Spatio-temporal gait analysis in children with cerebral palsy using, foot-worn inertial sensors.

A child's natural gait pattern may be affected by the gait laboratory environment. Wearable devices using body-worn sensors have been developed for gait analysis. The purpose of this study was to validate and explore the use of foot-worn inertial sensors for the measurement of selected spatio-temporal parameters, based on the 3D foot trajectory, in independently walking children with cerebral palsy (CP). We performed a case control study with 14 children with CP aged 6-15 years old and 15 age-matched controls. Accuracy and precision of the foot-worn device were measured using an optical motion capture system as the reference system. Mean accuracy±precision for both groups was 3.4±4.6cm for stride length, 4.3±4.2cm/s for speed and 0.5±2.9° for strike angle. Longer stance and shorter swing phases with an increase in double support were observed in children with CP (p=0.001). Stride length, speed and peak angular velocity during swing were decreased in paretic limbs, with significant differences in strike and lift-off angles. Children with cerebral palsy showed significantly higher inter-stride variability (measured by their coefficient of variation) for speed, stride length, swing and stance. During turning trajectories speed and stride length decreased significantly (p<0.01) for both groups, whereas stance increased significantly (p<0.01) in CP children only. Foot-worn inertial sensors allowed us to analyze gait spatiotemporal data outside a laboratory environment with good accuracy and precision and congruent results with what is known of gait variations during linear walking in children with CP.

Enhancement of autophagic flux after neonatal cerebral hypoxia-ischemia and its region-specific relationship to apoptotic mechanisms.

The multiplicity of cell death mechanisms induced by neonatal hypoxia-ischemia makes neuroprotective treatment against neonatal asphyxia more difficult to achieve. Whereas the roles of apoptosis and necrosis in such conditions have been studied intensively, the implication of autophagic cell death has only recently been considered. Here, we used the most clinically relevant rodent model of perinatal asphyxia to investigate the involvement of autophagy in hypoxic-ischemic brain injury. Seven-day-old rats underwent permanent ligation of the right common carotid artery, followed by 2 hours of hypoxia. This condition not only increased autophagosomal abundance (increase in microtubule-associated protein 1 light chain 3-11 level and punctuate labeling) but also lysosomal activities (cathepsin D, acid phosphatase, and beta-N-acetylhexosaminidase) in cortical and hippocampal CA3-damaged neurons at 6 and 24 hours, demonstrating an increase in the autophagic flux. In the cortex, this enhanced autophagy may be related to apoptosis since some neurons presenting a high level of autophagy also expressed apoptotic features, including cleaved caspase-3. On the other hand, enhanced autophagy in CA3 was associated with a more purely autophagic cell death phenotype. In striking contrast to CA3 neurons, those in CA1 presented only a minimal increase in autophagy but strong apoptotic characteristics. These results suggest a role of enhanced autophagy in delayed neuronal death after severe hypoxia-ischemia that is differentially linked to apoptosis according to the cerebral region.

Stroke Aphasia: 1,500 Consecutive Cases.

Background: To study the characteristics of vascular aphasia in a cohort of patients with a first-ever stroke. Methods: All patients admitted to the Lausanne neurology department for a first-ever stroke between 1979 and 2004 were included. Neurological examination including language was performed on admission. Stroke risk factors, stroke origin and location, associated symptoms and Rankin scale scores were recorded for each patient. The influence of these factors on aphasia frequency and subtypes was analyzed using logistic regression models. Results: 1,541 (26%) of patients included in this study had aphasia. The more frequent clinical presentations were expressive-receptive aphasia (38%) and mainly expressive aphasia (37%), whereas mainly receptive aphasia was less frequently observed (25%). In ischemic stroke, the frequency of aphasia increased with age (55% of nonaphasic vs. 61% of aphasic patients were more than 65 years old), female sex (40% of women in the nonaphasia group vs. 44% in the aphasia group) and risk factors for cardioembolic origin (coronary heart disease 20 vs. 26% and atrial fibrillation 15 vs. 24%). Stroke aphasia was more likely associated with superficial middle cerebral artery (MCA) stroke and leads to relevant disability. Clinical subtypes depended on stroke location and associated symptoms. Exceptions to the classic clinical-topographic correlations were not rare (26%). Finally, significant differences were found for patients with crossed aphasia in terms of stroke origin and aphasia subtypes. Conclusions: Risk factors for stroke aphasia are age, cardioembolic origin and superficial MCA stroke. Exceptions to classic clinical-topographic correlations are not rare. Stroke aphasia is associated with relevant disability. Stroke location and associated symptoms strongly influence aphasia subtypes.

Intracranial arterial and arteriovenous malformations presenting with infarction. Lausanne Stroke Registry study.

Cerebral aneurysms and arteriovenous malformations (AVMs) are well-known sources of intracranial hemorrhage, but can also manifest as other clinical symptoms or remain clinically asymptomatic. The aim was to document and analyze cases of aneurysm or AVM with brain infarction. Survey on 4804 stroke patients treated at the Department of Neurology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland between 1978 and 2000 using the Lausanne Stroke Registry. Twenty patients presented with cerebral aneurysm and 21 with cerebral AVM. Hemorrhage was present in 100% of the AVM and in 75% of the aneurysm patients; in one (5%) of the remaining aneurysm patients, aneurysm and infarction were located in different territories. Infarction associated with Sylvian artery aneurysm was found in three (15%), vertebrobasilar ischemia because of fusiform left vertebral artery aneurysm in one (5%), and dural fistula draining to the distal transversal and left sigmoid sinus associated with a stroke in the territory of the left anterior inferior cerebellar artery in one patient. Ischemic stroke is infrequent, but important, complication in unruptured intracranial aneurysms and AVMs. The early recognition and therapy of these vascular malformations in selected patients can avoid a major neurological deficit or death caused by their rupture.