Case gender and severity in cerebral palsy varies with intrauterine growth

BACKGROUND

There is an unexplained excess of cerebral palsy among male babies. There is also variation in the proportion of more severe cases by birth weight. It has recently been shown that the rate of cerebral palsy increases as intrauterine size deviates up or down from an optimum about one standard deviation heavier than population mean weight-for-gestation.

AIMS

To determine whether the gender ratio or the severity of cases also varies with intrauterine size.

METHODS

A total of 3454 cases of cerebral palsy among single births between 1976 and 1990 with sufficient data to assign case severity (based on intellectual impairment and walking ability) and to compare weight-for-gestation at birth to sex specific fetal growth standards, were aggregated from nine separate registers in five European countries.

RESULTS

The greater the degree to which growth deviates either up or down from optimal weight-for-gestation at birth, the higher is the rate of cerebral palsy, the larger is the proportion of male cases, and the more severe is the functional disability. Compared to those with optimum growth the risk of more severe cerebral palsy in male babies is 16 times higher for those with a birth weight below the 3rd centile and four times higher when birth weight is above the 97th centile. In contrast, for mild cerebral palsy in female babies the excess risks at these growth extremes are about half these magnitudes.

CONCLUSIONS

Among singleton children with cerebral palsy, abnormal intrauterine size, either small or large, is associated with more severe disability and male sex.

Niemann-Pick disease type A and B are clinically but also enzymatically heterogeneous: pitfall in the laboratory diagnosis of sphingomyelinase deficiency associated with the mutation Q292 K

This study describes a diagnostic pitfall in the laboratory diagnosis of patients with sphingomyelinase deficiency (SMD; Niemann-Pick disease types A and B; NPA and NPB), in cases where sphingomyelinase activity was not determined with sphingomyelin as the natural enzymic substrate. Four of 24 SMD patients studied had falsely normal or enhanced activity, when a so-called artificial sphingomyelinase substrate, 2-N-(hexadecanoyl)-amino-4-nitrophenyl phosphorylcholine (HNP), was used, whereas SMD was clear with the sphingomyelin substrate. Those four patients had the Q292 K mutation of the acid sphingomyelinase gene (SMPD1) on at least one allele. Three of the four patients (no data available from one) experienced only late-infantile or juvenile, though distinct, neurological involvement, where learning disabilities, hypo- or areflexia or mild ataxia were initial signs. The laboratory pitfall with HNP substrate, which is used in many laboratories, raises the risk that some SMD patients are overlooked, and it prevents the consideration of a late-manifesting neurological course in some patients as well as the planning of enzyme substitution therapy in non-neurological SMD (NPB) patients. Since classical NPB is very rare, it is suggested that SMD patients with late- or mild-manifesting neurological symptoms should better be assigned to additional SMD subgroups than grouped with NPB.

The development of cerebral perfusion in healthy preterm and term neonates

Quantitative measurement of cerebral blood flow (CBF) volume was performed by sonographic flowmetry of both internal carotid (ICA) and vertebral arteries (VA) in 113 healthy preterm and term infants of 32 - 42 weeks postmenstrual age (PA) in order to delineate the physiological characteristics of brain perfusion in a time period very sensitive to brain injury. Mean CBF volume increased with PA, beginning with 33 +/- 9 ml/min in neonates of 32 - 34 weeks and rising to 45 +/- 10, 58 +/- 13, 69 +/- 14, and 83 +/- 16 ml/min, respectively, in the PA groups of 35 - 36, 37 - 38, 39 - 40 and 41 - 42 weeks. There was no difference in CBF volume between the sexes. The bilateral sum of flow volumes in both ICA and VA rose markedly with PA. The relative contribution of bilateral VA flow volume to total CBF volume was 26 +/- 8 % and remained constant with PA. In addition, we calculated the approximate CBF (ml/100 g brain weight/min) using the brain weights of each child as estimated by means of an equation based on head circumference measurements. Estimated CBF correlated significantly with PA (r = 0.49; p </= 0.0001), reflecting the rising metabolic demand of the growing brain during the time period examined.

