Magnetic resonance fingerprinting-based myelin water fraction mapping for the assessment of white matter maturation and integrity in typical development and leukodystrophies

A quantitative biomarker for myelination, such as myelin water fraction (MWF), would boost the understanding of normative and pathological neurodevelopment, improving patients' diagnosis and follow-up. We quantified the fraction of a rapidly relaxing pool identified as MW using multicomponent three-dimensional (3D) magnetic resonance fingerprinting (MRF) to evaluate white matter (WM) maturation in typically developing (TD) children and alterations in leukodystrophies (LDs). We acquired DTI and 3D MRF-based R1, R2 and MWF data of 15 TD children and 17 LD patients (9 months-12.5 years old) at 1.5 T. We computed normative maturation curves in corpus callosum and corona radiata and performed WM tract profile analysis, comparing MWF with R1, R2 and fractional anisotropy (FA). Normative maturation curves demonstrated a steep increase for all tissue parameters in the first 3 years of age, followed by slower growth for MWF while R1, R2R2 and FA reached a plateau. Unlike FA, MWF values were similar for regions of interest (ROIs) with different degrees of axonal packing, suggesting independence from fiber bundle macro-organization and higher myelin specificity. Tract profile analysis indicated a specific spatial pattern of myelination in the major fiber bundles, consistent across subjects. LD were better distinguished from TD by MWF rather than FA, showing reduced MWF with respect to age-matched controls in both ROI-based and tract analysis. In conclusion, MRF-based MWF provides myelin-specific WM maturation curves and is sensitive to alteration due to LDs, suggesting its potential as a biomarker for WM disorders. As MRF allows fast simultaneous acquisition of relaxometry and MWF, it can represent a valuable diagnostic tool to study and follow up developmental WM disorders in children.

Case report: Exploring chemoradiotherapy-induced leukoencephalopathy with 7T imaging and quantitative susceptibility mapping

Chemotherapy and radiotherapy are widely used in the treatment of central nervous system tumors and acute lymphocytic leukemia even in the pediatric population. However, such treatments run the risk of a broad spectrum of cognitive and neurological deficits. Even though the correlation with cognitive decline is still not clear, neuroradiological defects linked to white matter injury and vasculopathies may be identified. Thanks to the use of 7T MRI it is possible to better define the vascular pattern of the brain lesions with the added advantage of identifying their characteristics and anatomical localization, which, however, are not evident with a conventional brain scan. Moreover, the use of Quantitative Susceptibility Mapping (QSM) makes it possible to discriminate between calcium deposits on vessels (chemo-radiation-induced) and hemoglobin deposition in radio-induced cavernomas, speculating, as a result, about the pathophysiology of iatrogenic brain damage. We describe the case of a 9 year-old boy with a T-type acute lymphoid leukemia who had previously been treated with polychemotherapy and high-dose RT. To better define the child's neuroradiological pattern, 7T MRI and QSM were performed in addition to conventional imaging examinations. Our case report suggests the potential usefulness of a QSM study to distinguish radio-induced vascular malformations from mineralizing microangiopathy.

Case report: Clinical and neuroradiological longitudinal follow-up in Leukoencephalopathy with Calcifications and Cysts during treatment with bevacizumab

Leukoencephalopathy with Calcifications and Cysts (LCC) is a rare genetic microangiopathy exclusively affecting the central nervous system caused by biallelic mutations in SNORD118. Brain magnetic resonance imaging (MRI) is often diagnostic due to the highly characteristic triad of leukoencephalopathy, intracranial calcifications, and brain cysts. Age at onset, presentation and disease evolution can all vary, ranging from pauci-symptomatic disease to rapid evolution of signs with loss of motor and cognitive abilities. No specific therapies for LCC are currently licensed. According to the literature, bevacizumab might represent an effective modality to improve the clinical and MRI features of the disease. However, uncertainty remains as to the true efficacy of this approach, when to begin therapy, appropriate dosing, and the consequences of drug withdrawal. According to CARE guidelines, we describe the long-term clinical and neuro-radiological follow-up of a 10-year-old child with LCC. We report disease evolution following repeated cycles of treatment with bevacizumab. Our case report suggests that repeated cycles of bevacizumab might effectively modify disease progression, possibly indicating a time-dependent effect.

3D-Flair sequence at 3T in cochlear otosclerosis

PURPOSE

To assess the capability of three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences in detecting signal alterations of the endolabyrinthine fluid in patients with otosclerosis.

MATERIALS AND METHODS

3D-FLAIR before and after (-/+) gadolinium (Gd) administration was added to the standard MR protocol and acquired in 13 patients with a clinical/audiological diagnosis of severe/profound hearing loss in otosclerosis who were candidates for cochlear implantation and in 11 control subjects using 3-T magnetic resonance imaging (MRI) equipment. The MRI signal of the fluid-filled cochlea was assessed both visually and calculating the signal intensity ratio (SIR = signal intensity cochlea/brainstem).

