Effects of ventriculoperitoneal shunt removal on cerebral oxygenation and brain compliance in chronic obstructive hydrocephalus

2001 ◽  
Vol 94 (4) ◽  
pp. 573-581 ◽  
Author(s):  
Toru Fukuhara ◽  
Mark G. Luciano ◽  
Christine L. Brant ◽  
Jennifer Klauscie
Keyword(s):  
Cerebral Oxygenation ◽  
Obstructive Hydrocephalus ◽  
Canine Model ◽  
Shunt Malfunction ◽  
Control Group ◽  
Chronic Obstructive ◽  
Content Type ◽  
Shunt Placement ◽  
Shunt Removal ◽  
Fine Print

Object. The pathophysiology of shunt malfunction has not been fully examined, probably because of the paucity of appropriate animal models. Using a canine model of chronic obstructive hydrocephalus, the effects of shunt placement and removal on physiological parameters were evaluated. Methods. Fifteen dogs, nine in which chronic hydrocephalus was induced and six controls, were used in the experiment. Thirteen weeks after the induction of hydrocephalus, intracranial pressure (ICP), tissue and cerebrospinal fluid O2 saturation, response to hyperventilation, and brain compliance at low (5–15 mm Hg) and high (15–25 mm Hg) pressures were measured (untreated stage). Following this procedure, ventriculoperitoneal shunts were implanted in the dogs suffering from hydrocephalus. Two weeks later, the same series of measurements were repeated (shunted stage), following which the shunt systems were removed. One week after shunt removal, the last measurements were obtained (shunt-removed stage). All dogs underwent magnetic resonance imaging four times: before induction of hydrocephalus and before each measurement. All dogs with hydrocephalus also had ventriculomegaly (1.42 ± 0.89 ml before induction of hydrocephalus compared with 3.4 ± 1.64 ml 13 weeks after induction, p = 0.0064). In dogs in the untreated hydrocephalus stage, ICP remained within the normal range (8.33 ± 2.60 mm Hg)—although it was significantly higher than that in the control group (5 ± 1.41 mm Hg, p = 0.014). Tissue O2 saturation in the dogs in the hydrocephalus group (26.1 ± 5.33 mm Hg) was lower than that in the dogs in the control group (48.7 ± 4.27 mm Hg, p < 0.0001). After the dogs underwent shunt placement, significant improvement was observed in their ICP (5.22 ± 2.17 mm Hg, p = 0.012) and tissue O2 saturation (35.2 ± 6.80 mm Hg, p = 0.0084). However, removal of the shunt reversed these improvements back to the preshunt status. Hyperventilation induced significant decreases in ICP and O2 saturation at every measurement time and induced a significant decrease in tissue O2 saturation during the shunted stage, but not during the untreated and shunt-removed stages. Brain compliance measured at high pressure demonstrated a significant gradual decrease at every measurement. Conclusions. In chronic obstructive hydrocephalus, shunt placement improves ICP and cerebral oxygenation as well as the response to hyperventilation in the tissue. Shunt removal reverses these improvements back to levels present during the untreated stage. The decrease in brain compliance may be one of the factors responsible for symptoms in shunt malfunction.

Endoscopic third ventriculostomy for shunt dysfunction in occlusive hydrocephalus: long-term follow up and review

2003 ◽  
Vol 98 (5) ◽  
pp. 1032-1039 ◽  
Author(s):  
Jürgen Boschert ◽  
Dieter Hellwig ◽  
Joachim K. Krauss
Keyword(s):  
Endoscopic Third Ventriculostomy ◽  
Obstructive Hydrocephalus ◽  
The Other ◽  
Third Ventriculostomy ◽  
Content Type ◽  
Shunt Placement ◽  
Occlusive Hydrocephalus ◽  
Shunt Dysfunction ◽  
Fine Print

