Diverticular Enlargement of Foramen of Luschka and Hydrocephalus in Child with Noonan Syndrome

The endoscopic treatment of fourth ventricle outlet obstruction: Report of two children and systematic review

Fourth ventricle outlet obstruction (FVOO) is a rare cause of hydrocephalus. In the last century, the standard treatment was the suboccipital craniotomy with magendieplasty or ventriculoperitoneal shunt (VP shunt). Since the beginning of the 21st century, the endoscopic third ventriculostomy (ETV) has been considered a less invasive alternative. The medical literature lacks sufficient reports of FVOO cases and strong evidence about ETV's efficacy in treating this condition. We report two cases of FVOO treated with ETV and review published similar cases. Clinical and radiological findings of two FVOO cases with outcomes after ETV were presented. Moreover, we conducted a systematic review after protocol registration in PROSPERO (CRD42021281474). MEDLINE, Embase, Scopus, and Web of Science were searched from inception till December 31, 2022. Studies were included if they reported cases of FVOO treated initially with ETV. Cases with Chiari malformation, Dandy-Walker malformation, tuberous sclerosis, trapped fourth ventricle, or space-occupying lesions were excluded. Two reviewers independently examined title/abstract records in the first stage and full-text publications in the second for eligibility. The primary outcome was the recurrence rate, defined by the need for re-ETV or other invasive treatments (e.g., VP shunt or magendieplasty). Other outcomes included clinical state at follow-up and mortality. Two cases, a 3-year-old male and 3.5-year-old female, with FVOO, were treated with ETV in our department by the same neurosurgeon (SH) in 2013 and 2021. Both cases improved significantly after ETV, and there was no recurrence through the follow-up. Besides the present cases, we found 57 other cases of FVOO treated with ETV reported in 17 studies between 2001 and 2021. The median age was 26 years, with an IQR from 2.4 to 59 years, and 56% of cases were females. The recurrence rate was 32% in the sample (19 out of 59), with a 95% CI from 21% to 46%. The median time to recure was 2 months with IQR from 1.25 to 26. A VP shunt was the treatment for recurrence in 68% and a re-ETV in 32%. At the follow-up (41 ± 29 months), only one case died, and one deteriorated clinically. FVOO is a rare cause of hydrocephalus encountered mainly in the first or sixth decades of life. ETV provides the first reasonable treatment. Despite the moderate recurrence rate, the outcomes are favorable.

Holocord Syrinx Associated with Shunt Malfunction in Tetraventricular Hydrocephalus

We present an uncommon case of holocord, "rosary bead-like," multiloculated syringomyelia consistent with a fourth ventricle outlet obstruction in a 2-month-old infant who was previously shunted for posthemorrhagic hydrocephalus of prematurity. The shunt malfunction resulted in a syringomyelia because of the simultaneous obstruction of the 3 outlets of the fourth ventricle, resulting in an enlargement of the central canal of the spinal cord. The syringomyelia resolved with shunt revision, avoiding further complex surgical procedures.

Fourth Ventricle Outlet Obstruction and Diverticular Enlargement of Luschka Foramina in a Child with Down Syndrome

INTRODUCTION

Hydrocephalus is not usually part of Down syndrome (DS). Fourth ventricle outlet obstruction is a rare cause of obstructive hydrocephalus, difficult to diagnose, because tetraventricular dilatation may suggest a communicant/nonobstructive hydrocephalus.

CASE PRESENTATION

We describe the case of a 6-year-old boy with obstructive tetraventricular hydrocephalus, caused by Luschka and Magen-die foramina obstruction and diverticular enlargement of Luschka foramina (the so-called fourth ventricle outlet obstruction) associated with DS. He was treated with endoscopic third ventriculostomy (ETV) without complications, and a follow-up MRI revealed reduction of the ventricles, disappearance of the diverticula, and patency of the ventriculostomy.

CONCLUSION

Diverticular enlargement of Luschka foramina is an important radiological finding for obstructive tetraventricular hydrocephalus. ETV is a viable option in tetraventricular obstructive hydrocephalus in DS.