Dejerine's syndrome or Spiller's syndrome?

We report the difference existing between two clinical syndromes: Spiller's syndrome is caused by a complete involvement of the medial hemimedulla, while Déjérine's syndrome is determined by lesions restricted to the anterior portion of the medial hemimedulla and is characterized by hypoglossal nerve palsy and contralateral hemiparesis.

Diffusion MRI: apparent diffusion coefficient (ADC) values in the normal brain and a classification of brain disorders based on ADC values

Diffusion-weighted imaging, dependent on motion of water molecules, provides information regarding tissue integrity. Apparent diffusion coefficient (ADC) values in the normal brain parenchyma, and those in a variety of lesions were studied by echo-planar diffusion MRI in 310 cases. Brain disorders were classified based on their ADC values, taking the ADC values of the normal brain white matter as the principal category. In the normal white matter ADC ranges were 0.60-1.05x10(-3)mm(2)/s, and the mean ADC value was 0.84+/-0.11x10(-3)mm(2)/s. It was possible to distribute brain disorders, as well as artefacts on diffusion MRI to five major categories: category 1, ADC similar to normal white matter; category 2, ADC lower than normal white matter; category 3, ADC higher than normal white matter; category 4, ADC similar to CSF; and category 5, markedly low or high ADC. Further studies can provide addition of different lesions as well as refinements of these categories.

Serum carotenoids and cerebral white matter lesions: the Rotterdam scan study

OBJECTIVES

To study the relation between serum levels of carotenoids and white matter lesions (WMLs) on magnetic resonance imaging (MRI).

DESIGN

Evaluation of cross-sectional data from a cohort study.

SETTING

The Rotterdam Scan Study.

PARTICIPANTS

Two hundred and three nondemented older persons, age 60 to 90, from the Rotterdam Scan Study.

MEASUREMENTS

Serum levels of carotenoids were determined. WMLs on MRIs were rated separately into periventricular and subcortical WMLs. Odds ratios (ORs) for the presence of severe WMLs (upper decile) were calculated per standard deviation (SD) increase in serum carotenoid level and per SD increase in overall carotenoid serum level. Effect modification by smoking status was studied through stratified analyses.

RESULTS

Increasing levels of all the separate carotenoids were associated with less severe periventricular WMLs, which reached statistical significance for the overall carotenoid serum level (OR 0.4 per SD; 95% confidence interval (CI) = 0.2-0.9). We found no association between carotenoid levels and the presence of severe subcortical WMLs (OR 1.2 per SD; 95% CI = 0.7-2.0). The association of carotenoid levels with severe periventricular WMLs was more marked in those who ever smoked (OR 0.1 per SD; 95% CI = 0.0-0.9) than in those who had never smoked (OR 0.9 per SD; 95% CI = 0.4-2.1).

CONCLUSIONS

These findings are compatible with the view that high levels of carotenoids may protect against WMLs in the periventricular region, in particular in smokers. Longitudinal studies with repeated measurements of both carotenoids and WMLs are necessary to explore this hypothesis further.

[Disorientation in patients with organic brain disorders]

The aim of the study was to designate conditions in which disorientation appears in patients with organic brain disorders. This was made through analysis of relations between the disorientation and 10 variables describing the disorders. 110 patients with various organic brain disorders was examined. In order to estimate the results of this investigation the method of cluster analysis (Wrocław taksonomy) was used. Disorientation appeared to be in one cluster with the disorder of gestalting function in the Bender test, diagnosis, psychomotoric slowing, aphasia, type and localization of lesion and age of the patients. These features may be the conditions in which disorientation appears in the patients with organic brain disorders.

[Progressive encephalopathies in children]

The Authors describe progressive encephalopathies in children hospitalized at the Department of Child Neurology Silesian Medical School from 1980 to 2000. They present ethiology, clinical symptoms and diagnostic protocol based on literature data and their own experience.

Neuronal migration disorders in man

A classification of neuronal migration disorders based on the gross morphology of the disorder with subclassifications according to the cause of the underlying disorder as far as that is known is presented. Emphasis is on disorders of the neocortex. The classical entities classical lissencephaly, cobblestone lissencephaly, polymicrogyria, neuronal heteropia within the white matter and leptomeningeal glial and glioneuronal heterotopia are described. Recent findings on the genetics of neuronal migration disorders are discussed. More subtle structural abnormalities such as cortical dysgenesis or dysplasia remain still more controversial as separate entities.

