Three-day CSF drainage barely reduces ventricular size in normal pressure hydrocephalus

ArticleinNeurology 79(3):237-42 · July 2012with25 Reads
DOI: 10.1212/WNL.0b013e31825fdf8a · Source: PubMed
External lumbar drainage (ELD) of CSF is a test to determine the suitability of a shunt for patients with normal pressure hydrocephalus (NPH), but its effect on ventricular volume is not known. This study investigates the effect of 3-day ELD of 500 mL on ventricular size and clinical features in patients with idiopathic NPH. Fifteen patients were investigated in a 1.5-T MRI scanner before and after ELD. Ventricular volume was measured manually. Clinical features involved motor and cognitive functions, testing primarily gait and attention. Reduction in ventricular volume was correlated to total drain volume and clinical parameters. Statistical tests were nonparametric, and p < 0.05 was required for significance. Drain volume was 415 mL (median 470 mL, range 160-510 mL). Ventricular size was reduced in all patients, averaging 3.7 mL (SD 2.2 mL, p < 0.001), which corresponded to a 4.2% contraction. The ratio of volume contraction to drain volume was only 0.9%. Seven patients improved in gait and 6 in attention. Ventricular reduction and total drain volume correlated neither with improvement nor with each other. The 7 patients with the largest drain volumes (close to 500 mL), had ventricular changes varying from 1.3 to 7.5 mL. Clinical improvement occurs in patients with NPH after ELD despite unaltered ventricles, suggesting that ventricular size is of little relevance for postshunt improvement or determining shunt function. The clinical effect provided by ELD, mimicking shunting, is probably related to the recurring CSF extractions rather than to the cumulative effect of the drainage on ventricular volume.
    • "We did not see advantages to using isotropic volume fraction compared to MD, or vice- versa. CBF in iNPH patients has been studied by DSC-MRI, PET and SPECT [24,30,37], but the first publication on iNPH using ASL appeared only very recently [38]. This was a study of CBF before and after CSF tap test that employed an ASL protocol with shorter post-label delay than ours (1.6 s vs. 2 s in our study). "
    [Show abstract] [Hide abstract] ABSTRACT: The objective was to identify changes in quantitative MRI measures in patients with idiopathic normal pressure hydrocephalus (iNPH) occurring in common after oral acetazolamide (ACZ) and external lumbar drainage (ELD) interventions. A total of 25 iNPH patients from two clinical sites underwent serial MRIs and clinical assessments. Eight received ACZ (125-375 mg/day) over 3 months and 12 underwent ELD for up to 72 hours. Five clinically-stable iNPH patients who were scanned serially without interventions served as controls for the MRI component of the study. Subjects were divided into responders and non-responders to the intervention based on gait and cognition assessments made by clinicians blinded to MRI results. The MRI modalities analyzed included T1-weighted images, diffusion tensor Imaging (DTI) and arterial spin labelling (ASL) perfusion studies. Automated threshold techniques were used to define regions of T1 hypo-intensities. Decreased volume of T1-hypointensities and decreased mean diffusivity (MD) within hypo-intensities was observed after ACZ and ELD but not in controls. Patients responding positively to these interventions had more extensive decreases in T1-hypointensites than non-responders: ACZ-responders (4,651 ± 2,909 mm(3)), ELD responders (2,338 ± 1,140 mm(3)), ELD non-responders (44 ± 1,188 mm(3)). Changes in DTI MD within T1-hypointensities were greater in ACZ-responders (7.9% ± 2%) and ELD-responders (8.2% ± 3.1%) compared to ELD non-responders (2.1% ± 3%). All the acetazolamide-responders showed increases in whole-brain-average cerebral blood flow (wbCBF) estimated by ASL (18.8% ± 8.7%). The only observed decrease in wbCBF (9.6%) occurred in an acetazolamide-non-responder. A possible association between cerebral atrophy and response was observed, with subjects having the least cortical atrophy (as indicated by a positive z-score on cortical thickness measurements) showing greater clinical improvement after ACZ and ELD. T1-hypointensity volume and DTI MD measures decreased in the brains of iNPH patients following oral ACZ and ELD. The magnitude of the decrease was greater in treatment responders than non-responders. Despite having different mechanisms of action, both ELD and ACZ may decrease interstitial brain water and increase cerebral blood flow in patients with iNPH. Quantitative MRI measurements appear useful for objectively monitoring response to acetazolamide, ELD and potentially other therapeutic interventions in patients with iNPH.
