Two computerized methods used to analyze intracranial pressure B waves: comparison with traditional visual interpretation

2001 ◽  
Vol 94 (3) ◽  
pp. 392-396 ◽  
Author(s):  
Anders Eklund ◽  
Aina Ågren-Wilsson ◽  
Nina Andersson ◽  
A. Tommy Bergenheim ◽  
Lars-Owe D. Koskinen ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Visual Analysis ◽  
Modern Technology ◽  
Computer Algorithms ◽  
Visual Interpretation ◽  
Content Type ◽  
Monitoring Time ◽  
Definition Of ◽  
Icp Recording ◽  
Fine Print

Object. Slow and rhythmic oscillations in intracranial pressure (ICP), also known as B waves, have been claimed to be one of the best preoperative predictive factors in idiopathic adult hydrocephalus syndrome (IAHS). Definitions of B waves vary widely, and previously reported results must be treated with caution. The aims of the present study were to develop a definition of B waves, to develop a method to estimate the B-wave content in an ICP recording by using computer algorithms, and to validate these procedures by comparison with the traditional visual interpretation. Methods. In eight patients with IAHS, ICP was continuously monitored for approximately 20 hours. The ICP B-wave activity as a percentage of total monitoring time (B%) was estimated by using visual estimation according to the definition given by Lundberg, and also by using two computer algorithms (Methods I and II). In Method I each individual wave was classified as a B wave or not, whereas Method II was used to estimate the B-wave content by evaluating the B-wave power in 10-minute blocks of ICP recordings. Conclusions. The two computerized algorithms produced similar results. However, with the amplitude set to 1 mm Hg, Method I yielded the highest correlation with the visual analysis (r = 0.74). At least 5 hours of monitoring time was needed for an acceptable approximation of the B% in an overnight ICP recording. The advantages of using modern technology in the analysis of B-wave content of ICP are obvious and these methods should be used in future studies.

Flushing in relation to a possible rise in intracranial pressure: documentation of an unusual clinical sign

2000 ◽  
Vol 92 (6) ◽  
pp. 1040-1044 ◽  
Author(s):  
Gregory W. Hornig
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Intracranial Pressure ◽  
Intraventricular Hemorrhage ◽  
Pneumococcal Meningitis ◽  
Clinical Importance ◽  
Neurological Deterioration ◽  
Content Type ◽  
Transient Nature ◽  
Fine Print

✓ This report documents clinical features in five children who developed transient reddening of the skin (epidermal flushing) in association with acute elevations in intracranial pressure (ICP). Four boys and one girl (ages 9–15 years) deteriorated acutely secondary to intracranial hypertension ranging from 30 to 80 mm Hg in the four documented cases. Two patients suffered from ventriculoperitoneal shunt malfunctions, one had diffuse cerebral edema secondary to traumatic brain injury, one was found to have pneumococcal meningitis and hydrocephalus, and one suffered an intraventricular hemorrhage and hydrocephalus intraoperatively. All patients were noted to have developed epidermal flushing involving either the upper chest, face, or arms during their period of neurological deterioration. The response was transient, typically lasting 5 to 15 minutes, and dissipated quickly. The flushing reaction is postulated to be a centrally mediated response to sudden elevations in ICP. Several potential mechanisms are discussed. Flushing has clinical importance because it may indicate significant elevations in ICP when it is associated with neurological deterioration. Because of its transient nature, the importance of epidermal flushing is often unrecognized; its presence confirms the need for urgent treatment.

Contemporary psychosurgery and a look to the future

2001 ◽  
Vol 95 (6) ◽  
pp. 944-956 ◽  
Author(s):  
Robert P. Feldman ◽  
Ronald L. Alterman ◽  
James T. Goodrich
Keyword(s):  
Modern Science ◽  
Psychiatric Disease ◽  
Content Type ◽  
Current State ◽  
Mind And Brain ◽  
Patient Selection Criteria ◽  
Definition Of ◽  
Historical Developments ◽  
The Mind ◽  
Fine Print

