT lesions. Our data suggest that the site, age, and histological characteristics of the lesion allow us to define VT dilation as a nosological entity distinct from other cystic dilations of the conus medullaris.

Cystic dilation of the conus ventriculus terminalis presenting as an acute cauda equina syndrome relieved by decompression and cyst drainage: case report

OBJECTIVE AND IMPORTANCE

The ventriculus terminalis of the conus, or "fifth ventricle" refers to the ependymal-lined space in the middle of the conus that is present in childhood and whose persistence into adulthood is rare. A number of cases of cystic dilatation of the ventriculus terminalis have been described in adulthood. Patients tend to present with either pain alone or gradually progressive conus or cauda equina syndromes with varying degrees of recovery after cyst drainage. Presentation with an acute cauda equina syndrome and its successful surgical management has not been previously reported.

CLINICAL PRESENTATION

A 57-year-old woman experienced back pain and bilateral sciatica ascribed to diabetic neuropathy for 2 years. Over a 24-hour period she developed bilateral lower extremity weakness, saddle anesthesia, and bowel and bladder incontinence. Lumbosacral magnetic resonance imaging demonstrated a large cystic dilatation of the ventriculus terminalis.

INTERVENTION

She was taken for emergency surgical decompression and cyst drainage. Immediately after surgery, she experienced significant increase in lower extremity strength and has since regained continence.

CONCLUSION

Cystic dilation of the ventriculus terminalis should be part of the differential diagnosis for a cauda equina syndrome; surgical decompression with simple cyst drainage can result in excellent clinical results.