Arterial blood pressure vs intracranial pressure in normal pressure hydrocephalus

Eide PK, Park E‐H, Madsen JR. Arterial blood pressure vs intracranial pressure in normal pressure hydrocephalus.
Acta Neurol Scand: 2010: 122: 262–269.
© 2010 John Wiley & Sons A/S. Objective – To characterize the association between arterial blood pressure (ABP) and intracranial pressure (ICP) in idiopathic normal pressure hydrocephalus (iNPH) patients, and its impact on outcome of shunt surgery. Materials and methods – We analyzed all 35 iNPH patients whose ABP and ICP were recorded simultaneously during 6 years (2002–2007). The static and pulsatile pressures were averaged over consecutive 6‐s intervals; the moving correlations between ICP and ABP (static and pulsatile) were determined during consecutive 4‐min periods to explore time‐related variations. Results – Neither static nor pulsatile ABP were altered in iNPH shunt responders. Elevated pulsatile ICP, but normal static ICP, was seen in responders. The time‐varying correlations of static and of pulsatile pressures were generally low, and did not differ between shunt responders/non‐responders. Conclusions – In iNPH shunt responders, static or pulsatile ABP were not altered and only pulsatile ICP was elevated.     

Cerebrospinal fluid outflow and intracranial pressure in hydrocephalic patients with external ventricular drainage

Klein O, Demoulin B, Jean Auque RT, Audibert G, Sainte‐Rose C, Marchal J‐C, Marchal F. Cerebrospinal fluid outflow and intracranial pressure in hydrocephalic patients with external ventricular drainage.
Acta Neurol Scand: DOI: 2010: 122: 140–147.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Background and purpose – The aim of this study was to monitor the 24 h cerebrospinal fluid (CSF) outflow and intracranial pressure (ICP) in hydrocephalic adult patients with external ventricular drainage (EVD). Patients and methods – Twelve patients (5M/7F) aged 30–69 years suffering from acute hydrocephalus requiring EVD were admitted in the neuro‐intensive care unit. The CSF collecting bag was continuously weighted using a high‐precision scale, the filtered output of which was fed at 1 Hz to a computer and converted to flow (Q′ext_csf). ICP was also recorded. Results – One patient was excluded because more than 80% of the Q′ext_csf data were rejected by the system. The mean ± SD Q′ext_csf and ICP were respectively 7.5 ± 3.4 ml/h (range 1.6–12.1 ml/h) and 12.4 ± 2.7 mmHg. Two patterns of Q′ext_csf were identified: a continuous profile and a discontinuous one with numerous bursts frequently associated with manoeuvres such as cough or chest physiotherapy. The short‐term variations of Q′ext_csf and ICP were usually unrelated. Conclusion – The study stresses the important inter and intra‐subject variability of Q′ext_csf in patients with EVD. The mean Q′ext_csf is lower than the reference production rate (21 ml/h), raising the question of persistent CSF absorption and/or depressed secretion. The independent changes of Q′ext_csf and ICP on the short term is likely to be explained by the pressure–volume characteristics of the intracranial space.     

Lack of relationship between resistance to cerebrospinal fluid outflow and intracranial pressure in normal pressure hydrocephalus

OBJECTIVE: To explore whether calculation of resistance to cerebrospinal fluid (CSF) outflow (Rout) by the lumbar constant rate infusion test in a reliable way predicts the intracranial pressure (ICP) profile in normal pressure hydrocephalus (NPH). METHODS: A prospective study was undertaken including 16 cases with clinical signs of normal pressure hydrocephalus that were investigated with both continuous ICP monitoring and the lumbar constant rate infusion test. Intracranial pressure monitoring was performed for about 24 h, and supplied with a simultaneous lumbar constant rate infusion test at the end of the monitoring period. The pressure recordings were analysed using the Sensometrics Pressure Analyser. Various characteristics of the pressure curves were compared. RESULTS: The continuous ICP recordings were considered as normal (mean ICP<11.5 mmHg) in all 16 cases. The lumbar infusion test showed an apparently abnormal resistance to CSF outflow (Rout) (> or =12.0 mmHg/ml/min) in 12 of 16 cases. There was no relationship between lumbar Rout and mean ICP during sleep. We could not find any relationship between lumbar Rout and number of nightly ICP elevations of 1525 mmHg lasting 0.5 or 1 min. Neither resistance to CSF outflow (Rout) nor mean ICP during sleep was related to the ventricular size. CONCLUSIONS: The results of this prospective study revealed no significant relationship between resistance to CSF outflow (Rout) and the ICP profile in NPH cases. The results also suggest that caution should be made when predicting the ICP profile on the basis of measuring the lumbar CSF pressure for a few minutes duration.     

