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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the function of monoaminergic neuron in the brainstem by measuring its metabolites using in vivo microdialysis following experimental subarachnoid hemorrhage in rats. Dialysis probe was implanted into the nucleus tractus solitarius (NTS) and continuous perfusion was then started. The perfusates were collected every 10-20 minutes and assayed by high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). The main monoamine metabolites in extracellular space measured in NTS were 3,4-dihydroxy-phenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA). The extracellular content of DOPAC was abruptly increased after cisternal autologous blood (0.3ml) injection, reached a peak at 20-40 minutes, and then decreased over 120 minutes. The content of HVA and 5-HIAA changed as well as DOPAC. These results showed non-specific response for ischemia of the brainstem, because the similar changes were seen after cisternal saline injection. The disappearance rate of monoamine metabolites after pargyline administration (75 mg/kg, i.p.) at various time periods after cisternal blood injection was most rapid at 2 days after SAH and recovered gradually. In particular the decline curve of DOPAC consisted of two compartments and early compartment was disturbed more severely than late compartment. These results indicate that the functional disturbance of nerve terminals is more severe than nerve cell body in adrenergic neurons.
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PMID:[Changes in monoamine metabolites measured by in vivo microdialysis of the brainstem following experimental subarachnoid hemorrhage in rats]. 137 47

Many patients survive aneurysmal SAH with minimal neurological deficits, but are at risk for developing further neurological insult from ischemia resulting from cerebral vasospasm. Nimodipine has proven to be effective in preventing this complication in a majority of patients studied, with hypotension the most severe adverse effect. Nimodipine alone, or in combination with other methods of therapy, may significantly improve the neurological outcome in this select patient population.
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PMID:Nimodipine: the use of calcium antagonists to prevent vasospasm following subarachnoid hemorrhage. 214 68

The timing of surgery for the ruptured aneurysm (SAH) remains controversial. After the period of delayed surgery, the early surgery is now more and more frequently advocated. This paper, study our experience in aneurysm surgery in two different periods, considering only patients admitted in grades I to IV, excluding grade V patients (deep coma, decerebration). During the former period (1972-1984) 328 patients were admitted and considered for delayed surgery, usually during the second week following SAH. 94.5% of patients were operated upon. 5.5% patients died before surgery, from ischemia (3%) or from rebleeding (2.5%). 38.5% were admitted between (D.O-D3) after SAH, D.O being the day of SAH. Only 5.7% were operated upon between D.O-D3. The higher peak of surgery was during the second week (41.8%) and during the third week (39.2%). During the later period (1985-1988) 106 patients were admitted, 50% of them between D.O and D3 after SAH. Every patient was operated upon. The patients admitted between D.O and D3 were operated upon as follows: between D.O and D3 = 32.1%, between D4 and D6 = 22.6%, between D7 and D15 = 34%, after D16 = 11.3%. The analysis of these sub-groups demonstrates that the distribution was related to the age and clinical status. Patients being awake and under 50 years of age were considered for early surgery. Patients being obnubilated or stuporous, and over 50 years of age were planned for delayed surgery. Angiographic spasm and extension of blood in CT Scan were taken in consideration to a lesser degree.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The same question for the past 20 years: when should a ruptured intracranial aneurysm be surgically treated? (Experience with 434 cases)]. 228 2

During cerebral aneurysms surgery, brain tissue may suffer for global or local ischemia due to deliberate hypotension and surgical manoeuvres. Somatosensory evoked potentials (SEPs) can detect functional derangements consequent to hypoxia, before a permanent brain damage is produced. Forty two patients, undergoing cerebral aneurysms surgery for treatment of SAH, were evaluated intraoperatively with SEP recordings. It has been stressed that no permanent neurological damage is to be expected if the absolute value of Central Conduction Time (CCT) does not exceed 9.5 ms for 10 min at least and the cortical waves are visible throughout the whole procedure. SEP changes are strictly related with MAP decrease and surgical handlings.
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PMID:Intra-operative monitoring by means of somatosensory evoked potentials during cerebral aneurysms surgery. 228 8

Knowledge of the local incidence of aneurysm rupture permits the conclusion that almost every patient in the population of 933,800 persons served by the authors' institution who was stricken by this catastrophe and survived long enough to be transported was treated at this center (121 patients during 34 months). Of these, 9.1% were admitted late (greater than 72 hours after subarachnoid hemorrhage (SAH]; of the remaining cases, 94.5% were seen within 24 hours and 50% within 6 hours post-SAH. Of the 121 patients, 10% were neurologically devastated on arrival, a late operation was planned for 19%, and the earliest possible surgery and nimodipine administration was selected for 71%. In this latter group, 50% of the operations were begun within 24 hours and 76% within 48 hours post-SAH. Sixty percent of all mortality and morbidity could be linked to the initial aneurysm bleed. The remaining 40% could be ascribed to potentially avoidable causes of unfavorable outcome. No less than 9.6% of all patients admitted within 24 hours after SAH suffered from "ultra-early" rebleeding during transportation or preparation for operation. The mortality rate from such rebleeding was 7.4%, compared with the 9.1% combined mortality rate from complications and late ischemia.
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PMID:Significance of "ultra-early" rebleeding in subarachnoid hemorrhage. 337 85

