R. Canapicchi

Correlation between visual function, neurodevelopmental outcome, and magnetic resonance imaging findings in infants with periventricular leucomalacia

AIM To evaluate the correlation between visual function and neurodevelopmental outcome in children with periventricular leucomalacia at 1 and 3 years. METHOD Visual acuity, visual field, ocular motility, and optokinetic nystagmus were tested in 29 infants with periventricular leucomalacia by brain magnetic resonance imaging. All infants also had a structured neurological examination and a Griffiths developmental assessment. RESULTS 21 of the infants showed at least one abnormality of visual function. The degree of visual impairment—that is, the number of visual tests showing abnormal results—correlated well with the results on developmental assessment at both ages. CONCLUSION Multivariate analysis showed that visual impairment was the most important variable in determining the neurodevelopmental scores of these infants, more than their motor disability and the extent of their lesions on magnetic resonance imaging.

White matter MRI hyperintensities in a hundred and twenty-nine consecutive migraine patients

The most frequently reported abnormal MRI finding in migraine is the presence of high signal white matter foci (WMF) on long TR images. Recently, WMF have been distinguished in periventricular WMF (PVF), when contiguous to ventricles, and deep WMF (DF), when far from these. DF, but not PVF, appear positively correlated with cerebrovascular risk factors and are called leukoaraiosis. In this study the MRI examination was performed in 129 consecutive migraine patients (83 of them had migraine without aura and 46 migraine with aura). In 19.3% of the migraineurs studied we observed WMF on T2 weighted images strictly localized in the deep white matter (DF). No PVF were observed. These findings were independent of the type of migraine and did not correlate with age, sex, disease duration, or frequency of attacks. The presence in a subgroup of migraineurs of leukoaraiosis (DF), for which a vascular genesis has been hypothesized, suggests that migraine could represent, a cerebrovascular risk factor in these patients.

CORRECTION BETWEEN CEREBRAL VISUAL IMPAIRMENT AND MAGNETIC RESONANCE IMAGING IN CHILDREN WITH NEONATAL ENCEPHALOPATHY

To identify brain lesions most often associated with cerebral visual impairment (CVI) after neonatal encephalopathy and to evaluate the prognostic value of MRI for visual outcome, the authors reviewed visual assessments and brain MRI of 80 infants and young children with documented perinatal hypoxic‐ischaemic and/or haemorrhagic insults. MRIs were classified according to the severity of lesions at the optic radiations and at the visual cortex; visual acuity was tested with the acuity card procedure. Among the 48 children found to have a CVI, 42 had moderate to severe lesibns of the optic radiations and 19 had lesions of the visual cortex. In both cases visual acuity was statically correlated with MRI grading, but the damage at the optic radiations was the better predictor. Early detection of abnormal MR findings in the visual cortex and. especially, at the optic radiations may indicate which infants with neonatal encephalopthy should receive longitudinal visual assessment and specific rehabilitation and educational management.

Reversible pseudoatrophy of the brain and mental deterioration associated with valproate treatment

Summary: Purpose: To describe an 11‐year‐old girl with symptomatic localization‐related epilepsy and normal intelligence who developed reversible mental deterioration and pseudoatrophic brain changes while receiving valproate (VPA).

Clinical outcome and magnetic resonance imaging of carbon monoxide intoxication. A long-term follow-up study.

Abstract The clinical and neuroradiological outcome of carbon monoxide (CO) intoxication was evaluated prospectively in 30 patients over a follow-up period of 3 years. Among the patients studied, 22 had been acutely exposed to CO while 8 were chronically exposed.One month after CO poisoning, 12 of the 22 patients with acute intoxication showed magnetic resonance imaging (MRI) abnormalities: 6 also had neurological sequelae and 6 were asymptomatic. The remaining 10 patients showed neither MRI abnormalities nor neurological sequelae. During the 3-year follow-up, 4 of the patients with both MRI abnormalities and neurological sequelae improved in both clinical features and MRI findings. One of the 6 asymptomatic patients with MRI abnormalities developed a progressive cognitive impairment 2 months after acute intoxication, with a concomitant severe worsening of the MRI lesions. Among the 10 patients with neither MRI abnormalities nor neurological sequelae, only 1 developed neurological sequelae after a clear period of 4 months.In the group of patients who experienced chronic CO intoxication, only 1 presented with a neuropsychiatric syndrome which improved at follow-up. Brain MRI showed white matter lesions which remained unchanged at control scan after 1 year.In conclusion, we observed that some patients with severe CO poisoning and neurological sequelae may fully regain normal functions after approximately 1 year. The presence of MRI lesions 1 month after CO poisoning did not accurately predict the subsequent outcome. The observation of a clear period longer than the usual 2–40 day interval in 2 patients should be considered for careful planning of follow-up and for prognosis in CO-poisoned patients.