RESULTS

We revealed no endocochlear signal abnormalities on T1-weighted -/+ Gd images for either group, while on 3D-FLAIR we found bilateral hyperintensity with enhancement after Gd administration in eight patients and bilateral hyperintensity without enhancement in one patient. No endocochlear signal abnormalities were detected in other patients or the control group.

CONCLUSION

Using 3-T MRI equipment, the 3D-FLAIR -/+ Gd sequence is able to detect the blood-labyrinth barrier (BLB) breakdown responsible for alterations of the endolabyrinthine fluid in patients with cochlear otosclerosis. We believe that 3D-FLAIR +/- Gd is an excellent imaging modality to assess the intra-cochlear damage in otosclerosis patients.

KEY POINTS

• Gd-enhanced T1-weighted MRI has limited application to detect intra-cochlear damage. • 3D-FLAIR is less sensitive to flux artefacts and allows multiplanar reconstruction. • Post-Gd 3D-FLAIR is advantageous as it may highlight the BLB breakdown. • Using 3D-FLAIR -/+ Gd, we were able to identify intra-cochlear signal hyperintensities. • 3D-FLAIR might be applied for monitoring disease progression and treatment response.

Delayed post-traumatic fronto-ethmoidal sinus mucocele evaluated with short and long TE MR spectroscopy

Mucoceles are slow-growing, benign, expansile, mucoid-filled masses developing after obstruction of the sinus ostium. Late post-traumatic mucoceles are relatively rare entities and the literature is limited to single case reports. We describe an unusual case of post-traumatic fronto-ethmoidal mucocele, evaluated with computed tomography (CT), magnetic resonance imaging (MRI) and proton MR-spectroscopy ((1)H-MRS). As a contribution to the diagnostic work-up of the mucocele, (1)H-MRS demonstrates a dominant peak at 2.0 ppm at long echo time (TE) and an additional component at 3.8 ppm at short TE due to mucus glycoprotein compounds of the mucocele.

6p25 interstitial deletion in two dizygotic twins with gyral pattern anomaly and speech and language disorder

Submicroscopic 6p25 deletion is now recognized as a clinically identifiable syndrome, characterized by intellectual disability, language impairment, hearing deficit, craniofacial, ophthalmologic, cardiac, and varying central nervous system anomalies. We report on two dyzogotic twins with a maternal segregating hemizygous interstitial deletion on chromosome 6p25.1, spanning 0.9 kb; the smallest ever reported. Both had dysmorphic features (prominence of the metopic suture, synophrys, hypertelorism, down-slanting palpebral fissures, tented mouth), and a distinct brain MRI, showing a focal significant increase of the right peri-frontal subarachnoid space, with shallow sulci and a mild anomaly of the gyral pattern. Such brain anomaly has never been reported in association with del 6p25. Both propositi had a borderline-mild intellectual disability, speech and language difficulties, and behavior abnormalities. Their mother, formally tested, had a borderline cognitive impairment. Although none of the genes mapping to the deleted region are apparently related to the phenotype, LYRM4 resulted down-regulated in the cerebellar cortex of schizophrenia patients compared with controls, and Lyrm4 was down-regulated in the prefrontal cortex of mice with microdeletions in the locus syntenic to human 22q11.2 patients affected by schizophrenia. These data are in agreement with the emerging concept that similar CNVs are pathogenic in patients affected by distinct neurological diseases, and that these loci are more general risk factors for different disorders. The resemblance of our patients to those with the more extensive 6p25.1p25.3 terminal deletion suggests that the gene/s responsible for the physical phenotype should reside in the 6p25.1 genomic region.

Sudden Sensorineural Hearing Loss: MR Imaging

Hearing loss greater than 30 dB over three contiguous pure-tone frequencies occurring within a three day period is defined as sudden hearing loss. It is usually sensorineural (SSNHL), unilateral and appears as an otologic emergency. SSNHL has many possibile etiologies such as: labyrinthine viral infection, ischemic or hemorrhagic illness, trauma, immuno-mediated inner ear disease, tumor, inner ear malformation, and an imbalance between perilymphatic and endolymphatic fluid pressure. Nevertheless in almost 80% of cases SSNHL belongs to the idiopathic category because the etiology is unknown. The aim of this study was to test the diagnostic impact of two MR devices. Fifteen cases of SSNHL studied with a 1.5 T unit in our hospital between January 2006 and December 2008 within two weeks of the onset were retrospectively evaluated. Since January 2009 three more patients affected by SSNHL have been scanned with a 3T MR unit. We discuss the diagnostic sensitivity, clinical usefulness and the cost-benefit ratio of the MR systems.

