Clinical observations on the relationship between cerebrospinal fluid pulse pressure and intracranial pressure

Summary A method is described for monitoring the relationship between CSF pulse pressure and ICP in clinical patients. Highly significant linear relationships were found during 65 continuous ICP recordings in 58 patients. The slope value of this relationship showed a positive correlation with the elastance coefficient, a volume-pressure parameter assessed by bolus injection. However, the correlation was too weak to allow for a confident prediction of the elastance coefficient on the basis of CSF pulse pressure in the individual patient. This was attributed to the variable magnitude of the volume change underlying the CSF pulse pressure: the pulsatile variation in cerebral blood volume. This quantity was calculated on the basis of a mathematical model from the slope value and the elastance coefficient and was found to vary between 0.36 and 4.38ml. During plateau waves a disproportionate increase in pulse pressure with the ICP was observed in contrast with a relative decrease in intracranial elastance. This phenomenon was ascribed to an increase in the pulsatile variation in cerebral blood volume. It is concluded that, under certain conditions, the intracranial volume-pressure relationship can be continuously monitored by means of CSF pulse pressure analysis. The findings during plateau waves suggest that the pulse pressure also reflects the state of the cerebral vasomotor tone.     

Computerized tomography-guided epidural blood patch in the treatment of spontaneous low cerebrospinal fluid pressure headache

A 54-year-old woman suffering from migraine for 35 years was referred to the pain clinic with a changed pattern of headache that had developed over the last 6 weeks. The pain was located in the central forehead region; aggravation in the prone and immediate relief in the supine position led to the hypothesis of a spontaneous low cerebrospinal fluid (CSF) pressure headache. Cisternography revealed a cyst-like formation in the cervico-thoracic region, indicating cerebrospinal fluid leakage. Magnetic resonance imaging (MRI) myelography confirmed ventral leakage but failed to locate the exact site. Computerized tomography (CT)-guided epidural blood patching between T1 and T2 completely relieved the headache.     

Rat model of spinal cord injury preserving dura mater integrity and allowing measurements of cerebrospinal fluid pressure and spinal cord blood flow

Purposes

Cerebrospinal fluid (CSF) pressure elevation may worsen spinal cord ischaemia after spinal cord injury (SCI). We developed a rat model to investigate relationships between CSF pressure and spinal cord blood flow (SCBF).

Methods

Male Wistar rats had SCI induced at Th10 (n = 7) or a sham operation (n = 10). SCBF was measured using laser-Doppler and CSF pressure via a sacral catheter. Dural integrity was assessed using subdural methylene-blue injection (n = 5) and myelography (n = 5).

Results

The SCI group had significantly lower SCBF (p < 0.0001) and higher CSF pressure (p < 0.0001) values compared to the sham-operated group. Sixty minutes after SCI or sham operation, CSF pressure was 8.6 ± 0.4 mmHg in the SCI group versus 5.5 ± 0.5 mmHg in the sham-operated group. No dural tears were found after SCI.

Conclusion

Our rat model allows SCBF and CSF pressure measurements after induced SCI. After SCI, CSF pressure significantly increases.     

The effects of verapamil on cerebrospinal fluid pressure in surgical patients

The effects of verapamil upon cerebrospinal fluid pressure (CSFP) were studied in twenty surgical patients without intracranial pathology who were divided into two groups of ten patients each: verapamil 0.075mg·kg^–1 was given in group 1 and 0.15mg·kg^–1 was given in group 2. A spinal needle was inserted into the subarachnoid space to permit continuous measurement of CSFP. Intravenous verapamil as a bolus produced a statistically significant increase in CSFP: from 6.0 ± 3.5 (mean ± SD) to 10.5 ± 4.3mmHg in group 1 (P < 0.01), and from 6.2 ± 3.1 to 12.6 ± 3.8mmHg in group 2 (P < 0.01). CSFP after verapamil attained its maximum in 0.5–1.5min, then gradually returned to control levels. Changes in CSFP were always associated with statistically significant decreases in arterial blood pressure and cerebral perfusion pressure, while the heart rate showed variable changes. It is concluded that a clinical dose of verapamil showed variable changes. It is concluded that a clinical dose of verapamil (0.075–0.15mg·kg^–1) has no neurological side effects in patients without intracranial hypertension. However, it must be emphasized that verapamil may increase CSFP to undesirable levels and should be avoided in patients with compromised intracranial compliance.(Nishikawa T, Namiki A: The effects of verapamil on cerebrospinal fluid pressure in surgical patients. J Anesth 1: 132–136, 1987)     

