Continuous monitoring of intracranial pressure with a miniaturized fiberoptic device

1987 ◽  
Vol 67 (2) ◽  
pp. 206-209 ◽  
Author(s):  
Richard C. Ostrup ◽  
Thomas G. Luerssen ◽  
Lawrence F. Marshall ◽  
Mark H. Zornow
Keyword(s):  
Intracranial Pressure ◽  
Pediatric Patients ◽  
Animal Experiments ◽  
Brain Parenchyma ◽  
Content Type ◽  
New Device ◽  
Fiberoptic Device ◽  
The Brain ◽  
Fiberoptic Catheter ◽  
Intravascular Pressure

✓ A No. 4 French fiberoptic catheter initially developed as an intravascular pressure sensor was incorporated into a system to be used as an intracranial pressure (ICP) monitor. Initially, a series of acute and chronic animal experiments carried out in the rabbit and pig, respectively, demonstrated the reliability and safety of the device. Subsequently, this new monitor was compared to a concurrently functioning ICP monitor in 15 adult and five pediatric patients. This clinical experience also confirmed the safety, accuracy, and reliability of the device. Since these initial studies, this monitor has been used to routinely measure ICP in a large number of adult and pediatric patients. The monitor has functioned well, and there have been no complications related to its use except for an occasional problem with breakage of the optic fiber as a result of patient movement or nursing maneuvers, which has been easily corrected by replacement of the probe. As nursing personnel and ancillary services have become familiar with this new monitor, breakage has not been a problem. This new device can be placed into the ventricular system, the brain parenchyma, or the subdural space, and appears to offer substantial advantages over other monitors presently in use.

A transparent sheath for endoscopic surgery and its application in surgical evacuation of spontaneous intracerebral hematomas

2000 ◽  
Vol 92 (6) ◽  
pp. 1053-1055 ◽  
Author(s):  
Tetsuhiro Nishihara ◽  
Akira Teraoka ◽  
Akio Morita ◽  
Keisuke Ueki ◽  
Keisuke Takai ◽  
...  
Keyword(s):  
Endoscopic Surgery ◽  
Brain Parenchyma ◽  
Bleeding Point ◽  
Content Type ◽  
Minimal Invasiveness ◽  
Surgical Evacuation ◽  
Endoscopic Evacuation ◽  
Surgical Field ◽  
The Brain ◽  
Fine Print

✓ The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86–100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.

Noninvasive localization of brain-stem lesions in the cat with multimodality evoked potentials

1981 ◽  
Vol 54 (6) ◽  
pp. 740-750 ◽  
Author(s):  
Richard P. Greenberg ◽  
Donald M. Stablein ◽  
Donald P. Becker
Keyword(s):  
Evoked Potentials ◽  
Brain Stem ◽  
Evoked Potential ◽  
Animal Experiments ◽  
Content Type ◽  
Central Nervous System Dysfunction ◽  
Multimodality Evoked Potentials ◽  
Stem Lesions ◽  
The Brain ◽  
Fine Print

✓ Multimodality evoked potential (MEP) data from over 300 comatose head-injured patients suggest that central nervous system dysfunction of the brain stem and/or hemispheres can be localized with this noninvasive neuroelectric technique. Based on this work, decerebrate motor posturing and prolonged coma are not associated with brain-stem dysfunction but rather with dysfunction of the hemispheres, while absent pupillary and oculocephalic responses are correlated with brain-stem dysfunction alone. However, the accuracy with which MEP data localized human brain-stem or hemispheric dysfunction could not be confirmed by pathological correlation because of low mortality and the small number of autopsies obtained in the patients who died. Therefore, this study was undertaken in an animal model of brain-stem lesion. Complete brain-stem transections were made at the cervicomedullary junction, the medulla just caudal to the eighth nerve, and at the intercollicular region. All cortical visual evoked potential (VEP) peaks were reduced in amplitude and delayed by each of the brain-stem transections, but none of the peaks was abolished. In spite of brain-stem transection, VEP's can be used to gain information about hemispheric function. Somatosensory (SEP) and auditory cortically generated evoked potentials (AEP) were abolished by these brain-stem transections, but early-latency brain-stem SEP and AEP data could accurately localize specific areas of brain-stem dysfunction caused by the lesions. Observations made on human MEP data seem to be confirmed by these animal experiments. Correlations between human and cat MEP data are discussed.

