Biomedical subjects
Publications and source records attributed to B De Toffol.
Neurological syndromes secondary to acute aortic dissection (AAD) are uncommon and usually consist of focal deficits after an embolic cerebral infarction. This article reports the observation of an AAD with the chief complaint of transient acute memory impairment-that is, a non-usual stroke-like symptom.
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Spinal muscular atrophy (SMA) is caused by SMN1 gene deletions or mutations, and ALS is the most frequent motor neuron condition in adults. The authors describe three families in which ALS and SMA coexist. The authors found that no SOD1 mutation was found within these families; all three ALS cases had at least two SMN1 copies; and an abnormal SMN1 gene locus did not explain the co-occurrence of these two motor neuron disorders in these families.
We studied the morphometric MRI findings and their correlation with cognitive functions in a population of 10 young adults shunted for congenital hydrocephalus related to spina bifida. Morphometric MRI analysis included measurement of the ventricular dilatation index, frontal and occipital parenchymal thickness and the size of the corpus callosum. The neuropsychological status was evaluated, notably to look for a discrepancy between verbal and performance skills, a finding which has previously been described in hydrocephalic children. We also investigated whether there was a correlation between cognitive function and cerebral morphometric indexes. In each case, MRI demonstrated the structural changes associated with the Chiari II malformation. The size of the lateral ventricles varied, ranging from important dilatation to small ventricles. Six patients had only partial development of the corpus callosum. All patients had a normal global IQ. In our population of young adults, we did not observe any discrepancy between verbal and visuospatial performances as has been described in children with hydrocephalus. We found no relationship between cognitive function and ventricle dilatation or parenchymal thickness or between the size of the corpus callosum and callosal transfer.
Hemimegalencephaly is a rare cerebral malformation that usually presents with mental retardation, controlateral hemiparesis and intractable seizures. We report a case of hemimegalencephaly diagnosed in adulthood based on MRI findings. The electroencephalogram initially suggested partial status epilepticus. The diagnosis of this cerebral malformation has been made easier thanks to recent progress in cerebral imagery with MRI. We describe and discuss the relevant encephalographic aspects.
123I-Iodolisuride has high specific affinity for binding on dopamine D2 receptors in the striatum and has been used in a few single photon emission computed tomography (SPECT) studies of extrapyramidal disorders. The diagnosis of Parkinson's disease (PD) is very difficult in the first 5 years of evolution, with 15-25% false positive diagnoses. The aim of this study was therefore to determine the value of iodolisuride SPECT in discriminating Parkinson's from the most frequent Parkinson-plus syndromes (PPS). Seventeen patients with an extrapyramidal syndrome had a SPECT examination 1 h after injection of 180-185 MBq of 123I-iodolisuride. They were followed under dopaminergic treatment for at least 2 years. After 2 years, they were separated in two groups according to specific clinical criteria and sensitivity to dopaminergic treatment: nine patients had PD (age = 59.8+/-8.8 years; Hoehn and Yahr = 1.8+/-0.7; evolution = 4.3+/-3 years) and eight had PPS (age = 71.6+/-7.3 years; Hoehn and Yahr = 2.9+/-2.0; evolution = 4.1+/-1.5 years). The binding potential of iodolisuride in the striatum was assessed by considering the striatum (S)/occipital lobe (O) ratio at the pseudo-equilibrium 1 h after injection. The S/O ratio was statistically different between PD and PPS (1.97+/-0.3 vs. 1.65+/-0.2 (P<0.02)). Iodolisuride SPECT could differentiate both groups with a sensitivity of 88.8% and a specificity of 75%. Iodolisuride is a good specific D2 receptor ligand for SPECT and complements specific clinical criteria for the diagnosis of Parkinson's disease and differentiation between different extrapyramidal disorders.
