Dyskinesia Impairment Scale scores in Dutch pre-school children after neonatal therapeutic hypothermia

BACKGROUND

Neonatal therapeutic hypothermia (TH) can ameliorate or prevent the development of dyskinetic cerebral palsy (CP) after hypoxic-ischemic encephalopathy (HIE). The Dyskinesia Impairment Scale (DIS) was recently launched to quantify dyskinetic (dystonic and choreatic) motor features in patients with CP. In TH treated children, who are at risk of developing dyskinetic CP, we aimed to determine DIS-scores at pre-school age.

METHOD

In 21 Dutch pre-school children (3-6 years of age) who had received TH according to the Dutch-Flemish treatment protocol, we determined DIS-scores. We associated DIS-scores with 1. age-matched control values (Kuiper et al., 2018) [1], and 2. previously reported DIS-score range in dyskinetic CP (Monbaliu E et al., 2015).

RESULTS

The motor phenotype was determined as: normal (n = 18/21), mildly impaired (reduced coordination (n = 2/21)) and abnormal (dyskinetic CP; n = 1/21). In absence of CP (n = 20/21), DIS-scores were lower (more favorable) than in dyskinetic CP, without any overlapping group scores (mean difference: 71 points; p < .05). However, the obtained DIS-scores were still higher than previously reported in healthy age-matched controls (mean difference: 14 points; p < .05). There was an association between DIS-scores and retrospective neonatal MRI (basal ganglia and thalamus injury on diffusion weighted imaging (DWI)) and (a)EEG parameters (p < .05).

CONCLUSION

In the vast majority (95%) of Dutch TH-HIE treated pre-school children, the phenotypic motor outcome was favorable. However, DIS-scores were moderately increased compared with healthy age-matched controls. Future studies may elucidate the significance of moderately increased DIS-scores should to further extent.

The splenium of the corpus callosum: embryology, anatomy, function and imaging with pathophysiological hypothesis

BACKGROUND AND PURPOSE

The splenium of the corpus callosum is the most posterior part of the corpus callosum. Its embryological development, anatomy, vascularization, function, imaging of pathology, possible pathophysiological mechanisms by which pathology may develop and the clinical consequences are discussed.

METHODS

A literature-based description is provided on development, anatomy and function. MR and CT images are used to demonstrate pathology. The majority of pathology, known to affect the splenium, and the clinical effects are described in three subsections: (A) limited to the splenium, with elaboration on pathophysiology of reversible splenial lesions, (B) pathology in the cerebral white matter extending into or deriving from the splenium, with special emphasis on tumors, and (C) splenial involvement in generalized conditions affecting the entire brain, with a hypothesis for pathophysiological mechanisms for the different diseases.

RESULTS

The development of the splenium is preceded by the formation of the hippocampal commissure. It is bordered by the falx and the tentorium and is perfused by the anterior and posterior circulation. It contains different caliber axonal fibers and the most compact area of callosal glial cells. These findings may explain the affinity of specific forms of pathology for this region. The fibers interconnect the temporal and occipital regions of both hemispheres reciprocally and are important in language, visuospatial information transfer and behavior. Acquired pathology may lead to changes in consciousness.

CONCLUSION

The development, location, fiber composition and vascularization of the splenium make it vulnerable to specific pathological processes. It appears to play an important role in consciousness.

Imaging of Clival Hypoplasia in CHARGE Syndrome and Hypothesis for Development: A Case-Control Study

BACKGROUND AND PURPOSE

We present the largest case series to date on basiocciput abnormalities in CHARGE syndrome (Coloboma of the eye, Heart defects, Atresia of the choanae, Retardation of growth and/or development, Genital and/or urinary abnormalities, and Ear abnormalities and/or deafness). We aimed to show that basiocciput abnormalities are common and may aid in diagnosis. We furthermore explored whether clivus size correlates with the type of chromodomain-helicase-DNA binding protein 7 gene (CHD7) mutation, which causes CHARGE syndrome, and with clinical criteria according to Blake et al and Verloes.

MATERIALS AND METHODS

We retrospectively analyzed the clivus of 23 patients with CHARGE syndrome with CHD7 mutations on MR imaging or CT. We recorded the size of the clivus, the Welcher angle, basilar invagination, and Chiari I malformations. We compared the clival size and Welcher angle of patients with CHARGE syndrome with those of 72 age-matched controls. Additionally, we tested for correlations between clivus size and mutation type or clinical criteria.

RESULTS

Eighty-seven percent of the patients with CHARGE syndrome had an abnormal clivus; 61% had a clivus >2.5 SD smaller than that of age-matched controls. An abnormally large Welcher angle was observed in 35%. Basiocciput hypoplasia was found in 70%, and basilar invagination, in 29%. None of the patients had a Chiari I malformation. At the group level, patients with CHARGE syndrome had a smaller clivus and larger Welcher angle than controls. No significant correlation between clivus size and mutation type or clinical criteria was found.

CONCLUSIONS

Most patients with CHARGE syndrome have an abnormal clivus. This suggests that clivus abnormalities may be used as an additional diagnostic tool. Our results provide evidence that CHD7, which is expressed in the presomitic mesoderm during somitogenesis, plays an important role in the formation of the clivus.

Amplitude-Integrated EEG and Cerebral Near-Infrared Spectroscopy in Cooled, Asphyxiated Infants

OBJECTIVE

To assess the predictive value of amplitude-integrated electroencephalography EEG (aEEG) and near-infrared spectroscopy (NIRS) during therapeutic hypothermia.

PATIENTS AND METHODS

We studied 39 cooled, asphyxiated infants. We assessed aEEG and calculated mean regional cerebral oxygen saturation (rcSO₂) during and after treatment. At 30 months, we performed a neurological examination and administered the Bayley Scales of Infant and Toddler Development, 3rd edition. We calculated the odds ratios (ORs) of abnormal aEEG and rcSO₂ for severely abnormal outcome.

