Diagnosis of “non-organic” limb paresis by a novel objective motor assessment: the quantitative Hoover’s test

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 “non-organic” 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. Received: 10 March 1997 Received in revised form: 21 April 1998 Accepted: 28 April 1998     

Effects of a novel NMDA receptor antagonist on experimental stroke quantitatively assessed by spectral EEG and infarct volume

Abstract

We used spectral electroencephalographic (EEC) analysis to demonstrate the physiological effect of focal brain ischaemia induced by permanent occlusion of the right middle cerebral artery in rats. A significant shift to lower frequency EEC activity occurred relative to the baseline power spectrum within one hour following the occlusion. Spectral EEG analysis also revealed a cerebroprotective effect of a noncompetitive N-methyl-D-aspartate receptor antagonist, CNS 1102, administered 15 min post-occlusion. Animals treated with this NMDA antagonist exhibited only 26.5% of the slowing in the ischaemic hemisphere compared to aminals given a placebo. Post-mortem analysis conducted 24 h later also revealed reduced infarction volumes for the treated animals, there was a highly significant correlation between the extent of spectral EEG slowing during the initial development of the infarction and subsequent lesion size. These results suggest that spectral EEG analysis may be useful in the early evaluation of experimental and perhaps human stroke and for monitoring the effects of cerebroprotective therapies. [Neurol Res 1994; 16: 443-448]     

Prediction of seizure outcome improved by fast ripples detected in low-noise intraoperative corticogram

Objective

Fast ripples (FR, 250–500 Hz) in the intraoperative corticogram have recently been proposed as specific predictors of surgical outcome in epilepsy patients. However, online FR detection is restricted by their low signal-to-noise ratio. Here we propose the integration of low-noise EEG with unsupervised FR detection.

High on clopidogrel treatment platelet reactivity is frequent in acute and rare in elective stenting and can be functionally overcome by switch of therapy

The benefit of adjusted antiplatelet therapy in patients with myocardial infarction after primary percutaneous coronary intervention is not well elucidated. We aimed to identify patients with high on treatment platelet reactivity and to gradually adjust antiplatelet therapy.