Cerebral hemodynamics in angioma patients: an intraoperative study

1987 ◽  
Vol 67 (6) ◽  
pp. 822-831 ◽  
Author(s):  
Werner Hassler ◽  
Helmuth Steinmetz
Keyword(s):  
Doppler Sonography ◽  
Perfusion Pressure ◽  
Normal Brain ◽  
Content Type ◽  
Vasomotor Reactivity ◽  
Brain Arteries ◽  
Normal Perfusion Pressure Breakthrough ◽  
The Brain ◽  
Intravascular Pressure ◽  
Flow Velocities

✓ Local hemodynamics were investigated during 33 operations for cerebral arteriovenous malformation (AVM). In all cases, microvascular Doppler sonography was used to measure flow velocities and vasomotor reactivity to CO2 changes. Intravascular pressure recordings were performed in six patients. The AVM feeders had low intravascular pressure, high flow velocity, low peripheral stream resistance, and very poor vasomotor reactivity. Remote brain arteries showed no abnormalities. Doppler findings in arterial branches of AVM feeders that supplied normal brain indicated arteriolar dilation in their peripheral distribution. On removal of the angiomas, the arteries that formerly supplied them showed a return to normal intravascular pressure, whereas flow velocities dropped far below normal in these vessels. Remote arteries and branches of the former AVM feeders supplying the brain did not show any signs of impaired vasomotor reactivity following angioma removal. The results are in contrast to the normal perfusion pressure breakthrough theory.

Simultaneous measurements of intracranial pressure parameters in the epidural space and in brain parenchyma in patients with hydrocephalus

2010 ◽  
Vol 113 (6) ◽  
pp. 1317-1325 ◽  
Author(s):  
Per Kristian Eide ◽  
Wilhelm Sorteberg
Keyword(s):  
Intracranial Pressure ◽  
Epidural Space ◽  
Pulse Pressure ◽  
Brain Parenchyma ◽  
Pressure Amplitude ◽  
Icp Monitoring ◽  
Simultaneous Measurements ◽  
Pulsatile Pressure ◽  
The Mean ◽  
The Brain

Object In this study, the authors compare simultaneous measurements of static and pulsatile pressure parameters in the epidural space and brain parenchyma of hydrocephalic patients. Methods Simultaneous intracranial pressure (ICP) signals from the epidural space (ICPEPI) and the brain parenchyma (ICPPAR) were compared in 12 patients undergoing continuous ICP monitoring as part of their diagnostic workup for hydrocephalus. The static ICP was characterized by mean ICP and the frequency of B waves quantified in the time domain, while the pulsatile ICP was determined from the cardiac beat–induced single ICP waves and expressed by the ICP pulse pressure amplitude (dP) and latency (dT; that is, rise time). Results The 12 patients underwent a median of 22.5 hours (range 5.9–24.8 hours) of ICP monitoring. Considering the total recording period of each patient, the mean ICP (static ICP) differed between the 2 compartments by ≥ 5 mm Hg in 8 patients (67%) and by ≥ 10 mm Hg in 4 patients (33%). In contrast, for every patient the ICP pulse pressure readings from the 2 compartments showed near-identical results. Consequently, when sorting patients to shunt/no shunt treatment according to pulsatile ICP values, selection was independent of sensor placement. The frequency of B waves also compared well between the 2 compartments. Conclusions The pulsatile ICP is measured with equal confidence from the ICPEPI and ICPPAR signals. When using the pulsatile ICP for evaluation of hydrocephalic patients, valid measurements may thus be obtained from pressure monitoring in the epidural space. Recorded differences in the mean ICP between the epidural space and the brain parenchyma are best explained by differences in the zero setting of different sensors.