Object. Despite a long and controversial history, psychosurgery has persisted as a modern treatment option for some severe, medically intractable psychiatric disorders. The goal of this study was to review the current state of psychosurgery. Methods. In this review, the definition of psychosurgery, patient selection criteria, and anatomical and physiological rationales for cingulotomy, subcaudate tractotomy, anterior capsulotomy, and limbic leukotomy are discussed. The historical developments, modern procedures, and results of these four contemporary psychosurgical procedures are also reviewed. Examples of recent advances in neuroscience indicating a future role for neurosurgical intervention for psychiatric disease are also mentioned. Conclusions. A thorough understanding of contemporary psychosurgery will help neurosurgeons and other physicians face the ethical, social, and technical challenges that are sure to lie ahead as modern science continues to unlock the secrets of the mind and brain.

Effect of stimulation of the medullary reticular formation on cerebral vasomotor tonus and intracranial pressure

1987 ◽  
Vol 66 (4) ◽  
pp. 548-554 ◽  
Author(s):  
Seigo Nagao ◽  
Tsukasa Nishiura ◽  
Hideyuki Kuyama ◽  
Masakazu Suga ◽  
Takenobu Murota
Keyword(s):  
Intracranial Pressure ◽  
Reticular Formation ◽  
Cerebral Blood Volume ◽  
Systemic Arterial Pressure ◽  
Brain Swelling ◽  
Dorsomedial Nucleus ◽  
Medullary Reticular Formation ◽  
Content Type ◽  
Fine Print ◽  
Stimulation Of

✓ The authors report the results of a study to evaluate the effect of stimulation of the medullary reticular formation on cerebral vasomotor tonus and intracranial pressure (ICP) after the hypothalamic dorsomedial nucleus and midbrain reticular formation were destroyed. Systemic arterial pressure (BP), ICP, and local cerebral blood volume (CBV) were continuously recorded in 32 cats. To assess the changes in the cerebral vasomotor tonus, the vasomotor index defined by the increase in ICP per unit change in BP was calculated. In 29 of the 32 animals, BP, ICP, and CBV increased simultaneously immediately after stimulation. The increase in ICP was not secondary to the increase in BP, because the vasomotor index during stimulation was significantly higher than the vasomotor index after administration of angiotensin II. The vasomotor index was high during stimulation of the area around the nucleus reticularis parvocellularis. In animals with the spinal cord transected at the C-2 vertebral level, ICP increased without a change in BP. These findings indicate that the areas stimulated in the medullary reticular formation play an important role in decreasing cerebral vasomotor tonus. This effect was not influenced by bilateral superior cervical ganglionectomy, indicating that there is an intrinsic neural pathway that regulates cerebral vasomotor tonus directly. In three animals, marked biphasic or progressive increases in ICP up to 100 mm Hg were evoked by stimulation. The reduction of cerebral vasomotor tonus and concomitant vasopressor response induced by stimulation of the medullary reticular formation may be one of the causes of acute brain swelling.

A clinical comparison of subdural screw pressure measurements with ventricular pressure

1983 ◽  
Vol 58 (1) ◽  
pp. 45-50 ◽  
Author(s):  
A. David Mendelow ◽  
John O. Rowan ◽  
Lilian Murray ◽  
Audrey E. Kerr
Keyword(s):  
Head Injury ◽  
Intracranial Pressure ◽  
Severe Head Injury ◽  
Fluid Pressure ◽  
Ventricular Catheter ◽  
Pressure Measurements ◽  
Content Type ◽  
Single Lumen ◽  
Ventricular Fluid Pressure ◽  
Fine Print

✓ Simultaneous recordings of intracranial pressure (ICP) from a single-lumen subdural screw and a ventricular catheter were compared in 10 patients with severe head injury. Forty-one percent of the readings corresponded within the same 10 mm Hg ranges, while 13% of the screw pressure measurements were higher and 46% were lower than the associated ventricular catheter measurements. In 10 other patients, also with severe head injury, pressure measurements obtained with the Leeds-type screw were similarly compared with ventricular fluid pressure. Fifty-eight percent of the dual pressure readings corresponded, while 15% of the screw measurements were higher and 27% were lower than the ventricular fluid pressure, within 10-mm Hg ranges. It is concluded that subdural screws may give unreliable results, particularly by underestimating the occurrence of high ICP.