Cerebrospinal fluid pterins and folates in Aicardi-Goutières syndrome: a new phenotype

OBJECTIVE

To describe three unrelated children with a distinctive variant of Aicardi-Goutières syndrome (AGS) characterized by microcephaly, severe mental and motor retardation, dyskinesia or spasticity, and occasional seizures.

RESULTS

Neuroimaging showed bilateral calcification of basal ganglia and white matter. CSF glucose, protein, cell count, and interferon alpha were normal. Abnormal CSF findings included extremely high neopterin (293 to 814 nmol/L; normal 12 to 30 nmol/L) and biopterin (226 to 416 nmol/L; normal 15 to 40 nmol/L) combined with lowered 5-methyltetrahydrofolate (23 to 48 nmol/L; normal 64 to 182 nmol/L) concentrations in two patients. The absence of pleocytosis and normal CSF interferon alpha was a characteristic finding compared to the classic AGS syndrome. Genetic and enzymatic tests excluded disorders of tetrahydrobiopterin metabolism, including mutation analysis of GTP cyclohydrolase feed-back regulatory protein. CSF investigations in three patients with classic AGS also showed increased pterins and partially lowered folate levels.

CONCLUSIONS

Intrathecal overproduction of pterins is the first biochemical abnormality identified in patients with AGS variants. Long-term substitution with folinic acid (2-4 mg/kg/day) resulted in substantial clinical recovery with normalization of CSF folates and pterins in one patient and clinical improvement in another. The underlying defect remains unknown.

Pyramidal tract damage correlates with motor dysfunction in bilateral periventricular leukomalacia (PVL)

In children with periventricular leukomalacia (PVL), motor dysfunction is thought to be related to involvement of pyramidal tract fibres in the periventricular white matter. The purpose of the present study was to test this hypothesis. Thirteen former preterm adolescents with PVL, ten of whom were suffering from bilateral spastic cerebral palsy, were studied by MRI. The severity of pyramidal tract damage was assessed on semicoronal MRI reconstructions along anatomical landmarks of somatotopy in the precentral gyrus and the internal capsule; for comparison, the overall volume of cerebral white matter (determined by automated volumetry) served as a global measure of lesion severity. The motor dysfunction of each of the four extremities correlated much more strongly with the severity of pyramidal tract damage assessed on the respective MRI reconstruction (range of correlation coefficients, 0.647 to 0.922) than with the total volume of white matter (range of correlation coefficients, - 0.458 to - 0.212; Spearman). These findings corroborate the notion that an involvement of pyramidal tract fibres in the periventricular white matter is indeed a relevant factor for motor dysfunction in children with PVL.

Malformations of the midline commissures: MRI findings in different forms of callosal dysgenesis

Malformations of the corpus callosum (CC) may occur in many different syndromes. Various forms have been observed. We report seven cases of malformation of the CC. Special attention is directed towards the development of the fornix and hippocampus as a hippocampal commissure is a prerequisite of normal hippocampal development. The clinical disability of the patients presented here differed significantly, which may in part be due to the different extent of this cerebral malformation. The relevance of the concomitant aplasia of the limbic system has not been addressed in detail previously in the literature.

Measurement of volume of cerebral blood flow in healthy preterm and term neonates with ultrasound

Changes in cerebral blood flow are important in the pathogenesis of ischaemic brain damage, but standard methods cannot measure volume of cerebral blood flow quantitatively in neonates. We used colour duplex sonography of the extracranial cerebral arteries to measure volume of global cerebral blood flow in 67 healthy preterm and term neonates. Volume of cerebral blood flow increased between the postmenstrual ages of 34 weeks (median 33 mL/min [range 23-43]) and 42 weeks (85 mL/min [57-104]). However, intersession and interobserver variability was quite large. This non-invasive method will allow quantitative bedside monitoring of global brain perfusion in preterm and term neonates with pathological disorders, and could also be used to monitor effects of neuroprotective measures.

