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Biomedical subjects

M Steinlin

Publications and source records attributed to M Steinlin.

At least 19 recordsLinked to original sources

Isotropic apparent diffusion coefficient mapping of postnatal cerebral development.

Diffusion-weighted imaging (DWI) allows us to image the motion of tissue water. This has been used to demonstrate acute ischaemia. Diffusion imaging is also sensitive to water movement along neuronal tracts. Our objective was to map brain maturation in vivo using maps of apparent diffusion coefficient (ADC). We studied 22 children without neurological disease aged between 2 and 720 days. MRI was performed at 1.5 tesla. Multislice single-shot echoplanar DWI was performed at b 0 and 1000 s/mm(2). ADC maps were generated automatically and measurements were performed in the basal ganglia, frontal and temporal white matter and the pons. There was a decrease over time in water diffusion in the areas examined, most marked in the frontal (0.887-1.898 x 10(-3) mm(2)/s) and temporal (1.077-1.748 x 10(-3) mm(2)/s)lobes. There was little change, after an initial decrease, in the basal ganglia (0.690-1.336 x 10(-3) mm(2)/s). There was a difference in water diffusion between the anterior (0.687-1.581 x 10(-3) mm(2)/s) and posterior (0.533-1.393 x 10(-3) mm(2)/s) pons. These changes correlate well with those observed in progressive myelination: the increased water content probably reflects incomplete myelination and the decrease with time in water motion reflects the increase in myelinated brain.

Brain Mapping↗

[Suspected muscular disease: what to do?].

During the last decades important progress in knowledge of hereditary neuromuscular problems could be achieved. Unfortunately, therapeutic management has not yet improved significantly, but diagnostic investigations have become less invasive for most disorders. For the clinician, the most important problem is still realizing that the complains of the patient could be a symptom of a neuromuscular problem. This should be followed by a careful history and clinical examination, to achieve a topical diagnosis (from motoneuron to muscle) and if ever possible already a clinical suspicion of the diagnosis. Investigations like neurophysiological technics, lab investigations, forearm ischemic exercise test or even muscular biopsy might be helpful to achieve this goal. Nowadays verification of the diagnosis is done in most cases by genetic DNA testing or by specific immunohistochemical staining or enzyme determination in muscular biopsy. This diagnostic way enhances the importance of history and clinical examination even in today's modern neurology.

Biopsy↗

Acute leukoencephalopathy after inhalation of a single dose of heroin.

We describe extended and repeat magnetic resonance (MR) examinations in the case of a 16-year-old male who developed acute left-sided sensorimotor hemiplegia after a single dose of inhaled heroin. MRI revealed symmetrical hyperintense signals in T 2 -weighted images and massive diffusion disorders in the diffusion weighted images predominantly in parieto-occipital subcortical white matter and both ventral globi pallidi with preservation of U fibers and no brain oedema. MR spectroscopy data were compatible with combined hypoxic and mitochondrial damage resulting in axonal injury without demyelination. Normal values and variations had been obtained from spectra of five age-matched subjects. This is the first reported MR follow-up study of leukoencephalopathy occurring acutely after a first inhaled dose of heroin. We postulate that toxic spongiform leukoencephalopathy in heroin addicts may be the outcome of a complex mechanism directly triggered by heroin and causing mitochondrial as well as hypoxic injury in specific and limited areas of white matter.

Acute Disease↗

Cognitive impairments in patients with congenital nonprogressive cerebellar ataxia.

