Surgical treatment of long-standing overt ventriculomegaly in adults (LOVA)

Acta Neurochir (2017) 159:71–79

Longstanding overt ventriculomegaly in adults (LOVA) is characterised by chronic hydrocephalus presumed to begin during infancy, but arresting before becoming clinically detectable. Later in life clinical features of hydrocephalus ensue, typically in the 5th or 6th decades. Only a relatively small number of LOVA case series have been published, and ambiguity remains regarding optimal management. This case series describes a series of patients with LOVA treated successfully at a single neurosurgical institution using endoscopic third ventriculostomy (ETV).

Methods: A series of 14 patients were diagnosed with LOVA using established clinical and radiological criteria. All patients underwent an ETV and their clinical conditions were followed up for up to 5 years post-operatively.

Results: Fourteen patients (100 %) reported either improvement or halt of progression in their presenting symptoms 3 months after ETV; 93 % of patients (n = 13) did not require any further surgical intervention. One patient (7 %) reported deterioration in symptoms beyond 3 months post-operatively, which necessitated further surgery (ventriculoperitoneal shunt). These promising outcomes after ETV are mirrored in numerous other LOVA case series. Other works have analysed the value of CSF shunting procedures in LOVA, with mixed results. A direct, prospective comparison of outcomes after shunt procedures and ETV, with a specific focus on LOVA patients, is yet to be completed. A minority of patients fail to respond, or develop recurrence of symptoms, months or years after initial surgical intervention.

Conclusions: ETV is an attractive option for surgical treatment of LOVA. After surgical treatment for LOVA, long-term follow-up should be considered to screen for late recurrence of the condition.

One-year outcome in patients with idiopathic normal-pressure hydrocephalus: comparison of lumboperitoneal shunt to ventriculoperitoneal shunt

J Neurosurg 125:1483–1492, 2016

Idiopathic normal pressure hydrocephalus (iNPH) is treated with cerebrospinal fluid shunting, and implantation of a ventriculoperitoneal shunt (VPS) is the current standard treatment. The objective of this study was to compare the efficacy and safety of VPSs and lumboperitoneal shunts (LPSs) for patients with iNPH.

Methods The authors conducted a prospective multicenter study of LPS use for patients with iNPH. Eighty-three patients with iNPH (age 60 to 85 years) who presented with ventriculomegaly and high-convexity and medial subarachnoid space tightness on MR images were recruited from 20 neurological or neurosurgical centers in Japan between March 1, 2010, and October 19, 2011. The primary outcome was the modified Rankin Scale (mRS) score 1 year after surgery, and the secondary outcome included scores on the iNPH grading scale (iNPHGS). A previously conducted VPS cohort study with the same inclusion criteria and primary and secondary end points was used as a historical control.

Results: The proportion of patients who achieved a favorable outcome (i.e., improvement of at least 1 point in their mRS score) was 63% (95% CI 51%–73%) and was comparable to values reported with VPS implantation (69%, 95% CI 59%–78%). Using the iNPHGS, the 1-year improvement rate was 75% (95% CI 64%–84%) and was comparable to the rate found in the VPS study (77%, 95% CI 68%–84%). The proportion of patients experiencing serious adverse events (SAEs) and non-SAEs did not differ signi cantly between the groups at 1 year after surgery (SAEs: 19 [22%] of 87 LPS patients vs 15 [15%] of 100 VPS patients, p = 0.226; non-SAEs: 24 [27.6%] LPS patients vs 20 [20%] VPS patients, p = 0.223). However, shunt revisions were more common in LPS-treated patients than in VPS-treated patients (6 [7%] vs 1 [1%]).

Conclusions The efficacy and safety rates for LPSs with programmable valves are comparable to those for VPSs for the treatment of patients with iNPH. Despite the relatively high shunt failure rate, an LPS can be the treatment of choice because of its minimal invasiveness and avoidance of brain injury.