Pneumocephalus following ventriculoperitoneal shunt

1975 ◽  
Vol 43 (5) ◽  
pp. 631-633 ◽  
Author(s):  
Lawrence H. Pitts ◽  
Charles B. Wilson ◽  
Herbert H. Dedo ◽  
Robert Weyand
Keyword(s):  
Cerebrospinal Fluid ◽  
Intracranial Pressure ◽  
Ventriculoperitoneal Shunt ◽  
Cerebrospinal Fluid Leakage ◽  
Congenital Defects ◽  
Content Type ◽  
Ventriculoperitoneal Shunting ◽  
Tegmen Tympani ◽  
Temporal Bones ◽  
Fine Print

✓ The authors describe a case of massive pneumocephalus following ventriculoperitoneal shunting for hydrocephalus. After multiple diagnostic and surgical procedures, congenital defects in the tegmen tympani of both temporal bones were identified as the sources for entry of air. A functioning shunt intermittently established negative intracranial pressure and allowed ingress of air through these abnormalities; when the shunt was occluded, air did not enter the skull, and there was no cerebrospinal fluid leakage. Repair of these middle ear defects prevented further recurrence of pneumocephalus.

Evaluation of a method for noninvasive intracranial pressure assessment during infusion studies in patients with hydrocephalus

2000 ◽  
Vol 92 (5) ◽  
pp. 793-800 ◽  
Author(s):  
Bernhard Schmidt ◽  
Marek Czosnyka ◽  
Jens Jürgen Schwarze ◽  
Dirk Sander ◽  
Werner Gerstner ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Intracranial Pressure ◽  
Time Course ◽  
Cerebral Blood Flow Velocity ◽  
Absolute Error ◽  
Content Type ◽  
Arterial Blood ◽  
Potential Clinical Benefit ◽  
The Mean ◽  
Fine Print

Object. A mathematical model previously introduced by the authors allowed noninvasive intracranial pressure (nICP) assessment. In the present study the authors investigated this model as an aid in predicting the time course of raised ICP during infusion tests in patients with hydrocephalus and its suitability for estimating the resistance to outflow of cerebrospinal fluid (Rcsf).Methods. Twenty-one patients with hydrocephalus were studied. The nICP was calculated from the arterial blood pressure (ABP) waveform by using a linear signal transformation, which was dynamically modified by the relationship between ABP and cerebral blood flow velocity. This model was verified by comparison of nICP with “real” ICP measured during lumbar infusion tests. In all simulations, parallel increases in real ICP and nICP were evident. The simulated Rcsf was computed using nICP and then compared with Rcsf computed from real ICP. The mean absolute error between real and simulated Rcsf was 4.1 ± 2.2 mm Hg minute/ml. By the construction of simulations specific to different subtypes of hydrocephalus arising from various causes, the mean error decreased to 2.7 ± 1.7 mm Hg minute/ml, whereas the correlation between real and simulated Rcsf increased from R = 0.73 to R = 0.89 (p < 0.001).Conclusions. The validity of the mathematical model was confirmed in this study. The creation of type-specific simulations resulted in substantial improvements in the accuracy of ICP assessment. Improvement strategies could be important because of a potential clinical benefit from this method.

Intracranial xanthogranuloma of the dura in Hand-Schüller-Christian disease

1993 ◽  
Vol 78 (2) ◽  
pp. 297-300 ◽  
Author(s):  
Zain Alabedeen B. Jamjoom ◽  
Vinita Raina ◽  
Abdulfattah Al-Jamali ◽  
Abdulhakim B. Jamjoom ◽  
Basim Yacub ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Clinical Features ◽  
Obstructive Hydrocephalus ◽  
Relevant Literature ◽  
Increased Intracranial Pressure ◽  
Falx Cerebri ◽  
Content Type ◽  
Tentorium Cerebelli ◽  
Ultrastructural Studies ◽  
Fine Print

✓ The authors describe a 37-year-old man with the classic clinical features of Hand-Schüller-Christian disease. He presented with symptoms of increased intracranial pressure due to obstructive hydrocephalus secondary to a huge xanthogranuloma involving falx cerebri and tentorium cerebelli. Immunohistochemical and ultrastructural studies failed to demonstrate Langerhans histiocytes, however. The implication of this finding is discussed in light of the recent relevant literature.