The effect of isoflurane on cerebrospinal fluid pressure in patients undergoing neurosurgery

Ten patients with intracerebral tumours (TC) and 13 patients with subarachnoid haemorrhage (SAH) from a ruptured cerebral arterial aneurysm were studied before intracranial surgery, and during a 3-h postoperative period. Cerebrospinal fluid pressure (CSFP) determined by an intraventricular (TC group) or intraspinal (SAH group) catheter, and mean arterial blood pressure (MABP) were recorded under neurolept anaesthesia (control) followed by isoflurane inhalation. These two measurements were performed during normocapnia. A third measurement was made during hypocapnia, with unchanged isoflurane concentration. After the experimental period, isoflurane remained the main anaesthetic agent throughout the surgical procedure. After recovery from anaesthesia, the patients were monitored with CSFP and blood pressure during the first postoperative hours, and the quality of breathing was assessed by hourly blood-gas analyses. The results show that isoflurane causes a 10-14% reduction of MABP with no further changes during hyperventilation. Mean CSFP increased 27% in the TC group, and 12% in the SAH group after isoflurane induction and decreased from these levels by 29% during hyperventilation in both groups. Consequently, the impact on cerebral perfusion pressure (CPP) by isoflurane was a 19% and 21% mean decrease in the TC and SAH group, respectively. Controlled hyperventilation reduced this effect by partially restoring control CPP values, with 8% and 14% increase, respectively. In the postoperative follow-up, all patients had normal breathing and blood pressure with low values of CSFP. It is concluded that isoflurane can be used in intracranial surgery with adequate safety if combined with controlled hyperventilation.     

The prognostic value of clinical characteristics and parameters of cerebrospinal fluid hydrodynamics in shunting for idiopathic normal pressure hydrocephalus

Summary Background. It is difficult to predict which patients with symptoms and radiological signs of normal pressure hydrocephalus (NPH) will benefit from a shunting procedure and which patients will not. Risk of this procedure is also higher in patients with NPH than in the overall population of hydrocephalic patients. The aim of this study is to investigate which clinical characteristics, CT parameters and parameters of cerebrospinal fluid dynamics could predict improvement after shunting. Methods. Eighty-three consecutive patients with symptoms and radiological signs of NPH were included in a prospective study. Parameters of the cerebrospinal fluid dynamics were measured by calculation of computerised data obtained by a constant-flow lumbar infusion test. Sixty-six patients considered candidates for surgery were treated with a medium-pressure Spitz-Holter valve; in seventeen patients a shunting procedure was not considered indicated. Clinical and radiological follow-up was performed for at least one year postoperatively. Findings. The odds ratio, the sensitivity and specificity as well as the positive and negative predictive value of individual and combinations of measured parameters did not show a statistically significant relation to clinical improvement after shunting. Conclusions. We conclude that neither individual parameters nor combinations of measured parameters show any statistically significant relation to clinical improvement following shunting procedures in patients suspected of NPH. We suggest restricting the term normal pressure hydrocephalus to cases that improve after shunting and using the term normal pressure hydrocephalus syndrome for patients suspected of NPH and for patients not improving after implantation of a proven well-functioning shunt. An erratum to this article is available at .     

Significance of the ventricular fluid pressure wave form in the diagnosis of cerebral circulatory arrest and brain death

Summary The fluctuations in the absolute value of the ventricular fluid pressure (VFP) with simultaneous changes in the amplitude and frequency of the oscillations of the ventricular fluid wave form are described in seven patients who developed brain death following either a head injury or a cerebrovascular accident, and are compared with those observed in nineteen patients who survived similar brain pathology. The findings in the two groups were significantly different. It is suggested that VFP monitoring does provide reliable evidence of brain death even while the patient is on artificial respiration.     

Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called “Normal pressure hydrocephalus” syndrome

Summary Fifty-four shunt-responsive patients were selected from a prospective protocol directed to study patients with suspected normal pressure hydrocephalus (NPH). Patients with gait disturbances, dementia, non-responsive L-Dopa Parkinsonism, urinary or faecal incontinence and an Evans ratio greater or equal to 0.30 on the CT scan were included in the study.As a part of their work-up all patients underwent intracranial pressure monitoring and hydrodynamic studies using Marmarou's bolus test. According to mean intracranial pressure (ICP) and the percentage of high amplitude B-waves, patients were subdivided in the following categories: 1) Active hydrocephalus (mean ICP above 15 mmHg), which is in fact no tone normal pressure hydrocephalus; 2) Compensated unstable hydrocephalus, when mean ICP was below 15 mmHg and B-waves were present in more than 25% of the total recording time and 3) Compensated stable hydrocephalus when ICP was lower or equal to 15 mmHg and beta waves were present in less than 25% of the total recording time.The majority of the patients in this study (70%) presented continuous high or intermittently raised ICP (active or unstable compensated hydrocephalus group). Mean resistance to outflow of CSF (Rout) was 38.8 mm Hg/ml/min in active hydrocephalus and 23.5 mm Hg/ml/min in the compensated group (Students t-test, p < 0.05). Higher resistance to outflow was found in patients with obliterated cortical sulci and obliterated Sylvian cisterns in the CT scan.No statistically significant correlation was found when plotting the percentage of beta waves against pressure volume index (PVI), compliance or Rout. An exponential correlation was found when plotting beta waves against the sum of conductance to outflow and compliance calculated by PVI method (r=0.79).Patients with the so-called normal pressure hydrocephalus syndrome have different ICP and CSF dynamic profiles. Additional studies taking into consideration these differences are necessary before defining the sensitivity, specificity and predictive value of ICP monitoring and CSF studies in selecting appropriate candidates for shunting.     

地氟醚对颅脑手术病人脑脊液压力及大脑中动脉血流速度的影响

目的 观察地氟醚以不同ＭＡＣ值维持麻醉期间对脑脊液压力（ＣＳＦＰ）和大脑中动脉血流速率（ＶｍＭＣＡ）的影响。方法 ６０名颅内肿瘤病人，随机分为２组，Ａ组选用地氟醚维持麻醉，Ｂ组选用异氟醚维持麻醉。每组病人又按维持麻醉的不同ＭＡＣ值分为三小组：分组ＭＡＣ值为０．５、０．８和１．１。通过蛛网膜下腔导管监测ＣＳＦＰ的变化，分别于麻醉前、诱导插管时观察记录，并于ＭＡＣ值稳定于预定值开始，每５分钟测量一次直     

Intracranial cerebrospinal fluid distribution and its postoperative changes in normal pressure hydrocephalus

Summary  Background. This study was conducted to investigate the usefulness of intracranial cerebrospinal fluid (CSF) volume measurement using MR-based methods in the management of patients with normal pressure hydrocephalus (NPH).  Methods. The study group comprised 19 patients with NPH who showed a favorable outcome after ventricular shunting, 15 normal volunteers (NV), and 15 patients with cerebrovascular disease (CVD). A 3D-fast asymmetric spin echo MR imaging sequence and the region-growing method were used to extract the CSF space from MR images. Ventricular volume (VV) and intracranial CSF volume (ICV) were measured and the VV/ICV ratio was calculated in each case. In NPH patients, the CSF volume was measured again after shunting.  Findings. The mean VV and VV/ICV ratio in the NPH group (91.1 mL and 45.2%, respectively) were significantly (p<0.01) higher than those in the NV group (26.5 mL and 13.7%) and in the CVD group (44.5 mL and 17.8%). On the other hand, mean ICV values were not significantly different among the three groups. The VV was markedly decreased postoperatively (mean −40.7%), whereas the ICV was unchanged, resulting in a marked reduction in the VV/ICV ratio (mean −39.3%).  Interpretation. These results suggest that patients with NPH have a unique intracranial CSF distribution, with an enlarged VV and a slightly increased ICV, resulting in a high VV/ICV ratio. Shunting led to dramatic improvement in our patients. It is likely that CSF measurement can provide valuable information in the management of patients with NPH.     