Classification of acquired lesions of the corpus callosum with MRI

MRI has facilitated diagnostic assessment of the corpus callosum. Diagnostic classification of solitary or multiple lesions of the corpus callosum has not attracted much attention, although signal abnormalities are not uncommon. Our aim was to identify characteristic imaging features of lesions frequently encountered in practice. We reviewed the case histories of 59 patients with lesions shown on MRI. The nature of the lesions was based on clinical features and/or long term follow-up (ischaemic 20, Virchow-Robin spaces 3, diffuse axonal injury 7, multiple sclerosis 11, hydrocephalus 5, acute disseminated encephalomyelitis 5, Marchiafava-Bignami disease 4, lymphoma 2, glioblastoma hamartoma each 1). The location in the sagittal plane, the relationship to the borders of the corpus callosum and midline and the size were documented. The 20 ischaemic lesions were asymmetrical but adjacent to the midline; the latter was involved in new or large lesions. Diffuse axonal injury commonly resulted in large lesions, which tended to be asymmetrical; the midline and borders of the corpus callosum were always involved. Lesions in MS were small, at the lower border of the corpus callosum next to the septum pellucidum, and crossed the midline asymmetrically. Acute disseminated encephalomyelitis and the other perivenous inflammatory diseases caused relatively large, asymmetrical lesions. Hydrocephalus resulted in lesions of the upper part of the corpus callosum, and mostly in its posterior two thirds; they were found in the midline. Lesions in Marchiafava-Bignami disease were large, often symmetrically in the midline in the splenium and did not reach the edge of the corpus callosum.

Assessment of hand after brain damage with the aim of functional surgery

The semiology of the hand after brain damage is really rich. Its clinical evaluation remains quite difficult and must be integrated in the neuro-orthopedic and cognitive context. Deficiency, neuropsychological, analytic and functional status, must be assessed before any surgical decision aiming the improvement of prehension. Neuropsychological evaluation precise the hemispheric specialization: right hemisphere lesions conduct to unilateral spatial neglect while left hemispherical lesions determine language troubles and gesture impairment (apraxia). The analytical evaluation describes motor and sensitive function and assesses spasticity and pain. Concerning the functional assessment, the Enjalbert's score seems to be the most adapted to the upper limb. The assessment of hand deficiency and its origin is necessary to orientate the surgical decision and includes the Zancolli classification for the fingers and wrist and the House classification for the thumb. These classification used for cerebral palsy seems to be insufficient for all the different situations occurring after brain damage. A new classification is proposed based on 3 parameters: fingers extension, thumb abduction and supination. Surgical decision should be examined only after an adapted rehabilitation program.

[Cortical dysgenesis: current classification, MRI diagnosis, and clinical review]

Cortical dysgenesis comprises a heterogenous group of genetic or acquired disturbances of cortical development which, due to progress in modern neuroimaging techniques, are increasingly recognized in association with a variety of clinical disorders. The spectrum of clinical manifestations, depending on type and extent of the alterations, includes severe mental retardation and epilepsy as well as neuropsychological deficits and psychiatric disorders. Up to now, the nomenclature of cortical malformations has been difficult and ambiguous. Recently, the understanding and terminology of these disorders has been facilitated by the proposal of a new classification scheme based on pathophysiological as well as pathogenetic mechanisms. This proposal has been elaborated by a group of experts and is not yet well-known in the German literature. Magnetic resonance imaging (MRI) allows diagnosis and classification in many cases of cortical dysgenesis during lifetime, thereby helping to identify prognostic and therapeutic options. Early diagnosis of cortical malformations is of particular importance in patients with drug-resistant epilepsy, as they can either be cured or benefit from epilepsy surgery. This review gives examples of the most relevant cortical malformations using the new classification scheme and summarizes their clinical as well as MRI characteristics. Besides routine MRI applications, some experimental techniques are discussed which may help to identify even subtle alterations.