Recognition of point-light biological motion displays by young children

We tested the ability of children 3-5 years of age to recognise biological motion displays. Children and adults were presented with moving point-light configurations depicting a walking person, four-legged animals (dogs), and a bird. Participants were able to reliably recognise displays with biological motion, but failed in the identification of a static (four consecutive frames taken from each sequence) version. The results indicate that, irrespective of the highly reduced and unusual structural information available in point-light displays, biological motion is sufficient for reliable recognition of human and non-human forms at an age as early as 3 years. Moreover, 5-year-olds exhibit the ceiling level of recognition. The findings are discussed in the context of the neuropsychological and brain mechanisms involved in biological motion perception.

Early left periventricular brain lesions induce right hemispheric organization of speech

Right-hemispheric organization of speech has been observed following early left-sided brain lesions involving the language cortex. The authors studied speech organization in hemiparetic patients with pre- and perinatally acquired lesions in the left periventricular white matter using fMRI, and found that right-hemisphere activation correlated with left facial motor tract involvement. This suggests that the impairment of speech motor output from the left hemisphere plays an important role in this alteration of language representation.

Functional MRI in a 6-year-old boy with unilateral cortical malformation: concordant representation of both hands in the unaffected hemisphere

Functional magnetic resonance imaging (fMRI) was performed in a 6-year-old boy with a complex malformation of the right hemisphere who suffered from pharmaco-refractory epilepsy. Clinical examination revealed left-sided hemiparesis and marked mirror movements of the opposite hand both during paretic and non-paretic hand movements. Functional MRI of repetitive unimanual grasping demonstrated that the two hands share a common cortical representation located in the central motor region of the unaffected left hemisphere. The affected right hemisphere did not show any activation during either task. This case study demonstrates the feasibility and usefulness of motor fMRI in young children before they undergo epilepsy surgery.

Proton MR spectroscopy reveals lactate in infantile neuroaxonal dystrophy (INAD)

Changes of cerebral metabolites detected by proton MR spectroscopy in two cases of infantile neuroaxonal dystrophy are described. A 6 11/12-year-old boy and a girl (aged 4 1/12 years at the first and 5 2/12 years at the second examination) with infantile neuroaxonal dystrophy were investigated by magnetic resonance imaging and spectroscopy of the basal ganglia. The signal intensity of the cerebellar cortex was increased on T2-weighted, proton density, and fluid attenuated inversion recovery images. The long echo time (135 ms) spectra revealed the presence of lactate in the basal ganglia of both cases in all investigations. The N-acetylaspartate/creatine ratio was reduced in Case 1 and in the second investigation of Case 2. The choline/creatine ratio was always increased. As the diagnosis of infantile neuroaxonal dystrophy is made by a synopsis of various clinical, neuropathological, neurophysiological, and neuroradiological data, the presence of lactate in the basal ganglia spectra may help to narrow down the diagnosis and can support the decision to perform more invasive diagnostic procedures (such as biopsies of skin, conjunctiva or even of the brain).

Late detection of neuroblastoma in a patient with prolonged cerebellar ataxia without opsoclonus

A 19-month-old boy presented with acute-onset cerebellar ataxia following immunisation. Ataxia was prolonged with a fluctuating course over a period of two years. Opsoclonus was never observed. Extensive diagnostic studies were negative during this time. Finally, a neuroblastoma was discovered. Ataxia disappeared completely during polychemotherapy. This report suggests that occult neuroblastoma must be considered in any child with unexplained prolonged cerebellar ataxia. Specific investigations are recommended for such cases.

Congenital bilateral perisylvian syndrome (CBPS): do concomitant esophageal malformations indicate a poor prognosis?

Congenital bilateral perisylvian syndrome (CBPS) is a syndrome of cortical malformation characterized by faciopharyngoglossomasticatory diplegia. We report on two cases of CBPS with associated esophageal malformations and a poor mental and motor development. The association of CBPS and esophageal malformations may indicate a subgroup of patients with a very early prenatal injury, characterised by a bad prognosis due to severe cortical disorganization. However, it can not be excluded that the association of CBPS and esophageal malformation is purely coincidental.

[Normal myelination in childhood brains using MRI--a meta analysis]

PURPOSE

To establish age limits for the assessment of normal myelination of the brain on T1-weighted (T1w) and T2-weighted (T2w) images.

