Biomedical subjects

M Maeder-Ingvar

Publications and source records attributed to M Maeder-Ingvar.

8 recordsLinked to original sources

PubMed2006

Intentional motor phantom limb syndrome.

OBJECTIVE: To investigate the clinical and anatomic correlates of a previously unreported form of chronic supernumerary phantom limb, which developed only in association with motor intent directed at a hemiplegic-anesthetic upper limb. METHODS: We explored the phenomenology of the phantom illusion in the light of motor control models. Hemodynamic correlates of supernumerary phantom limb were studied with an fMRI sensorimotor paradigm consisting of finger-thumb opposition movements. RESULTS: The kinesthetic-proprioceptive illusion of a third arm was triggered by any attempt to move the paretic limb, by bimanual actions, and by motor imagery involving the nonfunctional limb. The responsible lesion destroyed the posterior part of the posterior limb of the internal capsule on the opposite side, damaging corticospinal and thalamocortical tracts. Comparison between fMRI signals performed during virtual movement of the phantom hand vs imaginary movement of the paretic hand showed increased activation in thalamus and caudate nucleus in the first condition. CONCLUSIONS: A preserved sense of agency provided by intact premotor processes translating intention into action may lead to the vivid feeling of movement in a paralyzed limb, similar to kinesthetic illusions in amputees. The interruption of thalamic afferences may explain the persistence and stability of the phantom by preventing any correction of the mismatch between expected and effective movement. The increased blood oxygen level-dependent (BOLD) signal in the basal ganglia-thalamus-cortex pathway during movement of the supernumerary hand may reflect an abnormal closed-loop functioning of the thalamocortical system underlying the phantom phenomenon.

Aged↗

PubMed2006

Continuous assessment of electrical epileptic activity in acute stroke.

OBJECTIVE: To determine the incidence and risk factors of electrical seizures and other electrical epileptic activity using continuous EEG (cEEG) in patients with acute stroke. METHODS: One hundred consecutive patients with acute stroke admitted to our stroke unit underwent cEEG using 10 electrodes. In addition to electrical seizures, repetitive focal sharp waves (RSHWs), repetitive focal spikes (RSPs), and periodic lateralized epileptic discharges (PLEDs) were recorded. RESULTS: In the 100 patients, cEEG was recorded for a mean duration of 17 hours 34 minutes (range 1 hour 12 minutes to 37 hours 10 minutes). Epileptic activity occurred in 17 patients and consisted of RSHWs in seven, RSPs in seven, and PLEDs in three. Electrical seizures occurred in two patients. On univariate Cox regression analysis, predictors for electrical epileptic activity were stroke severity (high score on the National Institutes of Health Stroke Scale) (hazard ratio [HR] 1.12; p = 0.002), cortical involvement (HR 5.71; p = 0.021), and thrombolysis (HR 3.27; p = 0.040). Age, sex, stroke type, use of EEG-modifying medication, and cardiovascular risk factors were not predictors of electrical epileptic activity. On multivariate analysis, stroke severity was the only independent predictor (HR 1.09; p = 0.016). CONCLUSION: In patients with acute stroke, electrical epileptic activity occurs more frequently than previously suspected.

Adult↗

PubMed2005

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.

Adult↗

PubMed2003

Ictal bradycardia in a young child with focal cortical dysplasia in the right insular cortex.

We report on a three and a half year old child with episodic sinus bradycardia during habitual seizures and prolonged interictal discharges due to focal cortical dysplasia in the anterior 2/3 of the insula and the inferior frontal cortex. Seizure-induced bradycardia is rarely reported in children. Bradycardia is suspected to be related to sudden death, a rare complication of a chronic seizure disorder. Several well-documented cases in adult patients reveal a high incidence of temporal epilepsy, but MRI and PET studies in healthy subjects suggest a major role of the insular cortex, especially the right, in cardiac regulation. Our finding underlines the predominance of the right insula in cardiac control, which already seems to be present in children.

Bradycardia↗

PubMed2003

Treatment with Sulthiame (Ospolot) in benign partial epilepsy of childhood and related syndromes: an open clinical and EEG study.

The effect of Sulthiame on the EEG and on clinical seizures was evaluated in an open uncontrolled study in 25 children with focal sharp waves on the EEG (FSW). 16 children had typical benign partial epilepsy with rolandic spikes (BPERS), 5 children with atypical forms and 4 children with no clinical seizures but cognitive disturbances possibly related to the FSW. The effect of Sulthiame in suppressing the EEG discharges was evaluated on the waking and sleep EEG before introduction of the drug, and at 3 - 6 months, 6 to 12 months and beyond while under therapy. The children were followed clinically for one to several years. The EEG discharges disappeared or decreased under Sulthiame in 13/21 cases at 3 to 6 months but reappeared in 3/13 cases beyond this period. No case had a worsening of the EEG or of clinical seizures under Sulthiame, and no cognitive stagnation was noted. Our data confirm the good tolerance and positive effects on the EEG and justify systematic trials of this drug in the partial "functional" epilepsies, especially when negative cognitive consequences of the epileptic discharges are suspected.