RESULTS

At 6 and 12 hours, severely abnormal aEEGs predicted severely abnormal outcomes (OR, 7.7 [95% confidence interval, CI, 1.39-42.6] and 24.4 [95% CI 4.2-143] respectively), as did epileptic activity (OR 28.9, 4.6-183). During the first 48 hours, rcSO₂ was not associated with outcome, but at 72 hours after birth and after rewarming it was, with ORs for severely abnormal outcomes of 12.8 (1.31-124) and 21.6 (1.05-189), respectively. In multivariate analyses, aEEG and rcSO₂ remained independently predictive in the model at 48 hours and significantly from 72 hours after birth onward.

CONCLUSION

aEEG was a strong predictor of adverse outcome. After 48 hours of cooling, a higher rcSO₂ was associated with a severely abnormal outcome, adding to the predictive value of aEEG in cooled, asphyxiated infants.

[Acute flaccid myelitis after a respiratory tract infection; first Dutch case related to enterovirus type D68 infection]

BACKGROUND

Acute flaccid myelitis (AFM) is a relatively rare disorder affecting the anterior horn of the spinal cord and brain stem. It is characterised by rapid progressive weakness of the limbs and respiratory muscles, often combined with cranial nerve dysfunction. This used to be seen in infections with the polio virus, but in recent years, AFM has been mainly associated with enterovirus D68 infection.

CASE DESCRIPTION

A boy of nearly 4 years-old developed rapidly progressive weakness and respiratory failure after an upper airway infection. Initially, Guillain-Barré syndrome was suspected, but after further investigations enterovirus D68 was detected in the nasopharyngeal aspirate and the diagnosis of AFM was made.

CONCLUSION

Progressive weakness after a respiratory tract infection should raise the suspicion of enterovirus-associated AFM. This syndrome can be distinguished from Guillain-Barré syndrome by its more rapid progression, asymmetrical weakness and greater involvement of the upper limbs. The diagnosis can be confirmed by typical findings on MRI and electromyography of the spinal cord and brain stem, combined with the detection of enterovirus D68 in nasopharyngeal specimens.

Sulphonylurea therapy improves cognition in a patient with the V59M KCNJ11 mutation

BACKGROUND

KCNJ11 mutations are a common cause of diabetes diagnosed in the first 6 months of life, and approximately 25% of patients have neurological features. Sulphonylureas have been shown to improve glycaemic control and also motor function, but the impact on cognitive function has not been extensively addressed previously.

METHODS

The patient had a low birth weight and was found to have diabetes at the age of 2 days. The patient was treated with insulin from diagnosis. The child also had marked developmental delay so that his average functional age was 2.5 years when he was 12 years old. A V59M mutation in KCNJ11 was found on sequencing, resulting in a diagnosis of intermediate developmental delay, epilepsy, neonatal diabetes (DEND) syndrome. Identification of a Kir6.2 mutation allowed insulin injections to be replaced by glibenclamide tablets.

RESULTS

This resulted not only in improved glycaemic control (HbA(1c) fell from 8.1 to 6.5%), but also an impressive improvement in many aspects of cognitive function, with the functional age increasing to 4 years within 6 months of treatment change.

CONCLUSIONS

This is the first clear report of cognitive function improving in a patient with the neurological features associated with a K(ATP) channel mutation following transfer to sulphonylureas. The finding of cognitive improvement suggests that glibenclamide is likely to be acting directly on the brain and not just on nerve and muscle, improving muscle strength.

Diffusion tensor imaging and chemical shift imaging assessment of heterogeneity in low grade glioma under temozolomide chemotherapy

Diffusion tensor imaging and multiple voxel magnetic resonance spectroscopy were performed in the MRI follow-up of a patient with a glioma treated with temozolomide chemotherapy. Tumor shrinkage was paralleled by reductions in choline level and by increases in apparent diffusion coefficient indicating decreased cellularity. Within the tumor, choline level and apparent diffusion coefficient showed a significant inverse correlation (P < 0.01). Fractional anisotropy distribution in the tumor correlated positively with N-acetyl aspartate level (P < 0.001), indicating that these parameters reflect (remaining) axonal structure. Tumor lactate level, also found to decrease under therapy, did not correlate with any other parameter.

MR spectroscopy and diffusion tensor imaging of the brain in congenital muscular dystrophy with merosin deficiency: metabolite level decreases, fractional anisotropy decreases, and apparent diffusion coefficient increases in the white matter

Brain magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in one patient with merosin-deficient congenital muscular dystrophy (MDCMD) revealed significant metabolite (choline, creatine, N-acetyl aspartate) level reductions, fractional anisotropy (FA) reduction and increased apparent diffusion coefficient (ADC) in the white matter (p<0.01, all). In the gray matter, the MRS properties did not differ significantly from those in controls. The ADC and FA, however, differed significantly as in the white matter, although the differences were less pronounced. This is the first quantitative MR study of the brain in a patient with MDCMD, which revealed that the concentrations of all MRS measured metabolites were decreased only in the white matter. This observation, combined with the DTI observed ADC increases and FA decrease, indicated a presence of vasogenic edema in the white matter.

Diffusion tensor imaging and magnetic resonance spectroscopy of the brain in a patient with Sturge-Weber syndrome

Quantitative brain MR spectroscopy (MRS) and diffusion tensor imaging (DTI) were used to characterize one patient with Sturge-Weber syndrome. Choline increases and N-acetylaspartate decreases were observed in pathologic frontal gray matter tissue compared to contralateral unaffected brain tissue without any change in the diffusion tensor imaging parameters (fractional anisotropy, apparent diffusion coefficient). The N-acetylaspartate decreases and/or choline increases observed here and in eight previously described Sturge-Weber patients probably reflect neuronal loss or dysfunction and demyelination as a result of recurrent seizures.

Cerebral 1H MR spectroscopy revealing white matter NAA decreases in glutaric aciduria type I

MR spectroscopy in two patients with glutaric aciduria type I revealed reductions in the white matter N-acetylaspartate signal, in the more severe case accompanied by a loss of glutamate and the appearance of lactate signals.