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Spectral analysis of the EEG alpha rhythm was studied in nine temporal epileptic right-handed patients in order to predict localization of the speech area. We studied the variation of the spectral power of the alpha rhythm during an activation paradigm previously validated in normal right-handed subjects. Significant alpha power decreases in the left hemisphere during writing with the right hand (as compared to resting) and/or significant alpha power decreases in the right hemisphere during left-hand recognition and classification of cardboard objects (as compared to resting) were considered as consistent with left-hemisphere dominance for language. The results of EEG spectral analysis were compared with those of the Wada test. The left hemisphere was dominant for language according to the Wada test in eight subjects and the right hemisphere in one subject. Six patients had a significant alpha power reduction in the hemisphere concerned during lateralized cognitive tasks, consistent with language localization in the left hemisphere according to the Wada test. The three remaining patients had no significant EEG spectral power variations. A significant decrease of alpha power in the active hemisphere during cerebral activation seems statistically related to left-hemispheric dominance for language in right-handed subjects (hemispheric specialization). However, the localization of the speech area using this electrophysiological method does not appear clinically relevant for a case-by-case decision in individual patients.
We report on a case of palatal myoclonus associated with olivary hypertrophy on magnetic resonance imaging (MRI) in a 63-year-old man. This rare radiological finding must be differentiated from a brainstem tumor.
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We report the case of a 65 year-old man with a dysglobulinemic neuropathy associated with anti-Mag antibodies. Central (cerebellar) or peripheric (proprioceptive) origin of the gate disorder are discussed.
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Eleven patients with Juvenile Myoclonic Epilepsy were treated using small doses of a sustained-release form of valproic acid (500 mg/day). This treatment has lasted for an average of 33 months (8-69) and has been continued in all of the patients. None of them has experienced a new generalized tonic-clonic seizure. The myoclonias have become considerably less frequent and less intense. No side-effects have been spontaneously reported by the group of patients. Thus, we suggest to start newly diagnosed patients on small doses of valproic acid.
In order to clarify the relationship between developmental dysphasia and EEG abnormalities, paroxysmal activities during sleep were studied in a series of 24 children with expressive developmental dysphasia (mean age 8 years) and compared to a control group of 39 children (mean age 9 years). The children of both groups were selected excluding cases with prior history of neurological disease or epilepsy. In the control group, 37 children had normal sleep EEG while 2 children had paroxysmal abnormalities. In the dysphasic group, epileptic abnormalities were observed in 9 cases, rare in 4 cases and frequent in 5 cases (density: 2.5 to 66.2% of total sleep time). Nevertheless, paroxysmal abnormalities did not reach the frequency described in the Landau-Kleffner syndrome, and it is unlikely that EEG abnormalities could have produced dysphasia.
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The effects of maintaining lateral gaze (as opposed to looking straight ahead) on electroencephalographic spectral power were tested in 12 right handed male subjects during eye opening (EO) and eye closure (EC). Our working hypothesis, based on Kinsbourne's paradigm, was that maintaining right lateral gaze activates the left hemisphere while maintaining left lateral gaze activates the right hemisphere, this activation resulting in a reduction in the spectral power over the hemisphere in question. Results showed that the variations in spectral power involved mainly the alpha frequency band. In the EC condition, the results were consistent with our working hypothesis: right lateral gaze produced a marked reduction in left hemispheric spectral power. In the EO condition, alpha power was constantly higher in the right hemisphere whether lateral gaze was maintained to the right or to the left. This can possibly be due to an attentional effect. Results are discussed with regard of the type of alpha rhythm and of the activation of cortical oculomotor centres. They shed light on the controversy concerning the existence of specific EEG correlates of cognitive activity, which preferentially involve each of the cerebral hemispheres.
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We studied the relationships between clinical variables and those related to the states of vigilance in 18 cases of benign partial epilepsy with centro-temporal spike-waves, 22 cases of definite symptomatic partial epilepsy, and 16 cases of undetermined partial epilepsy. The time of day during which the seizures appeared and the paroxysmal activity densities during non-REM and REM sleep are not distributed differently among the 3 electro-clinical types. However, the benign epilepsy with centro-temporal spikes group had more patients with sleep-sensitive paroxysmal activities. Patients who mainly had nocturnal seizures were found to have more frequent generalized seizures and a greater sleep-sensitive paroxysmal activity. Three cases demonstrated continuous spike-waves during sleep. The patients who had little or no paroxysmal activity during sleep were the youngest. This study illustrates that sleep-sensitive seizures and paroxysmal activities are not specific to benign childhood epilepsy with centro-temporal spikes, and that seizures and paroxysmal activities are two manifestations associated with epilepsy, affected in different ways by states of vigilance.