METHOD

Comparison of previous publications (Barkovich et al. 1988, Grodd 1993, Hayakawa et al. 1990, Hittmair et al. 1994, Martin et al. 1988/1990/1991, Nakagawa et al. 1998, Staudt et al. 1993/1994, Stricker et al. 1990).

RESULTS

Despite technical and methodological differences, these studies principally agreed on the timing of myelination for most regions of the brain. Thus, a common time-table could be established: At 1 month, myelin is visible on both T1w and T2w in the medulla oblongata, tegmentum pontis, cerebellar peduncles and vermis, quadrigeminal plate, decussation of superior cerebellar peduncles, thalamus, posterior limb of internal capsule, optic radiation, corona radiata. Thereafter, the myelin-typical signal in the different regions of the brain should be present at the following ages (M = months): anterior limb of internal capsule (2 M: T1w; 7 M: T2w), splenium of corpus callosum (4 M: T1w; 6 M: T2w), genu of corpus callosum (6 M: T1w; 8 M: T2w), centrum semiovale (2 M: T1w; 7 M: T2w). Branching of myelin into the gyri of the telencephalon (= arborization) appears at the latest at: occipital lobe (5 M: T1w; 12 M: T2w) and frontal lobe (7 M: T1w; 14 M: T2w).

CONCLUSION

These extracted age limits can be used for a more reliable assessment of myelination than the time-tables from a single study.

The pyramidal tract in congenital hemiparesis: relationship between morphology and function in periventricular lesions

Three-dimensional MRI data sets were obtained from 12 young adult patients with congenital spastic hemiparesis caused by unilateral periventricular white matter lesions. The impact of these lesions on corticospinal projections to the upper and lower extremities was assessed on reconstructed semi-coronal planes following anatomical landmarks of somatotopic organization in the precentral gyrus and in the internal capsule: a more anterior plane running through the hand-knob of the precentral gyrus and the anterior portion of the posterior limb of the internal capsule representing projections to the upper extremity, and a more posterior plane running through the top of the precentral gyrus and the middle portion of the posterior limb of the internal capsule representing projections to the lower extremity. In addition, the total lesion extent was determined volumetrically, and Wallerian degeneration was assessed qualitatively in the internal capsule and quantitatively by measuring brainstem asymmetry. We found a strong correlation between motor dysfunction of the upper and lower limb and the lateral extent of the periventricular lesion measured on the respective semi-coronal planes. The total lesion volume and the degree of Wallerian degeneration correlated less strongly, both reaching statistical significance only with motor impairment of the hand.

Acute encephalopathy associated with vigabatrin in a six-month-old girl

PURPOSE

Vigabatrin (VGB) is a new-generation anticonvulsant used in the treatment of partial seizures and West syndrome. Side effects of VGB treatment in adults and children are well described. Acute encephalopathy with VGB has recently been reported in eight adults. They developed stupor, confusion, and electroencephalographic abnormalities after starting VGB. Does the acute encephalopathy with VGB also occur in childhood?

METHODS

We describe a 6-month-old girl with infantile Alexander disease with hydrocephalus who developed similar clinical symptoms with apathia, somnolence, and sopor, as well as slowing of the background activity in EEG, 3 days after starting VGB. After exclusion of shunt dysfunction, encephalitis, metabolic dysfunction, and renal failure, VGB was discontinued.

RESULTS

During the next 2 days, symptoms subsided, and after 10 days, EEG background activity returned to the one before starting VGB.

CONCLUSIONS

Acute encephalopathy associated with VGB in children seems to be very rare, but should not be ignored.

