Prolonged Vertical Nystagmus After Pentobarbital Sodium Administration

1975 ◽  
Vol 80 (1) ◽  
pp. 151-152 ◽  
Author(s):  
Simmons Lessell ◽  
Philip A. Wolf ◽  
David Chronley
Keyword(s):  
Pentobarbital Sodium ◽  
Vertical Nystagmus

Isolated, monocular vertical nystagmus: single symptom of an extensive intracerebral tumor

2011 ◽  
Vol 42 (S 01) ◽  
Author(s):  
V Haug ◽  
M von Rhein ◽  
K Frauenknecht ◽  
J Faber ◽  
B Reitter
Keyword(s):  
Intracerebral Tumor ◽  
Vertical Nystagmus

Pulmonary interstitial compliance: a function of the osmotic constituents of the interstitium

1982 ◽  
Vol 53 (2) ◽  
pp. 324-329 ◽  
Author(s):  
P. D. Snashall ◽  
S. J. Keyes ◽  
B. M. Morgan ◽  
K. F. Chung
Keyword(s):  
Hydrostatic Pressure ◽  
Left Atrial ◽  
Interstitial Water ◽  
Dry Weight ◽  
Colloid Osmotic Pressure ◽  
Water Volume ◽  
Direct Puncture ◽  
Vascular Volume ◽  
Pentobarbital Sodium ◽  
Interstitial Volume

We have attempted to dehydrate the lung interstitium to determine the nature of forces holding water in that compartment. We administered furosemide with and without bovine albumin intravenously to rabbits (n = 21) 1813;24 h before they were anesthetized with pentobarbital sodium. Renal pedicels were ligated and 51Cr-labeled EDTA was injected to estimate lung interstitial water volume. After a period of equilibration the thorax was rapidly opened, and left atrial pressure was measured by direct puncture. 125I-labeled albumin was injected to label the lung vascular volume, and the rabbits were killed 3 min later. Lungs were removed and drained of blood, and extravascular water volume, interstitial volume, and dry weight were determined. Results from these rabbits were compared with a group of normal (n = 4) and overhydrated (n = 6) rabbits. We have found that lung interstitial water is removed in proportion to the change in intravascular forces. We estimate interstitial compliance to be 1.76% cmH2O-1. Our results are compatible with the hypothesis that removal of water is opposed by an increase in interstitial colloid osmotic pressure and not by a fall of hydrostatic pressure. This implies that in the normally hydrated state interstitial hydrostatic pressure is ambient.

scholarly journals Upbeat vertical nystagmus after brain stem cavernoma resection: a rare case of nucleus intercalatus/nucleus of roller injury

2020 ◽  
Vol 267 (10) ◽  
pp. 2865-2870
Author(s):  
Torstein R. Meling ◽  
Aria Nouri ◽  
Adrien May ◽  
Nils Guinand ◽  
Maria Isabel Vargas ◽  
...  
Keyword(s):  
Rare Case ◽  
Vascular Malformations ◽  
Clinical Manifestations ◽  
Neurological Injury ◽  
Medial Longitudinal Fasciculus ◽  
Blurred Vision ◽  
Complete Excision ◽  
First Case ◽  
Vertical Nystagmus ◽  
Upbeat Nystagmus

Abstract Introduction CNS cavernomas are a type of raspberry-shaped vascular malformations that are typically asymptomatic, but can result in haemorrhage, neurological injury, and seizures. Here, we present a rare case of a brainstem cavernoma that was surgically resected whereafter an upbeat nystagmus presented postoperatively. Case report A 42-year old man presented with sudden-onset nausea, vomiting, vertigo, blurred vision, marked imbalance and difficulty swallowing. Neurological evaluation showed bilateral ataxia, generalized hyperreflexia with left-sided predominance, predominantly horizontal gaze evoked nystagmus on right and left gaze, slight left labial asymmetry, uvula deviation to the right, and tongue deviation to the left. MRI demonstrated a 13-mm cavernoma with haemorrhage and oedema in the medulla oblongata. Surgery was performed via a minimal-invasive, midline approach. Complete excision was confirmed on postoperative MRI. The patient recovered well and became almost neurologically intact. However, he complained of mainly vertical oscillopsia. The videonystagmography revealed a new-onset spontaneous upbeat nystagmus in all gaze directions, not suppressed by fixation. An injury of the rarely described intercalatus nucleus/nucleus of Roller is thought to be the cause. Conclusion Upbeat nystagmus can be related to several lesions of the brainstem, including the medial longitudinal fasciculus, the pons, and the dorsal medulla. To our knowledge, this is the first case of an iatrogenic lesion of the nucleus intercalatus/nucleus of Roller resulting in an upbeat vertical nystagmus. For neurologists, it is important to be aware of the function of this nucleus for assessment of clinical manifestations due to lesions within this region.

Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

Monocular Vertical Nystagmus as an Initial Sign of Chiasmal Glioma

1979 ◽  
Vol 87 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Joel A. Schulman ◽  
William T. Shults ◽  
J. Mcandrew Jones
Keyword(s):  
Initial Sign ◽  
Vertical Nystagmus

Interaction of right and left carotid sinus baroreflexes in the dog

1986 ◽  
Vol 250 (1) ◽  
pp. H96-H107 ◽  
Author(s):  
A. S. Greene ◽  
M. J. Brunner ◽  
A. A. Shoukas
Keyword(s):  
Heart Rate ◽  
Tidal Volume ◽  
Carotid Sinus ◽  
The Other ◽  
Reflex Response ◽  
Pentobarbital Sodium ◽  
Simultaneous Excitation ◽  
Carotid Sinus Baroreflex ◽  
The Right ◽  
Sinus Pressure

Carotid sinus reflex interactions were studied in 10 dogs anesthetized with pentobarbital sodium. The right and left carotid sinus regions were isolated and perfused at controlled pressures. Pressure in the right and left carotid sinuses were independently varied, and the resulting steady-state reflex changes in arterial pressure, heart rate, respiratory frequency, tidal volume, and total ventilation were measured. Reflex changes when carotid sinus pressure was changed on one side were strongly influenced by pressure in the contralateral carotid sinus (P less than 0.05). Right carotid sinus gain was found to be 0.628 +/- 0.058 at a left carotid sinus pressure of 50 mmHg and 0.148 +/- 0.027 when left carotid sinus pressure was 200 mmHg. Similar results were found for left carotid sinus gain. Suppression was also found for heart rate, respiratory rate, tidal volume, and total ventilation. The hypothesis that rapid resetting of one carotid sinus baroreflex might influence responses from the other side was also tested. Although ipsilateral resetting was consistently observed, no contralateral component of the resetting was detected. An additional inhibitory summation between the right and left carotid sinuses was found such that simultaneous excitation of both receptors resulted in a smaller reflex response than did the sum of individual responses. Sympathetic denervation of the carotid sinus region had no effect.

Characterization of synaptically mediated fast and slow inhibitory processes in piriform cortex in an in vitro slice preparation

1988 ◽  
Vol 59 (5) ◽  
pp. 1352-1376 ◽  
Author(s):  
G. F. Tseng ◽  
L. B. Haberly
Keyword(s):  
Membrane Potential ◽  
Piriform Cortex ◽  
Reversal Potential ◽  
Pyramidal Cells ◽  
Membrane Depolarization ◽  
Resting Membrane Potential ◽  
Excitatory Postsynaptic Potential ◽  
Pentobarbital Sodium ◽  
Postsynaptic Potential ◽  
Conductance Increase