Visual function in children with hemiplegia in the first years of life

The aim of this study was to evaluate the incidence of visual function abnormalities in children with infantile hemiplegia, and the relation between visual abnormalities and type of lesion, as shown by brain MRI. Visual function was tested (grating acuity, visual field size, binocular optokinetic nystagmus [OKN], and ocular movements) in a group of 47 children with congenital or early acquired hemiplegic cerebral palsy (mean age 25 months, range 8 to 52 months). The cohort was subdivided into four groups according to MRI findings: brain malformations (n=5), abnormalities of the periventricular white matter (n=20), cortical‐subcortical lesions (n=16), and non‐progressive postnatal brain injuries (n=6). More than 80% of the children showed abnormal results in at least one visual test: acuity was the least impaired function, while visual field and OKN were abnormal in more than 50% of the cohort. No specific correlation could be identified between the type and timing of the lesions and visual function. Unlike adults with stroke, visual field defects were not always related to contralateral damage in the optic radiations or in the visual cortex. These results indicate that visual abnormalities are common in children with hemiplegia, and that they cannot always be predicted by MRI. All children with hemiplegia need a detailed assessment of visual function.

MRI findings and sensorimotor development in infants with bilateral spastic cerebral palsy

The correlation between MRI findings and sensorimotor development was investigated in a group of 48 infants with bilateral spastic cerebral palsy (CP). The ages at MRI examination and cognitive assessment were fairly homogeneous (mean 15 months and 17 months, respectively). The following MRI parameters were scored: size of lateral ventricles, extension of white matter lesions and of white matter reduction, thinning of corpus callosum, presence and size of cystic areas, dimension of subarachnoid spaces and presence of cortical abnormalities. Cognitive assessment included Griffiths Developmental Scales and Uzgiris-Hunt Scales. The patients were subdivided into six classes according to intellectual level (DSM-III-R). For the whole group a highly significant correlation was found between all MRI parameters and the level of cognitive development. This result was probably due to the inclusion of 14 untestable, severely mentally retarded infants, who showed very severe MRI abnormalities. However, when the untestable infants were excluded from the analysis, it was the presence of cysts and the entity of white matter reduction that correlated with both Griffiths Scales and Uzgiris-Hunt Scales. These results indicate the clinical value of MRI findings and particularly of white matter abnormalities for early identification of sensorimotor impairment in infants with bilateral spastic CP.

Acuity card testing in children with cerebral palsy related to magnetic resonance images, mental levels and motor abilities

Visual acuity testing using Teller Acuity Cards was carried out on 78 infants and children affected by cerebral palsy (CP). Age of testing was between 3 and 109 months. The aim of the study was to investigate the usefulness of acuity cards in patients with CP, and to relate visual outcome with the type of CP, MRI findings, mental levels and motor disabilities. Visual acuity estimates were obtained for 60 children: acuity values were within normal values for age for 17 and below the 5th percentile for 43. Cerebral blindness was diagnosed in 10 patients. Eight infants were not testable, mainly because of behavioural problems. The overall success rate was 88%. Visual impairment in most infants with low acuity and in all blind children was not due to ophthalmological abnormalities. Visual outcome was significantly related to the type of CP, with hemiplegic children showing the best results and tetraplegics the worst. Cerebral blindness was significantly correlated with tetraplegia, the severity of lesions in the optic radiations, and visual cortex areas, as indicated by MRI, and the degree of mental, motor and oculomotor deficit. These correlations were mainly due to the blind subjects, who consistently showed major MRI abnormalities and severe motor, mental and oculomotor impairment. Longitudinal results obtained for 45 children showed visual outcome stable over time in 64.4% of cases, improvement in 6.6% and deterioration in 28.9%.

Reorganisation of the sensorimotor cortex after early focal brain lesion: a functional MRI study in monozygotic twins

Sensorimotor cortical reorganization after early brain lesions was studied by means of fMRI in two pairs of monozygotic twins, in each of which one member had a focal brain injury. This offered a unique opportunity to reduce the wide intersubject variability of the controls often found in similar studies. Activation images were acquired during a motor task (sequential opposition finger movements) and a sensory task (passive brushing of palm and fingers). During the tasks with the recovered hand, constant findings in the lesioned subjects were the activation of the undamaged areas adjacent to lesion site and the activation of the ipsilateral sensorimotor cortex. Bilateral activation of the primary sensorimotor cortex was never observed in the healthy co-twin controls.

Visual function and EEG reactivity in infants with perinatal brain lesions at 1 year.

The aim of this study was to examine the correlation between EEG, visual, and brain MRI findings in 19 term infants with perinatal brain lesions. All 19 had their visual acuity and visual fields assessed and had an EEG and a brain MRI performed at 1 year of age. Four of the five infants with normal optic radiations and occipital cortices on MRI had normal vision. Involvement of optic radiations and occipital cortices was only associated with visual abnormalities in eight of 14 infants. The correlation between visual abnormalities and EEG findings was stronger. All infants with a completely normal EEG from the posterior regions had normal vision and all those with an EEG non-reactive to eye closure had visual abnormalities, irrespective of MRI data. A reactive EEG with other abnormal features (such as spikes, rapid or slow activities) was accompanied by abnormal vision in five of eight participants. Results suggest that there is a better correlation between visual function and EEG activity than between visual function and involvement of the classical visual areas of the occipital cortex and optic radiations on brain MRI at 1 year of age.