Diffusion tensor MRI and MR spectroscopy in long lasting upper motor neuron involvement in amyotrophic lateral sclerosis

Upper motor neuron (UMN) dysfunction in Amyotrophic Lateral Sclerosis (ALS) is not easy to identify clinically: Diffusion Tensor Imaging (DTI) and single-voxel Magnetic Resonance Spectroscopy (H-MRS) can identify markers of UMN involvement. The aim of this study was to correlate brain DTI and MRS data with clinical parameters in ALS patients (PALS). We studied 32 PALS using Magnetic Resonance Imaging. The subjects were subdivided into definite/probable (D/P) and possible/suspected (P/S). DTI indices included Fractional Anisotropy (FA) and averaged Apparent Diffusion Coefficient (avADC). Anatomical areas were sampled by positioning regions of interest along corticospinal tracts, from the precentral cortex to the bulb. H-MRS voxels were localized bilaterally in precentral regions. D/P-PALS showed significantly lower FA values than healthy controls in almost all regions, whereas P/S-PALS FA values were significantly lower only in the left precentral gray matter (GM), right precentral white matter (WM), cerebral peduncles (CP), left hemipons, and left bulbar pyramid (BP). Significantly higher avADC values were observed in the D/P-PALS right precentral GM, precentral WM, right semioval center-posterior limb of the internal capsule (SC-PLIC), and left CP; and in the precentral WM, right SC-PLIC, left CP, and right hemipons of P/S-PALS. With increasing disability, only D/P-PALS showed significantly reduced FA values in the left precentral WM and hemipons, and increased avADC values in the precentral WM. Significantly lower N-acetylaspartate (NAA)/creatine-phosphocreatine complex (Cr) and higher choline (Cho)/Cr and myoinositol (mI)/Cr ratios were found in D/P-PALS, while only higher Cho/Cr and mI/Cr ratios were found in P/S-PALS. Our data highlight the usefulness of DTI and H-MRS in assessing UMN involvement. Given FA sensitivity and specificity, despite the small number of PALS, our findings support its use as a diagnostic marker in D/P-PALS.

Proton MR spectroscopy of mitochondrial diseases: analysis of brain metabolic abnormalities and their possible diagnostic relevance

BACKGROUND AND PURPOSE

Proton (hydrogen-1 [(1)H]) MR spectroscopy is a useful diagnostic tool in many metabolic diseases, but only scattered and inconclusive data are available on mitochondrial diseases. We performed MR imaging and (1)H MR spectroscopy of the brain in patients with different types of primary mitochondrial diseases to investigate the role of (1)H MR spectroscopy in the clinical evaluation of these disorders.

METHODS

In 15 patients (11 adults, four children) with mitochondrial diseases, localized MR spectra were obtained at short TEs in cerebellar white matter, paratrigonal white matter, and parieto-occipital cortex that appeared normal on MR images. Additional spectra of basal ganglia and cortical gray matter structural lesions were obtained in three patients.

RESULTS

A significant choline reduction and N-acetylaspartate reduction were found in areas that appeared normal on MR images. Lactate was never found in areas that appeared normal on MR images, except in two children in whom MR studies were performed during episodes of symptom exacerbation and revealed elevated lactate both in areas that appeared damaged on MR images and in normal-appearing areas. An additional abnormal signal at 0.9 ppm was found in a consistent number of studies.

CONCLUSION

(1)H MR spectroscopy proved to be a useful investigational tool for mitochondrial diseases, as it enabled detection of metabolic abnormalities even in areas of brain that appeared normal on MR images, especially when it was performed during episodes of clinical relapses or clinical exacerbation.

Unusual clinical and magnetic resonance imaging findings in a family with proteolipid protein gene mutation

BACKGROUND

Pelizaeus-Merzbacher disease (PMD) and a complicated form of familial spastic paraparesis (spastic paraplegia 2 [SPG2]) are X-linked development disorders of myelin formation caused by a mutation in the proteolipid protein (PLP) gene. Spastic paraplegia 2 is allelic to PMD. The wide range of PLP mutations results in a corresponding large spectrum of clinical severity in PMD, with a continuum of signs and symptoms to SPG2.

OBJECTIVE

To report the results of genetic, neurophysiologic, and neuroimaging investigations performed in a child affected by a mild ataxic and spastic form of PLP-related disorder and in his relatives.

RESULTS

A missense mutation in exon 6 of the PLP gene (Q233P) was found in the proband and in the female obligate carriers. In the proband, evoked potentials were altered and remained unchanged during the 7 years of follow-up. Magnetic resonance imaging of the child demonstrated patchy hyperintensities of the paraventricular white matter, with microcystic components. These latter findings, along with pallidal calcium deposition, were also present in 2 females heterozygous for PLP mutation.

