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 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Although patients with acute type A aortic dissection are best managed by emergency surgical intervention, preoperative stroke is known to be an independent predictor of late mortality and is considered by some to be a contraindication to operation because of the risk of precipitating hemorrhagic cerebral infarction and poor long-term outcome. In a series of 272 consecutive, unselected patients with aortic dissection undergoing surgical treatment during a 25-year span (1963-1987), 128 (47 +/- 3% [+/- 70% confidence level (CL)]) had an acute type A dissection. A total of seven patients with acute type A dissection (2.6 +/- 1% of all patients, 5.5 +/- 2% of the acute type A cohort) developed a new stroke preoperatively. Thirteen (4.8 +/- 1%) patients had a diminished or absent carotid pulse, only four (31 +/- 13%) of whom sustained a stroke. One patient died in the immediate postoperative period due to severe brain injury, yielding an operative mortality rate of 14 +/- 14%. Two patients had persistent neurological deficits and died within 4 months of operation; the actuarial survival estimate at 1 year was 57 +/- 19% (mean +/- SEM). One patient recovered function of one upper extremity (preoperative left hemiparesis compounded by paraplegia) but died 6 years later. The remaining three long-term survivors (43 +/- 19%) had major resolution of their neurological deficits and are clinically well 2-8 years postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Surgical management of acute aortic dissection complicated by stroke. 276 34

Both I-123 IMP scintigraphy and MRI have been suggested as sensitive detectors of changes shortly after acute cerebral infarction. We compared the uptake of N-isopropyl I-123 p-iodoamphetamine (IMP) and MR spectroscopy of the brain after internal carotid artery ligation. Thirteen gerbils were lightly anesthetized with ether. After neck dissection, an internal carotid artery was occluded. After 2.8 hours, 100 muCi I-123 IMP was injected intravenously into the 13 experimental animals plus three controls. Seven gerbils remained asymptomatic while six developed hemiparesis. At 3 hours after ligation, the animals were killed. The brains were bisected and T1 and T2 relaxation times were determined for the right and left hemispheres by MR spectroscopy immediately after dissection. I-123 IMP uptake was then determined in the samples. Interhemispheric differences in uptake for I-123 IMP were 0.1 +/- 1.7% (SEM) in the control, 33.5 +/- 10% in the asymptomatic and 54.6 +/- 9.7% in the symptomatic animals. Significant differences were seen with I-123 IMP in 6/7 asymptomatic and 6/6 symptomatic animals. In conclusion, I-123 is more sensitive than T1 or T2 relaxation times for the detection of cerebral perfusion abnormalities. Prolongation in T1 and T2 relaxation times correlates closely with increased brain tissue water content and the development of symptoms, indicators of structural brain damage and probable infarction.
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PMID:Comparison of I-123 IMP cerebral uptake and MR spectroscopy following experimental carotid occlusion. 404 77

The differentiation of "non-organic" limb weakness from genuine paralysis is sometimes difficult in neurological practice. To address this problem, we developed a computerized quantitative method, based on the Hoover's test principle, that determines the extent of involuntary limb activation when contralateral movement is performed. Measurements of hip or arm extension isometric force are performed during direct maximal voluntary effort and during contralateral hip flexion. Maximal involuntary/voluntary force ratio (IVVR) is calculated. IVVR of the lower limbs in ten healthy subjects was 0.614, 0.044 (mean, SEM). Similar results were obtained from seven patients with genuine weakness and in the non-affected limbs of nine patients with "non-organic" mono- or hemiparesis. In contrast, IVVR in the affected limbs in the "non-organic" group was markedly increased (2.48, 0.61; P < 0.001). The same pattern was elicited in the upper limbs (2.27, 0.46 vs 0.406, 0.06; P < 0,001). We conclude that Hoover's sign in "nonorganic" paralysis is a preservation or increase of a normal synkinetic phenomenon. Quantitative measurement of the IVVR can serve as a useful ancillary test in diagnosing non-organic weakness in either lower or upper limbs.
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PMID:Diagnosis of "non-organic" limb paresis by a novel objective motor assessment: the quantitative Hoover's test. 984 Mar 52

