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Biomedical subjects

E M Manno

Publications and source records attributed to E M Manno.

8 recordsLinked to original sources

Mannitol bolus preferentially shrinks non-infarcted brain in patients with ischemic stroke.

Changes in brain tissue volume in six patients who had acute complete middle cerebral artery (MCA) infarctions and CT evidence of midline shift were measured using the brain boundary shift integral (BBSI) on sequential T1-weighted MR images acquired before and after a 1.5-g/kg bolus infusion of mannitol. At 50 to 55 minutes after the baseline scan, total brain volume decreased by 8.1 +/- 2.8 mL (0.6%, p < 0.005). Brain in the noninfarcted hemisphere shrank more (0.8 +/- 0.4%) than in the infarcted hemisphere (0.0 +/- 0.5%, p < 0.05).

Adult↗

The effects of mannitol on cerebral edema after large hemispheric cerebral infarct.

OBJECTIVE: To evaluate the effect of a single large dose of mannitol on midline tissue shifts after a large cerebral infarction. BACKGROUND: Theoretically, mannitol use in the largest cerebral infarctions may preferentially shrink noninfarcted cerebral tissue, thereby aggravating midline tissue shifts and worsening neurologic status. To test this theory, we studied patients with hemispheric infarctions using continuous and sequential MRI during administration of a single dose of mannitol. METHODS: Patients with neurologic deterioration from complete middle cerebral artery (MCA) infarctions and CT evidence of at least 3 mm of midline shift were studied using T1-weighted three-dimensional multiplanar rapid acquisition gradient echo image data sets acquired at 5- to 10-minute intervals before, during, and after a 1.5 gm/kg bolus infusion of mannitol. Horizontal and vertical displacements were calculated by previously described methods. Glasgow Coma Scale (GCS) and MCA Stroke Scale (MCASS) were measured before and after mannitol administration. Mean changes in tissue shifts were compared using repeated measures analysis of variance. Clinical variables were compared using paired t-tests. RESULTS: Seven patients were enrolled. The final average change in midline shift compared with the initial displacement was 0.0 +/- 1 mm for horizontal (F = 0.06, p = 0.99) and 0.25 +/- 1.3 mm for vertical displacement (F = 0.06, p = 0.99). Whereas average scores for the group did not change, MCASS improved in two, GCS improved in three, and pupillary light reactivity returned in two patients. No patient worsened. CONCLUSIONS: Acute mannitol used in patients with cerebral edema after a large hemispheric infarction does not alter midline tissue shifts or worsen neurologic status.

Adult↗

Effects of induced hypertension on transcranial Doppler ultrasound velocities in patients after subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Transcranial doppler ultrasound (TCD) is used after subarachnoid hemorrhage to detect cerebral vasospasm and is often treated with induced hypertension. Cerebral autoregulation, however, may be disturbed in this population, raising the possibility that TCD velocities may be elevated by induced hypertension. To study this possibility, we performed continuous TCD monitoring of the middle cerebral artery during the induction and withdrawal of induced hypertension in patients after subarachnoid hemorrhage. METHODS: Twenty-eight patients were studied during the induction and withdrawal of hypertension using primarily phenylephrine. Continuous monitoring was performed on the middle cerebral artery with the highest flow velocity. Treatment was based on rising TCD velocities or clinical evidence for cerebral vasospasm. Mean arterial pressure and mean TCD velocities were recorded every minute. A change of > 15% from starting TCD values was considered significant. Cerebral autoregulation was calculated as a percentage of intact autoregulation. Patients were subsequently divided into groups of disturbed and intact autoregulation. RESULTS: In 10 of 19 patients (53%), TCD velocities changed by > 15% and paralleled changes in mean arterial pressure. This directly altered the TCD interpretation of the grade of vasospasm in 7 of 19 patients (36%). Three additional patients had smaller absolute changes in TCD velocities. No clinical difference could be identified between patients with disturbed and intact autoregulation. CONCLUSIONS: In patients with disturbed autoregulation after subarachnoid hemorrhage, induced hypertension can alter cerebral blood flow velocities. The level of autoregulation needs to be considered when interpreting TCD velocities in patients after subarachnoid hemorrhage.

Adult↗

Mechanical ventilation for ischemic stroke and intracerebral hemorrhage: indications, timing, and outcome.