CONCLUSION

The unusual genetic, magnetic resonance imaging, and clinical findings of this family confirm the wide variability of PLP-related disorders.

De novo complete trisomy 5p: clinical and neuroradiological findings

Partial or complete duplication of 5p is a rare chromosomal abnormality in which genotype-phenotype correlation studies are hampered by other commonly associated chromosomal abnormalities. We report on a new patient in whom a complete de novo trisomy 5p in all metaphases represented the only chromosomal aberration. The present case further contributes to delineate the typical clinical picture of the trisomy 5p syndrome. Long-term clinical follow-up demonstrated low levels of secretory immunoglobulin A (IgA) on several occasions and likely related to the patient's recurrent respiratory infections (RRIs), a main clinical feature of the trisomy 5p syndrome. An extensive neuroradiological study detected a progressive triventricular hydrocephalus during the fist year of life with subsequent stabilization. Neuronal migration disorders were also present and probably account for the drug-resistant epilepsy presented by the patient.

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.

Fetal intracranial hemorrhage: is minor maternal trauma a possible pathogenetic factor?

OBJECTIVE

The occurrence of fetal intracranial hemorrhage before labor has been repeatedly observed. The aim of this study was to evaluate the sonographic appearance of fetal intracranial hemorrhage in relation to its location. Possible causative factors were also evaluated.

DESIGN

Five consecutive cases of fetal intracranial hemorrhage were identified at a single ultrasound unit between 1996 and 1999. In utero magnetic resonance imaging was also performed in four of these cases. Autopsy was performed after pregnancy termination or intrauterine fetal death (one case of each), and neurological follow-up was initiated in the three surviving infants.

RESULTS

Hydrocephaly was the predominant sonographic finding associated with intraventricular or subependymal hemorrhage; sonography provided the correct diagnosis in the former (two cases), whereas magnetic resonance imaging was necessary in the latter. Massive intraparenchymal hemorrhage was depicted as an irregular echoic mass, whereas extradural hemorrhage had a cystic appearance. History of minor maternal physical trauma without maternal or placental injury was elicited in all cases. Ultrasound examinations performed before or shortly after the trauma were available in all cases and showed normal fetal anatomy.

CONCLUSIONS

The sonographic appearance of fetal intracranial hemorrhage is variable, depending on its location. Even though sonography detected an intracranial anomaly in all cases, magnetic resonance imaging was necessary to establish the hemorrhagic nature of isolated subependymal and extradural hemorrhage. The similarity of histories involving minor maternal physical trauma in all cases, together with the absence of any known factor predisposing to fetal hemorrhage, may suggest that trauma is at least a contributing factor to the pathogenesis of fetal intracranial hemorrhage.

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 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.

Reversible brain creatine deficiency in two sisters with normal blood creatine level

We describe a new creatine metabolism disorder in 2 young sisters who suffered from mental retardation and severe language delay. Blood examination, investigation of the most common neurometabolic disorders, and brain magnetic resonance imaging were normal. Diagnosis was established only by means of in vivo proton magnetic resonance spectroscopy, which disclosed generalized depletion of creatine in the brain. Creatine monohydrate oral administration led to almost complete brain creatine level restoration along with improvement of the patients' disabilities.

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.

MRI and clinical characteristics of children with hemiplegic cerebral palsy

Magnetic resonance imagings of 91 children with hemiplegic cerebral palsy were analysed with the aim of clustering their features into fairly homogeneous forms. In addition, the different clinical patterns of each form were described. Four main types of lesion were distinguished: form 1 (13 cases), which comprised brain malformations, form 2 (41 subjects), which grouped abnormalities of the periventricular white matter, form 3 (27 children), which was represented by cortical-subcortical lesions, and form 4 (10 subjects), which grouped non-progressive postnatal brain injuries. None of the children had normal MRI and a high incidence of bilateral lesions was found, especially in form 2. A left motor involvement was prevalent in the sample and was noted in all but the third form. The severity of impairment was mainly moderate in forms 1 and 3, mild in the others. The upper limb was found to be more affected in all forms except the second one, which presented a greater involvement of the lower limb. Mental retardation occurred in about one-third of the children with forms 1 and 4, less often in the other two. Seizures occurred in about half of the children with forms 1 or 3, while the incidence was lower in forms 4 and 2. A strong correlation between the presence of seizures and mental retardation was observed. The results of this study show the importance of MRI in the evaluation of children with hemiplegic cerebral palsy.

