Relationship between visual evoked potentials and intracranial pressure

1981 ◽  
Vol 55 (6) ◽  
pp. 909-916 ◽  
Author(s):  
Donald H. York ◽  
Morris W. Pulliam ◽  
John G. Rosenfeld ◽  
Clark Watts
Keyword(s):  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Severe Head Injury ◽  
Potential Role ◽  
Content Type ◽  
The Relationship ◽  
Normal Latency ◽  
Fine Print ◽  
Visual Evoked

✓ The relationship between intracranial pressure (ICP) and latency of visual evoked potentials (VEP) was investigated in hydrocephalic patients with suspected shunt malfunction and in patients with severe head trauma. A positive correlation of increase in latency of wave N2 (normal latency 71 ± 9.2 msec) of the VEP with elevations in ICP was observed. A potential role for VEP in both the assessment of shunt function and the monitoring of patients with severe head injury is suggested by these findings.

Nonlinear Analysis of Visual Evoked Potentials Elicited by Color Stimulation

1997 ◽  
Vol 36 (04/05) ◽  
pp. 315-318 ◽  
Author(s):  
K. Momose ◽  
K. Komiya ◽  
A. Uchiyama
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Second Order ◽  
First Order ◽  
The Relationship ◽  
Perceived Color ◽  
Second Order Nonlinearity ◽  
Visual Evoked

Abstract:The relationship between chromatically modulated stimuli and visual evoked potentials (VEPs) was considered. VEPs of normal subjects elicited by chromatically modulated stimuli were measured under several color adaptations, and their binary kernels were estimated. Up to the second-order, binary kernels obtained from VEPs were so characteristic that the VEP-chromatic modulation system showed second-order nonlinearity. First-order binary kernels depended on the color of the stimulus and adaptation, whereas second-order kernels showed almost no difference. This result indicates that the waveforms of first-order binary kernels reflect perceived color (hue). This supports the suggestion that kernels of VEPs include color responses, and could be used as a probe with which to examine the color visual system.

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.

Pattern-reversal visual evoked potentials in patients with hydrocephalus

1985 ◽  
Vol 62 (2) ◽  
pp. 234-237 ◽  
Author(s):  
Shakir M. Alani
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Right Hemisphere ◽  
Visual Pathway ◽  
Pattern Reversal ◽  
Field Stimulation ◽  
Content Type ◽  
Clinical Methods ◽  
The Right ◽  
Visual Evoked

✓ Pattern-reversal visual evoked potentials (VEP's) in response to whole- and half-field stimulation were studied in 10 patients with hydrocephalus. Abnormalities consistent with optic nerve dysfunction were recorded in four patients. Two patients had response asymmetry to half-field stimulation, which suggested dysfunction of the visual pathway in the right hemisphere. The remaining four patients had normal responses. Measurement of VEP's was repeated after the surgical treatment of hydrocephalus in four patients, and showed marked improvement in two of the three patients with preoperative abnormalities. This study suggests that, in patients with hydrocephalus, VEP's are more sensitive than clinical methods in detecting visual pathway dysfunction and that they can be useful in the follow-up monitoring of surgically treated hydrocephalic patients.

scholarly journals Visual evoked potentials show strong positive association with intracranial pressure in patients with cryptococcal meningitis

2015 ◽  
Vol 73 (4) ◽  
pp. 309-313 ◽  
Author(s):  
Marcelo Adriano da Cunha Silva Vieira ◽  
Maria do Amparo Salmito Cavalcanti ◽  
Dorcas Lamounier Costa ◽  
Kelsen Dantas Eulálio ◽  
Otoni Cardoso do Vale ◽  
...  
Keyword(s):  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Lumbar Puncture ◽  
Visual Evoked Potentials ◽  
Cryptococcal Meningitis ◽  
Positive Association ◽  
Strong Positive Correlation ◽  
Flash Visual Evoked Potentials ◽  
Strong Positive Association ◽  
Visual Evoked

Objective : To verify the relationship between intracranial pressure and flash visual evoked potentials (F-VEP) in patients with cryptococcal meningitis. Method The sample included adults diagnosed with cryptococcal meningitis admitted at a reference hospital for infectious diseases. The patients were subjected to F-VEP tests shortly before lumbar puncture. The Pearson’s linear correlation coefficient was calculated and the linear regression analysis was performed. Results : Eighteen individuals were subjected to a total of 69 lumbar punctures preceded by F-VEP tests. At the first lumbar puncture performed in each patient, N2 latency exhibited a strong positive correlation with intracranial pressure (r = 0.83; CI = 0.60 - 0.94; p < 0.0001). The direction of this relationship was maintained in subsequent punctures. Conclusion : The intracranial pressure measured by spinal tap manometry showed strong positive association with the N2 latency F-VEP in patients with cryptococcal meningitis.