General Neuropsychological Deficit Scale sans IQ

The General Neuropsychological Deficit Scale (GNDS) of Halstead-Reitan Neuropsychological Test Battery (HRNTD) is a summary measure used to differentiate brain-damaged from normal subjects. This study seeks to determine what happens to the GNDS if the IQ-related items are dropped. A sample of 40 heterogeneously brain-damaged patients with HRNTB scores was obtained. There were 36 men and 4 women. All subjects were right-handed except for three left-handed men and one ambidextrous male. The sample ranged in age from 16 to 66 years and in education from 8 to 22 years. Severity criteria were set for normal, mild, moderate, and severe brain damage based on published guidelines from Reitan and Wolfson (1992). Dropping the IQ-related items had little effect as 95% of the subjects fell in the same impairment severity classification category as before.

Clinical features of 21 patients with lissencephaly type I (agyria-pachygyria)

Lissencephaly (agyria-pachygyria) is the most severe neuronal migration disorder, characterized by total or partial absence of gyri. In this study, 21 patients with lissencephaly type I (9 girls, 12 boys) with a mean age of 19 +/- 21 months (2 weeks-8 years) were evaluated clinically and graded according to neuroradiological findings (19 patients by magnetic resonance imaging MRI and 2 by computed tomography CT). Three patients were classified as lissencephaly grade 2 and 18 patients as grade 3 or 4. Clinically, 12 patients (57%) had microcephaly, and eight (38%) had facial dysmorphism. All the patients had prominent psychomotor retardation, moderate to severe; the most frequent neurological findings were spastic guadriplegia (36.4%) and hypotonia with exaggerated tendon reflexes (27.3%). Seventy-eight percent of the patients had epileptic seizures resistant to conventional treatment. Lissencephaly is a cerebral cortical malformation that should be considered in children with developmental delay with or without microcephaly and facial dysmorphism. In addition, it should be investigated in the etiology of early-onset childhood epilepsy.

Neuroimaging: do we really need new contrast agents for MRI?

The use of exogenous contrast media in magnetic resonance imaging of the brain has brought dramatic improvement in the sensitivity of detection and delineation of pathological structures, such as primary and metastatic brain tumors, inflammation and ischemia. Disruption of the blood brain barrier leads to accumulation of the intravenously injected contrast material in the extravascular space, leading to signal enhancement. Magnetic resonance angiography benefits from T(1)-shortening effects of contrast agent, improving small vessel depiction and providing vascular visualization even in situations of slow flow. High speed dynamic MRI after bolus injection of contrast media allows tracer kinetic modeling of cerebral perfusion. Progressive enhancement over serial post-contrast imaging allows modeling of vascular permeability and thus quantitative estimation of the severity of blood brain barrier disruption. With such an array of capabilities and ever improving technical abilities, it seems that the role of contrast agents in MR neuroimaging is established and the development of new agents may be superfluous. However, new agents are being developed with prolonged intravascular residence times, and with in-vivo binding of ever-increasing specificity. Intravascular, or blood pool, agents are likely to benefit magnetic resonance angiography of the carotid and cerebral vessels; future agents may allow the visualization of therapeutic drug delivery, the monitoring of, for example, gene expression, and the imaging evaluation of treatment efficacy. So while there is a substantial body of work that can be performed with currently available contrast agents, especially in conjunction with optimized image acquisition strategies, post processing, and mathematical analysis, there are still unrealized opportunities for novel contrast agent introduction, particularly those exploiting biological specificity. This article reviews the current use of contrast media in magnetic resonance neuroimaging, discusses some of the developing strategies for new applications of imaging with these agents and finally offers some views and indications for contrast agents currently under development, as well as some speculation on unsolved problems in neuroimaging, and opportunities for novel contrast agents.

Focal cortical dysplasia: comparison of MRI and FDG-PET

PURPOSE

The purpose of this work was to compare the use of MRI and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis of focal cortical dysplasia (FCD).

METHOD

Nineteen patients with surgically proven FCD were analyzed retrospectively. MRI was performed in all patients, and FDG-PET was performed in 17 patients. We compared the MR and FDG-PET findings of FCD according to the histologic findings that were classified into three grades.

RESULTS

Four cases were classified as Grade I, 4 cases as Grade II, and 11 cases as Grade III FCD. The lesions were detected on MRI in 9 (82%) of the 11 patients with Grade III FCD and in only 1 (13%) of the 8 patients with Grade I and II FCD. Cortical hypometabolism of the lesion was revealed on FDG-PET in 6 (86%) of the 7 patients with Grade I and II FCD and in 9 (90%) of the 10 patients with Grade III FCD. The extent of the cortical abnormality was larger on FDG-PET than on MRI in 11 (65%) of the 17 patients.