Pressure compensation in shunt-dependent hydrocephalus with CSF shunt malfunction

This study is a retrospective analysis of intracranial pressure (ICP) and cerebral perfusion pressure (CPP) data from 56 children with active hydrocephalus and cerebrospinal fluid (CSF) shunt malfunction. The pressures were measured from a separately sited CSF access device placed in the frontal horn of the lateral ventricle. Of the patients, 79% had an elevated ICP (mean 20±12 mmHg). A subgroup of patients demonstrated ten different forms of CSF-filled swelling. This group had significantly lower ICP recordings (P=0.000075) with a mean ICP of 8.5 mmHg compared with the remainder (22.9 mmHg). This pressure ’compensation’ was because of additional nonphysiological accommodation of CSF volume. Overall the CPP was normal in 35% of cases despite normal ICP occurring in only 11% of cases. The CPPs were not significantly different in those with and without compensation. Measurement of ICP may not always be a reliable indicator of shunt malfunction in shunt- dependent children who present with compensatory CSF-filled spaces. Received: 10 March 2000     

Implementation of a new CSF dynamic device: a multicenter feasibility study in 562 patients

Malm J, Sundström N, Cesarini KG, Edsbagge M, Kristensen B, Leijon G, Eklund A. Implementation of a new CSF dynamic device: a multicenter feasibility study in 562 patients.
Acta Neurol Scand: 2012: 125: 199–205.
© 2011 John Wiley & Sons A/S. Objectives – The cerebrospinal fluid (CSF) infusion test is frequently used when selecting hydrocephalus patients for shunt surgery. Very little has been reported regarding adverse events. We present a prospective feasibility study. Methods – Standardized devices for measuring CSF dynamics were built and 562 patients investigated: Needles were placed by lumbar puncture (LP). An automatic CSF infusion protocol was performed. Course of events during the investigation as well as adverse events were registered. Results – Preoperative evaluation of normal‐pressure hydrocephalus was the most common indication (63%), followed by evaluation of shunt function (23%) and intracranial pressure recordings (14%). The LP was successfully performed in all but nine cases with 24 patients (4.3%) reporting major discomfort. Ringer infusion was performed in 474 investigations, and a valid measurement of the outflow resistance was received in 439 (93%). During the infusion phase, 17 (4%) patients reported severe headache. Infusion volume was significantly higher in patients having subjective symptoms during the infusion phase compared with those without adverse events. During 269 preoperative CSF tap tests, six (2%) patients had severe headache. Post‐investigational headache was reported by 83 (15%) patients at the 24‐h follow‐up. No serious adverse events were observed. Conclusion – Infusion testing was safe and without serious adverse events with a high rate of successful procedures. The investigation was associated with expected mild to moderate discomfort.     

How does CSF dynamics change after shunting?

Objective –  Hydrocephalus is much more complex than a simple disorder of cerebrospinal fluid (CSF) circulation. Shunting primarily corrects disturbed fluid flow which may have an impact on cerebral blood flow and metabolism. We studied hydrocephalic patients before and after shunting to characterize changes in their CSF compensatory parameters.
Material and methods –  We selected 25 patients and studied them retrospectively. All patients had ventriculomegaly and clinical symptoms of normal pressure hydrocephalus. After shunting, they were still presenting with some adverse symptoms, mainly headaches, slow improvement or no improvement of ventriculomegaly. Therefore, they underwent further infusion studies to assess shunt function. In all cases, the shunts were confirmed to be draining CSF adequately. Parameters of CSF dynamics: baseline intracranial pressure (ICP), resistance to CSF outflow, cerebrospinal elasticity, content of vasogenic pressure waves (pulse, respiratory and B waves) and compensatory reserve assessed as moving correlation coefficient between mean CSF pressure and pulse amplitude (RAP), were compared before and after shunting.
Results –  Mean ICP and resistance to CSF outflow decreased ( P  < 0.003) after shunting. All vasogenic pressure waves decreased ( P  < 0.005). Compensatory reserve (RAP) significantly improved ( P  < 0.005).
Conclusion –  A functioning shunt has an important impact on CSF circulation and pressure–volume compensation. Infusion studies can demonstrate the return of disturbed CSF dynamics to normal values even if clinical or radiological changes are not dramatic.     