OBJECTIVE: To report neuropsychologic functions and developmental problems of patients with congenital nonprogressive cerebellar ataxia. BACKGROUND: Growing interest in cerebellar function has prompted closer attention to cognitive impairments in patients with cerebellar damage. METHODS: The authors studied 11 patients with nonprogressive congenital ataxia (NPCA) with Wechsler's intelligence testing, with additional tests of attention, memory, language, visual perception, and frontal functions. RESULTS: Seven of the 11 patients had an IQ of 60 to 92, with marked nonverbal deficits and subnormal to normal verbal performance (group A). Four patients had an IQ of 30 to 49 without pronounced profile asymmetry (group B). Four of the 7 group A patients had decreased alertness and sustained attention, but all had normal selective attention. Tests of frontal functions and memory yielded higher verbal scores than nonverbal scores. There was no deficit on the Aachener Naming Test (similar to the Boston Naming Test), because there were marked difficulties in the majority with visuoconstructive tasks and visual perception. Group B was significantly abnormal in almost all subtests, having a less prominent but similar profile. CONCLUSION: Patients with NPCA have significant cognitive deficits with an asymmetric profile and better verbal than nonverbal performance. Effects on nonverbal performance of longstanding deficits in visuospatial input during learning, the influence of impaired procedural learning, and asymmetric plasticity of the cerebral hemispheres may contribute to this uneven neuropsychological profile.

Adolescent↗

Neonatal Escherichia coli meningitis: spinal adhesions as a late complication.

We describe two boys who had severe spinal complications in adolescence after a favorable initial recovery from neonatal Escherichia coli meningitis. Due to spinal granulomatous adhesions, one boy died after an attempted scoliosis operation (high cord lesion). The other showed severe progressive neurological deterioration with spinal and cerebellar symptoms. Conclusion The severe complication of chronic arachnoiditis with spinal adhesion may occur many years after neonatal acute bacterial meningitis.

Adolescent↗

Interhemispheric interactions analyzed by coherence during flexor spasms.

OBJECTIVE: We used coherence analysis to test for leading discharges on an ipsilateral right mesial temporal lesion in a 5 year old boy with flexor spasms. METHOD: Digital EEG analysis with video-EEG telemetry was performed preparatory to epilepsy surgery. RESULTS: Study of 10 spasms with head drop and subsequent flexion of both arms demonstrated an interhemispheric time lag with secondary bilateral synchrony, with a mean difference of 17 ms. The right hemisphere led. After a lesionectomy with resection of epileptic regions (performed with electrocorticographical guidance), the patient has been seizure-free for 4 years. Pathology confirmed a low-grade mixed glioma and cortical dysgenesis. CONCLUSION: The coherence analysis demonstrated a pathway of secondary generalization, confirming that the lesional side was leading during ictal generalized discharges in flexor spasms.

Brain↗

Cerebellar involvement in metabolic disorders: a pattern-recognition approach.

Inborn errors of metabolism can affect the cerebellum during development, maturation and later during life. We have established criteria for pattern recognition of cerebellar abnormalities in metabolic disorders. The abnormalities can be divided into four major groups: cerebellar hypoplasia (CH), hyperplasia, cerebellar atrophy (CA), cerebellar white matter abnormalities (WMA) or swelling, and involvement of the dentate nuclei (DN) or cerebellar cortex. CH can be an isolated typical finding, as in adenylsuccinase deficiency, but is also occasionally seen in many other disorders. Differentiation from CH and CA is often difficult, as in carbohydrate deficient glycoprotein syndrome or 2-L-hydroxyglutaric acidaemia. In cases of atrophy the relationship of cerebellar to cerebral atrophy is important. WMA may be diffuse or patchy, frequently predominantly around the DN. Severe swelling of white matter is present during metabolic crisis in maple syrup urine disease. The DN can be affected by metabolite deposition, necrosis, calcification or demyelination. Involvement of cerebellar cortex is seen in infantile neuroaxonal dystrophy. Changes in DN and cerebellar cortex are rather typical and therefore most helpful; additional features should be sought as they are useful in narrowing down the differential diagnosis.

Adolescent↗

Non-progressive congenital ataxias.