Time-of-flight magnetic resonance angiography in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils

The purpose of this study was to evaluate time-of-flight magnetic resonance angiography (MRA) in the follow-up of intracranial aneurysms treated with Guglielmi detachable coils (GDCs). From January 1998 to January 2002 27 MRA and intra-arterial digital subtraction angiography (IADSA) examinations were analyzed for residual aneurysms and arterial patency following GDC placement. A total number of 33 intracranial aneurysms was analyzed, including 18 located in the posterior circulation. The MRA analysis was based on source images in combination with maximum intensity projections. The IADSA was used as the reference standard. Two aneurysms were excluded from evaluation, because of susceptibility artefacts from other aneurysms, which were clipped. Sensitivity and positive predictive values of MRA in revealing residual aneurysms were, respectively, 89% and 80%. Specificity in ruling out remnant necks and residual flow around coils was, respectively, 91% and 97%, with a negative predictive value of, respectively, 95% and 100%. Specificity and negative predictive value of MRA for arterial occlusion were, respectively, 87% and 100% for the parent arteries and, respectively, 85% and 100% for the adjacent arteries. MRA is a reliable diagnostic tool in the follow-up of GDC treatment, and it may replace IADSA in excluding residual flow around coils and aneurysmal necks and in ruling out arterial occlusion.

1H chemical shift imaging of the brain in guanidino methyltransferase deficiency, a creatine deficiency syndrome; guanidinoacetate accumulation in the gray matter

MR spectroscopy results in a mild case of guanidinoacetate methyltransferase (GAMT) deficiency are presented. The approach differs from previous MRS studies in the acquisition of a chemical shift imaging spectral map showing gray and white matter with the corresponding spectra in one overview. MR spectroscopy revealed guanidinoacetate (GAA) in the absence of creatine. New is that GAA signals are more prominent in gray matter than in white. In the prevailing view, that enzyme deficiency is localized in liver and pancreas and that all GAA is transported into the brain from the blood and the cerebrospinal fluid, this would be compatible with a more limited uptake and/or better clearance of GAA from the white matter compared to the grey matter.

Cerebral activation related to skills practice in a double serial reaction time task: striatal involvement in random-order sequence learning

We used functional Magnetic Resonance Imaging (fMRI) to examine the distribution of cerebral activation related to prolonged skill practice. In a bimanual variant of the Serial Reaction Time Task (SRT), simultaneous finger movements of the two hands were made in response to randomly ordered pairs of visual stimuli (Double SRT, DoSRT). Extended practice by a week of daily performance resulted in gradual decrease of reaction times, associated with an increased involvement of the ventral putamen and globus pallidus, reaching statistical significance only on the left side (Statistical Parametric Mapping, SPM99). This increase was complementary to a decrease of cortical activations. The striatal activation after training on random order stimuli indicates that the striatum is not exclusively involved in sequence learning. This extended function implies a role in the acquisition of basic visuomotor skills that includes the specific selection of the appropriate muscles in response to independent stimuli.

Evidence of enhancement of spatial attention during inhibition of a visuo-motor response

A visuo-motor task was used as the setting for a study into inhibition in six healthy volunteers using fMRI. The task involved responding to colored stimuli, which appeared at random positions in the left and right visual field, with the corresponding hand. The volunteers were asked to respond to green colored stimuli ("go" response) and to inhibit responses to red stimuli ("no-go" response). The task was presented in a block design with blocks of three types; only "go" trials, a pseudo-random mixture of "go" and "no-go" tasks ("go/no-go" block), and "visual control." ANCOVA analysis of the fMRI data was performed within the framework of SPM99. Increased activation in the go vs visual control comparison was found in the bilateral motor and medial premotor cortices associated with the action of the button press response, as well as parietal regions attending to the task of identifying the visual field. The go/no-go vs visual control comparison showed a similar pattern, plus additional prefrontal areas that have previously been shown to be associated with inhibition. The direct comparison of the go and go/no-go blocks highlighted large differences not only in the prefrontal cortices, associated with inhibition, but also particularly in the right parietal cortex. We interpret the increased parietal activation, during inhibition, as representing a heightened spatial attention required for the correct execution of the inhibition task.

Curved reconstructions versus three-dimensional surface rendering in the demonstration of cortical lesions in patients with extratemporal epilepsy

RATIONALE AND OBJECTIVES

To compare the visibility and localization of extratemporal cortical lesions in extratemporal epilepsy by using curved reconstruction (CR) and three-dimensional surface rendering (3D SR) of 3D-acquired MR images and to study the degree of confidence with which localizations are made, particularly at the gyral level.

METHODS

Twenty patients with extratemporal epilepsy, based on seizure symptomatology and/or scalp electroencephalographic registrations, with an extratemporal structural lesion on conventional MR imaging, were selected for this study by a neuroradiologist with extensive experience in the assessment of epilepsy patients. Transverse T2 spin-echo, coronal fluid-attenuated inversion recovery, and transverse 3D-acquired/two-dimensionally reconstructed T1 MR images were used for the selection. A second neuroradiologist (observer 1) and a radiology resident (observer 2) assessed CR and 3D SR in random order. Both observers were masked to all patient data. The subjective visibility of lesions and gyral location were scored. The interobserver agreements for lesion visibility and localization and for degree of confidence were compared for CR and 3D SR.

RESULTS

For both observers, the lesion was visible in 55% of 3D SRs and 95% of CRs. The proportion with "very clearly visible" lesions on 3D SR was 19% (4/20) according to observer 1 and 30% (6/20) according to observer 2. For CR, this proportion was substantially higher: 55% for both observers. This difference was significant for observer 1 but not for observer 2. The interobserver agreement was high for both methods. Agreement on gyral localization was 28% for CR and 40% for 3D SR. The percentage of similar confidence scores for the same gyral localization and for gyral localization with a maximum difference of one gyrus between the observers did not differ significantly for CR or 3D SR. The observers were more often confident in agreed cases in CR and moderately confident in 3D SR.