Prediction of shunt response in idiopathic normal pressure hydrocephalus by combined lumbar infusion test and preoperative imaging scoring

Background and purpose

Idiopathic normal pressure hydrocephalus (iNPH) is a potentially treatable disorder, but prognostic tests or biomarkers are lacking. The aim was to study the predictive power of clinical, neuroimaging and lumbar infusion test parameters (resistance to outflow R_out, cardiac-related pulse amplitude PA and the PA to intracranial pressure ICP ratio).

Methods

In all, 127 patients diagnosed with iNPH who had a lumbar infusion test, a subsequent ventriculo-peritoneal shunt operation and at least 2 months of postoperative follow-up were retrospectively included. Preoperative magnetic resonance images were visually scored for NPH features using the iNPH Radscale. Preoperative and postoperative assessment was performed using cognitive testing, as well as gait and incontinence scales.

Results

At follow-up (7.4 months, range 2–20 months), an overall positive response was seen in 82% of the patients. Gait was more severely impaired at baseline in responders compared to non-responders. The iNPH Radscale score was borderline significantly higher in responders compared with non-responders, whereas no significant differences in infusion test parameters were seen between responders and non-responders. Infusion test parameters performed modestly with high positive (75%–92%) but low negative (17%–23%) predictive values. Although not significant, PA and PA/ICP seemed to perform better than R_out, and the odds ratio for shunt response seemed to increase in patients with higher PA/ICP, especially in patients with lower iNPH Radscale scores.

Conclusion

Although only indicative, lumbar infusion test results increased the likelihood of a positive shunt outcome. Pulse amplitude measures showed promising results that should be further explored in prospective studies.     

Cerebral critical closing pressure in hydrocephalus patients undertaking infusion tests

Abstract

Objectives:

Links between cerebrospinal fluid (CSF) compensation and cerebral blood flow (CBF) have been studied in many clinical scenarios. In hydrocephalus, disturbed CSF circulation seems to be a primary problem, having been linked to CBF disturbances, particularly in white matter close to surface of dilated ventricles. We studied possible correlations between cerebral haemodynamic indices using transcranial Doppler (TCD) ultrasonography and CSF compensatory dynamics assessed during infusion tests.

Methods:

We analysed clinical data from infusion tests performed in 34 patients suspected to suffer from normal pressure hydrocephalus, with signals including intracranial pressure (ICP), arterial blood pressure (ABP) and TCD blood flow velocity (FV). Cerebrospinal fluid compensatory parameters (including elasticity) were calculated according to a hydrodynamic model of the CSF circulation. Critical closing pressure (CrCP) was calculated with the cerebrovascular impedance methodology, while wall tension (WT) was estimated as CrCP-ICP. Closing margin (CM) was expressed as the difference between ABP and CrCP.

Results:

Intracranial pressure increased during infusion from 6.7?±?4.6 to 25.0?±?10.5?mmHg (mean?±?SD; P?<?0.001), resulting in CrCP rising by 22.9% (P?<?0.001) and WT decreasing by 11.3% (P?=?0.005). Closing margin showed a tendency to decrease, albeit not significantly (P?=?0.070) due to rising ABP (9.1%; P?=?0.005). Closing margin at baseline ICP was inversely correlated to brain elasticity (R?=?(0.358; P?=?0.038), while being significantly different from zero for the whole duration of the tests (52.8?±?22.8?mmHg; P?<?0.001). Neither CrCP nor WT was correlated with CSF compensatory parameters.