Object. Endoscopic third ventriculostomy (ETV) is the treatment of choice for occlusive (noncommunicating) hydrocephalus. Nevertheless, its routine use in patients who have previously undergone shunt placement is still not generally accepted. The authors' aim was to investigate the long-term effects of ETV in a group of prospectively chosen patients. Methods. Patients who underwent ETV and had previously undergone shunt placement for occlusive hydrocephalus were followed prospectively for at least 3 years (range 36–103 months, mean 63.6 months). Nine female and eight male patients ranging from 8 to 54 years of age (mean 32 years) had undergone shunt placement 0.7 to 23.5 years (mean 8.1 years) before ETV. Fifteen patients were admitted with underdrainage and two with overdrainage. In six cases, ETV was performed as an emergency operation. The origin of hydrocephalus was aqueductal stenosis in 12 cases and aqueductal compression by a tumor in two cases. Three patients suffered from a fourth ventricle outlet syndrome, and in two patients an additional malresorptive component was suspected. Thirteen patients underwent ETV with shunt removal and insertion of an external drain in one session. The drain served as a safety measure; it could be opened if raised intracranial pressure or ventricular dilation was observed on postoperative imaging studies. In the other four patients the shunt was initially ligated and then removed during a second operation. Fourteen patients (82%) have remained shunt free. The other three patients, including the two with an additional malresorptive component, needed shunt reimplantation 3 days, 2 weeks, or 7 months after ETV. Conclusions. Use of ETV is safe and effective for the treatment for shunt dysfunction in patients with obstructive hydrocephalus.

Isolated fourth ventricle as a complication of ventricular shunting

1978 ◽  
Vol 49 (6) ◽  
pp. 910-913 ◽  
Author(s):  
John C. Hawkins ◽  
Harold J. Hoffman ◽  
Robin P. Humphreys
Keyword(s):  
Computerized Tomography ◽  
Fourth Ventricle ◽  
Obstructive Hydrocephalus ◽  
Normal Function ◽  
Shunt Malfunction ◽  
Cerebellar Dysfunction ◽  
Content Type ◽  
Isolated Fourth Ventricle ◽  
Ventricular Shunting ◽  
Fine Print

✓ Signs of cerebellar dysfunction combined with signs suggestive of shunt malfunction developed in three children with obstructive hydrocephalus. Shunt function was normal. In all cases, the cerebellar signs persisted and computerized tomography scans revealed enlargement of the fourth ventricle. Shunting of the fourth ventricle returned the patients to normal function.

Sylvian aqueduct syndrome and global rostral midbrain dysfunction associated with shunt malfunction

1999 ◽  
Vol 90 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Giuseppe Cinalli ◽  
Christian Sainte-Rose ◽  
Isabelle Simon ◽  
Guillaume Lot ◽  
Spiros Sgouros
Keyword(s):  
Pressure Gradient ◽  
Obstructive Hydrocephalus ◽  
Shunt Malfunction ◽  
Shunt Revision ◽  
Third Ventriculostomy ◽  
Content Type ◽  
Upward Gaze Palsy ◽  
Ocular Signs ◽  
Gaze Palsy ◽  
Fine Print