    Full-text · Article · Apr 2015
  • [Show abstract] [Hide abstract] ABSTRACT: Objective: Negative-pressure hydrocephalus (NegPH) is a rare clinical entity characterised by enlarged ventricles and symptoms consistent with increased intracranial pressure (ICP) in the setting of negative ICP. Little has been published regarding appropriate treatment and outcomes of negative-pressure hydrocephalus patients, and no data have been published demonstrating successful therapy producing acceptable long-term outcomes. Here we present 8 cases successfully treated by titrated external ventricular drainage (TEVD), including drainage at negative (subatmospheric) pressure, and subsequent low-pressure ventriculoperitoneal shunting. Methods: A retrospective audit of all cases of negative-pressure hydrocephalus occurring at a university teaching hospital between 2006 and 2012 was undertaken. The clinical features of these cases, results of radiological investigations, treatment, and outcome were drawn from the patients' records. Results: Eight cases of NegPH were identified. All patients had at least one preceding intracranial procedure (mean number of procedures 3.0). All cases were treated using TEVD, titrated to produce between 5 and 15 mL per hour of CSF drainage, including drainage under subatmospheric pressure if this was required to maintain CSF flow. Mean delay from first negative ICP to TEVD was 1.8 days. All 8 patients demonstrated clinical improvement. TEVD resulted in improvement in Glasgow Coma Scale (mean increase 4.6, p=0.003), and increases in ICP (mean increase 8.5, p<0.001). Mean length of follow-up was 471.8 days. At follow-up, four patients had returned to pre-morbid functioning, three had a reduction in functioning attributable to their initial presentation (not NegPH), and one had died of unknown cause. Illustrative case descriptions are included. Conclusions: Negative-pressure hydrocephalus is a rare but underrecognised syndrome that can be successfully treated by timely external ventricular drainage titrated to maintain CSF flow, and subsequent low-pressure ventriculoperitoneal shunting.
    Article · Nov 2013
  • [Show abstract] [Hide abstract] ABSTRACT: Although it has been nearly 50 years since its first description of clinical and radiological, there is considerable uncertainty about the diagnosis of normal pressure hydrocephalus because it shares the semiotics with the group of dementias. Hakim's triad (impaired gait, initially type clumsiness of the lower limbs followed over time by inability to ambulate or maintain an erect posture; cognitive impairment, initially limited to worsening deficits in memory fixation and execution of complex actions; the urinary disorder, initially type "urgent urination" and then complete urinary incontinence) characterizes the progressive course of the adult chronic hydrocephalus. The clinical onset is typically nonspecific, subtle, and most often monosymptomatic. The first diagnostic procedure is a head CT scan and/or brain MRI, which shows an abnormal dilatation of the lateral ventricles and the third ventricle, associated to variable brain atrophy. Not all subjects will develop a set of symptoms, since the altered cerebrospinal fluid dynamics can remain stable for many years or get progressively worse until the appearance of the clinical triad of normal pressure hydrocephalus. The test of intrathecal infusion (Katzman test) carried out at constant speed with the introduction of saline solution into the lumbar subarachnoid space and the concomitant detection of cerebrospinal fluid pressure establishes that patients with outflow resistance ranging from 12 to 19 mmHg/ml/ min can improve clinically after surgery. This method requires extensive and prolonged experience of the center of application and the use of computer systems. The withdrawal of lumbar cerebrospinal fluid provides for the evacuation of 30-50 cc of cerebrospinal fluid by lumbar puncture under local anesthesia, preceded and followed by gait assessment and neuropsychological tests. It also uses the continuous withdrawal of CSF with an intrathecal catheter placed for 3 days, in order to drain approximately 135 ml/24 h and the aim of reducing false negatives. After surgery, the patient is usually able to regain a good quality of life, with independence in daily living activities. The duration of such postsurgical improvement is variable, but patients may improve again readjusting the opening pressure of the programmable valve, although a high comorbidity index is strictly related to a poor outcome.
    Full-text · Chapter · Jan 2014 · Clinical neurology and neurosurgery
Show more