CONCLUSIONS

These results suggest that CRs of the brain surface are superior to 3D SR for the visualization of extratemporal cortical lesions in patients with drug-resistant extratemporal epilepsy. If lesions are seen, no significant difference was found between the two techniques for localization; however, the degree of confidence appears higher for CR at the gyral level.

Language localization in cases of left temporal lobe arachnoid cyst: evidence against interhemispheric reorganization

We investigated whether left-hemisphere arachnoid cysts lead to reorganization of the language function using PET. A group analysis demonstrated that patients showed no more right-hemisphere activation than a matched control group. Several patients had clear language localizations in the left hemisphere during language comprehension; none of the patients showed right-hemisphere activation. We conclude that left-hemisphere tissue must suffer considerable compromise before reorganization of language into the right hemisphere becomes necessary. Language activations within the left hemisphere are clearly displaced. This is consistent with mere physical displacement in some patients rather than reorganization within the left hemisphere; in others intrahemispheric reorganization cannot be excluded.

Proton magnetic resonance spectroscopy of temporal lobe white matter in patients with histologically proven hippocampal sclerosis

The purpose of this study was to assess temporal lobe white matter changes accompanying hippocampal sclerosis on magnetic resonance (MR) imaging using single-voxel 1H MR spectroscopy and to strengthen the hypothesis that these white matter changes are caused by myelin alterations. In 11 patients with histologically proven hippocampal sclerosis, preoperative coronal fluid-attenuated inversion recovery images were visually assessed by two experienced neuroradiologists for hippocampal signal increase and size decrease, atrophy of collateral white matter, and temporal lobe gray/white matter demarcation loss. Single-voxel 1H MR spectroscopy of the white matter of each anterior temporal lobe was also performed, excluding the amygdala and hippocampus. The N-acetyl-aspartate (NAA)/choline and NAA/creatine ratios were calculated. In 12 healthy volunteers both temporal lobes were spectroscopically examined. In all patients the excised hippocampi were histologically assessed for the presence of sclerosis, and the excised neocortical temporal lobes were examined for gray and white matter abnormalities. MRI abnormalities were found on the right in six patients, on the left in four, and one scan was normal. Hippocampal signal increase was seen in nine patients, hippocampal size decrease in ten, atrophy of collateral white matter in nine, and gray/white matter demarcation loss in six. A significant decrease in the NAA/choline ratio was found in temporal lobe white matter ipsilateral to the pathologic hippocampus (symptomatic side), compared with the contralateral, asymptomatic side (P < 0.01), and also compared with controls (P < 0.001). The ipsilateral NAA/creatine ratio was also significantly decreased (P < 0.05) compared with the contralateral side and the control subjects (P < 0.001). Histological examination showed hippocampal sclerosis to a different degree in all patients. Neither gliosis nor cortical dysplasia was found in the ipsilateral, symptomatic temporal lobe. Significant decrease in the mean of NAA/choline ratios is found in temporal lobe white matter of patients with histologically confirmed hippocampal sclerosis. As this indicates neuronal loss or dysfunction, the number of axons may be reduced, with associated decrease in myelin density.

Asymmetrical myelination of the posterior limb of the internal capsule in infants with periventricular haemorrhagic infarction: an early predictor of hemiplegia

AIM

To prospectively assess the predictive value of asymmetrical myelination on MRI of the posterior limb of the internal capsule (PLIC) in newborn infants with an intraventricular haemorrhage (IVH) associated with unilateral haemorrhagic parenchymal involvement (PI), for subsequent development of a hemiplegia.

METHODS

12 preterm infants (GA 25-36 wks) and 4 full-term infants were studied. Using cranial ultrasound (US), the pre-term infants were diagnosed to have an IVH with unilateral PI. The term infants presented with a porencephalic cyst (PC) on the first postnatal US, following an antenatal IVH with PI. MRI was performed at 40 wks postmenstrual age in the pre-term infants and during the first 2 weeks of life in the full-term infants, using a 1.5T magnet. Using an inversion recovery sequence, the myelination of the internal capsule was recorded as normal, abnormal or equivocal. Neurological assessment > or = 12 months disclosed the presence of a hemiplegia or asymmetry in tone pattern.

RESULTS

All 4 cases with a normal internal capsule had a normal outcome in spite of the development of a PC. All 9 cases with an abnormal PLIC developed a hemiplegia, while 1 of the 3 cases with an equivocal PLIC is normal on neurological assessment, one developed a mild asymmetry in tone and 1 a mild hemiplegia.

CONCLUSION

While a symmetrical signal intensity within the internal capsule on MRI, performed at 40 weeks PMA, in infants with an IVH and unilateral PI appears to be strongly related to a normal outcome, an asymmetrical PLIC is an early predictor of future hemiplegia.

Subcortical laminar heterotopia in two sisters and their mother: MRI, clinical findings and pathogenesis

MR imaging, clinical data and underlying pathogenesis of subcortical laminar heterotopia (SCLH), also known as band heterotopia, in two sisters and their mother are presented. On MR imaging a different degree of SCLH was found in all three affected family-members. The inversion recovery sequence was considered most useful in the demonstration of the heterotopic band of gray matter and the assessment of cortical thickness. The younger sister presented with epileptic seizures at the age of five months and a delayed achievement of developmental milestones. The older sister of seven years had epileptic seizures since the age of one year, and developmental delay. Their mother has only had one seizure-like episode at the age of 39. Her psychomotor development had been normal. Investigation of DNA samples of the three female family-members revealed a mutation in the X-linked doublecortin gene. Within families with band heterotopia, this gene has also been related to male family members with lissencephaly.

MR contribution in surgery of epilepsy

The contribution of MR imaging in patients with drug-resistant epilepsy considered for surgical therapy is discussed. In this review we focus on: (a) focal abnormalities (mesial temporal sclerosis, focal migration disorders, hamartomatous lesions and low-grade tumours, phakomatosis and vascular malformations) associated with therapy-resistant partial epilepsy, requiring resective surgery; (b) abnormalities leading to generalized seizures that require more drastic surgical procedures, such as callosotomy and functional hemispherectomy; and (c) localisation of implanted depth-electrodes.