Discussion:

Critical closing pressure increases and WT decreases during infusion tests. Closing margin at baseline pressure may act as an indicator of the cerebrospinal compensatory reserve.     

Rehabilitation effects in idiopathic normal pressure hydrocephalus: a randomized controlled trial

Journal of Neurology - Gait–balance disturbances are core symptoms of idiopathic normal pressure hydrocephalus (iNPH). However, the rehabilitation effects of cerebrospinal fluid (CSF)...     

Cerebrospinal fluid dynamics and long-term survival of the Strata valve in idiopathic normal pressure hydrocephalus

Lundkvist B, Koskinen L‐OD, Birgander R, Eklund A, Malm J. Cerebrospinal fluid dynamics and long‐term survival of the Strata^® valve in idiopathic normal pressure hydrocephalus.
Acta Neurol Scand: 2011: 124: 115–121.
© 2010 John Wiley & Sons A/S. Objective – Cerebrospinal fluid (CSF) dynamics and long‐term shunt survival of the Strata^® CSF shunt were evaluated in patients with idiopathic normal pressure hydrocephalus (INPH). Subjects and methods – Seventy‐two patients with INPH received a Strata^® valve. A CSF infusion test, neuroimaging and video recording of gait were performed at baseline and at 6 months (n = 68) after surgery. Long‐term shunt survivals were obtained from patient records. Results – The shunt survival at 1 year was 94% and at 3 years 92.5%. Forty‐nine patients (72%) had an improved gait. Two patients were improved despite non‐functioning shunts, indicating a possible placebo response. Nineteen patients were not improved at the 6‐month follow‐up. The shunt tests revealed a functioning shunt in 12; thus, unnecessary shunt revisions could be avoided. Seventeen patients showed a siphoning effect. Shunt revisions were made in six patients. Eight hygromas/subdural hematomas were found. Conclusions – The long‐term survival of the Strata^® valves was good, and a concern of complications is not a reason to exclude elderly with INPH from shunt surgery. Studies are needed to evaluate pros and cons of the anti‐siphon device. Using a CSF shunt test, unnecessary shunt revisions may be avoided.     

Slight elevation of baseline intracranial pressure after fluid infusion into CSF space in patients with hydrocephalus

Abstract

Objective: To investigate the elevation of resting cerebrospinal fluid (CSF) pressure recorded after a CSF infusion test in patients with hydrocephalus.

Material and methods: Fifty patients (30 men and 20 women, mean age 68 ± 13 years) with ventriculomegaly and clinical symptoms of normal pressure hydrocephalus have been studied. Lumbar (56%) or intraventricular (44%) computerized infusion studies were performed to investigate the hydrodynamics of CSF. After infusion, the fall in ICP was recorded until a steady-state level was achieved and the difference between pre- and post-infusion resting ICP was calculated (ΔICP).

Results: A positive difference (>2 mm Hg) between post- and pre-infusion resting ICP was identified in 31 infusion tests (62%). The mean value of the difference was 6.7 with an SD of 3.5 mm Hg. The patients who demonstrated this phenomenon had a greater elastance coefficient (p>0.05); ΔICP was positively correlated with age (R=0.27; p=0.03), with the size of the brain's ventricles (R=0.63, p=0.03) and inversely with the severity of clinical impairment (Stein-Langfitt score R=–0.61, p=0.02; normal pressure hydrocephalus score: R=0.54; p<0.05). ΔICP was independent of the site of infusion (lumbar or ventricular).

Conclusion: In patients with a 'stiffer' brain, ICP returns to the resting level after the infusion test at a slightly higher level than before the test. The magnitude of this increase is greater when ventricles are more dilated and clinical symptoms are less severe.     