OBJECTIVE: To compare the incidence, indication, and timing of intubation and outcome in patients with cerebral infarction (ISCH) and intracerebral hemorrhage (HEM) requiring mechanical ventilation (MV). BACKGROUND: Poor outcomes have been reported for ISCH patients requiring MV. Because the target population, pathophysiology, and management of ISCH and HEM patients differ considerably, we compared the characteristics of patients with ISCH and HEM who required MV. METHODS: A retrospective review of ISCH and HEM stroke patients who underwent MV at a tertiary care academic center from 1994 to 1997 was performed to determine age, sex, type, and location of stroke (anterior or posterior circulation); brainstem dysfunction at intubation (pupillary, corneal, and oculocephalic reflexes); indication for intubation (neurologic deterioration, cardiopulmonary deterioration, or elective intubation for surgery); timing of intubation (on presentation or later); comorbidities; and outcome (hospital disposition). RESULTS: A total of 230 patients, 74 with ISCH and 156 with HEM (mean age, 61 +/- 16 years; male-to-female ratio, 1.15:1), underwent MV. Intubation rates were 6% for ISCH patients and 30% for HEM patients. Two-thirds of the patients required intubation on presentation (84% were intubated for neurologic deterioration) and 131 patients (57%) died (ISCH, 55%; HEM, 58%). Signs of brainstem dysfunction predicted a higher mortality for both groups. Additionally, early intubation and older age predicted mortality for HEM, and male gender predicted mortality in ISCH. Stroke location and comorbidities did not influence outcome. CONCLUSIONS: MV in acute stroke is associated with high mortality. Mortality and outcome were similar for ISCH and HEM; however, the factors predictive of outcome may differ and influence decisions about the use of MV in such patients.

Adult↗

Transcranial Doppler ultrasonography in the neurocritical care unit.

TCD ultrasonography is a noninvasive means to study the cerebral vasculature. By varying the depth and angle of insonation of a pulsed sound wave, the direction and velocity profile of the cerebral arteries can be ascertained. This can be used to identify areas of focal stenosis and increased resistance and to estimate the adequacy of cerebral flow. TCD ultrasonography commonly is used in SAH to detect cerebral vasospasm. Many centers interpret rising velocities as increasing vessel narrowing and initiate medical strategies based on these values. TCD use in head trauma is less clearly defined. TCD ultrasonography is considered an acceptable confirmatory test for the determination of brain death. TCD ultrasonography is capable of studying dynamic cerebrovascular processes. By being able to determine vessel patency, TCD may become a useful adjuvant to thrombolytic therapy. Continuous monitoring of flow velocities and profiles along with testing to cerebrovascular reserve promises to be a future active area of research.

Brain Death↗

The safety and efficacy of cyclosporine A in the prevention of vasospasm in patients with Fisher grade 3 subarachnoid hemorrhages: a pilot study.

OBJECTIVE: To evaluate the safety and any potential effect of cyclosporine A (CycA) in preventing cerebral vasospasm. METHODS: Nine patients with Fisher Grade 3 subarachnoid hemorrhages were studied. After a loading dose of 7.5 mg/kg of CycA was administered every 12 hours for two doses, enteral treatment with CycA was started within 72 hours of the onset of the subarachnoid hemorrhage. Whole blood CycA levels were titrated to maintain levels of 50 to 400 ng/kg. Transcranial doppler ultrasonography was performed daily. Middle cerebral artery velocities were used to assess the degree of vasospasm. Angiography was performed to confirm the vasospasm in symptomatic patients, or it was performed if transcranial doppler ultrasonograms were unobtainable. Patients were treated with a standard pharmacological regimen of nimodipine. Induced hypertension, hemodilution, and hypervolemia were instituted at the discretion of the neurosurgical team. Intra-arterial papaverine was infused into the vasospastic vessels of three recalcitrant patients. Outcome was assessed at 6 months with the Glasgow Outcome Scale. RESULTS: All the patients displayed evidence of vessel narrowing, which was disclosed by transcranial doppler ultrasonography or angiography. Five patients developed ischemic deficits, two were treated with intra-arterial papaverine, and three died of complications secondary to vasospasm. No significant hepatic, renal, or infectious complication developed as a result of the administration of CycA. CONCLUSIONS: CycA proved safe to use but failed to prevent the development of cerebral vasospasm or delayed ischemic deficits in patients considered at high risk.

Adolescent↗

Predictors of outcome after anterior temporal lobectomy: positron emission tomography.

We assessed the relationship between temporal lobe metabolism measured quantitatively and qualitatively with PET using [18F]-fluorodeoxyglucose (FDG) and postoperative seizure frequency after anterior temporal lobectomy. Forty-three patients with refractory partial epilepsy had anterior temporal lobectomy and preoperative assessment with PET-FDG. Qualitative PET analysis was performed visually by two blinded observers, and quantitative PET analysis was performed using an anatomic template for six control and six temporal lobe subregions, deriving an asymmetry index for each region. Seizure outcome was assessed 1 year after surgery; patients were classified as being seizure-free or as having persistent seizures. Qualitative data were analyzed using Fisher's exact test and the t test, and quantitative data were analyzed using a repeated-measures ANOVA. Thirty-two patients (74%) were seizure-free at follow-up, and 11 had persistent seizures, although most improved. Twenty-nine of 35 patients (83%) with restricted temporal lobe hypometabolism by visual analysis were seizure-free, compared with three of eight patients (37.5%) with normal scans or multilobar hypometabolism. Quantitative analysis revealed that an asymmetry of mesial temporal lobe glucose consumption (uncal region) correlated with improved surgical outcome (p < 0.02). We developed a logistic regression model to predict individual outcome based on the asymmetry in uncal metabolism. Lateral temporal metabolism did not correlate with outcome. We conclude that both visual PET analysis and quantitative PET analysis predict outcome after temporal lobectomy, although quantitative measures offer more precise information.

Adolescent↗