Proinflammatory cytokines in the cerebrospinal fluid of patients with lumbar radiculopathy

In pathologic radicular pain of lumbar spinal stenosis, cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukins (ILs) play a crucial role in the pathogenesis of nerve degeneration and pain. We investigated TNF-α and IL-6 levels in the cerebrospinal fluid (CSF) of patients with radicular pain caused by lumbar spinal stenosis (LSS). A total of 30 LSS patients and 10 age-matched controls were examined. CSF samples were obtained adjacent to the level of stenosis in 30 LSS patients, and at the L4–L5 level in the 10 control patients. TNF-α and IL-6 levels in the samples were analyzed using enzyme-linked immunosorbent assays (ELISA). We compared the amounts of TNF-α and IL-6 with severity of pain (low back and leg pain), walking ability, and severity of stenosis (cross-sectional area of dural space). The concentration of IL-6 was significantly higher in LSS patients than in controls, but TNF-α levels were beneath the limit of detection. There was no correlation between IL-6 levels and severity of pain or walking ability (p > 0.05). However, there was a significant correlation between IL-6 levels and severity of stenosis (p < 0.05). The current study showed that the increased CSF IL-6 levels in LSS patients with radicular pain were not correlated with pain severity; although not proven in this study, the increase in CSF IL-6 concentration could indicate pathological nerve damage or degeneration of lumbar radiculopathy represented by the severity of stenosis.     

Increased levels of somatomedins in human lumbar and central cerebrospinal fluid after subarachnoid haemorrhage

Summary The somatomedins, multitargit growth-promoting peptide hormones, were measured with radio receptor assay in cerebrospinal fluid (CSF) after subarachnoid haemorrhage (SAH) in 21 patients and after head injury in 2 patients.In the first group of 10 patients, lumbar (n=8) or central (n=2) CSF was collected on days three, six and nine after SAH. 6 of the 8 patients with SAH showed an increase in somatomedin concentrations ranging between 0.52–1.26 U/ml while 2 patients fell within the normal range between 0.19–0.48 U/ml. In the 2 patients with head injury, the somatomedin concentrations were scarcely detectable.In the second group of 13 patients with SAH, CSF was collected peroperatively during surgical clipping of an aneurysm. These patients fell into two groups: 6 patients who had CSF somatomedin levels within the normal range and 7 patients with pathologically increased somatomedin concentrations ranging between 0.38–1.26 U/ml. Neither the neurological condition nor the cerebral vascular diameter correlated with the somatomedin concentrations. It is suggested that the increased somatomedin levels in CSF after SAH could be a compensatory response in order to stimulate cerebral anabolism after injury.This work was supported by grants from Karolinska Institutet, the Swedish Medical Research Council, Sävstaholmsföreningen, and Loo and Hans Osterman Research Fund.     

Diagnosis of genuine stress incontinence—a comparison of the fluid bridge (flow) test and a pressure test

Two urodynamic investigations designed to make a diagnosis of genuine stress incontinence were compared in 103 women complaining of stress incontinence and 19 continent women. A fluid bridge (flow) test and a stress urethral pressure profile (using a microtip catheter system) were performed. Both tests gave similar results, confirming the diagnosis in 90% of the incontinent group.     

Visualization of cerebrospinal fluid flow in syringomyelia through noninvasive magnetic resonance imaging with a time-spatial labeling inversion pulse (Time-SLIP)

Context: We report a case of syringomyelia assessed by magnetic resonance imaging (MRI) with a time-spatial labeling inversion pulse (Time-SLIP), which is a non-contrast MRI technique that uses the cerebrospinal fluid (CSF) as an intrinsic tracer, thus removing the need to administer a contrast agent. Time-SLIP permits investigation of flow movement for over 3 seconds without any limitations associated with the cardiac phase, and it is a clinically accessible method for flow analysis.