Posture-related changes in the pressure environment of the ventriculoperitoneal shunt system

2000 ◽  
Vol 93 (4) ◽  
pp. 614-617 ◽  
Author(s):  
Yoshinaga Kajimoto ◽  
Tomio Ohta ◽  
Hiroji Miyake ◽  
Masanori Matsukawa ◽  
Daiji Ogawa ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Perfusion Pressure ◽  
Upright Position ◽  
Intraabdominal Pressure ◽  
Preventive Effect ◽  
Shunt System ◽  
Content Type ◽  
Vp Shunt ◽  
Programmable Valve ◽  
Fine Print

Object. The purpose of this study is to clarify the whole pressure environment of the ventriculoperitoneal (VP) shunt system in patients with successfully treated hydrocephalus and to determine which factor of the pressure environment has a preventive effect on overdrainage.Methods. Thirteen patients with hydrocephalus who had been treated with VP shunt therapy by using a Codman– Hakim programmable valve without incidence of overdrainage were examined. The authors evaluated intracranial pressure (ICP), intraabdominal pressure (IAP), hydrostatic pressure (HP), and the perfusion pressure (PP) of the shunt system with the patients both supine and sitting.With patients supine, ICP, IAP, and HP were 4.6 ± 3 mm Hg, 5.7 ± 3.3 mm Hg, and 3.3 ± 1 mm Hg, respectively. As a result, the PP was only 2.2 ± 4.9 mm Hg. When the patients sat up, the IAP increased to 14.7 ± 4.8 mm Hg, and ICP decreased to −14.2 ± 4.5 mm Hg. The increased IAP and decreased ICP offset 67% of the HP (42.9 ± 3.5 mm Hg), and consequently the PP (14 ± 6.3 mm Hg) corresponded to only 33% of HP.Conclusions. The results observed in patients indicated that IAP as well as ICP play an important role in VP shunt therapy and that the increased IAP and the decreased ICP in patients placed in the upright position allow them to adapt to the siphoning effect and for overdrainage thereby to be avoided.

Carotid paraclinoid aneurysms with intradural origin and intracavernous location

1978 ◽  
Vol 48 (4) ◽  
pp. 526-533 ◽  
Author(s):  
Stephen Nutik
Keyword(s):  
Carotid Artery ◽  
Internal Carotid Artery ◽  
Internal Carotid ◽  
Precise Definition ◽  
Separate Entity ◽  
Content Type ◽  
Paraclinoid Aneurysms ◽  
Planning Treatment ◽  
Definition Of ◽  
Fine Print

✓ Five cases of a congenital berry aneurysm of the internal carotid artery with origin partially intradural and fundus mainly intracavernous are presented. Angiography does not allow a precise definition of the amount of aneurysm that is intradural, a fact of importance when planning treatment of these cases. However, the angiographic features are characteristic of the type and suggest that these aneurysms be grouped together as a separate entity.

A method of estimating intracranial decompensation in man

1976 ◽  
Vol 45 (2) ◽  
pp. 155-158 ◽  
Author(s):  
Jerzy Szewczykowski ◽  
Pawel Dytko ◽  
Adam Kunicki ◽  
Jolanta Korsak-Sliwka ◽  
Stanislaw Sliwka ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Intracranial Pressure ◽  
Characteristic Feature ◽  
Computer System ◽  
Monitoring System ◽  
New Method ◽  
Icp Monitoring ◽  
Content Type ◽  
On Line ◽  
Fine Print

✓ A new method of estimating intracranial decompensation in man is described. An on-line computer system is connected to an intracranial pressure (ICP) monitoring system to compute regression plots of mean ICP vs standard deviation; standard deviation is used as a measure of ICP instability. Two zones with distinctly different slopes are a characteristic feature of these plots. It is thought that the changes of slope signify intracranial decompensation.

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