 

DTI-MRI biomarkers in the search for normal pressure hydrocephalus aetiology

DTI chronic hydro

Neurosurg Rev (2015) 38:239–244

Normal pressure hydrocephalus (NPH) is a clinical syndrome characterized by gait disturbances, urinary incontinence and dementia. Clinical presentation overlaps with Alzheimer disease (AD).Early recognition thus early intervention (shunting) is important for successful treatment, but lack of a diagnostic test with sufficient sensitivity and specificity complicates the diagnosis.

We performed literature search and composed a structured review of imaging biomarkers of NPH. Morphometric studies are not sufficient to diagnose NPH. Hydrocephalus is a common finding in elderly people due to the symmetric brain atrophy and is even more pronounced in patients with AD. The key MRI biomarker seems to be diffusion tensor imaging (DTI). According to recent studies, the DTI analysis of the splenium corporis callosi, posterior limb of internal capsule, hippocampus and fornix combined with measurement of Evans index is a promising MRI biomarker of NPH and could be used for NPH diagnostics and in the differential diagnosis from AD and other dementias.

Evans’ Index Revisited: The Need for an Alternative in Normal Pressure Hydrocephalus

Neurosurgery 68:939–944, 2011 DOI: 10.1227/NEU.0b013e318208f5e0

The international guidelines for the diagnosis of normal pressure hydrocephalus (NPH) define ventricular enlargement as Evans’ index greater than 0.3.

OBJECTIVE: To establish whether there is a correlation between Evans’ index and ventricular volume (VV) in NPH and whether choosing different planes for the measurements could produce significantly different results.

METHODS: Pre–shunt insertion, thin-section CT scans of the brains of 10 patients with shunt-responsive NPH were reviewed retrospectively, measuring Evans’ index, frontal horn index, VV, and total intracranial volume (ICV). The ventricular/intracranial volume index (VV/ICV) was calculated. Correlation between each of the linear indices and VV and VV/ICV was done.

RESULTS: Significant differences were found in the index values calculated at different planes. The frontal horn index at a plane 16 mm parallel to the anterior commissure– posterior commissure (AC-PC) plane showed best correlation with VV and VV/ICV (r: 0.658 and 0.587, respectively). Evans’ index, also obtained at a plane 16 mm parallel to the AC-PC plane, showed best correlation with VV and VV/ICV (r: 0.619 and 0.498, respectively).

CONCLUSION: Evans’ index value can vary significantly in a patient with NPH, depending on the level of the brain CT scan image at which the frontal horns and maximal inner skull diameters are measured. Evans’ index is not an ideal method for estimating the VV in NPH patients. Volumetric measurements represent the logical accurate estimate of true ventricular size as well as the size of the other intracranial compartments.

Evaluation of ventriculomegaly using diffusion tensor imaging: correlations with chronic hydrocephalus and atrophy

J Neurosurg 112:832–839, 2010. (DOI: 10.3171/2009.7.JNS09550)

Ventriculomegaly is a common imaging finding in many types of conditions. It is difficult to determine whether it is related to true hydrocephalus or to an atrophic process by using only imaging procedures such as MR imaging after traumatic injury, stroke, or infectious disease. Diffusion tensor (DT) imaging can distinguish the compression characteristics of white matter, indicating that increased diffusion anisotropy may be related to white matter compression. In this preliminary study, the authors compared the DT imaging findings of ventriculomegaly with those of chronic hydrocephalus or atrophy to clarify the potential of diffusion anisotropy in the identification of hydrocephalus. Methods. Ten patients with chronic hydrocephalus, 8 patients with atrophy (defined by conventional devices and surgical outcome), and 14 healthy volunteers underwent DT imaging. Images were acquired before and after shunting or once in cases without shunting. The fractional anisotropy (FA) values at many points around the lateral ventricle were evaluated. Results. The FA patterns around the lateral ventricle in the chronic hydrocephalus and atrophy groups were different. Especially in the caudate nucleus, FA was increased in the chronic hydrocephalus group compared with the atrophy group. Furthermore, the FA values returned to normal levels after shunt placement. Conclusions. Assessment of the FA value of the caudate nucleus may be an important, less invasive method for distinguishing true hydrocephalus from ventriculomegaly. Further research in a large number of patients is needed to verify the diagnostic ability of this method.