Findings: We investigated an 85-year-old male experiencing progressive gait disturbance, with leg numbness and muscle weakness. Conventional MRI revealed syringomyelia from C7 to T12, with multiple webs of cavities. We then applied the Time-SLIP approach to characterize CSF flow in the syringomyelic cavities. Time-SLIP detected several unique CSF flow patterns that could not be observed by conventional imaging. The basic CSF flow pattern in the subarachnoid space was pulsatile and was harmonious with the heartbeat. Several unique flow patterns, such as bubbles, jumping, and fast flow, were observed within syringomyelic cavities by Time-SLIP imaging. These patterns likely reflect the complex flow paths through the septum and/or webs of cavities.

Conclusion/Clinical Relevance: Time-SLIP permits observation of CSF motion over a long period of time and detects patterns of flow velocity and direction. Thus, this novel approach to CSF flow analysis can be used to gain a more extensive understanding of spinal disease pathology and to optimize surgical access in the treatment of spinal lesions. Additionally, Time-SLIP has broad applicability in the field of spinal research.     

Analysis of potential diagnostic biomarkers in cerebrospinal fluid of idiopathic normal pressure hydrocephalus by proteomics

Summary Background. The pathogenesis of idiopathic normal pressure hydrocephalus (INPH) is unknown, and the syndrome of INPH remains a diagnostic and therapeutic challenge. The present study investigated the disease-specific proteins that aid in the diagnosis and treatment of INPH and thus to study their role in the disease process. Methods. A comparative proteomic analysis was used for clinical screening of cerebrospinal fluid (CSF) proteins in 15 patients with INPH and compared with 12 normal subjects. Furthermore, enzyme linked immunosorbent assay (ELISA) was performed for comparison with CSF proteins between individual INPH patients and controls. Results. Seven proteins and their isoforms, including leucine-rich α-2-glycoprotein (LRG), α1-antichymotrypsin, apolipoprotein D, apolipoprotein J, haptoglobin α1, serum albumin, and α-1-microglobulin/bikunin precursor showed significant changes in CSF of INPH patients compared with controls by proteomic analysis. And significant higher CSF levels of LRG in INPH patients compared with controls were found by ELISA. Conclusions. These results indicate that there are significant differences in the expression of certain proteins in the CSF of patients with INPH and normal subjects. In particular, the CSF level assay of LRG suggests that LRG is a specific biomarker for INPH and has potential use in the diagnosis and indication for CSF shunting.     

冲击载荷造成椎管内压力变化与脊髓损伤程度的评估

目的 观察脊柱遭受轴向撞击时椎管内的压力变化,从撞击－压力变化－脊髓损伤的角度分析脊柱骨折类型与脊髓损伤程度间的关系,为脊髓损伤程度的早期评估提供实验依据。方法 应用ＢＩＭ－Ｉ型立式生物撞击机高速准静态轴向加载和应力遮挡技术建立脊椎爆裂型骨折模型,观察８具新鲜尸体的脊柱标本Ｔ１０￣Ｌ４节段受垂直撞击瞬间椎管内的压力变化,将大体解剖观察与放射影像学技术相结合,记录脊柱骨折类型及脊柱损伤程度。结果 发     

Highly sensitive detection of beta-2 transferrin in rhinorrhea and otorrhea as a marker for cerebrospinal fluid (C.S.F.) leakage

Summary As beta-2 transferrin is almost specific to the cerebrospinal fluid, its detection in rhinorrhea or otorrhea fluids demonstrates the occurrence of CSF fistula. We describe a highly sensitive method based on immunoaffinity-mediated capillary blotting for the detection of this cathodic isoform of transferrin in minute amounts (3 l) of rhinorrhea or otorrhea fluids. Application of this method in a series of 10 patients with CSF fistula is reported.