Adolescent↗

PubMed1999

Home and hospital treatment of acute seizures in children with nasal midazolam.

Rectal diazepam is widely used in the treatment of acute seizures in children but has some disadvantages. Nasal/sublingual midazolam administration has been recently investigated for this purpose but never at home or in a general paediatric hospital. The aim of this open study was to determine the efficacy, the tolerance and the applicability of nasal midazolam during acute seizures in children both in hospital and at home. We included known epileptic children for treatment at home and all children with acute seizures in the hospital. In all, 26 children were enrolled, 11 at home and 17 in the hospital (including two treated in both locations); only one had simple febrile seizure. They had a total of 125 seizures; 122 seizures (98%) stopped within 10 minutes (average 3.6 minutes). Two patients in the hospital did not respond and in three, seizures recurred within 3 hours. None had serious adverse effects. Parents had no difficulties administering the drug at home. Most of those who were using rectal diazepam found that nasal midazolam was easier to use and that postictal recovery was faster. Among 15 children who received the drug under electroencephalogram monitoring (six without clinical seizures), the paroxysmal activity disappeared in ten and decreased in three. Nasal midazolam is efficient in the treatment of acute seizures. It appears to be safe and most useful outside the hospital in severe epilepsies, particularly in older children because it is easy for parents to use. These data should be confirmed in a larger sample of children. Its usefulness in febrile convulsions also remains to be evaluated.

Acute Disease↗

PubMed1999

Visual stimulus-dependent changes in interhemispheric EEG coherence in humans.

We analyzed the coherence of electroencephalographic (EEG) signals recorded symmetrically from the two hemispheres, while subjects (n = 9) were viewing visual stimuli. Considering the many common features of the callosal connectivity in mammals, we expected that, as in our animal studies, interhemispheric coherence (ICoh) would increase only with bilateral iso-oriented gratings located close to the vertical meridian of the visual field, or extending across it. Indeed, a single grating that extended across the vertical meridian significantly increased the EEG ICoh in normal adult subjects. These ICoh responses were obtained from occipital and parietal derivations and were restricted to the gamma frequency band. They were detectable with different EEG references and were robust across and within subjects. Other unilateral and bilateral stimuli, including identical gratings that were effective in anesthetized animals, did not affect ICoh in humans. This fact suggests the existence of regulatory influences, possibly of a top-down kind, on the pattern of callosal activation in conscious human subjects. In addition to establishing the validity of EEG coherence analysis for assaying cortico-cortical connectivity, this study extends to the human brain the finding that visual stimuli cause interhemispheric synchronization, particularly in frequencies of the gamma band. It also indicates that the synchronization is carried out by cortico-cortical connection and suggests similarities in the organization of visual callosal connections in animals and in man.

Adult↗

PubMed1997

The spectrum of acquired cognitive disturbances in children with partial epilepsy and continuous spike-waves during sleep. A 4-year follow-up case study with prolonged reversible learning arrest and dysfluency.

We report a longitudinal study (7-11 years) of a previously normal boy (MR) who presented from the age of 5 years with rare partial motor seizures and atypical 'absences'. The history revealed a stagnation in development and speech difficulties a few months before onset of his epilepsy. The first waking electroencephalogram (EEG) showed rare generalized discharges during hyperventilation. Magnetic resonance imaging revealed an arachnoid cyst in the frontotemporal region. Although his epilepsy never became severe, he experienced important learning difficulties. Subsequent EEGs became increasingly active with left focal epileptic activity and continuous spike-waves during sleep (CSWS) present from the first sleep EEG. The first neuropsychological evaluation (7 years) showed a speech dysfluency, word finding and naming problems, inattention and low intelligence quotient. Carbamazepine was changed to clobazam and later ethosuximide was added with a rapid improvement (within 1 month) in linguistic and cognitive performances as well as in behaviour. Furthermore, the patient showed considerable progress in acquisition over the next months whereas learning to read had previously been very difficult. The epileptic activity gradually disappeared and he was able to follow regular school at an age-appropriate level. This case adds a new facet to the already recognized more obvious acquired neuropsychological disturbances known to occur in some partial childhood epilepsy syndromes with CSWS (aphasia, dementia). It manifested as prolonged insidious stagnation in learning and subtle language disability. This study documents rapid specific language improvement with change in anti-epileptic drugs and a restored immediate and long-term learning capacity, suggesting a direct but 'hidden' role of epilepsy.

Anticonvulsants↗