- Neurosurgery Division, Department of Surgery, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria
Correspondence Address:
Chizowa Okwuchukwu Ezeaku, Neurosurgery Division, Department of Surgery, Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria.
DOI:10.25259/SNI_635_2024
Copyright: © 2024 Surgical Neurology International This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, transform, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.How to cite this article: Edward Oluwole Komolafe, Chizowa Okwuchukwu Ezeaku, Gabriel Owoicho Ejembi, Christopher Obinna Anele, Simon Adewale Balogun. The clinical spectrum and management outcome of adult-onset aqueductal stenosis: Insight from South-West Nigeria. 04-Oct-2024;15:360
How to cite this URL: Edward Oluwole Komolafe, Chizowa Okwuchukwu Ezeaku, Gabriel Owoicho Ejembi, Christopher Obinna Anele, Simon Adewale Balogun. The clinical spectrum and management outcome of adult-onset aqueductal stenosis: Insight from South-West Nigeria. 04-Oct-2024;15:360. Available from: https://surgicalneurologyint.com/?post_type=surgicalint_articles&p=13132
Abstract
Background: Adult-onset aqueductal stenosis (AOAS) is an uncommon cause of hydrocephalus in adults. Its etiopathogenesis is poorly understood, with various proposed mechanisms, spectrum of presentation, and management. Very little has been reported on this anomaly in African literature. This study aimed to describe the pattern of presentation, clinical spectrum, and early outcomes following the shunt procedure in our population practice setting.
Methods: This was a retrospective case series of patients with non-tumoral AOAS managed between 2008 and 2023 in a tertiary center in South-West Nigeria. Relevant demographic, clinical-radiologic, and outcome data were retrieved and analyzed.
Results: There were seven males and one female. Their age ranged from 18 to 50 years. The duration of symptoms ranged from 3 to 120 months. All patients admitted having headaches; however, visual deterioration (n = 5) was the most common presenting symptom. Features of endocrinopathy (n = 1), cerebellar dysfunction (n = 2), cognitive deficit (n = 2), spontaneous cerebrospinal fluid leak (n = 1), and sphincteric dysfunction (n = 1) were also observed. The mean Evan’s index at the presentation was 0.43. Ventriculoperitoneal shunt (VPS) insertion was performed in seven patients with good outcomes. One patient opted for a referral. One patient had shunt revision 6 years later on account of shunt disconnection.
Conclusion: AOAS is an infrequent cause of hydrocephalus in our setting, with most patients seeking medical consultation following visual deterioration. Proper evaluation of adults with long-standing headaches and associated features is advocated to avert total visual loss in this subgroup. VPS insertion is a viable treatment option with a good outcome.
Keywords: Adult-onset aqueductal stenosis, Africa, Profile, Ventriculoperitoneal shunt
INTRODUCTION
Aqueductal stenosis (AS) is a common cause of obstructive hydrocephalus, especially in neonates and infants. It is characterized by a narrowed cerebral aqueduct and tri-ventriculomegaly (of the lateral and third ventricles).[
MATERIALS AND METHODS
This is a single institutional retrospective review of cases of AOAS managed at our tertiary institution between 2008 and 2023. Only patients aged ≥18 years with non-tumoral AS were included in the study. Patients with a history of cranial surgery or those diagnosed with hydrocephalus during infancy were excluded from the study. All patients underwent detailed neurological examinations and neuroophthalmic evaluations. AS in the absence of any extrinsic cause was confirmed using brain magnetic resonance imaging (MRI) studies. Patients’ neuroimages were analyzed using RadiAnt DICOM Viewer (version 2024.1, Beta). The third ventricular width was defined as the maximum interthalamic distance at the level of the foramen of Monro. Relevant demographic, clinical-radiologic, and management outcome data were retrieved in a predesigned form using Microsoft Excel. These variables were analyzed using IBM Statistical Package for the Social Sciences version 27, and the mean, median, and frequency of various variables were presented. Following ventricular-peritoneal shunt insertion, the assessment of clinical features was classified as resolution (complete remission of clinical feature[s]), improved, and stable (no improvement or deterioration). The outcome was good if ≥50% of the patient’s clinical features improved and poor if <50% of clinical improvement.