Late whiplash syndrome: a clinical and magnetic resonance imaging study

Cervical hyperextension injuries are common and are associated with significant morbidity. Clinically two syndromes are described: "acute" whiplash syndrome and "late" whiplash syndrome (in which the patients are still symptomatic after six months despite normal physical and radiological examination). In order to clarify the pathology of the persistent pain in late whiplash syndrome we performed a cervical spine magnetic resonance imaging (MRI) in 33 consecutive patients suffering from this condition. Twenty-six patients (78.8%) showed MRI abnormalities, the most common MRI finding (57.6%) was pre-existent spondylosis. Indeed, the group of patients with spondylosis and other MRI changes had higher clinical scores than those without MRI abnormalities as measured by a three-point grading system based upon the symptoms and signs shown. Several MRI changes, most of them already demonstrable by standard X-ray were seen among 33 patients suffering from late whiplash syndrome. Although no one of these findings appears to be specific and certainly related to the previous neck injury, they could represent a risk factor for a longer pain duration.

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

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.

Epilepsy and malformations of the cerebral cortex

Abnormal cortical development is increasingly recognized as a cause of human epilepsy. Development of the cerebral cortex involves three distinct but overlapping processes consisting of neuronal and later glial proliferation, neuronal migration and cortical organization. Cortical malformations can originate from abnormalities of any or all of these processes. Certain malformations are known to be genetically determined, while for others a genetic origin has been hypothesized. In addition, there are some that may be linked to prenatal insult. Some malformations are notably more epileptogenic than others. In specific forms, epileptogenesis appears to originate from intrinsic properties of the dysplastic tissue, and is stereotyped in expression. Cortical malformations are also known that are affected by age-related influence and may be accompanied by different epileptic syndromes, sometimes with good long-term outcome. In patients with intractable seizures which are symptomatic of a cortical malformations it is necessary to diagnose the type of malformation and the associated epileptic syndromes and to assess the characteristics of epileptogenesis. Planning of surgical treatment of the associated epilepsy must rely on careful evaluation of all these informations.

Prenatal diagnosis of periventricular hemorrhage by fetal brain magnetic resonance imaging

Following the incidental diagnosis of triventricular hydrocephalus in a fetus 34 weeks after the mother's last menstrual period, during an uneventful pregnancy, 1.5-T brain magnetic resonance (MR) was carried out. A subependymal hemorrhage, which had not been revealed by transabdominal ultrasound, was found; this finding was confirmed by neonatal brain ultrasound and MR. Fetal MR allowed identification of the hemorrhage as the cause of the hydrocephalus and also established its time of occurrence. Unexplained hydrocephalus should be included among the indications for fetal MR.

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

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).

METHODS

Assessment of mental function using Wechsler Intelligence Scale for Children-III (WISC) and Raven's Progressive Matrices (PM), EEG recordings while awake and asleep, and brain magnetic resonance imaging (MRI), were performed at the beginning of VPA therapy, after 2 years and 8 months of treatment and following VPA discontinuation.

RESULTS

After 2 years and 6 months on VPA (< or = 26 mg/kg/day) the girl insidiously developed mental deterioration (loss of 18 IQ points and drop in age-adjusted PM score from the 95th to the 50th percentile) associated with MRI-documented pseudoatrophy of the brain. Onset of severe cognitive impairment coincided with serum VPA concentrations near 100 microg/ml. There were no other manifestations of drug toxicity or hyperammonemia. Background EEG activity was normal. Reduction of VPA dosage and subsequent discontinuation 4 months later resulted in disappearance of clinical symptoms with a 20-point improvement at IQ testing and recovery of previous PM score. Repeat MRI showed disappearance of pseudoatrophic changes.

CONCLUSIONS

The striking cognitive improvement and reversal of pseudoatrophic brain changes following VPA discontinuation strongly suggest a drug-induced condition. Based on this and previous reports, the syndrome of VPA-associated mental deterioration and pseudoatrophy of the brain appears to encompass different but possibly related clinical entities, which include parkinsonism with cognitive deterioration, mental deterioration with signs of VPA-toxicity, and isolated mental deterioration, as seen in our patient. A drug-induced effect should be considered whenever cognitive deterioration and imaging findings of brain atrophy occur in VPA-treated patients.

