Long-term follow-up of successful treatment for dandy-walker syndrome (DWS)

Abstract

Background: Various managements of Dandy-Walker syndrome (DWS) from open excision of the cysts to CSF diversion have been reported. However, optimal treatment for DWS remains elusive. Methods: Cyst fenestration was employed firstly, but failed 15 days after the surgery. Then a ventriculoperitoneal (VP) shunt was inserted and the patient discharged from hospital 13 days after the second surgery. During the 12-year follow-up, CT scanning, MRI, and X-radiation were performed. Results: CT scanning showed that the size of ventricular system gradually returned to normal. MRI revealed similar changes of the ventricular system, and further revealed the development of supratentorial brain. The results of X-radiation during the follow-up years showed that the peritoneal end of the shunt might be already out of the abdominal cavity. Slow refilling of the shunt valve may suggest that the shunt could be probably not functional. Conclusion: The treatment of the patient was successfully, and the abnormal cerebral ventricle system gradually recovered during the 12-year follow-up. Because the patient might be probably independent on the shunt, further choice of the shunt removal should be thinking thoroughly, considering both safety and quality of life for the patient.

Introduction

Dandy-Walker syndrome (DWS) is a brain malformation, characterized by posterior fossa cyst, cystic dilatation of the fourth ventricle, cerebellar vermis dysgenesis, and an upwardly displaced tentorium [1,2]. Various managements of DWS have been reported from open excision of the cysts to CSF diversion [3,4]. Ventriculoperitoneal (VP) and cystoperitoneal (CP) shunt insertion, either alone or in combination, were the most common choices in the treatment of DWS. Ventriculoperitoneal shunting was recommended to be the choice of initial treatment, due to its relative low rate of migration and relative simplicity of surgery [4,5].

DWS causes motor dysfunction and mental retardation lead to poor prognosis for normal intellectual development [6]. Many successful surgical treatments of DWS were reported [7,8]. However, the recovery process of the enlarged cerebral ventricle system has been less reported during the long-term follow-up periods [9].

In this report, a 2-year-old boy suffered from DWS was successfully treated and followed up for 12 years post surgery.

Case report

A 2-year-old boy, who was born by normal vaginal delivery following an uneventful pregnancy, admitted to hospital due to headache, appetite loss and vomiting. The head circumference (HC) was 51 cm. The result of examination showed that there’s no abnormality of intelligence and development. The boy represented unsteady walking gaits and paralysis of facial muscles, with full consciousness and eye movement desensitization. Computed tomography (CT) of brain revealed a huge fan-shaped cyst in the posterior fossa connected with the fourth ventricle, brainstem forward, absent of vermis, upward shift of the transverse sinuses, and symmetric enlargement of supratentorial ventricles (Figure 1A). Magnetic resonance imaging (MRI) showed dysgenesis of corpus callosum as well as an extremely dilatation of the two lateral ventricles, the third ventricle, the aqueduct of Silvius and the fourth ventricle (Figure 3). Combined the results of CT and MRI, the boy was diagnosed with Dandy-walker syndrome (DWS). Informed consent was obtained from the patient’s father.

Figure 1.

CT scanning of brain. A. Pre-operative CT scanning showed a greatly enlarged brain ventricle system. B. CT image of 11 days after the first surgery showed pneumocephalus and a dilated ventricle system as large as preoperation. C. CT image of one week after the second surgery showed a slight decrease of ventricle system.

Figure 3.

Magnetic resonance imaging (MRI). Pre-operative MRI showed that dysgenesis of corpus callosum and an extremely dilatation of ventricle system. MRI during the 12-year follow-up showed a gradually decrease of ventricle system and development of supratentorial brain.

Obstructing arachnoid membrane was excised via an open surgical technique to facilitate spinal fluid flow. The symptom such as vomiting and headache was relieved in the first several days after surgery. However, on postoperative day 7, the intracranial pressure increased and almost reached the preoperative level on the 15 day. The CT image of 11 days after the first surgery showed pneumocephalus and a dilated ventricle system as large as preoperation (Figure 1B). Then we performed ventriculoperitoneal (VP) shunt insertion. After the second surgery, the symptom like vomiting and headache vanished, CT image of one week showed a slight decrease of ventricle system (Figure 1C), and the patient discharged from hospital 13 days after the second surgery.

The period of follow-up was 12 years, and CT scanning and MR were performed every one or two years. The results of CT scanning showed that the size of ventricular system greatly decreased during the 9 months post surgery and has been slowly decreasing up to 4 years, but the ventricular system was still abnormal (Figure 2). From 6 years to 12 years, the CT results revealed that the size of ventricular system gradually returned to normal with slightly changes and the size of the dilated forth ventricular was obviously reduced (Figure 2). MRI revealed similar changes of the ventricular system and further showed the development of supratentorial brain (Figure 3).

Figure 2.

CT images during the 12-year follow-up showed that the size of the dilated ventricle system gradually returned to normal.

The patient was 2 years old and about 95 cm tall at admission. Considering the growth of boy and the permanent placement of shunt, we intentionally inserted a longer shunt about 95 cm (Figure 4). The boy was proximately 1.55 meter tall in 2013 and the results of X-radiation on 2013 showed that the peritoneal end of the shunt was already out of the abdominal cavity (Figure 4). The bounce was very slow after pressing the shunt valve, suggesting that the shunt could be probably not functional. Up to 2013, he has been in good condition without any abnormalities in intelligence or developmental disorders.

Figure 4.

Images of X-radiation during the follow-up years. Image of 12 years post-surgery showed that the peritoneal end of the shunt was already out of the abdominal cavity.

Discussion

In the early series, based on the knowledge of treatment of hydrocephalus which is also a typical symptom for DWS, surgical management involved resection of the posterior fossa membranes was employed to circulate the cerebrospinal fluid. DWS occurs one in every 30,000 live births [10]. Barely 60 cases of DWS had been reported in China till the year 2000, which indirectly led to the lack of knowledge about the treatment for the DWS. In this case, the intracranial pressure got back to the preoperative level on 15th day after the first surgical management of arachnoid membrane excision, which further proved that membrane resection is not a proper choice for the treatment of DWS especially for younger children as reported by Mohanty et al. in 2006 [11].

VP shunt, a most common pediatric neurosurgical procedure [12,13], was applied in our case. During the 12-year follow-up, CT scanning and MRI revealed the healing process of the enlarged cerebral ventricle system. X-radiation showed that the peritoneal end of the shunt might be already out of the abdominal cavity and the bounce was very slow after pressing the shunt valve.

The removal of VP shunt has been described as the ultimate treatment of the slit ventricle syndrome [14] and it is also the ultimate success for the treatment of DWS. Baskin et al. introduced a protocol in which fiberoptic intracranial pressure monitoring was used after removal of the patients’ ventricular shunt systems, and they found that 64% of the patients were no longer shunt dependent after a mean follow-up period of 21.4 months [14].

In our case, the possibly ineffective shunt might have multiple unfavorable effects on the patient’s quality of life. With the growth of height, the shunt might cause discomfort for the patient due to the growing intension. Part of the shunt route underneath skin is visible, which might negatively impact the appearance and mental health of the patient. Considering the internationally increasing importance of patients’ health, both in physical and psychological conditions, whether and how to remove the shunt would be a critical issue for this case in the future.

Here we report a successful treatment of DWS using VP shunting with a 12-year follow-up. Our results may provide insight into the recovery process for cerebral ventricle system after the VP shunting for DWS. Further choice of the shunt removal should be thinking thoroughly, considering both safety and quality of life for the patient.

Disclosure of conflict of interest

None.