CONCLUSION

FDG-PET is more useful in delineating the cortical abnormality in patients with mild degrees of FCD. The extent of the lesion was larger or similar on FDG-PET compared with that of the MRI.

Central nervous system sarcoidosis: follow-up at MR imaging during steroid therapy

PURPOSE

To document the changes observed at sequential magnetic resonance (MR) imaging of sarcoidosis lesions of the central nervous system (CNS) during treatment with corticosteroids.

MATERIALS AND METHODS

The abnormalities detected in 24 patients (mean follow-up, 36 months) were compared before and after therapeutic periods (n = 75) that were divided into attack (high-dose), upkeep (decreased-dose), and minimal (low-dose) periods. Parenchymal lesions were classified as type 1 (enhanced with gadolinium), type 2 (demyelinating), or type 3 (lacunar) and were assessed as regressing, stable, or progressing.

RESULTS

Seven of the 24 patients had several types of lesions. Isolated type 3 lesions (six patients) were the only lesions not associated with neurologic deficit. Type 1 lesions (13 patients) regressed in 22 of 22 attack periods and progressed in nine of 27 upkeep and minimal periods. MR imaging depicted relapses in patients with multifocal CNS involvement or long-standing CNS impairment or in those who had previously received steroid therapy. Type 2 (seven patients) and type 3 (13 patients) lesions remained stable in 68 of 68 therapeutic periods. Type 1 lesions appeared in three patients with type 2 and type 3 lesions during two upkeep and three minimal periods. Findings at follow-up MR imaging contributed to the reintroduction of high-dose corticosteroid therapy in eight patients.

CONCLUSION

MR imaging can be used to differentiate between reversible and irreversible lesions in CNS sarcoidosis. MR imaging can be a useful tool for adjusting treatment to prevent irreversible CNS damage.

[For what reasons is the neurologic status of very premature infants altered between 1 and 2 years in a follow-up study? The contribution of a Frache-Comté region study]

BACKGROUND

The purpose of this population-based study was firstly to compare the neuro-developmental outcome at one and two years of very preterm infants, and secondly, to identify the risk factors for a misdiagnosis of cerebral impairment at the age of one year.

POPULATION AND METHODS

The preterm cohort included 203 infants born between 25 and 32 weeks of gestational age in the region of Franche-Comté (France) during a two-year period. The control group included 196 full-term infants born in the same maternity wards. Neuro-developmental assessments were performed by pediatricians or physicians, both at one and two years of age, on 94% (161/171) surviving preterms and 89% (173/195) full-terms.

RESULTS

There is a fair correlation between the two neurological evaluations of the control group (170/173, 98% have the same classification at the age of one and two). There is a weak correlation (kappa = 0.37) between the two neurological evaluations of the preterm group. Sixteen preterms (10%) had been classified more abnormal at one year than they were at two years. The presence of a broncho-pulmonary dysplasia, linked to male sex and extreme prematurity, was statistically linked to this first kind of misclassification. Seventeen preterms (10%) had been considered more normal at one year than they were at two years. The presence of a diplegia, family precariousness and the examination at one year of age by a general practitioner were statistically linked to this second kind of misclassification.

CONCLUSION

This prospective population-based study identifies structural situations (bronchopulmonary dysplasia linked to extreme prematurity) and environmental situations (family precariousness, examiner's qualifications) linked to a misclassification of the neurological status of one-year-old former preterm infants.

Pontocerebellar hypoplasia--how many types?

An original article describes a sibship with early fatal pontocerebellar hypoplasia of a yet unclassified type, with the accompanying features of polyhydramnios and neonatal myoclonus. Autopsy in one patient excluded spinal anterior horn involvement, which argues against pontocerebellar hypoplasia type I (PCH-1). The present PCH classification and literature are briefly reviewed. Four previous publications bear similarity to the present report. Definite classification as a genetically separate entity, however, remains elusive pending localization and identification of the gene(s) involved.

Defining and categorizing leukoencephalopathies of unknown origin: MR imaging approach

PURPOSE

To categorize leukoencephalopathies of unknown origin into a few major groups by using magnetic resonance (MR) imaging criteria to facilitate further studies, and to assess the possibility of defining "new" (i.e., until now unknown) disease entities within these major groups.