Intravenous immunoglobulin versus corticosteroid in treatment of Graves' ophthalmopathy

We compared the effectiveness of systemic corticosteroids with the use of high-dose intravenous immunoglobulin (IVIG) in the treatment of Graves' ophthalmopathy. This was performed as a prospective, nonrandomized study including a blinded ophthalmological and orbital computed tomographic (CT) evaluation. The two groups of patients were not significantly different in relation to sex composition, age distribution, duration of Graves' disease, and ophthalmopathy and previous hyperthyroidism. All patients were followed up by endocrinologic evaluation and blinded ophthalmological (before therapy = B, at the end of therapy = E, and 6 months after the end = 6M) and orbital CT (B and E) evaluations. Twenty-seven patients treated with IVIG were followed up after the end of treatment for an average of 21 months (range 12 to 48 months). Soft tissue involvement (NOSPECS) improved or disappeared in 32 of 35 (90%) patients treated with IVIG and in 25 of 27 (92.5%) patients treated with corticosteroids. Diplopia improved or disappeared in 22 of 29 (75%) patients treated with IVIG and in 16 of 20 (80%) patients treated with corticosteroids. The results observed by clinical evaluation were confirmed with orbital CT score in 30 IVIG patients and in the corticosteroid-treated patients; a significant reduction of extraocular muscle thickness was observed after treatment in both groups. Proptosis improved or disappeared in 20 of 31 (65%) patients treated with IVIG and in 15 of 24 (62%) patients treated with corticosteroids. Mean values of proptosis evaluated by Hertel's exophthalmometer showed a slight reduction both in IVIG as well as in corticosteroid-treated patients. It is interesting to observe that in 28 IVIG-treated patients in whom it was possible to evaluate soft tissue involvement, proptosis and diplopia in the period between the fifth and sixth month from the start of therapy, the most important part of the amelioration (if responders) was already obtained at that time. Responder patients were defined in relation to the decrease in the highest NOSPECS class or grade. Among IVIG-treated patients 26 of 34 (76%) responded; while in the corticosteroid group 18 of 27 (66%) responded to treatment. The prevalences of patients who responded to the treatments were not significantly different in the two groups (Chi-square). The initial values of the subjective eye score were similar in the two groups, and a significant reduction was observed in both. Major side effects requiring discontinuation of the corticosteroid therapy were observed in two patients with hemorrhagic gastritis and in one patient with manic-depressive psychosis. Among 15 patients submitted to the evaluation of bone mineral content before and after corti-costeroid therapy, 4 presented signs of osteoporosis and 3 a reduction of bone mineral content. Moderate and minor side effects were more frequently noted in steroid-treated patients than in the IVIG group. These data suggest that IVIG is safe and effective in reducing the eye changes in patients with Graves' ophthalmopathy.

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.

MRI and MR angiography of vertebral artery dissection

A review of 4,500 angiograms yielded 11 patients with dissection of the vertebral arteries who had MRI and (in 4 patients) MR angiography (MRA) in the acute phase of stroke. One patient with incidental discovery at arteriography of asymptomatic vertebral artery dissection and two patients with acute strokes with MRI and MRA findings consistent with vertebral artery dissection were included. Dissection occurred after neck trauma or chiropractic manipulation in 4 patients and was spontaneous in 10. Dissection involved the extracranial vertebral artery in 9 patients, the extra-intracranial junction in 1, and the intracranial artery in 4. MRI demonstrated infarcts in the brain stem, cerebellum, thalamus or temporo-occipital regions in 7 patients with extra- or extra-intracranial dissections and a solitary lateral medullary infarct in 4 patients (3 with intracranial and 1 with extra-intracranial dissection). In 2 patients no brain abnormality related to vertebral artery dissection was found and in one MRI did not show subarachnoid haemorrhage revealed by CT. Intramural dissecting haematoma appeared as crescentic or rounded high signal on T1-weighted images in 10 patients examined 3-20 days after the onset of symptoms. The abnormal vessel stood out in the low signal cerebrospinal fluid in intracranial dissections, whereas it was more difficult to detect in extracranial dissections because of the intermediate-to-high signal of the normal perivascular structures and slow flow proximal and distal to the dissection. In two patients examined within 36 h of the onset, mural thickening was of intermediate signal intensity on T1-weighted images and high signal on spin-density and T2-weighted images. MRA showed abrupt stenosis in 2 patients and disappearance of flow signal at and distal to the dissection in 5. Follow-up arteriography, MRI or MRA showed findings consistent with occlusion of the dissected vessel in 6 of 8 patients.

Bilateral parasagittal parietooccipital polymicrogyria and epilepsy

We describe 9 patients with a bilateral malformation of cortical development, centered around the parasagittal and mesial aspects of the parietooccipital cortex, with magnetic resonance imaging findings suggestive of polymicrogyria. No familial distribution or etiologic factors were identified. Location in a watershed area between anterior and posterior cerebral arteries suggests postmigratory perfusion failure as the underlying cause. In most patients the malformation was detected by magnetic resonance imaging after computed tomography scans with 10-mm-thick sections were considered normal. Seizures, present in all, had started between the ages of 20 months and 15 years (mean, 9 years) and were intractable in 7. Complex partial seizures with or without minor automatisms were the most frequent ictal pattern. In only 4 patients these were preceded by symptoms indicating posterior onset. Interictal electroencephalograms showed both diffuse and bilateral parietooccipital or temporal abnormalities. The range of IQ scores indicated average intelligence to mild retardation. Several patients presented deficits on neuropsychological tasks requiring performance under time constraints, suggesting that the malformation may result in cognitive slowing. Early diagnosis of this malformation may be difficult because of the lack of neurological signs, relatively late seizure onset, difficulty in localizing seizure onset, and inability to recognize the cortical abnormality on computed tomography scans.