Autoregulation of cerebral blood flow after experimental fluid percussion injury of the brain

1980 ◽  
Vol 53 (4) ◽  
pp. 500-511 ◽  
Author(s):  
W. Lewelt ◽  
L. W. Jenkins ◽  
J. Douglas Miller
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
Intracranial Pressure ◽  
Severe Injury ◽  
Content Type ◽  
Fluid Percussion ◽  
Arterial Blood ◽  
Fluid Percussion Injury ◽  
The Brain

✓ To test the hypothesis that concussive brain injury impairs autoregulation of cerebral blood flow (CBF), 24 cats were subjected to hemorrhagic hypotension in 10-mm Hg increments while measurements were made of arterial and intracranial pressure, CBF, and arterial blood gases. Eight cats served as controls, while eight were subjected to mild fluid percussion injury of the brain (1.5 to 2.2 atmospheres) and eight to severe injury (2.8 to 4.8 atmospheres). Injury produced only transient changes in arterial and intracranial pressure, and no change in resting CBF. Impairment of autoregulation was found in injured animals, more pronounced in the severe-injury group. This could not be explained on the basis of intracranial hypertension, hypoxemia, hypercarbia, or brain damage localized to the area of the blood flow electrodes. It is, therefore, concluded that concussive brain injury produces a generalized loss of autoregulation for at least several hours following injury.

Hydrostatically raised intracranial pressure

1972 ◽  
Vol 37 (6) ◽  
pp. 695-699 ◽  
Author(s):  
Timo Kuurne ◽  
Henry Troupp
Keyword(s):  
Blood Pressure ◽  
Intracranial Pressure ◽  
Respiratory Arrest ◽  
Carbon Dioxide Tension ◽  
Experimental Models ◽  
Raised Intracranial Pressure ◽  
Acid Base Balance ◽  
Content Type ◽  
Base Balance ◽  
The Brain

✓ Hydrostatic pressure with artificial cerebrospinal fluid (CSF) was applied through a needle inserted into the cisterna magna of rabbits breathing spontaneously. Blood pressure, confluens sinuum pressure and oxygen tension, respiratory rate and volume, and acid-base balance were recorded until respiratory arrest. Blood pressure and confluens sinuum pressure and respiratory volume rose; confluens sinuum oxygen and arterial carbon dioxide tension dropped. The significant similarities and differences in changes in the same parameters following local cold injury to the brain are discussed. Comparisons between different experimental models for raised intracranial pressure must take into consideration the differing reactions of the brain.

The intracranial pressure in infants

1980 ◽  
Vol 52 (5) ◽  
pp. 693-699 ◽  
Author(s):  
Keasley Welch
Keyword(s):  
Intracranial Pressure ◽  
Normal Child ◽  
Expectant Management ◽  
Normal Pressure ◽  
Infantile Hydrocephalus ◽  
Content Type ◽  
Ventricular Hemorrhage ◽  
The Brain ◽  
Fine Print

✓ In infancy, the intracranial pressure (ICP) is normally maintained at a level that is very low by standards that apply later in life. There is little or no overlap of normal pressure and the pressure in infantile hydrocephalus. Knowledge of the normal pressure may allow expectant management of milder instances of infantile hydrocephalus. During the first few days after birth, as the volume of the brain decreases so does its turgor, and subatmospheric ICP is common. Hydrocephalus may be masked or attenuated in severity during that time or may be incorrectly suspected in a normal child because of the increase in circumference of the head accompanying the restitution of volume. The postnatal decrease in ICP may be responsible for ventricular hemorrhage in the newborn.