MATERIALS AND METHODS

MR images of 92 patients (55 male, 37 female; mean age, 9.3 years) with a leukoencephalopathy were examined by using a scoring list of 68 items. Seven major categories were defined according to the predominant location of the white matter abnormalities. Statistical analysis was used to assess the validity of these seven categories.

RESULTS

Statistical analysis results showed that the seven categories could be well distinguished by either using the defining variables initially accepted as inclusion criteria or selecting a few other variables found to have discriminating value. The additional variables confirmed that the categories are essentially distinct and vary systematically with regard to items other than the inclusion criteria. The existence of two recently defined leukoencephalopathies was confirmed, but no consistent evidence of other new disease entities could be provided.

CONCLUSION

Establishing these seven categories helps in the interpretation of individual studies by demonstrating features that the patient has in common with other patients, and it may facilitate further research on homogeneous subgroups of patients and allow pooling of data across multiple centers.

Analysis of cystic intracranial lesions performed with fluid-attenuated inversion recovery MR imaging

BACKGROUND AND PURPOSE

T1-, T2-, and proton density (PD)-weighted sequences are used to characterize the content of cystic intracranial lesions. Fluid-attenuated inversion recovery (FLAIR) MR sequences produce T2-weighted images with water signal saturation. Therefore, we attempted to verify whether FLAIR, as compared with conventional techniques, improves the distinction between intracranial cysts with a free water-like content versus those filled with a non-free water-like substance and, consequently, aids in the identification of these lesions as either neoplastic/inflammatory or maldevelopmental/porencephalic.

METHODS

Forty-five cystic intracranial lesions were studied using T1-weighted, T2-weighted, FLAIR, and PD-weighted sequences. By means of clustering analysis of the ratio in signal intensity between the cystic intracranial lesions and CSF, the intracranial lesions were classified as filled with a free water-like content or with a non-free water-like substance. The results were compared with their true content as evaluated either histologically or on the basis of clinical, neuroradiologic, and follow-up features (necrotic material, 13 cases; accumulation of intercellular proteinaceous/myxoid material, eight cases; keratin, five cases; CSF, 19 cases). Cystic intracranial lesions were divided into two clinical groups, neoplastic/inflammatory and maldevelopmental/porencephalic, to evaluate the level of accuracy of each MR technique. The difference in absolute value signal intensity between CSF and cystic intracranial lesion content was calculated on FLAIR and PD-weighted images.

RESULTS

PD-weighted and FLAIR sequences, unlike T1- and T2-weighted sequences, accurately depicted all cystic intracranial lesions containing necrotic or myxoid/proteinaceous intercellular material (non-free water-like) and most CSF-containing cystic intracranial lesions (free water-like). All imaging techniques inaccurately showed some of the keratin-containing cystic intracranial lesions and pineal cysts. The overall error rate was 22% for T1-weighted, 27% for T2-weighted, 9% for FLAIR, and 13% for PD-weighted sequences. The signal intensity difference between CSF and cystic intracranial lesion content was higher with FLAIR imaging.

CONCLUSIONS

FLAIR imaging depicts far more accurately the content of cystic intracranial lesions and better reveals the distinction between maldevelopmental/porencephalic and neoplastic/inflammatory lesions than do conventional sequences. FLAIR has the added advantage of a higher signal intensity difference between cystic intracranial lesions and CSF.

Validity of a cognitive computerized assessment system in brain-injured patients

The primary objective of the study was to investigate the criterion validity of the Cognitive Drug Research (CDR) computerized system in assessing cognitive functioning among persons with brain injury or other organic illness. Understanding the cognitive effects of pharmacotherapy is important in improving long-term rehabilitation outcomes in persons with organic disorders. The CDR system evaluates cognitive skills of attention, short-term or working memory, long-term memory, and visuomotor and motor functioning. For validity testing, correlation coefficients were obtained from an analysis of CDR scores to IQ and Folstein Mini-Mental State Exam (MMSE) scores. Subtests of the CDR system that correlated with the MMSE were choice reaction time (R = -0.542, p = 0.04), spatial working memory (R = 0.938, p = 0.01), and word recognition (R = -0.949, p = 0.01). These tests primarily measured attention and working memory. Correlations between the CDR and IQ scores were not evident. In summary, the data suggest the CDR assessment system has high patient acceptability by persons with traumatic brain injury, and is a useful tool in assessing certain domains of cognition, specifically short-term memory, discrimination, and identification skills.