Correlation between cerebral visual impairment and magnetic resonance imaging in children with neonatal encephalopathy

To identify brain lesions most often associated with cerebral visual i mpairment (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 lesions 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.

[111In-DTPA-D-Phe]-octreotide scintigraphy in functioning and non-functioning pituitary adenomas

Scintigraphy with [111In-DTPA-D-Phe]-octreotide is a recently developed technique for imaging somatostatin receptors in many neuroendocrine tumors. A good correlation between high [111In-DTPA-D-Phe]-octreotide uptake and the response to octreotide therapy has been proved in TSH- and GH-secreting pituitary adenomas, while few and conflicting scintigraphic data on somatostatin receptors in non-functioning tumors have been reported in the literature. The present study presents the results obtained with [111In-DTPA-D-Phe]-octreotide scintigraphy in thirteen patients with GH-secreting pituitary adenoma, four patients with inappropriate TSH-secretion and twelve patients with non-functioning pituitary adenoma. Twelve out of the 13 patients with GH-secreting pituitary adenomas had a positive scan; moreover, in 5/6 patients with a GH-secreting microadenoma (tumor size range 5-8 mm) a positive scan was found. Two TSH-secreting macroadenomas had a positive scan while a negative scan was obtained for a TSH-secreting pituitary microadenoma and in a patient with non-neoplastic, inappropriate secretion of TSH. Finally, only 2/12 patients with non-functioning pituitary adenoma showed a positive scan. In conclusion, [111In-DTPA-D-Phe]-octreotide scintigraphy is a useful tool to confirm the presence of somatostatin receptors in selected patients with GH- and TSH-secreting pituitary adenoma. The role of [111In-DTPA-D-Phe]-octreotide scintigraphy in non-functioning pituitary tumors remains to be established, but it could be useful for octreotide treatment in patients who refuse surgery or who are poor surgical candidates.

White matter hyperintensities in Parkinson's disease. Clinical correlations

OBJECTIVES

To verify recent preliminary data indicating that white matter hyperintensities on magnetic resonance imaging are more abundant in patients with Parkinson's disease (PD) than in healthy subjects and to examine possible correlation between these abnormalities and clinical features of PD.

DESIGN

Magnetic resonance imaging data on patients with PD and normal subjects were compared as to frequency, extent, and topographic location of white matter hyperintensities; moreover, in the PD group, we studied the possible correlation of white matter hyperintensities with clinical features such as severity, disease duration, and therapy.

SETTING

The outpatient clinic of the Institute of Clinical Neurology and the Neuroradiology Unit of the University of Pisa (Italy).

PATIENTS

We studied 102 nondemented patients with idiopathic PD and 68 sex- and age-matched healthy controls, all screened for absence of cerebrovascular risk factors.

OUTCOME MEASURES

White matter hyperintensities were classified as periventricular hyperintensities and deep hyperintensities. Frequency, extent, and topographic location of both periventricular and deep hyperintensities were evaluated. The clinical parameters examined were disease duration, treatment type, and disease severity (using Hoehn and Yahr staging and the Unified Parkinson's Disease Rating Scale), as well as disease progression index (ratio between Hoehn and Yahr stage and disease duration).

RESULTS

The frequency and the extent of periventricular hyperintensities were significantly higher in patients with PD than in healthy subjects. Moreover, within the PD group, the patients who had periventricular hyperintensities had significantly shorter disease duration and greater disease severity, ie, a higher disease progression index, than those who did not.

CONCLUSION

These data suggest that periventricular hyperintensities may represent a marker for a clinical subtype of PD characterized by a more rapid neurodegenerative process.

Radiological findings in a case of Menkes' disease

Menkes' disease, a neurodegenerative progressive X-linked disorder, was diagnosed in a 4-month-old child. The diagnosis was made on the combination of clinical features with laboratory and radiological findings. The pathogenesis of the skeletal findings in Menkes' disease is as yet unclear. Because of the severity of the prognosis and in order to plan treatment, the correct diagnosis has to be reached quickly. Typical manifestations of the syndrome are likely to develop after 3 months of age, with a pleiotropic appearance. In the present case, on the basis of the clinical investigation the patient underwent retrograde cystourethrography, roentgenographic examination of the skeleton, and magnetic resonance imaging of the brain. On analysis of the magnetic resonance imaging, we detected one-sided involvement of both subcortical and cortical parenchyma resembling a unilateral ischemic lesion such as, to our knowledge, has not yet been reported.