Object. This study is a retrospective analysis of clinical data obtained in 28 patients affected by obstructive hydrocephalus who presented with signs of midbrain dysfunction during episodes of shunt malfunction.Methods. All patients presented with an upward gaze palsy, sometimes associated with other signs of oculomotor dysfunction. In seven cases the ocular signs remained isolated and resolved rapidly after shunt revision. In 21 cases the ocular signs were variably associated with other clinical manifestations such as pyramidal and extrapyramidal deficits, memory disturbances, mutism, or alterations in consciousness. Resolution of these symptoms after shunt revision was usually slow. In four cases a transient paradoxical aggravation was observed at the time of shunt revision. In 11 cases ventriculocisternostomy allowed resolution of the symptoms and withdrawal of the shunt.Simultaneous supratentorial and infratentorial intracranial pressure recordings performed in seven of the patients showed a pressure gradient between the supratentorial and infratentorial compartments, with a higher supratentorial pressure before shunt revision. Inversion of this pressure gradient was observed after shunt revision and resolution of the gradient was observed in one case after third ventriculostomy. In six recent cases, a focal midbrain hyperintensity was evidenced on T2-weighted magnetic resonance imaging sequences at the time of shunt malfunction. This rapidly resolved after the patient underwent third ventriculostomy.Conclusions. It is probable that in obstructive hydrocephalus, at the time of shunt malfunction, the development of a transtentorial pressure gradient could initially induce a functional impairment of the upper midbrain, inducing upward gaze palsy. The persistence of the gradient could lead to a global dysfunction of the upper midbrain. Third ventriculostomy contributes to equalization of cerebrospinal fluid pressure across the tentorium by restoring free communication between the infratentorial and supratentorial compartments, resulting in resolution of the patient's clinical symptoms.

Optimum degree of hemodilution for brain protection in a canine model of focal cerebral ischemia

1994 ◽  
Vol 80 (3) ◽  
pp. 469-475 ◽  
Author(s):  
Sun Ho Lee ◽  
Roberto C. Heros ◽  
John C. Mullan ◽  
Kazuyoshi Korosue
Keyword(s):  
Cerebral Artery ◽  
Focal Cerebral Ischemia ◽  
Arterial Occlusion ◽  
Canine Model ◽  
Control Group ◽  
Left Middle Cerebral Artery ◽  
Content Type ◽  
Infarction Size ◽  
Infarction Volume ◽  
Fine Print

✓ The ability of hemodilution to lower blood viscosity and increase cerebral blood flow has been proven experimentally; however, the optimum hematocrit for maximum oxygen delivery to ischemic brain tissue is not known, and a study was designed to determine this. Fifty dogs were selected for inclusion in the study using criteria based on changes in somatosensory evoked potentials at the time of arterial occlusion, which were found in a previous study to predict the development of a moderate infarction of relatively constant size. Infarctions were induced by permanent occlusion of the left middle cerebral artery and the azygous anterior cerebral artery. The animals selected for inclusion were divided into five groups of 10 dogs each: 1) a control group; 2) a group with 25% hematocrit; 3) a group with 30% hematocrit; 4) a group with 35% hematocrit; and 5) a group with 40% hematocrit. Isovolemic hemodilution was accomplished 1 hour after occlusion of vessels using dextran infusion and blood withdrawal. The animals were sacrificed after 6 days and infarction volume was determined from fluorescein-stained sections. Statistical analysis was performed using Student's t-test and one-way analysis of variance. Mean infarction volume for each group, expressed as a percentage of total hemispheric volume ± 1 standard error of the mean, was 28.3% ± 2.8% for the control group, 33.6% ± 3.4% for the 25% hematocrit group, 17.1% ± 2.2% for the 30% hematocrit group, 29.2% ± 4.3% for the 35% hematocrit group, and 29.9% ± 2.1% for the 40% hematocrit group. The 30% hematocrit group showed the smallest average infarction size and this size differed significantly (p = 0.02) from the average infarction size in the control animals. These results show that, in this model of focal ischemia, a hematocrit of approximately 30% is optimum for protecting the brain.

Intracisternal BioGlue injection in the fetal lamb: a novel model for creation of obstructive congenital hydrocephalus without additional chemically induced neuroinflammation

2019 ◽  
Vol 24 (6) ◽  
pp. 652-662 ◽  
Author(s):  
Marc Oria ◽  
Soner Duru ◽  
Federico Scorletti ◽  
Fernando Vuletin ◽  
Jose L. Encinas ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Repeated Measures ◽  
Obstructive Hydrocephalus ◽  
Critical Threshold ◽  
Control Group ◽  
Chronic Obstructive ◽  
Fetal Sheep ◽  
Cisterna Magna ◽  
Lateral Ventricles ◽  
Fetal Lamb