Fast fluid-attenuated inversion recovery (FLAIR) compared with T2-weighted spin-echo in the magnetic resonance diagnosis of mesial temporal sclerosis

RATIONALE AND OBJECTIVES

The authors compare coronal fast fluid-attenuated inversion recovery (FLAIR) with coronal T2-weighted spin-echo (SE) magnetic resonance (MR) techniques in the diagnosis of mesial temporal sclerosis (MTS).

METHODS

In this prospective study, the authors assessed MR scans of 30 patients with drug-resistant temporal lobe epilepsy (based on clinical symptomatology and electroencephalographic registrations) with MR features suggestive of MTS. MR scans of age-, sex-, and scanner-matched patients, referred for MR assessment of white matter disease, without a history of epilepsy and with no visible abnormalities on MR, were used as controls. In 16 patients the MR diagnosis was confirmed by histologic abnormalities consistent with MTS. Coronal T2 SE and FLAIR images of patients and controls were presented to two experienced radiologists in random order for independent blinded review. Hippocampal and associated extrahippocampal temporal lobe abnormalities were used for the diagnosis of MTS.

RESULTS

The sensitivity of observer A was 97% for the T2 SE sequence and 100% for the FLAIR; the specificity of observer A for both techniques was 100%. The sensitivity of observer B was 53% for T2 SE and 83% for FLAIR; the specificity for observer B was 93% for the T2 SE and 100% for FLAIR.

CONCLUSION

Coronal FLAIR images provide a similar or increased yield in the detection of MTS compared with T2-weighted SE images.

Relevance of temporal lobe white matter changes in hippocampal sclerosis. Magnetic resonance imaging and histology

RATIONALE AND OBJECTIVES

To evaluate the diagnostic relevance of ipsilateral atrophy of the collateral white matter in the parahippocampal gyrus (ACWMp) and temporal lobe gray/white matter demarcation loss (GWDL) on magnetic resonance imaging in patients with histologically confirmed hippocampal sclerosis. In the second part of this investigation, histologic specimens were analyzed to find an explanation for GWDL.

METHODS

Retrospective visual assessment of hippocampal signal intensity and size and of ACWMp and GWDL was performed using 4- to 5-mm coronal T2-weighted spin-echo magnetic resonance images of 80 patients with histologically proven hippocampal sclerosis and of 30 age-matched controls without epilepsy. Frequency of occurrence and likelihood ratios of ACWMp and GWDL were calculated and their contribution to the diagnosis of hippocampal sclerosis was assessed, particularly in patients with no or restricted hippocampal abnormalities (either high signal or smaller size) on magnetic resonance imaging. The second part of the study involved the morphologic histologic assessment of neocortical temporal lobe specimens of all patients. Myelin density was evaluated in specimens of a subgroup of six patients with hippocampal sclerosis and GWDL on MRI and six patients with hippocampal sclerosis without GWDL.

RESULTS

ACWMp was found in 68% and GWDL in 65% of patients with hippocampal sclerosis on magnetic resonance imaging. Both features had an infinite positive likelihood ratio. Sixty-two patients (77.5%) had concomitant hippocampal signal increase and smaller size. Eighteen patients (22.5%) had no or restricted hippocampal abnormalities on magnetic resonance imaging. When using ACWMp and GWDL as additional diagnostic parameters, 13 of these 18 patients were more unambiguously diagnosed as having hippocampal sclerosis. No significant morphologic differences were found between GWDL-positive and GWDL-negative specimens. A significantly lower average myelin stain was found in the white matter of the GWDL-positive group compared to the GWDL-negative group.

CONCLUSIONS

ACWMp and GWDL can improve the visual diagnosis of hippocampal sclerosis, particularly in patients with no or restricted hippocampal abnormalities. These results suggest that loss of myelin may be the underlying cause of GWDL in association with hippocampal sclerosis.

Correlation between neonatal cranial ultrasound, MRI in infancy and neurodevelopmental outcome in infants with a large intraventricular haemorrhage with or without unilateral parenchymal involvement

During a 7-year-period, 1625 infants of 34 weeks gestation or less were enrolled in a prospective ultrasound (US) study. One hundred and eleven (6.8%) infants developed a large intraventricular haemorrhage (IVH) with or without unilateral parenchymal involvement (PI). Fifty-six of these 111 infants survived (50.4%) and in 23 (41%) of them a magnetic resonance imaging (MRI) study was performed beyond 12 months corrected age. There appeared to be a good agreement between neonatal ultrasound findings and MRI changes noted in infancy. Of the 10 cases with a large IVH without PI (group A), seven had a VP shunt with complete decompression of previously enlarged ventricles. Six of these seven infants had periventricular hyperintensity (PVHI) but none developed cerebral palsy (CP). Two of the ten cases without a VP shunt had irregular ventricular enlargement (VE) with PVHI in one. Both developed CP. Seven cases showed thinning of the corpus callosum. Of the 13 cases with a large IVH associated with PI (group B), the site of the PI could still be recognised on MRI and the degree of communication of the porencephalic cyst (PC) with the lateral ventricles correlated well with neonatal US findings. On MRI, VE was present in only 6 cases. Wallerian degeneration was present in 9/13 infants and all but one developed a hemiplegia. In 12/13 cases there was thinning of the corpus callosum, either focal or diffuse. PVHI was present in all infants. In 6/13 PVHI was only present around the PC. Neurodevelopmental outcome differed for both groups. CP was only present in 2/10 infants in group A, compared to 11/ 13 in group B. Global delay, in the absence of CP, was more common in infants with a large IVH than in those with associated PI.