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.

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%.

Neuroimaging and functional outcome of neonatal leukomalacia

Leukomalacia is a major cause of neurological impairment in the high-risk newborn. It can be identified during the early postnatal period by means of ultrasound (US) imaging of the brain, through the anterior fontanel. Magnetic resonance imaging (MRI) permits an optimal differentiation of brain tissue and of its abnormalities, without resorting to ionizing radiation or intravenous contrast. It is particularly appropriate for following the evolution of leukomalacia, after fontanel closure. Ninety-five fullterm and preterm infants with cystic and non-cystic leukomalacia, documented by US, were clinically followed-up until at least 12 months of corrected age. Thirty-two had a severe neurological outcome (mainly cerebral palsy, sometimes associated with mental retardation and/or cerebral visual impairment). The prognosis was worse in cystic leukomalacia than in prolonged flare. Electroencephalogram (EEG) carried out in the first 2 weeks of life provided valuable indexes of further outcome, especially for US findings of more uncertain prognosis. MRI was carried out at around 12 months of corrected age, by means of an apparatus operating at 0.5 Tesla. The main categories of abnormalities observed were the following: cystic lesions, enlarged ventricles with irregular outlines, delayed myelination, high intensity areas in the long TR (repetition time) images within the white matter, cortical atrophy. MRI findings correlated well with the results of US imaging and often with motor, cognitive and visual impairments. Nevertheless, clinical features cannot be predicted by neuroimaging alone and a comprehensive approach, including longitudinal functional and electrophysiological testing, is highly recommended.

High-dose intravenous immunoglobulin treatment in Graves' ophthalmopathy

We have evaluated the efficacy of high-dose intravenous immunoglobulin treatment in Graves' ophthalmopathy, and have carried out a prospective randomized clinical trial, including a single-blind evaluation, whereby 14 patients were assigned to two different treatment groups: 7 patients were treated with intravenous immunoglobulin and orbital radiotherapy (Group 1) and 7 patients were given intravenous immunoglobulin alone (Group 2). The results of the intravenous immunoglobulin treatment were also compared with those obtained in a Historical Control Group (12 patients) treated with systemic methylprednisolone and orbital irradiation. Degree of ocular involvement and response to treatment were assessed by ophthalmopathy index. The mean initial and final ophthalmopathy index showed no significant difference among the three groups. Comparison between the mean initial and final ophthalmopathy index showed a statistically significant reduction (p less than 0.005) in all three groups, the observed changes being confirmed by orbital computerized tomography in Groups 1 and 2. Corticosteroid treatment was associated with major and minor side effects, while no important adverse reactions were observed during intravenous immunoglobulin treatment. Even considering our results as preliminary, we conclude that intravenous immunoglobulin treatment is effective and safe in improving Graves' ophthalmopathy.

[Somatosensory evoked potentials after stimulation of the posterior tibial nerve in multiple sclerosis: comparative analysis with other modalities of evoked response and magnetic resonance]

Electrophysiological tests have proved to be a valuable method in assessing multiple sclerosis (MS) patients. In the last few years, scalp recorded short latency somatosensory evoked potentials to stimulation of nerves in the "lower extremity" have been more and more extensively employed. Some studies have aimed at comparing the sensitivity of MR imaging and multimodality evoked potentials, with somewhat conflicting results. In the present study posterior tibial nerve somatosensory evoked potentials (ptnSEPs) were performed in 29 MS patients with the aim to investigate the ability in revealing spinal cord conduction abnormalities and the sensitivity towards other evoked potentials and MR in MS. ptnSEPs showed a high percentage of abnormalities which did not significantly differ from that of visual evoked potentials; moreover in conjunction with median nerve SEPs can be used to localize thoracic or lumbar cord demielinating lesions, not evidenced on MR imaging. These results confirm that ptnSEPs, although non specific and crude in terms of precise localization, are a sensitive tool in detecting lesions, even subclinical, in MS patients. Moreover in anatomic regions like spinal cord where MR imaging is not very sensitive because the lower signal-to-noise ratio, they represent the only method available for demonstrating lesions.

Spontaneous recanalization of carotid artery occlusion following non traumatic dissection

We studied 7 patients with internal carotid occlusion following spontaneous arterial dissection. All presented strokes, in one associated with Horner's syndrome. The doppler examination showed carotid occlusion, but only angiography established the diagnosis of vascular disease. Spontaneous recanalization was observed in 6 cases, treated only by antiplatelet drugs.