OBJECTIVEThe authors hypothesized that new agents such as BioGlue would be as efficacious as kaolin in the induction of hydrocephalus in fetal sheep.METHODSThis study was performed in 34 fetal lambs randomly divided into 2 studies. In the first study, fetuses received kaolin, BioGlue (2.0 mL), or Onyx injected into the cisterna magna, or no injection (control group) between E85 and E90. In the second study, fetuses received 2.0-mL or 2.5-mL injections of BioGlue into the cisterna magna between E85 and E90. Fetuses were monitored using ultrasound to assess lateral ventricle size and progression of hydrocephalus. The fetuses were delivered (E120–E125) and euthanized for histological analysis. Selected brain sections were stained for ionized calcium binding adaptor 1 (Iba1) and glial fibrillary acidic protein (GFAP) to assess the presence and activation of microglia and astroglia, respectively. Statistical comparisons were performed with Student’s t-test for 2 determinations and ANOVA 1-way and 2-way repeated measures for multiple determinations.RESULTSAt 30 days after injection, the lateral ventricles were larger in all 3 groups that had undergone injection than in controls (mean diameter in controls 3.76 ± 0.05 mm, n = 5). However, dilatation was greater in the fetuses injected with 2 mL of BioGlue (11.34 ± 4.76 mm, n = 11) than in those injected with kaolin (6.4 ± 0.98 mm, n = 7) or Onyx (5.7 ± 0.31 mm, n = 6) (ANOVA, *p ≤ 0.0001). Fetuses injected with 2.0 mL or 2.5 mL of BioGlue showed the same ventricle dilatation but it appeared earlier (at 10 days postinjection) in those injected with 2.5 mL. The critical threshold of ventricle dilatation was 0.1 for all the groups, and only the BioGlue 2.0 mL and BioGlue 2.5 mL groups exceeded this critical value (at 30 days and 18 days after injection, respectively) (ANOVA, *p ≤ 0.0001). Moderate to severe hydrocephalus with corpus callosum disruption was observed in all experimental groups. All experimental groups showed ventriculomegaly with significant microgliosis and astrogliosis in the subventricular zone around the lateral ventricles. Only kaolin resulted in significant microgliosis in the fourth ventricle area (ANOVA, *p ≤ 0.005).CONCLUSIONSThe results of these studies demonstrate that BioGlue is more effective than Onyx or kaolin for inducing hydrocephalus in the fetal lamb and results in a volume-related response by obstructive space-occupancy without local neuroinflammatory reaction. This novel use of BioGlue generates a model with potential for new insights into hydrocephalus pathology and the development of therapeutics in obstructive hydrocephalus. In addition, this model allows for the study of acute and chronic obstructive hydrocephalus by using different BioGlue volumes for intracisternal injection.

Evaluation of endorphin content in the CSF of patients with trigeminal neuralgia before and after Gasserian ganglion thermocoagulation

1981 ◽  
Vol 55 (6) ◽  
pp. 935-937 ◽  
Author(s):  
Giuseppe Salar ◽  
Salvatore Mingrino ◽  
Marco Trabucchi ◽  
Angelo Bosio ◽  
Carlo Semenza
Keyword(s):  
Cerebrospinal Fluid ◽  
Trigeminal Neuralgia ◽  
Control Group ◽  
Gasserian Ganglion ◽  
Content Type ◽  
Group Of Seven ◽  
Idiopathic Trigeminal Neuralgia ◽  
Significant Difference ◽  
Before And After ◽  
Fine Print

✓ The β-endorphin content in cerebrospinal fluid (CSF) was evaluated in 10 patients with idiopathic trigeminal neuralgia during medical treatment (with or without carbamazepine) and after selective thermocoagulation of the Gasserian ganglion. These values were compared with those obtained in a control group of seven patients without pain problems. No statistically significant difference was found between patients suffering from trigeminal neuralgia and those without pain. Furthermore, neither pharmacological treatment nor surgery changed CSF endorphin values. It is concluded that there is no pathogenetic relationship between trigeminal neuralgia and endorphins.