CONCLUSION

Combining neonatal US with MRI in infancy enhances our understanding of the long-term effects of severe haemorrhagic brain lesions, occurring in preterm infants.

doublecortin is the major gene causing X-linked subcortical laminar heterotopia (SCLH)

Subcortical laminar heterotopia (SCLH), or 'double cortex', is a cortical dysgenesis disorder associated with a defect in neuronal migration. Clinical manifestations are epilepsy and mental retardation. This disorder, which mainly affects females, can be inherited in a single pedigree with lissencephaly, a more severe disease which affects the male individuals. This clinical entity has been described as X-SCLH/LIS syndrome. Recently we have demonstrated that the doublecortin gene, which is localized on the X chromosome, is implicated in this disorder. We have now performed a systematic mutation analysis of doublecortin in 11 unrelated females with SCLH (one familial and 10 sporadic cases) and have identified mutations in 10/11 cases. The sequence differences include nonsense, splice site and missense mutations and these were found throughout the gene. These results provide strong evidence that loss of function of doublecortin is the major cause of SCLH. The absence of phenotype-genotype correlations suggests that X-inactivation patterns of neuronal precursor cells are likely to contribute to the variable clinical severity of this disorder in females.

Assessment of the preferred plane and sequence in the depiction of mesial temporal sclerosis using magnetic resonance imaging

RATIONALE AND OBJECTIVES

Definition of optimal magnetic resonance (MR) scanning plane and conventional MR sequence for the detection of mesial temporal sclerosis (MTS).

METHODS

Coronal and axial T2-weighted images and axial T2-weighted images parallel to the long axis of the hippocampus (APLAH) and coronal inversion recovery (IR) images were obtained in patients with medically intractable temporal lobe epilepsy in their phase 1 preoperative evaluation. Thirty-three consecutive MR scans were reviewed by a panel of three radiologists. Twenty-three patients had MR abnormalities consistent with MTS, and ten scans were normal. To assess the best single scanning technique, another group of three radiologists, who were masked to all patient data, individually assessed the different planes and sequences of the 33 studies presented separately in a random fashion. For each plane and sequence, the likelihood (L) ratio for the correct diagnosis was determined separately.

RESULTS

For all planes considered separately, a likelihood ratio of 4.4 was optimal for the coronal T2-weighted images. The likelihood ratio of APLAH T2 was 2.2; of axial T2, 3.9; of coronal IR, indefinite because of 100% specificity.

CONCLUSIONS

For the assessment of MTS, coronal T2-weighted images were considered the best single scanning technique.

Infarcts in the vascular distribution of the middle cerebral artery in preterm and fullterm infants

Twenty-three infants with an infarct in the territory of the middle cerebral artery are reported. The diagnosis was made using cranial ultrasound in all, confirmed on postmortem in two cases and on MRI, performed during the neonatal period or in infancy, in 18 of the 20 survivors. Involvement of the main branch was present in 7 cases and three of these had a gestational age of less than 35 weeks. In the other 16 infants, involvement of a cortical branch or one or more of the lenticulostriate branches was present and all but three of these had a gestational age of 34 weeks or less. While involvement of the main branch was usually diagnosed on postnatal day 1 or 2 using ultrasound, involvement of the lenticulostriate branches was noted as a wedgeshaped echogenic lesion in the caudate nucleus, thalamus or putamen, between day 4 up till day 24, and at term age in one of the cases. Neurodevelopmental outcome of those with involvement of the main branch was disappointing as all survivors developed a hemiplegia, associated with epilepsy in two; while so far only three of the other 16 infants developed cerebral palsy, one a hemiplegia and one athetoid cerebral palsy. Global delay was present in a further three cases. Infarcts in the region of the middle cerebral artery can occur in both preterm as well as fullterm infants. Involvement of the main branch also occurred in infants with a gestational age below 35 weeks and resulted in the development of a hemiplegia in all survivors. Involvement of one of the other branches was especially common in preterm infants, who had a more favourable outcome. As the lesion in the latter group was usually not present before the end of the first week, serial ultrasound up till term age is needed in order to identify these lesions.

Is 11C-flumazenil PET superior to 18FDG PET and 123I-iomazenil SPECT in presurgical evaluation of temporal lobe epilepsy?

OBJECTIVE

To determine the contribution of 18FDG PET, 11C-flumazenil PET, and 123I-iomazenil SPECT to the presurgical evaluation of patients with medically intractable complex partial seizures.

METHODS

Presurgical evaluation was performed in 23 patients, who were considered candidates for temporal lobe resective surgery (14 females and nine males with a median age of 34 (range 13 to 50) years). The presurgical diagnosis was based on seizure semiology as demonstrated with ictal video recording, ictal and interictal scalp EEG recordings, and MRI.

RESULTS

Eighteen patients had convergent findings in clinical semiology, interictal and ictal EEG with scalp and sphenoidal electrodes, and MRI that warranted surgery without depth EEG (DEEG). In five patients with insufficient precision of localisation, DEEG with intracerebral and subdural electrodes was performed. MRI showed abnormalities in 22 out of 23 patients. Of these 22, 18 had mesial temporal sclerosis. This was limited to the mesial temporal lobe in four and more widespread in the temporal lobe in 14 patients. In one patient only enlargement of the temporal horn was found and in three others only white matter lesions were detected. 18FDG PET showed a large area of glucose hypometabolism in the epileptogenic temporal lobe, with an extension outside the temporal lobe in 10 of 23 patients. Only in one of these patients DEEG showed extratemporal abnormalities that were concordant with a significant extratemporal extension of hypometabolism in 18FDG PET. 18FDG PET was compared with the results of scalp EEG: in none of the patients was an anterior temporal ictal onset in scalp EEG related to a maximum hypometabolism in the mesial temporal area. By contrast, the region of abnormality indicated by 11C-flumazenil PET was much more restricted, also when compared with DEEG findings. Extension of abnormality outside the lobe of surgery was seen in only two patients with 11C-flumazenil and was less pronounced compared with the intratemporal abnormality. Both 18FDG PET and 11C-flumazenil PET reliably indicated the epileptogenic temporal lobe. Thus these techniques provide valuable support for the presurgical diagnosis, especially in patients with non-lesional MRI or non-lateralising or localising scalp EEG recordings. In those patients in whom phase 1 presurgical evaluation on the basis of classic methods does not allow a localisation of the epileptogenic area, PET studies may provide valuable information for the strategy of the implantation of intracranial electrodes for DEEG. Previous studies have suggested that 11C-flumazenil binding has a closer spatial relationship with the zone of ictal onset than the area of glucose hypometabolism, but this study suggests rather that the decrease in the 11C-flumazenil binding simply reflects a loss of neurons expressing the benzodiazepine-GABA receptor. 11C-flumazenil PET did not prove to be superior to 18FDG PET.