1. Intracellular recordings were obtained from anatomically verified layer II pyramidal cells in slices from rat piriform cortex cut perpendicular to the surface. 2. Responses to afferent and association fiber stimulation at resting membrane potential consisted of a depolarizing potential followed by a late hyperpolarizing potential (LHP). Membrane polarization by current injection revealed two components in the depolarizing potential: an initial excitatory postsynaptic potential (EPSP) followed at brief latency by an inhibitory postsynaptic potential (IPSP) that inverted with membrane depolarization and truncated the duration of the EPSP. 3. The early IPSP displayed the following characteristics suggesting mediation by gamma-aminobutyric acid (GABA) receptors linked to Cl- channels: associated conductance increase, sensitivity to increases in internal Cl- concentration, blockage by picrotoxin and bicuculline, and potentiation by pentobarbital sodium. The reversal potential was in the depolarizing direction with respect to resting membrane potential so that the inhibitory effect was exclusively via current shunting. 4. The LHP had an associated conductance increase and a reversal potential of -90 mV in normal bathing medium that shifted according to Nernst predictions for a K+ potential with changes in external K+ over the range 4.5-8 mM indicating mediation by the opening of K+ channels and ruling out an electrogenic pump origin. 5. Lack of effect of bath-applied 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) or internally applied ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid (EGTA) on the LHP and failure of high amplitude, direct membrane depolarization to evoke a comparable potential, argue against endogenous mediation of the LHP by a Ca2+ activated K+ conductance [gK(Ca)]. However, an apparent endogenously mediated gK(Ca) with a duration much greater than the LHP was observed in a low percent of layer II pyramidal cells. Lack of effect of 8-Br-cAMP also indicates a lack of dependence of the LHP on cAMP. 6. Other characteristics of the LHP that were demonstrated include: a lack of blockage by GABAA receptor antagonists, a probable voltage sensitivity (decrease in amplitude in the depolarizing direction), and an apparent brief onset latency (less than 10 ms) when the early IPSP was blocked by picrotoxin. The LHP was unaffected by pentobarbital sodium when the early IPSP was blocked by picrotoxin. 7. Both the LHP and early IPSP were blocked by low Ca2+/high Mg2+, consistent with disynaptic mediation.(ABSTRACT TRUNCATED AT 400 WORDS)

Effect of inspired CO2 on ventilation and perfusion heterogeneity in hyperventilated dogs

1993 ◽  
Vol 75 (3) ◽  
pp. 1306-1314 ◽  
Author(s):  
K. B. Domino ◽  
E. R. Swenson ◽  
N. L. Polissar ◽  
Y. Lu ◽  
B. L. Eisenstein ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Partial Pressure ◽  
Respiratory Rate ◽  
Dead Space ◽  
Pressure Difference ◽  
Inert Gas ◽  
Ventilation Distribution ◽  
Pentobarbital Sodium ◽  
Ventilation And Perfusion ◽  
Paco2 Level

We studied the effect of inspired CO2 on ventilation-perfusion (VA/Q) heterogeneity in dogs hyperventilated under two different tidal volume (VT) and respiratory rate conditions with the use of the multiple inert gas elimination technique. Dogs anesthetized with pentobarbital sodium were hyperventilated with an inspired fraction of O2 of 0.21 by using an increased VT (VT = 30 ml/kg at 18 breaths/min) or an increased respiratory rate (VT = 18 ml/kg at 35 breaths/min). The arterial CO2 tension (PaCO2) was varied to three levels (20, 35, and 52 Torr) by altering the inspired PCO2. The orders of type of ventilation and PaCO2 level were randomized. Compared with normocapnia, VA/Q heterogeneity was increased during hypocapnia induced by increased respiratory rate ventilation, which was indicated by an increase in dispersion indexes and arterial-alveolar inert gas partial pressure difference areas (P < 0.01). In contrast, VA/Q heterogeneity was not affected by hypocapnia when a large VT ventilation was used. Under the conditions of our study, hypercapnia did not result in statistically significant changes in VA/Q heterogeneity with either type of ventilation. Increased VT ventilation reduced dead space at all PaCO2 levels (P < 0.01) and reduced the log standard deviation of the ventilation distribution during normocapnia (P < 0.05) and hypocapnia (P < 0.01). We conclude that hypocapnia increased VA/Q heterogeneity when hyperventilation was achieved with a rapid respiratory rate. Therefore, a lack of improvement in VA/Q matching with inhaled CO2 may be associated with the use of a large VT. These data suggest that hypocapnic bronchoconstriction may be important in mediating hypocapnia-induced VA/Q inequality in dogs.

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