CSF outflow resistance as predictor of shunt function. A long-term study

OBJECTIVES: Little is known about the long-term impact of a CSF shunt on the human CSF hydrodynamic system. In patients with communicating hydrocephalus, patency of the shunt system is not regularly assessed. In order to reveal postoperative changes in the CSF hydrodynamic system, we prospectively investigated the features of the system in shunted patients with idiopathic adult hydrocephalus syndrome (IAHS) over a 3-year period. MATERIAL AND METHODS: Thirty-two patients with IAHS were studied at baseline and at 3, 9, 18 and 36 months postoperatively. All patients were operated on with a Hakim standard valve system and a ventriculo-peritoneal approach. At each visit, the patients were investigated with computed tomography/magnetic resonance imaging, video recording of gait and a lumbar constant pressure infusion method. Six brand-new Hakim valves were investigated in a bench test, and these results were compared with the in vivo results. RESULTS: After shunt insertion, the CSF outflow resistance was significantly decreased (13.6 vs 3.8 mmHg/ml/min). The mean outflow resistance of the six in vitro tested valves corresponded to the postoperative values. The variation in resistance in the functioning shunts at different postoperative investigations was negligible. The mean intracranial pressure in the supine position was 13.8 mmHg at the baseline and 14.3, 14.5, 14.8 and 15.7 mmHg at the follow-up visits, respectively. Postoperatively, the CSF pressure after sitting for 10 min (i.e. 'siphoning effect') decreased significantly (mean decrease -5.3, -5.4, -4.7 and -5.3 mmHg at each visit, respectively). Shunt-related complications occurred in seven patients (underdrainage four, overdrainage three). Despite a functioning shunt, eight patients never improved and another nine patients first improved but later deteriorated. CONCLUSIONS: The CSF outflow resistance is much decreased postoperatively and does not alter over time in patients with functioning shunts. We consider CSF outflow resistance to be a reliable indicator of shunt function and of fundamental importance to distinguish a dysfunctioning shunt from an aggravation of the primary condition in patients with communicating hydrocephalus. The unaltered intracranial pressure together with the in vitro model results, suggests that the intra-abdominal pressure might be a major determinant of the postoperative intracranial pressure.     

Brain MRI as a predictor of CSF tap test response in patients with idiopathic normal pressure hydrocephalus

In this study, our objective was to identify the characteristic morphological features of brain MRI associated with a positive cerebrospinal fluid (CSF) tap test in patients with idiopathic normal pressure hydrocephalus (iNPH). Patients diagnosed with clinical suspected iNPH were evaluated. All patients underwent a mini-mental state examination, a brain MRI, and a CSF tap test. The severities of clinical symptoms were rated before and after the CSF tap test. Characteristic brain MRI findings including frontal convexity narrowing, parietal convexity narrowing, upward bowing of the corpus callosum, empty sella, narrowing of the CSF space at the high convexity, marked dilatation of the Sylvian fissure, and disproportion between narrowing of the CSF space at the high convexity and dilatation of the Sylvian fissure (“mismatch” sign) on T1-weighted or FLAIR image were analyzed. Forty-three patients (33 males/ten females, mean age 76.9 ± 6.9 years) with possible iNPH participated in this study. The presence versus absence of empty sella (52.4 vs. 14.3%, OR 6.6, 95% CI 1.5–29.4, p = 0.02) and “mismatch” sign (45.5 vs. 9.5%, OR 7.9, 95% CI 1.5–42.5, p = 0.02) were associated with positive CSF tap test responses. The sensitivity, specificity, positive predictive value, and negative predictive value of the presence of either of these two MRI features in the prediction of CSF tap response were 72.7, 81, 80, and 73.9%, respectively. Specific brain MRI features can be used as markers for the identification of potential CSF tap test responders in iNPH patients. These features may serve as supplemental evidence in the diagnosis of iNPH patients.     

Intracranial pressure,its components and cerebrospinal fluid pressure–volume compensation

Clinical measurement of intracranial pressure (ICP) is often performed to aid diagnosis of hydrocephalus. This review discusses analysis of ICP and its components' for the investigation of cerebrospinal fluid (CSF) dynamics. The role of pulse, slow and respiratory waveforms of ICP in diagnosis, prognostication and management of hydrocephalus is presented. Two methods related to ICP measurement are listed: an overnight monitoring of ICP and a constant‐rate infusion study. Due to the dynamic nature of ICP, a ‘snapshot’ manometric measurement of ICP is of limited use as it might lead to unreliable results. Therefore, monitoring of ICP over longer time combined with analysis of its waveforms provides more detailed information on the state of pressure–volume compensation. The infusion study implements ICP signal processing and CSF circulation model analysis in order to assess the cerebrospinal dynamics variables, such as CSF outflow resistance, compliance of CSF space, pressure amplitude, reference pressure, and CSF formation. These parameters act as an aid tool in diagnosis and prognostication of hydrocephalus and can be helpful in the assessment of a shunt malfunction.     