Congenital ataxias (CA) are rare, predominantly non-progressive syndromes characterized by marked hypotonia, developmental delay followed by the appearance of ataxia. Most children show marked speech and cognitive developmental problems. Non- progressive CA (NPCA) can be divided into pure CA without additional symptoms and syndromes with CA. Pure CA can be due to cerebellar malformations as (hereditary or non-hereditary) cerebellar hypoplasia, Dandy Walker syndrome, or occasionally supratentorial abnormalities. Ataxic syndromes are less frequent, but more distinctive. There are syndromes (e.g. Joubert syndrome) where ataxia is a cardinal feature and others where ataxia is only an occasional symptom. Acquired ataxias, due to congenital cytomegalovirus infection or perinatal problems, form a small third group. In about half of all cases with NPCA, aetiology and inheritance are still unknown. Diagnosis of NPCA is made by a typical history and careful clinical examination. Diagnosis of a more distinctive ataxic syndrome may be possible on clinical grounds. Neuroimaging with special attention to the posterior fossa will aid accurate clinical classification. Early progressive ataxias require careful differentiation from other types.

Ataxia↗

Congenital ataxia of parietal origin? Report of two cases.

Congenital cerebellar ataxia is usually thought to be of cerebellar origin. We report two children with congenital cerebellar ataxia, in whom neuroimaging investigations suggest the possibility of a parietal etiology. The two boys showed hypotonia, delayed motor and cognitive development followed by marked, truncally pronounced ataxia. In one case infantile spasms were treated successfully with adrenocorticotropic hormone, although in follow-up the child suffered from occasional seizures. Magnetic resonance imaging showed in one case parieto-occipital pachygyria and in the other there was marked pachygyria, most pronounced over the parieto-occipital area. In both children cerebellar structures were normal. Cerebello-parietal connections are known to be responsible for acquired parietal limb ataxia. Although not proven, parietal lesions are the most likely etiology of congenital cerebellar ataxia in these two children. Therefore, cerebral, especially parietal pathology must be considered in children with congenital ataxia.

Brain Diseases↗

Non-progressive congenital ataxia with or without cerebellar hypoplasia: a review of 34 subjects.

Information on the long-term development of larger series of children with non-progressive congenital ataxia (NPCA) is scarce. We have updated a personal cohort of subjects previously diagnosed as having NPCA. Children with brain malformations, acquired neurological illness, or defined syndromes were excluded. From 58 subjects, 34 were available for review (including three pairs of siblings). All our subjects had delayed motor and speech development. Truncal ataxia persisted but became less significant. Two subjects developed spasticity and three a focal dystonia. Epilepsy was a feature in 10 of the subjects. Cognitive impairment was present in 22 of 34 subjects. MRI was normal in 15 of 27. There were no obvious correlations between degree of motor delay, severity of ataxia, cognitive impairment, and neuroimaging. Although genetically and clinically not a homogeneous entity, NPCA is a helpful diagnostic label. Major problems arise in the majority of subjects related to cognitive impairment and less to neurological symptoms. Early individual prognosis is not possible from early developmental milestones, neurological signs, or neuroimaging.

Adolescent↗

Adverse effects of vigabatrin in Angelman syndrome.

New antiepileptic drugs designed for enhancing GABAergic inhibition, such as vigabatrin (VGB) may be effective in Angelman syndrome (AS), because associated convulsions could be related to a reduced GABA-receptor density or receptor abnormality. From our preliminary experiences in four children with AS treated with VGB, we conclude that it may induce and increase seizures in patients with AS.

Adult↗

Predicting the outcome of postasphyxial hypoxic-ischemic encephalopathy within 4 hours of birth.

OBJECTIVE: To build models that predict severe adverse outcome within 4 hours of birth in patients with postasphyxial hypoxic-ischemic encephalopathy. The goal was to develop models for selecting patients for therapeutic trials of neuroprotective medications. STUDY DESIGN: Retrospective cohort study with follow-up to a minimum age of 12 months of 164 "outborn" term infants admitted to a tertiary neonatal intensive care unit, and 14 "inborn" term infants in the two tertiary perinatal centers in a regionalized setting. After performing univariate screening tests, multivariate models of association between risk factors and "severe adverse outcome" (death or major neurosensory impairment) were constructed. RESULTS: Of 178 infants with postasphyxial hypoxic-ischemic encephalopathy of defined severity admitted consecutively between 1985 and 1992, 48 died, 40 survived with major neurosensory impairment, and 13 were lost to follow-up. The important predictors of severe adverse outcome in the first 4 hours were delayed onset of breathing, administration of chest compressions, and seizures. At 60 minutes of age, based on predicted probabilities of > 0.50, the sensitivity of the predictive model was 85% and specificity 68%. The parameter estimates of the predictive models are reported. CONCLUSIONS: Age of onset of breathing, administration of chest compressions, and age of onset of seizures were the most important variables predictive of adverse outcome in this study. Although fairly sensitive and specific, these predictive models should be applied with caution. To build more accurate models, a template for the conduct of a large, multicenter prospective study is provided.