CONCLUSION

In 21 patients sufficient material was obtained at surgery for a pathological examination. In 17 mesial temporal sclerosis, in one an oligodendroglioma grade B, in another a vascular malformation and in two patients no abnormalities were found. Although all 21 patients with pathological abnormality showed hypometabolic zones with 18FDG PET and a decreased uptake in 11C-flumazenil binding, there was no strong correlation between pathological diagnosis and functional abnormal areas in PET. Grading of medial temporal sclerosis according to the Wyler criteria showed no correlation with the degree of hypometabolism in either 18FDG or 11C-flumazenil PET. The interictal 123I-iomazenil SPECT technique was highly inaccurate in localising the lobe of surgery.

The posterior fontanelle: a neglected acoustic window

The additional information, obtained when using the posterior fontanelle routinely as the second acoustic window, is illustrated in four infants. Three of them are full-term infants with hypoxic ischaemic encephalopathy. In newborn infants, who are still too unstable to be transported to the magnetic resonance unit, extensive damage in the occipital subcortical white matter and/or cortex can be visualised by performing cranial ultrasound through the posterior fontanelle.

Fast spin-echo MR of contact points on implanted intracerebral stainless steel multicontact electrodes

A three-dimensional fast spin-echo MR technique is proposed for locating contact points on implanted intracerebral multicontact electrode bundles, Coronal or sagittal reformatting shows the entire trajectory of the electrode bundles. The contract points are clearly visible owing to the absence of coating material associated with a slightly larger susceptibility artifact. Potentially, this technique may preclude postimplantation thin-section CT, with its associated high radiation dose.

Rapidly progressive enlargement of the fourth ventricle in the preterm infant with post-haemorrhagic ventricular dilatation

Six preterm infants who developed disproportionate enlargement of the 4th ventricle during the neonatal period, associated with post-haemorrhagic ventricular dilatation (PHVD), before shunt placement are reported. Five of the six preterm infants developed cyanotic spells and/or bradycardias at the time of rapid enlargement of the 4th ventricle, suggestive of raised posterior fossa pressure, which resolved following insertion of and drainage from a subcutaneous reservoir. In one of the three survivors an isolated 4th ventricle was subsequently diagnosed later in infancy, requiring drainage. These data suggest that a combination of an enlarged 4th ventricle on ultrasound and cyanotic spells and/or bradycardias should lead to rapid release of raised pressure in the posterior fossa. Long-term follow-up of these children is necessary, as isolation of the 4th ventricle can subsequently develop.

Haemorrhagic-ischaemic lesions of the neonatal brain: correlation between cerebral visual impairment, neurodevelopmental outcome and MRI in infancy

The relationship between the degree of cerebral visual impairment, established using the acuity card procedure, and the extent of neurological sequelae was assessed in 65 at-risk neonates in a prospective follow-up study. MRI and CT scans were performed in all infants with severe neurological sequelae. 11 of 12 children with an acuity at or below the 10th centile at 18 months developed cerebral palsy: the underlying condition was extensive cystic leukomalacia in all. An acuity above the 10th centile was no guarantee of normal development, as 10 out of 52 such infants developed cerebral palsy. MRI and CT scans showed that periventricular high signal intensity in the occipital area was a non-specific finding with regard to visual function. Extensive periventricular white matter loss and involvement of the striate/parastriate cortex was found in the most severely visually impaired infants.

Temporal lobe epilepsy: the various MR appearances of histologically proven mesial temporal sclerosis

PURPOSE

To determine the frequency of appearance of various MR signs in mesial temporal sclerosis, to determine the optimal scanning planes for their visualization, and to propose a histologic explanation for the diminished demarcation between gray and white matter in the temporal lobe, a frequent MR finding in patients with mesial temporal sclerosis.

METHODS

MR scans of 14 surgically treated patients with epilepsy and histologically proven mesial temporal sclerosis were assessed for the presence of six features: feature 1, high signal intensity in the hippocampus; 2, reduced hippocampal size; 3, ipsilateral atrophy of the hippocampal collateral white matter; 4, enlarged temporal horn; 5, reduced gray-white matter demarcation in the temporal lobe; and 6, decreased temporal lobe size.

RESULTS

Feature 1 was present in 14 patients and was best appreciated on the T2-weighted images in planes parallel to the long axes of the hippocampi. Feature 2, present in 12 patients, and feature 6, present in 9 patients, were optimally seen in the coronal planes and on the inversion-recovery sequences in particular. Feature 3, present in 12 patients, was optimally seen on the coronal T2-weighted images. Feature 4, seen in 11 patients, was equally well seen in all planes (transverse, coronal, and parallel to the long axes of the hippocampi). Feature 5, seen in 10 patients, was best appreciated on the T2-weighted images in the planes of the long axes of the hippocampi. Histologic investigation of the temporal lobe white matter in the 10 patients with feature 5 demonstrated on the MR scan showed abnormalities in 7 cases. Oligodendroglia cell clusters were found in 6, with concomitant corpora amylacea in 1 case and perivascular macrophages with pigment a sole finding in another case.

CONCLUSION

Of the six features found in cases of mesial temporal sclerosis on MR, increased hippocampal signal intensity is the most consistent. A decreased gray-white matter demarcation in the temporal lobe parenchyma is also a frequent feature of this disease. A combination of multiple scanning planes results in an optimal demonstration of lesions.