scholarly journals Direct evidence for a key role of protein kinase C in the development of vasospasm after subarachnoid hemorrhage

1992 ◽  
Vol 76 (4) ◽  
pp. 635-639 ◽  
Author(s):  
Shigeru Nishizawa ◽  
Nobukazu Nezu ◽  
Kenichi Uemura
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Direct Evidence ◽  
Control Group ◽  
Content Type ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Fine Print

✓ Vascular contraction is induced by the activation of intracellular contractile proteins mediated through signal transduction from the outside to the inside of cells. Protein kinase C plays a crucial role in this signal transduction. It is hypothesized that protein kinase C plays a causative part in the development of vasospasm after subarachnoid hemorrhage (SAH). To verify this directly, the authors measured protein kinase C activity in canine basilar arteries in an SAH model with (γ-32P)adenosine triphosphate and the data were compared to those in a control group. Protein kinase C is translocated to the membrane from the cytosol when it is activated, and the translocation is an index of the activation; thus, protein kinase C activity was measured both in the cytosol and in the membrane fractions. Protein kinase C activity in the membrane in the SAH model was remarkably enhanced compared to that in the control group. The percentage of membrane activity to the total was also significantly greater in the SAH vessels than in the control group, and the percentage of cytosol activity in the SAH group was decreased compared to that in the control arteries. The results indicate that protein kinase C in the vascular smooth muscle was translocated to the membrane from the cytosol and was activated when SAH occurred. It is concluded that this is direct evidence for a key role of protein kinase C in the development of vasospasm.

Risk of late stroke and survival following carotid endarterectomy procedures for symptomatic patients

1990 ◽  
Vol 73 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Dennis A. Turner ◽  
Jay Tracy ◽  
Stephen J. Haines
Keyword(s):  
Carotid Endarterectomy ◽  
Life Table ◽  
Stroke Risk ◽  
Neurological Symptoms ◽  
Treatment Modalities ◽  
Control Group ◽  
Content Type ◽  
Postoperative Stroke ◽  
Fine Print

✓ The long-term outcome following carotid endarterectomy for neurological symptoms was analyzed using a retrospective life-table approach in 212 patients who had undergone 243 endarterectomy procedures. The postoperative follow-up period averaged 38.9 ± 2.1 months (mean ± standard error of the mean). The endpoints of stroke and death were evaluated in these patients. Patient groups with the preoperative symptoms of amaurosis fugax, transient ischemic attack, and prior recovered stroke were similar in terms of life-table outcome over the follow-up period. Sixty-two percent of symptomatic patients were alive and free of stroke at 5 years. The late risk of stroke (after 30 days postoperatively) averaged 1.7% per year based on a linear approximation to the hazard at each life-table interval (1.3% per year for ipsilateral stroke). The trend of late stroke risk was clearly downward, however, and could be fitted more accurately by an exponential decay function with a half-life of 33 months. Thus, the risk of stroke following carotid endarterectomy for neurological symptoms was highest in the perioperative period, slowly declined with time, and occurred predominantly ipsilateral to the procedure. The definition of a prospective medical control group remains crucial for a critical analysis of treatment modalities following the onset of premonitory neurological symptoms. In the absence of an adequate control group for this series, the calculated perioperative and postoperative stroke risk from this study was compared to data obtained from the literature on stroke risk in medically treated symptomatic patients. This uncontrolled comparison of treatment modalities suggests the combined perioperative and postoperative stroke risk associated with carotid endarterectomy to be modestly improved over medical treatment alone.