Alexander disease--classification revisited and isolation of a neonatal form

Alexander disease is usually classified according to the age of onset, e.g. an infantile form with onset during the first two years of life, a juvenile form with onset in childhood, mainly school age. It has been recognized, however, that the clinical course can be very variable within these groups. Thus, this clinical classification is not a useful predictor of severity and progression of the disease. This is demonstrated here on the basis of the history of seven own patients and a literature review. Only an onset in very early infancy, during the neonatal period, seemed to be associated with a rather uniform pattern of disease course, often leading to early death. This neonatal form showed very stereotyped symptoms, in part different from later onset: Early, often intractable, generalized seizures; hydrocephalus with raised intracranial pressure due to aqueductal stenosis because of pathological astroglia proliferation; lack of developmental progression but without prominent spasticity or ataxia; elevated CSF protein content. This was associated with the well-established neuroradiological findings, e.g. severe white matter affection with fronto-temporal predominance, involvement of basal ganglia and periventricular enhancement as an obligatory symptom. The identification of this early onset form is especially important as seizures and signs of raised intracranial pressure may mislead the diagnosis.

Hemolytic-uremic syndrome with involvement of basal ganglia and cerebellum

Hemolytic-uremic syndrome is a microangiopathy often associated with neurologic symptoms. Several patients with persistent lesions in cerebrum and basal ganglia have been reported. We present two children with bilateral basal ganglia and additional unilateral cerebellar lesions in magnetic resonance imaging. These resolved completely in one child. In the other child there were still residuals after 11 weeks. The neurologic symptoms of both improved after several therapeutic plasma exchanges and disappeared after months.

Brain lesions in preterms: origin, consequences and compensation

Twenty-nine high-risk preterm born children, from a cohort with cerebral blood flow (CBF) measurements in the first 2 d of life, were examined prospectively at the age of 5.5-7 y neurologically, neuropsychologically and by magnetic resonance imaging (MRI). They were compared to 57 control children in terms of neurology and neuropsychology. Abnormal MRI was found in 19 children. Low oxygen delivery to the brain was found in 63% of them, in contrast to 12.5% in those with normal MRI, indicating neonatal hypoxia-ischemia as an important factor. The MRI abnormalities were mainly periventricular lesions (n = 19), especially periventricular leucomalacia (PVL, n = 17). Three of the very preterm children had severe cerebellar atrophy in addition to relatively mild periventricular abnormalities. MRI showed specific morphological correlates for the major disabilities, e.g. spastic CP (involvement of motor tracts), mental retardation (bilateral extensive white matter reduction or cerebellar atrophy) and severe visual impairment (severe optic radiation involvement). A morphological correlate for minor disabilities, i.e. functional variations in motor performance or intelligence, was not found, with the exception that symptoms of attention deficit hyperactivity disorder were related to mild MRI abnormalities. This could mean that with respect to cognitive functions, mild or unilateral periventricular MRI lesions could be compensated. However, as among preterms without mental retardation (n = 19), IQ was generally and significantly lower than in the control group; other, more chronic pathogenetic factors, not detectable by MRI alone, may play a role.

[How early and how specifically can hypoxic-ischemic brain lesions be detected with diagnostic imaging?]

Pathogenic events affecting the developing brain cause malformations or lesions, the pattern of which depend on the stage of brain development. While in the past diagnosis of these patterns was made by post mortem examinations, today advances of brain imaging allow this already during life time. The patterns of hypoxic-ischemic brain injuries on magnetic resonance imaging (MRI) are well known for the older child (after progress of myelination). This paper addresses the question how early and how specific these patterns can be recognized by two imaging methods, e.g. cranial ultrasound and magnetic resonance imaging. It concludes, that neonatal MRI but also neonatal ultrasound can reliably detect major lesions but may fail in the detection of less extensive patterns. Most authors therefore conclude, that a routine use of MRI for the detection of hypoxic-ischemic lesions during the neonatal period is not recommended and should rather be reserved for later controls.

Cerebral manifestation of Wilson's disease successfully treated with liver transplantation

The main indication for orthotopic liver transplantation (OLTx) in Wilson's disease (WD) is severe hepatic decompensation. Our 15-year-old patient is the second case to date in whom OLTx was performed because of neurologic manifestations resulting from WD. His initial condition involving recurrent headaches, tremor, and athetoid hand movements progressively deteriorated during therapy with D-penicillamine, zinc sulfate, and trientine until he was severely dysarthric, unable to walk, and bedridden. After OLTx, his neurologic condition became almost normal.