RESULTS
Within the review period, 63 patients presented with adult-onset hydrocephalus. However, only 8 (12.7%) met the selection criteria. There were seven males and one female. The median age at presentation was 29 years. The median duration of symptoms was 9 months. Based on the Fukuhara classification, two had subacute symptomatology, while the others had chronic symptomatology. While all patients admitted having headaches, visual deterioration (n = 5) was the most common reason for presentation. The mean Evan’s index and maximum third ventricular width at presentation were 0.43 (range 0.40–0.48) and 2.04 cm (range: 1.28 cm–3.44 cm), respectively. Visual acuity and fundoscopy were normal in three cases [Serial Nos. 2, 8, and 6,
Seven patients had ventriculoperitoneal shunt (VPS) insertion, the treatment modality available in our institution. The remaining one opted for a referral. The intraoperative findings were clear CSF under high pressure during ventricular cannulation. All CSF cultured from intraoperative specimens returned negative. Headache was the first symptom to subside following CSF diversion, and all admitted to complete resolution. All patients who had shunt insertion had good outcomes, with one patient [serial No. 4,
Figure 1:
(a) T1 sequence depicting triventriculomegaly with stenosis of the aqueduct and small fourth ventricle and (b) T2 sequence depicting the downward bowing of the third ventricle with an enlarged and empty sella (indicated by the red arrow). The site of aqueductal stenosis is indicated with a blue arrow.
Figure 3:
(a) Triventriculomegaly with stenosed aqueduct and small fourth ventricle. (b) Note the enlarged and empty sella (indicated by the red arrow) and pulsion diverticulum (indicated by the yellow arrow) of the frontal horn of the lateral ventricle communicating with (c) the defect on the posterior wall of the frontal sinus (indicated by the blue arrow). Fluid collection (likely cerebrospinal fluid) is noted within the frontal sinus.
DISCUSSION
Our series included eight patients with non-tumoral AOAS. Although retrospective, with a small sample size and short follow-up, we present early comprehensive data on this anomaly in our subpopulation to aid in promoting awareness of this condition. A male preponderance was observed in our series, similar to that of Tisell et al., Locatelli et al., and Montemurro et al.[
Whether AOAS is primarily idiopathic, due to a primary insult in adulthood, or a delayed presentation of congenital AS remains unclear. Kita et al. reported a case of late-onset idiopathic AS in a 17-year-old male with an earlier normal ventricular system from previous MRI scans performed in childhood.[
Pyogenic ventriculitis and intraventricular hemorrhage can result in secondary stenosis of the aqueduct through gliosis due to inflammation and occasionally from direct blockage with fibrinopurulent debris or clot, respectively.[
All of our patients presented with symptoms of increased ICP. This was corroborated by neuroimaging features and intraoperative findings of the CSF at high pressure following ventricular cannulation. In addition, features suggestive of endocrinopathy, cerebellar dysfunction, and cognitive and sphincteric dysfunction were observed. Other researchers have reported similar presentation patterns.[
Headache in AOAS is attributed to the effect of raised ICP due to CSF obstruction. Similar to the findings by Tisell et al., headache was also the most common symptom in our series and resolved completely following CSF diversion.[
Rarely, following long-standing ICP and trans-mantle pulsatile stress in AS. There is progressive thinning of the ventricular wall with the formation of a pulsion diverticulum commonly observed on the lateral ventricles. This may rupture spontaneously, resulting in a ventriculostomy and a reduction in ICP.[
Although ETV is generally recommended in the management of AOAS.[
CONCLUSION
AOAS is an infrequent cause of hydrocephalus in our setting, with most patients seeking medical consultation following visual deterioration. Its multifactorial etiopathogenesis and varying clinical spectrum could make early diagnosis elusive. Proper evaluation of adults with long-standing headaches and associated features is advocated to avert total visual loss in this subgroup. VPS insertion is a viable treatment option with a good outcome.
Ethical approval
The Institutional Review Board approval is not required as it is retrospective study.
Declaration of patient consent
Patient’s consent was not required as there are no patients in this study.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
Disclaimer
The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.
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