Effect of sympathectomy on spinal blood flow autoregulation and posttraumatic ischemia

1982 ◽  
Vol 56 (5) ◽  
pp. 706-710 ◽  
Author(s):  
Wise Young ◽  
Vincent DeCrescito ◽  
John J. Tomasula
Keyword(s):  
Blood Flow ◽  
Spinal Injury ◽  
Sympathetic Ganglia ◽  
Control Group ◽  
Content Type ◽  
Systemic Pressure ◽  
Sympathetic Regulation ◽  
Mean Systemic Pressure ◽  
Paravertebral Sympathetic Ganglia ◽  
Fine Print

✓ The hypothesis that the paravertebral sympathetic ganglia play a role in spinal blood flow regulation was tested in cats. Five cats were subjected to paravertebral sympathectomy, two to combined sympathectomy-adrenalectomy, three to adrenalectomy alone, and five controls received no treatment. Laminectomy was carried out to expose the T4–10 cord, and autoregulation was tested by measuring blood flow from the lateral columns with the hydrogen clearance technique during manipulation of systemic pressure with intravenous saline infusion and nitroprusside administration. The cord was then contused at T-7 with a 400 gm-cm impact injury. Posttraumatic blood flow was recorded, and neurophysiological function was assessed with somatosensory evoked potential (SEP) monitoring. Before injury, blood flow in the untreated (control) group had no consistent relationship with mean systemic pressure over the range 80 to 160 mm Hg. In contrast, in all cats with paravertebral sympathectomy, whether accompanied by adrenalectomy or not, blood flows increased with systemic pressure (correlation coefficient 0.86, p < 0.01). After injury, the control and adrenalectomized cats showed blood flow decreases of > 60% to 4 to 6 ml/100 gm/min (p < 0.01) by 2 to 3 hours. However, cats with paravertebral sympathectomy maintained blood flow above 9 ml/100 gm/min for up to 3 hours after injury. All the sympathectomized cats recovered their SEP by the 3rd hour after injury, compared with none of the controls. Thus, in the absence of the paravertebral sympathetic ganglia, spinal blood flow autoregulation was impaired and the typical posttraumatic loss in blood flow did not occur. The sympathectomy also protected the spinal cords from the neurophysiological loss usually seen in 400 gm-cm injury. The data suggest the need for caution in using acetylcholine blocking agents to paralyze animals in experimental spinal injury, since these agents alter sympathetic activity and may influence the injury process. The spinal cord is an excellent model in which to investigate sympathetic regulation of central nervous system blood flow.

Effect of hyperglycemia on brain pH levels in areas of focal incomplete cerebral ischemia in monkeys

1986 ◽  
Vol 65 (5) ◽  
pp. 693-696 ◽  
Author(s):  
W. Richard Marsh ◽  
Robert E. Anderson ◽  
Thoralf M. Sundt
Keyword(s):  
Adverse Effect ◽  
Cerebral Ischemia ◽  
Cell Damage ◽  
Treated Group ◽  
Squirrel Monkeys ◽  
Control Group ◽  
Content Type ◽  
Brain Ph ◽  
Fine Print ◽  
Incomplete Ischemia

✓ The adverse effect of a minimal cerebral blood flow (CBF) in models of global ischemia has been noted by many investigators. One factor believed important in this situation is the level of blood glucose, since a continued supply of this metabolite results in increased tissue lactate, decreased brain pH, and increased cell damage. The authors have extended these observations to a model of focal incomplete ischemia. Brain pH was measured in fasted squirrel monkeys in regions of focal incomplete ischemia after transorbital occlusion of the middle cerebral artery (MCA). In both control and hyperglycemic animals, CBF was reduced to less than 30% of baseline. At 3 hours after MCA occlusion, brain pH in the control group was 6.66 ± 0.68 as compared to 6.27 ± 0.26 in the glucose-treated group. This difference was statistically significant by Student's unpaired t-test (p < 0.05). Thus, hyperglycemia results in decreased tissue pH in regions of focal incomplete cerebral ischemia in monkeys.

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