Apgar Score↗

Positive epileptiform discharges in children with neuronal migration disorders.

Most epileptiform abnormalities show a negative polarity on EEG. Focal positive spike waves have rarely been identified in seizure disorders and are generally associated with physiological and neurological impairment. Results of EEG, computed tomography, MRI, and pathologic studies of 15 children with focal neuronal migration disorders who underwent surgery for refractory localization-related epilepsy were compared to examine the association between positive discharges and other findings. Subjects were studied both ictally and interictally by scalp EEG with the International 10-20 system and zygomatic or sphenoidal electrodes, and video EEG telemetry. The 5 children with positive discharges were significantly more likely to develop hemiparesis during the preoperative period (P < or = .025). Correlations were observed between positive discharges and lesions apparent on MRI situated around the rolandic fissure (P < or = .025). Children with positive discharges had a significantly less favorable outcome after surgical treatment (P < or = .025). Positive epilepti-form discharges in children with neuronal migration disorders may signal a more dysfunctional cortex leading to a focal neurological deficit or a more extended lesion than is detected on MRI. This would explain the less favorable outcome of seizures after surgery, since the epileptogenic areas and neuronal migration lesions cannot be completely resected.

Brain↗

Follow-up in children with Joubert syndrome.

Although Joubert syndrome (JS) was first reported in 1969 by Joubert et al (21), the long-term outcome is not yet documented. We report 19 children (4 pairs of siblings) from a single institution diagnosed with JS. Nine children were last seen between ages 10 and 18 years, seven between ages 1 and 4 years. Three children died before 3 years of age, showing marked breathing problems and minimal development. The 16 surviving children showed variable motor development, walking was typically achieved between 2 and 10 years, two children did not learn to walk. Cognitive development showed four with development quotient (DQ) of 30 or less and nine with DQ of 60-85, the others could not be judged confidently. Siblings did not show similar development and sex was not predicting outcome. The following oculomotor problems were seen: mystagmus in 11, ocular motor apraxia in six, isolated ptosis in two, and vertical gaze palsy in three. Additional features were retinal involvement in eight and kidney involvement in four, in one of them after normal previous ultrasound. In conclusion development of children with JS can be split into distinct subgroups, with one group dying at a young age. Those who survive show variable motor and cognitive development and can be grouped into those with DQ of less than 30 or those with DQ between 60 and 85. Ophthalmological and renal involvement may change or develop over the years and should be followed carefully.

Adolescent↗

[Back pain in children: symptoms which should be taken seriously].

Back pain in children is a rare but serious problem. The varied etiologies and the necessary diagnostic workup are illustrated in 8 children. Infectious processes were found in 3 children, spondylodiscitis twice and epidural abscess once. Tumours (one eosinophilic granuloma and one spinal ependymoma) were present in 2 boys. One girl had a herniated lumbar disc. Malformations (spondylolysis and diastematomyelia) were the cause of symptoms in 2 children. Leading symptom in all 8 children was back pain lasting from 3 days to 2 years. Careful clinical neurological examination, parameters of inflammation in the blood and conventional radiography of the spine were helpful in guiding further investigations. Scintigraphy was useful for localization of infectious and tumorous diseases. MRI was superior to CT in evaluating tumours and malformations of the spinal cord. In most cases CT was sufficient in workup of infectious and osseous processes.

Adolescent↗