Role of DESH,callosal angle and cingulate sulcus sign in prediction of gait responsiveness after shunting in iNPH patients

Primary endpoint of this single-centre, prospective consecutive cohort study was to evaluate DESH score, CA, CSS and Evans index of suspected iNPH patients against the reference standard of lumbar infusion test (LIT) and external lumbar drainage (ELD) in prediction of gait response after VP shunt implantation in patients with idiopathic normal pressure hydrocephalus (iNPH). Patients were assigned to NPH and non-NPH groups based on LIT and ELD results. Age-matched controls were added for group comparison. 32 NPH, 46 non-NPH and 15 control subjects were enrolled in the study. There were significant differences in mean preoperative DESH scores of NPH, non-NPH and control groups (6.3 ± 2.3 ([±SD]) (range 2–10) vs 4.5 ± 2.4 (range 0–10) vs 1.0 ± 1.2 (range 0–4)). Differences in mean CA and Evans index were not significant between NPH and non-NPH groups. CSS showed 62.5% sensitivity, 60.87% specificity, 52.63% PPV and 70% NPV for differentiation of NPH and non-NPH groups. A CA of 68 degrees had 48.49% sensitivity, 76.09% specificity, 59.26% PPV 67.31% NPV and DESH score of 4 had 93.75% sensitivity, 41.30% specificity, 52.63% PPV and 90.48% NPV for differentiation between NPH and non-NPH groups. The groups of probable iNPH patients with gait impairment diagnosed by high DESH score or positive functional testing did not overlap and DESH score did not correlate with gait improvement after ELD. DESH score should not be used as a simple diagnostic or prognostic marker of iNPH and we could not confirm the benefit of measurement of callosal angle and cingulate sulcus sign.     

Pathogenesis and pathophysiology of idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH), the most common type of adult‐onset hydrocephalus, is a potentially reversible neuropsychiatric entity characterized by dilated ventricles, cognitive deficit, gait apraxia, and urinary incontinence. Despite its relatively typical imaging features and clinical symptoms, the pathogenesis and pathophysiology of iNPH remain unclear. In this review, we summarize current pathogenetic conceptions of iNPH and its pathophysiological features that lead to neurological deficits. The common consensus is that ventriculomegaly resulting from cerebrospinal fluid (CSF) dynamics could initiate a vicious cycle of neurological damages in iNPH. Pathophysiological factors including hypoperfusion, glymphatic impairment, disturbance of metabolism, astrogliosis, neuroinflammation, and blood‐brain barrier disruption jointly cause white matter and gray matter lesions, and eventually lead to various iNPH symptoms. Also, we review the current treatment options and discuss the prospective treatment strategies for iNPH. CSF diversion with ventriculoperitoneal or lumboperitonealshunts remains as the standard therapy, while its complications prompt attempts to refine shunt insertion and develop new therapeutic procedures. Recent progress on advanced biomaterials and improved understanding of pathogenesis offers new avenues to treat iNPH.     

Interest of dual‐task‐related gait changes in idiopathic normal pressure hydrocephalus

Background: Gait disorders in patients with idiopathic normal pressure hydrocephalus (iNPH) share similar characteristics found in pathologies presenting with higher‐level gait disorders that have been specifically associated with gait changes during walking while simultaneously performing an attention‐demanding task (i.e. dual tasking). The current study assessed the effect of cerebrospinal fluid (CSF) tapping on quantitative gait modification during single and dual tasking in patients with a suspicion of iNPH. Methods: Of 53 patients suspected of iNPH, 18 have been included in this study. Gait analysis during single‐ and dual‐task condition (walking and backward counting) before and after tapping of 40 ml CSF has been performed. Results: Gait speed (P < 0.01) and stride length (P < 0.05) were significantly improved during dual‐task conditions after CSF tapping compared to the gait performance before spinal tapping, without such improvement for gait parameters during single‐tasking. Conclusion: Dual‐tasking condition better reveals gait improvement after CSF tapping than single‐tasking in patients suspected of iNPH.     