The relationship between visual seizures and visual evoked potentials

1985 ◽  
Vol 28 (3-4) ◽  
pp. 297-305 ◽  
Author(s):  
John R. Hughes ◽  
James L. Stone ◽  
Boris A. Vern ◽  
Anne C. Weiss ◽  
John J. Fino ◽  
...  
Keyword(s):  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
The Relationship ◽  
Visual Evoked

scholarly journals Abnormal Electroretinograms and Visual Evoked Potentials in Chronic Papilledema Using Time-Difference Analysis

1981 ◽  
Vol 8 (3) ◽  
pp. 243-248 ◽  
Author(s):  
T.H. Kirkham ◽  
S.G. Coupland
Keyword(s):  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
High Frequency ◽  
Time Difference ◽  
Frequency Signal ◽  
High Frequency Signal ◽  
Difference Analysis ◽  
Chronic Papilledema ◽  
Visual Evoked

SUMMARY:Visual function is usually considered to be normal in papilledema. We report previously undescribed abnormalities in the electroretinograms (ERG) and visual evoked potentials (VEP) of two patients with chronic papilledema. The steady-state latencies of the ERG and VEP were calculated using time-difference analysis. The ERG was abnormal under both scotopic (slow) and photopic (fast) flicker conditions, but the VEP was abnormal only to fast flicker photopic stimulation. This may indicate a relative vulnerability of a high frequency signal system under conditions of raised intracranial pressure. The abnormalities resolved rapidly once the intracranial pressure had been normalised. The cause of the V EP and particularly the ERG abnormalities remains unknown.

Regional cerebral blood flow, sensory evoked potentials, and intracranial pressure in dogs with MCA occlusion by embolization or trapping

1983 ◽  
Vol 58 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Yoshikazu Okada ◽  
Takeshi Shima ◽  
Mitsuo Yamamoto ◽  
Tohru Uozumi
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked ◽  
Fine Print

✓ Regional cerebral blood flow (rCBF), sensory evoked potentials (SEP), and intracranial pressure (ICP) were investigated in dogs with focal cerebral ischemia produced by a silicone cylinder embolus in the middle cerebral artery (MCA) trunk as compared to that produced by trapping the same vessel. These variables were measured at intervals of 1 hour for a period of 6 hours after MCA occlusion. In the embolized animals, rCBF decreased most extensively at the basal ganglia, from a control level of 53.9 ± 3.9 (mean ± SE) to 21.5 ± 2.7 ml/100 gm/min at the 6th hour. Sensory evoked potentials decreased progressively from the resting level of 100% to 53.0% ± 7.2% at the 3rd hour. Intracranial pressure, measured by epidural pressure on the occluded side, increased rapidly during the first 3 hours, from 10.6 ± 0.3 to about 30 cm H2O. In the animals with trapping, the decreases in rCBF and declines of SEP were significantly less than those in the embolized animals, and no evident brain swelling was observed. This study demonstrates that MCA trunk occlusion by silicone cylinder embolization produces a more marked decrease in deep CBF, with diminution of SEP and increase in ICP, than that produced by trapping.

Initial CT findings in 753 patients with severe head injury

1990 ◽  
Vol 73 (5) ◽  
pp. 688-698 ◽  
Author(s):  
Howard M. Eisenberg ◽  
Howard E. Gary ◽  
E. Francois Aldrich ◽  
Christy Saydjari ◽  
Barbara Turner ◽  
...  
Keyword(s):  
Head Injury ◽  
Intracranial Pressure ◽  
Severe Head Injury ◽  
Ct Scans ◽  
Midline Shift ◽  
Prospective Multicenter Study ◽  
Content Type ◽  
Ct Findings ◽  
Subarachnoid Blood ◽  
Fine Print

✓ In this prospective multicenter study, the authors have examined data derived from the initial computerized tomography (CT) scans of 753 patients with severe head injury. When the CT findings were related to abnormal intracranial pressure and to death, the most important characteristics of the scans were: midline shift; compression or obliteration of the mesencephalic cisterns; and the presence of subarachnoid blood. Diffuse hemispheric swelling was also found to be associated with an early episode of either hypoxia or hypotension.

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