Cerebral proton magnetic resonance spectroscopic imaging in a neonate with tuberous sclerosis

On the basis of detection of cardiac tumours and an intracerebral subependymal mass, the diagnosis of tuberous sclerosis was made in a fullterm neonate. To evaluate cerebral metabolism cerebral mass proton magnetic resonance spectroscopic imaging (1H-MRSI) was performed. A local decrease in N-acetyl-aspartate (NAA), and an increase in choline signals were found. Lactate could neither be demonstrated in the subependynal nodule, nor in the surrounding tissue, thereby rendering the possibility of a high-grade malignant tumour less likely. No major changes were found at 3 and 6 months of age. The present study demonstrates, that 1H-MRSI may be helpful in metabolic evaluation of cerebral masses in patients with tuberous sclerosis.

Correlation between the degree of periventricular leukomalacia diagnosed using cranial ultrasound and MRI later in infancy in children with cerebral palsy

During a period of 30 months, 504 infants of 34 weeks gestation or less were enrolled in a prospective cranial ultrasound study. Ninety-two (18.4%) infants developed different degrees of periventricular leukomalacia (PVL), being transient periventricular echogenicities (PVE) in 75, localised cystic lesions in 7 and extensive cysts in 10. Eight of 75 (10.6%) infants with PVE, 4 of the 6 (66.6%) survivors with localised cysts and all 8 survivors with extensive cysts developed cerebral palsy in infancy and MRI studies could be performed in 15 of these 20 infants between 11 and 32 months of age. Neurological sequelae were most severe among the infants with extensive cysts and none were able to walk, while 6 of the 12 who developed cerebral palsy following either PVE or localised cysts had learned to walk independently. There appeared to be a good correlation between the degree of PVL, diagnosed using ultrasound, and the extent of MRI changes noted in infancy. Ventricular enlargement and delay in myelination were more common in infants with cystic lesions and periventricular hyperintensity (PVHI) was present in all infants, but most extensive in the cases with extensive cysts. MRI performed later in infancy may, even in the absence of neonatal cranial ultrasound, provide information about both the presence as well as the degree of leukomalacia, which the child may have suffered in the neonatal or antenatal period.

MRI of the pulmonary artery after arterial switch operation for transposition of the great arteries

Twenty-six children who underwent an arterial switch operation for transposition of the great arteries were examined with MRI and Doppler ultrasound (US). The aim was to determine the capability of MRI for detecting a possible stenosis of the pulmonary arteries. In 10 children angiocardiography (ACG) was done after the MRI examination. Using ACG as the gold standard, MRI was sensitive in the detection of pulmonary artery stenosis. MRI was more precise in the localization of a stenosis than was Doppler US. Right ventricular hypertrophy was a sensitive indicator of pulmonary artery stenosis. These results suggest that MRI could serve as a screening examination for pulmonary artery stenosis after an arterial switch operation.

Detection of aortic dissection by magnetic resonance imaging in adults with Marfan's syndrome

Marfan's syndrome is a connective tissue disorder, which mainly affects the cardiovascular system, together with ocular, skeletal and connective tissue. The cardiovascular manifestations in particular determine the mortality of this disorder. We studied 13 patients, suffering of Marfan's syndrome, with suspected aortic dilatation by means of magnetic resonance imaging (MRI). Aneurysmal dilatation of the aortic root and dissection were the two major findings in our study. Two of the five patients with dissections presented without relevant symptoms in the medical history nor at the time of the MRI examination.

Rolandic spikes in the inter-ictal EEG of children: contribution to diagnosis, classification and prognosis of epilepsy

The clinical correlates of Rolandic spikes were studied in 47 children to determine the significance of this EEG finding to the diagnosis and classification of epilepsy. The children were classified into 'functional' and 'organic' groups, with and without epilepsy. Children with epilepsy were further subdivided into those with Rulandic and those with non-Rulandic seizures. In children without neurological abnormalities, the EEG finding of Rolandic spikes plays a decisive role in the diagnosis of an epileptic syndrome as benign focal epilepsy of childhood with centro-temporal spikes (BECT), a diagnosis with an excellent prognosis. Neurological and neuroradiological examinations of the 'functional' group revealed that the Rolandic spike may occur as a true 'functional' spike. The frequency of a family history of epilepsy among neurologically normal children with Rolandic spikes suggests, in addition to the inheritance of BECT and the EEG trait, the existence of a hereditary susceptibility to epilepsy.

Nonaneurysmal perimesencephalic subarachnoid hemorrhage: CT and MR patterns that differ from aneurysmal rupture

We describe a characteristic distribution of cisternal blood in 52 patients with nonaneurysmal subarachnoid hemorrhage proved by a normal angiogram. On CT, the center of the bleeding was located immediately anterior to the brainstem in all patients, which was confirmed in four patients who were studied with MR imaging. Extension to the ambient cisterns or to the basal parts of the sylvian fissures was common, but the lateral sylvian or anterior interhemispheric fissures were never completely filled with blood. Rupture into the ventricular system did not occur. MR demonstrated downward extension of the blood anterior to the brainstem as far as the medulla, but failed to detect the source of hemorrhage. Our aim was to determine whether this so-called nonaneurysmal perimesencephalic hemorrhage could be distinguished from aneurysmal subarachnoid hemorrhage on early CT scans. Two neuroradiologists were shown a consecutive series of 221 CT scans of patients with subarachnoid hemorrhage who subsequently underwent angiography. Only one patient with a basilar artery aneurysm on angiography was incorrectly labeled by both observers as having a nonaneurysmal perimesencephalic pattern of hemorrhage. The high predictive value of the perimesencephalic pattern of hemorrhage for a normal angiogram (0.95 and 0.94, respectively, for the two observers) and the excellent interobserver agreement (kappa 0.87) demonstrate that nonaneurysmal perimesencephalic hemorrhage can be distinguished on CT in the majority of patients. Recognition of this pattern of hemorrhage is important as patients with this subset of subarachnoid hemorrhage have an excellent prognosis.