神经内镜第三脑室底造瘘术治疗梗阻性脑积水及其术后颅内压的监测

目的探讨神经内镜第三脑室底造瘘术（ETV）治疗梗阻性脑积水的效果及其术后颅内压（ICP）监测的意义。方法采用ETV治疗梗阻性脑积水36例，其中术后行ICP动态监测9例。结果术后患者症状缓解33例（91．7％），复查头颅CT或MRI示脑室系统较术前缩小；3例（8.3％）肿瘤引起的梗阻性脑积水症状缓解不明显，改行脑室-腹腔分流术。本组无死亡病例。9例术后行ICP监测结果示：①ETV术后18h内平均ICP〈10mmHg，18h后平均ICP轻度上升，稳定于10-12mmHg之间，肿瘤引起的脑积水ICP上升较快；②4例单纯导水管梗阻性脑积水术后使用甘露醇，用药后1-2h ICP下降1-2mmHg，2h后ICP逐渐恢复至用药前水平。结论①ETV后18h内ICP稍低，可能与术中放出脑脊液过多有关，可暂不应用脱水药物；②肿瘤引起的梗阻性脑积水应积极治疗原发病变。     

Assessment of idiopathic normal pressure patients in neurological practice: the role of lumbar infusion testing for referral of patients to neurosurgery

Background and purpose:  In neurological practice patients with tentative idiopathic normal pressure hydrocephalus (iNPH) usually are referred to neurosurgery based on clinical and radiological findings. Hydrodynamic assessment using lumbar infusion testing might be helpful in selecting patients. To retrospectively analyse lumbar infusion tests done in neurological practice in iNPH patients to see how infusion test results relate to the clinical course and shunt response.
Materials and methods:  Sixty-three consecutive patients with Possible / Probable iNPH were tested during a 1-year period. The pre-operative lumbar infusion tests were assessed according to two strategies: (i) Determining the resistance to cerebrospinal fluid (CSF) outflow ( R _out). (ii) Quantification of the CSF pressure (CSFP) pulsatility during lumbar infusion ( Q _pulse). The results were related to the prospectively followed clinical course and shunt response after 12 months.
Results:  The lumbar infusion-derived parameters R _out and Q _pulse related weakly. Shunt response after 12 months was not related to R _out, but was highly related to the Q _pulse. False negative results of lumbar infusion testing were observed in 16% of the patients.
Discussion:  In neurological practice lumbar infusion testing may be useful for determining which patients to refer to neurosurgery. Our data favour determination of CSFP pulsatility ( Q _pulse) rather than R _out for prediction of shunt response.     

Increased cerebrospinal fluid chitotriosidase index in patients with multiple sclerosis

Verbeek MM, Notting EA, Faas B, Claessens‐Linskens R, Jongen PJH. Increased cerebrospinal fluid chitotriosidase index in patients with multiple sclerosis.
Acta Neurol Scand: 2010: 121: 309–314.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objective – To investigate chitotriosidase (CTTS) activity in serum and cerebrospinal fluid (CSF) in multiple sclerosis (MS) patients in relation to disease course and CSF markers for immune activation or inflammation. Materials and methods – We studied 80 patients with relapsing–remitting MS (RRMS), 24 with secondary progressive MS (SPMS), 20 with primary progressive MS (PPMS) and 29 patients with other neurological disorders (OND). We measured CTTS activity and studied the correlation with CSF mononuclear cell count (MNC) and intrathecal IgG production. Results – CTTS activity was significantly higher in CSF, but not in serum, from the total MS group compared with OND and controls. In RRMS and SPMS CTTS, index was increased compared with controls (RRMS, 0.10 ± 0.21; SPMS, 0.10 ± 0.15; controls, 0.021 ± 0.020), but not in PPMS (0.061 ± 0.052). CTTS index was higher in MS patients with elevated MNC or CSF‐restricted oligoclonal IgG bands than in MS patients without these CSF findings. Conclusions – CTTS index is elevated in RRMS and SPMS. The CTTS index is related to CSF markers of inflammation or immune activation.