Clinical analysis of aqueductal stenosis in patients with hydrocephalus in a Kenyan setting

Clinical analysis of aqueductal stenosis in patients with hydrocephalus in a Kenyan setting

Loyal Poonamjeet Kaur^1,&, Nderitu Joseph Munyiri¹, Wekesa Vincent Dismus^1,2

 

¹Department of Surgery, University of Nairobi, Kenya ²Department of Surgery, University of Nairobi, Kenya

 

 

^&Corresponding author
Loyal Poonamjeet Kaur, Department of Surgery, University of Nairobi, Kenya

 

 

 

 

Aqueductal stenosis (AS) is a pathological condition causing triventricular obstructive hydrocephalus which requires a clinical and radiological diagnosis. Patients develop symptoms like headache, cognitive and gait impairment, and urinary incontinence [1]. Clinical presentation, neuro-radiological identification, and management of hydrocephalus secondary to aqueductal stenosis are specific [2]. Treatment options for hydrocephalus due to aqueductal stenosis includes insertion of ventriculopertitoneal shunt (VP) and Endoscopic Third ventriculostomy (ETV) [3-6]. It is the scope of this paper to focus on the disease burden of aqueductal stenosis for a setting for which it remains largely unknown.

 

 

In a descriptive cross-sectional study, 258 records of patients at the Kenyatta National Hospital diagnosed with hydrocephalus were analyzed after ethical approval from Kenyatta National Hospital- University of Nairobi (KNH-UON) ethics and research committee from January 2010 to May 2016. Patients with a diagnosis of hydrocephalus due to aqueductal stenosis were included in this study. The variables collected include: patients age, sex, mode of delivery, associated comorbidities, presenting complaints, neurosurgical intervention performed, Kafarnosky score. Data were divided into 2 sets based on the patient's age i.e. whether < 1 year or > 12 years. Data were recorded on google data collection form and analyzed using Google spreadsheets.

 

 

In a sample study of 258 cases of hydrocephalus, aqueductal stenosis was identified as a cause of hydrocephalus in 52 cases (20%). The male to female sex ratio for this condition was 3:2. There were 25 cases (9.6%) of aqueductal stenosis in patients < 1year, of which 15 cases presented at birth with only 6 having undergone caesarean section; and 10 cases presented before the age of 6 months. 3 out of the 25 cases of aqueductal stenosis in <1 year old age group were premature. There were 27 (10.4%) cases of patients who were > 12 years old who were diagnosed with hydrocephalus due to aqueductal stenosis.

 

Associated conditions : these were almost exclusively seen in the age group of < 1 years. In 3 cases there was associated bilateral CTEV and spina bifida, 5 cases had associated spina bifida alone, 1 case had bilateral CTEV and 1 case of Arnold Chiari Type 2 malfomation with aqueductal stenosis. Meningitis was a co-morbidity in 6 cases while HIV was present in 3 cases. There was only 1 case of Arnold Chiari Type 1 malformation as an associated co-morbidity in the age group > 12 years.

 

Presenting complaints: for patients who were less than 1 years the main presenting complaints were increase in head circumference, tense anterior fontanelle and sunset eyes in all. Generalized tonic clonic seizures were seen in 5 cases, vomiting in 5 cases, regression of milestones in 5 cases, refusal to breastfeed in 3 cases; hotness of body, nuchal rigidity, and positive Kernings sign were seen in 6 cases. The median head circumference was 48.5cm for neonates who presented at birth and for 48.75cm those who presented before 6 months of age. For patients who were > 12 years the main presenting complaint was headache (19 cases), followed by deterioration of vision (10 cases), abnormal gait (8 cases), convulsions (5 cases), Vomitting ( 5 cases) stool and urine incontinence (4 cases). Other less common presenting complaints were confusion, loss of consciousness, slurred speech, hemiparesis, mutism, abnormal behavior and hiccups (Figure 1).

 

Neurosurgical interventions: as shown in Figure 2 below, majority of the patients (28 cases) had insertion of ventriculoperitoneal shunt (VPS). For those aged >12 years, 13 out of the 27 patients had Endoscopic Third Ventriculostomy (ETV) carried out and 1 had both ETV and VPS shunt insertion. For those who were < 1year old, 8 patients underwent ETV alone while 2 cases had both ETV and VP shunt insertion.

 

Kafarnosky score: the Kafarnosky score for patients who were 12 years and above was estimated preoperative, 1 month post-operative and 6 month post-operative (Figure 3). Majority of the patients preoperatively had a Kafarnosky score of 60 and below. The Kafarnosky score improved markedly in 6 month post-operatively with 19 out of the 27 patients having a score of 100.

 

 

Aqueductal stenosis is the commonest cause of congenital hydrocephalus. There has been paucity of data regarding the prevalence of this condition in our setting. There were 52 cases out of the 258 (20%) cases of hydrocephalus that had aqueductal stenosis as a cause of hydrocephalus, with a rate off 9.6% having congenital aqueductal stenosis and rate of 10% in adults. This is lower compared to reported cases of 30-40% with a varying prevalence of 15-60% of hydrocephalus in children and 10-40% of cases in adults [7,8]. There was a bimodal distribution seen with age with one peak being before the age of 1 years and the second peak being after 12 years which compares with previously documented data [9]. The male to female ratio in this study of 3:2 differs from that documented of 14:13 [9,10]. The presenting complaint for hydrocephalus differed according to the age of presentation. Early onset aqueductal stenosis was mainly associated with increase in head circumference, tense anterior fontanelle, sunset eyes. The main complaints for late onset were headache, visual deterioration, urine incontinence, abnormal gait, abnormal behavior. Both groups had convulsions and vomiting. These results are synchronous with previous studies [11]. Tremors have been reported in previous studies as a presenting complaint but this was not seen in this study [12]. Procedures available in the treatment of hydrocephalus include ventriculoperitoneal shunt and more recently Endoscopic Third ventirulostomy. The documented success rate for ETV is 75% [13] and is reported to have a shorter hospital stay compared to shunt insertion [14].

 

 

Aqueductal stenosis contributes a significant burden of morbidity in patients with hydrocephalus. Clinical presentation differs according to patients´ age. Accurate diagnosis and treatment remain a cardinal to improving patient outcome.

 

 

The authors declare no competing interest.

 

 

All three authors have made substantial contributions to conception and design, acquisition of data, analysis and interpretation of data and drafting the article or revising it critically for important intellectual content; and final approval of the version to be published. All authors have read and approved the final manuscript.

 

 

We would like to thank the Kenyatta National Hospital records team for facilitating the retrieval for the records.

 

 

Figure 1: common presenting complaints in patients with hydrocephalus due to aqueductal stenosis in a Kenyan setting. The most common complaints are: increase in head circumference, tense anterior fontanelle and sunset eyes in <1 year and headache, loss of vision, abnormal gait, convulsions, Vomiting stool and urine incontinence

Figure 2: neurosurgical interventions including Endoscopic third ventriculostomy (ETV) and Ventriculoperitoneal (VP) shunting carried out for patients with hydrocephalus due to aqueductal stenosis in the two age groups. In some patients VP shunt was placed before ETV was done

Figure 3: kafarnosky score of patients aged > 12 years who were diagnosed with hydrocephalus due to aqueductal stenosis. This figure compares the Kafanosky score pre and post operatively

 

 

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