Despite its efficacy in preventing rebleeding, the anticipated strong trend in favor of early intracranial surgery has not been achieved. Early intracranial operation remains a useful choice in the management of recent SAH in good-risk patients, but patients must be carefully selected on an individual basis. Many patients will undoubtedly benefit from early surgery but it is not a panacea. Further investigation of surgical treatment in combination with improved preoperative and postoperative medical therapy will be required to ameliorate the outcome of SAH. In particular, the prevention and treatment of cerebral infarction deserves attention. The results of the antifibrinolytic and timing of intracranial surgery studies point to the need for an effective prevention treatment regimen for vasospasm. Further studies about the efficacy of calcium channel blocking drugs in prevention of ischemia after SAH are needed among patients given antifibrinolytic drugs or having early operation. All the advances in treatment are predicated on prompt diagnosis of SAH in good-condition patients. The medical community needs to maintain a high degree of vigilance for the diagnosis of SAH in all patients complaining of a new, unusual or severe headache. Early referral to properly equipped and staffed medical facilities remains a keystone to effective treatment of SAH.
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PMID:Early management of the patient with recent aneurysmal subarachnoid hemorrhage. 381 Jul 3

In this prospective study we report the outcome for all patients with a verified aneurysmal SAH managed at the Department of Neurosurgery at the University Hospital in Lund, Sweden during the four-year span from June 1, 1989 to May 31, 1993. A total of 275 patients were admitted during the study period. The vast majority of patients (196 individuals, i.e. 71%) was admitted within 24 h after the bleed. Mean age was 54.3 years and the female/male ratio 1.8/1. Nimodipine was administered in 231 (84%) of the 275 patients. We clipped the ruptured aneurysm in 199 patients. At follow-up 3 months after the bleed 161 patients were classified as having made a good neurological recovery (59%). The morbidity was 20% and 59 patients (21%) had died. The overwhelming cause for morbidity and mortality was damage from the initial bleed (62 patients, 23%). Notably, considering morbidity and mortality, delayed ischemia was less frequent than both surgical complications and rebleeding, respectively. Of the 275 patients, 13 (5%) patients made an unfavorable outcome due to delayed ischemic deterioration. There was a strict correlation between the initial clinical condition and final outcome. Of 51 grade V patients, only 2 made a good recovery. There was also a strict correlation between the amount of extravasated blood and outcome. There was no difference in clinical outcome between patients with arterial hypertension versus normotensive individuals. The mortality rate was worse for posterior circulation aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Which are the major determinants for outcome in aneurysmal subarachnoid hemorrhage? A prospective total management study from a strictly unselected series. 783 9

The possibility of measuring cerebral blood flow by mobile bedside units with the intravenous 133-Xenon technique increased the interest to monitor haemodynamic changes after head injury and subarachnoid haemorrhage in intensive care. Time course of resting CBF after trauma is variable (reduced CBF, hyperemia) and there is no strong correlation to clinical outcome. Additional studies of CBF/CO2 reactivity show normal and impaired CO2 response in the acute stage after trauma (day 1-8). A permanently impaired CO2 reactivity correlates with severe brain damage and bad outcome (GOS 1,2). A normal or improving CO2 reactivity indicates a favourable outcome (GOS 3-5). There was no significant correlation between CBF and ICP, nor between CBF and CPP. A CPP of more than 70 mmHg did not guarantee a sufficient CBF in every case indicating the variability of the limits of autoregulation. As therapeutic hyperventilation may lead to ischemia, mannitol was preferred to reduce ICP and increased low CBF to normal values. This fact should be considered in the treatment of patients with low CBF and normal CO2 reactivity. Delayed ischemic neurological deficits ("vasospasm") are well-known as significant complications of the clinical course following SAH. Immediately postoperatively performed CBF measurements enable to detect ischemia and allow to start early antiischemic therapy. During "vasospasm" CBF showed a better correlation to the neurological status than blood flow velocity in the basal arteries measured by transcranial doppler sonography. Furthermore hyperemia after SAH could only be verified by CBF measurements.
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PMID:Xenon 133--CBF measurements in severe head injury and subarachnoid haemorrhage. 790 78

Many patients survive SAH with minimal neurologic deficits but are at risk for developing further neurologic insult from ischemia resulting from cerebral vasospasm. Nursing care of the patient experiencing vasospasm is challenging. The nurse who is knowledgeable about the signs and symptoms of cerebral ischemia and necessity for continually reviewing the patient's neurologic status can initiate prompt treatment to prevent further ischemic damage. Recognition of this critical problem is the first step toward combating its ominous effects.
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PMID:Cerebral vasospasm: early detection and intervention. 805 86

Two hundred seventy-three Patients with acute SAH were treated within the last 46 months (1.4.1991 to 31.1.1995). Diagnosis was made upon visible SAH on CT-scans or bloody spinal tap regardless of a negative CT-scan. These patients harbored 194 aneurysms, 25 AVM and cavernomas. Within the same time-period we treated 27 Patients without SAH but harboring vascular malformations (17 aneurysms, 10 AVM and cavernomas). In 30 patients (11%) no bleeding source was detectable. Fourteen of these patients (5.1%) had blood concentrated within the perimesencephalic cisterns on the CT-scans. On admission all of these 14 patients (8 men, 6 female, aged 30 to 63 years) were awake and without mentionable neurological deficit, equalling Hunt & Hess grade 1 (11 patients) and 2 (3 patients). Neither the initial nor control angiography revealed a vascular malformation as a bleeding source. MRI-scans performed for 11 patients did not reveal further etiological clues. During a follow-up interval of 3 to 48 months, none of these patients suffered a rebleeding. Vasospasm was not or only slightly present, no ischemia leading to neurological deficit. GOS reached 5 and Karnofsky-scale was 100 for all of these patients. We conclude that the perimesencephalic SAH is a homogeneous entity with a different natural course than the common aneurysmatic SAH. Probably leakage within the capillary or venous circulation causes this form of SAH with a benign clinical course. Further experience is required to determine whether control angiography is mandatory in these patents with a distinct CT appearance.
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PMID:[Perimesencephalic subarachnoid hemorrhage--an independent clinical picture of non-aneurysmatic subarachnoid hemorrhage with a benign course]. 877 69


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