It is widely assumed that only limited improvement in functional mobility is possible beyond the subacute period following ischemic stroke. Contrary to this notion, we studied "neurologically plateaued" stroke patients with chronic hemiparesis to assess whether a "task-oriented" treadmill-training regimen would improve walking speed, cadence, and gait cycle symmetry on a modified "Get-Up and Go" task. Five male patients with a mean age of 60.4 +/- 2.7 years (mean +/- S.D.) status post ischemic stroke (> 6 months prior) participated in this nonrandomized low-intensity treadmill exercise pilot study three times/week for 3 months. All patients had mild to moderate gait asymmetries due to residual hemiparesis. Patients were videotaped before and after 3 months of treadmill aerobic exercise (AEX) while performing a functional task consisting of arising from a chair, walking 3.1 m without an assistive device as fast as safely possible, and returning to sit. Gait events were timed using a 2-D Peak Motus video analysis system. After 3 months AEX training, times for the overall "get-up and return-to-sit" (GURS) task and the "straight-away walk" (SAW) segment decreased from 8.2 +/- 1.4 sec to 6.5 +/- 0.8 sec (mean +/- SEM) (p < 0.05), and from 3.7 +/- 1 sec to 2.8 +/- 0.7 sec (p < 0.05), respectively. These data represent improvements of 21% and 24% for the GURS and SAW segments, respectively. Mean velocity increased from 0.9 +/- 0.2 to 1.2 +/- 0.21 m/sec, a 33% improvement (p < 0.01). Mean cadence (steps/min) increased from 89 +/- 9 to 97 +/- 8, a 9% increase (p < 0.05). Mean stance and swing duration diminished for both paretic (P) and nonparetic (NP) limbs, and the intralimb stance/swing ratio values moved toward normal for both the paretic and nonparetic limbs. However, these latter changes reached significance only for the P limb. Interlimb stance symmetry was unchanged. The more impaired subjects experienced the greatest gains in gait velocity and temporal measures. Collectively, these findings indicate that treadmill exercise improves functional overground mobility in individuals with chronic, stable hemiparesis.
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PMID:Effects of aerobic treadmill training on gait velocity, cadence, and gait symmetry in chronic hemiparetic stroke: a preliminary report. 1122 51

It is well known that stroke patients walk with reduced speed, but their potential to increase walking speed can also be impaired and has not been thoroughly investigated. We hypothesized that failure to effectively recruit both hip flexor and ankle plantarflexor muscles of the paretic side limits the potential to increase walking speed in lower functioning hemiparetic subjects. To test this hypothesis, we measured gait kinematics and kinetics of 12 persons with hemiparesis following stroke at self-selected and fast walking conditions. Two groups were identified: (1) lower functioning subjects (n=6) who increased normalized walking speed from 0.52 leg lengths/s (ll/s, SEM: 0.04) to 0.72 ll/s (SEM: 0.03) and (2) higher functioning subjects (n=6) who increased walking speed from 0.88 ll/s (SEM: 0.04) to 1.4 ll/s (SEM 0.03). Changes in spatiotemporal parameters, joint kinematics and kinetics between self-selected and fast walking were compared to control subjects examined at matched walking speeds (0.35 ll/s (SEM: 0.03), 0.63 ll/s (SEM: 0.03), 0.92 ll/s (SEM: 0.04) and 1.4 ll/s (SEM: 0.04)). Similar to speed-matched controls, the higher functioning hemiparetic subjects increased paretic limb hip flexion power and ankle plantarflexion power to increase walking speed. The lower functioning hemiparetic subjects did not increase power generation at the hip or ankle to increase walking speed. This observation suggests that impaired ankle power generation combined with saturation of hip power generation limits the potential to increase walking speed in lower functioning hemiparetic subjects.
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PMID:Capacity to increase walking speed is limited by impaired hip and ankle power generation in lower functioning persons post-stroke. 1878 92