Systemic hypotension in neurosurgery

1975 ◽  
Vol 43 (5) ◽  
pp. 579-589 ◽  
Author(s):  
David Yashon ◽  
Alfred P. Magness ◽  
W. Michael Vise
Keyword(s):  
Intracranial Pressure ◽  
Vascular Endothelial Cells ◽  
Systemic Blood Pressure ◽  
Vascular Endothelial ◽  
Content Type ◽  
Profound Hypotension ◽  
Clip Application ◽  
Low Glucose ◽  
The Brain ◽  
Elevated Lactate

✓ The authors review the intraoperative use of elective hypotension to reduce the probability of hemorrhage, to increase pliability of the aneurysmal sac for ease of clip application, and to control hemorrhage. The optimum agent and techniques for lowering systemic blood pressure remain controversial, but trimethaphan, sodium nitroprusside, and halothane have been found most useful. When cerebral blood flow falls below the brain's capacity to autoregulate, distinct time-related alterations occur biochemically and histologically. The profile of prolonged reduced adenosine triphosphate (ATP), low phosphocreatine, low glucose, and elevated lactate and lactate/pyruvate ratio is associated with swelling of perivascular astrocytes and “blebbing” of vascular endothelial cells with subsequent cerebral damage. To prevent permanent alteration it is desirable to observe time constraints and to employ other means of protection such as hypothermia, although the authors believe the latter unnecessary for short hypotensive periods. It has been proposed, but not substantiated, that anesthetics which depress rate of cerebral oxygen consumption but do not affect cerebral ATP level protect the brain from hypotension. Several investigations suggest that halothane, a vasodiltor, satisfies the safety requirement. The most prominent contraindication to halothane, however, is elevation of intracranial pressure. At present hypotensive surgery for aneurysmorrhaphy is usually performed when intracranial pressure has returned to normal. Experimentally the electroencephalogram has been observed to show alterations prior to biochemical parameters for following brain vulnerability, so that it conceivably could be an effective monitoring technique during prolonged profound hypotension.

Reevaluation of an experimental streptococcal canine brain abscess model

1987 ◽  
Vol 67 (5) ◽  
pp. 717-720 ◽  
Author(s):  
Henry Kurzydlowski ◽  
Cynthia Wollenschlager ◽  
Frank R. Venezio ◽  
Mona Ghobrial ◽  
Morris Marc Soriano ◽  
...  
Keyword(s):  
Brain Abscess ◽  
Antimicrobial Therapy ◽  
Brain Parenchyma ◽  
Antimicrobial Treatment ◽  
Histopathological Study ◽  
Bacterial Inoculation ◽  
Content Type ◽  
Treatment Regimens ◽  
The Brain ◽  
Fine Print

✓ An experimental cerebral abscess model in which alpha-hemolytic Streptococci were inoculated into the brain parenchyma of dogs was evaluated for assessment of antimicrobial therapy. Intracerebral ring-enhancing lesions were visualized by computerized tomography, but they resolved after time without therapeutic intervention. Histopathological study demonstrated evolution of the lesions into sterile granulomas. Quantitative cultures were performed and uniformly became sterile in the early cerebritis stage, approximately 3 days after bacterial inoculation. Therefore, this brain abscess model should not be utilized for the evaluation of new antimicrobial treatment regimens. Rather, other models which document persistent viable organisms within cerebral abscesses need to be developed.

Experimental identification of the subarachnoid and subpial compartments by intracranial pressure measurements

1974 ◽  
Vol 40 (5) ◽  
pp. 609-616 ◽  
Author(s):  
Alfonso Schettini ◽  
Edward K. Walsh
Keyword(s):  
Intracranial Pressure ◽  
Viscoelastic Behavior ◽  
Experimental Methods ◽  
Transitional Region ◽  
Pressure Measurements ◽  
Correct Interpretation ◽  
Content Type ◽  
Experimental Identification ◽  
Depth Determination ◽  
The Brain

✓ Because of the range of pressures associated with the intracranial system, correct interpretation of epidural intracranial pressure measurements requires an accurate means of measuring the pressure, the depth at which the pressure is measured, and the region of the system associated with that depth. A measurement system is described that provides such an accurate pressure/depth determination and maintains a uniform rate-of-insertion of the pressure transducer; the latter provision is important because of the viscoelastic behavior of the brain tissue. Use of these experimental methods to determine the pressure in three distinct intracranial regions is described, namely, in the subarachnoid and the subpial compartments and a transitional region between these two.

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