Neuropsychological consequences of childhood medulloblastoma and possible interventions: A review.

BACKGROUND: Children who have been treated for a medulloblastoma often suffer long-term cognitive impairments that often negatively affect their academic performance and quality of life. In this article, we will review the neuropsychological consequences of childhood medulloblastoma and discuss the risk factors known to influence the presence and severity of these cognitive impairments and possible interventions to improve their quality of life. METHODS: This narrative review was based on electronic searches of PubMed to identify all relevant studies. RESULTS: Although many types of cognitive impairments often emerge during a child's subsequent development, the core cognitive domains that are most often affected in children treated for a medulloblastoma are processing speed, attention and working memory. The emergence and magnitude of these deficits varies greatly among patients. They are influenced by demographic (age at diagnosis, parental education), medical and treatment-related factors (perioperative complications, including posterior fossa syndrome, radiation therapy dose, etc.), and the quality of interventions such as school adaptations provided to the child or rehabilitation programs that focus on cognitive skills, behavior and psychosocial functioning. CONCLUSION: These patients require specialized and coordinated multidisciplinary rehabilitation follow-up that provides timely and adapted assessments and culminates in personalized intervention goals being set with the patient and the family. Follow-up should be continued until referral to adult services.

The Renpenning syndrome spectrum: new clinical insights supported by 13 new PQBP1-mutated males.

Since the first reports of polyglutamine-binding protein 1 (PQBP1) mutations in Renpenning syndrome and related disorders, the spectrum of PQBP1-linked clinical manifestations has been outlined from rare published case reports. The phenotypic description is often obtained from medical archives, and therefore, heterogeneous. Moreover, some aspects such as brain imaging or cognitive and behavioral functioning are rarely described. In this study, 13 PQBP1-mutated French patients were subjected to a standardized clinical, cognitive and behavioral assessment. Physical measurements of their relatives were also collected. We report on a recognizable clinical and radiological phenotype. All patients presented with microcephaly, leanness and mild short stature, relative to familial measurements. Three new clinical features are described: upper back progressive muscular atrophy, metacarpophalangeal ankylosis of the thumb and velar dysfunction. The specific facial dysmorphic features included at least four of the following signs: long triangular face, large ridged nose, half-depilated eyebrows, dysplastic or protruding ears and rough slightly sparse hair. An over-aged appearance was noticed in elderly patients. Cortical gyrification was normal based on available magnetic brain imaging of six patients. PQBP1-linked microcephaly (or Renpenning syndrome) is an X-linked mental retardation syndrome, which has clinically recognizable features.

[Structural and functional imaging: particularities in children]. / Imagerie morphologique et fonctionnelle: particularités chez l'enfant.

Surgery of partial epilepsies in childhood has largely benefited from the recent advances of imaging techniques, which carry a triple goal: (1) to contribute to the localization of the epilepsy onset zone, (2) to detect and delineate an underlying lesion, and (3) to study the spatial relationship between the epileptogenic zone and the neighboring functional cortex, in order to select patients and plan the resection. This noninvasive presurgical imaging workup must be compared to clinical and electrical data to estimate the postoperative prognosis, while invasive techniques such as SEEG, cortical stimulations, and IAT often remain indispensable in difficult cases, i.e., in cryptogenic epilepsies. As in adults, advances in MRI allow us to detect more and more subtle underlying lesions, but this requires repeating MR studies during early childhood and using adapted sequence parameters to account for ongoing myelination. Ictal SPECT and PET imaging prove especially useful in planning depth electrode placement when video-EEG is not contributive, when MRI looks normal or shows multiple abnormalities, or in cases of discrepant findings. Multimodal imaging greatly enhances the sensitivity of all of these techniques. Finally, functional MRI of motor and language functions provide noninvasive cortical mapping of essential functions, using age-adapted paradigms, in cooperating children from age five to six and from IQs around 60.

Intellectual prognosis of the Dandy-Walker malformation in children: the importance of vermian lobulation.

Half of patients with the Dandy-Walker malformation (DWM) have normal intellectual development. We aimed to identify feature on MRI associated with good intellectual prognosis. We reviewed 20 patients with DWM diagnosed on MRI, mean age 14.6+/-9.9 years. We assessed their intellectual development and related it to the MRI features. We found two groups with a statistically different intellectual outcome. All 14 patients with normal intellectual development had a normal lobulation of the vermis, without supratentorial anomalies. Of the six patients with mental retardation, three had an abnormal vermis, together with dysgenesis of the corpus callosum. In the other three, there were normal vermian anatomy with associated anomalies. Normal lobulation of the vermis, in the absence of any supratentorial anomaly, appears to be a good prognostic factor in DWM. Preservation of cerebrocerebellar pathways and neonatal plasticity could explain the normal intellectual development. These findings might be useful in prenatal diagnosis.

Functional imaging in the work-up of childhood epilepsy.

In children with medically intractable lesional epilepsy, surgery is deemed successful if the epileptogenic focus can be removed while major neurological functions are spared. Current techniques rely on invasive intracranial recordings. The new developments in functional imaging offer the possibility of localizing the epileptogenic focus noninvasively (PET/SPECT) and mapping cognitive functions (fMRI). Ictal SPECT shows hyperperfusion in the focus and has proved to have better localizing value than interictal PET or SPECT, which show focal hypometabolism or hypoperfusion. Ictal SPECT is useful for deciding on the placement of intracranial electrodes in extratemporal epilepsies, particularly in young children. Functional MRI has proved highly accurate for localizing motor and language networks, thus offering the possibilities of replacing the Wada test (language hemispheric lateralization) and studying postlesional brain plasticity. Despite the difficulties of functional imaging in children owing to the limited cooperation that can be expected, ethical constraints, and poor normative data, SPECT/PET and fMRI provide clinically useful information for presurgical work-up of childhood epilepsies.

Intracranial venous anomalies associated with atretic cephalocoeles.

BACKGROUND: Midline scalp lesions are frequent in children. They include soft-tissue masses and atretic meningocoeles. Their recognition is important as their treatment differs. Intracranial venous anomalies are known to be associated with atretic cephalocoeles. MATERIALS AND METHODS: A retrospective study was undertaken to assess the frequency of intracranial venous anomalies associated with atretic meningocoeles (AT). Thirty-one patients with AT were studied by MRI. There were 13 meningocoeles and 14 encephalocoeles; 4 have not yet received surgery. RESULTS: Venous anomalies were found when the cephalocoeles lay above the torcular. They include absence of the straight sinus and duplication of the longitudinal sinus. CONCLUSION: Venous anomalies are frequent in atretic cephalocoeles and are part of the dysraphic state.

Functional MR evaluation of temporal and frontal language dominance compared with the Wada test.

OBJECTIVE: To evaluate the reliability of temporal and frontal functional MRI (fMRI) activation for the assessment of language dominance, as compared with the Wada test. PATIENTS AND METHODS: Ten patients with temporal lobe epilepsy were studied using blood oxygen level dependent fMRI and echoplanar imaging (1.5-T). Three tasks were used: semantic verbal fluency, covert sentence repetition, and story listening. Data were analyzed using pixel by pixel autocorrelation and cross-correlation. fMRI laterality indices were defined for several regions of interest as the ratio (L - R)/(L + R), L being the number of activated voxels in the left hemisphere and R in the right hemisphere. Wada laterality indices were defined as the difference in the percentages of errors in language tests between left and right carotid injections. RESULTS: Semantic verbal fluency: The asymmetry of frontal activation was correlated with Wada laterality indices. The strongest correlation was observed in the precentral/middle frontal gyrus/inferior frontal sulcus area. Story listening: The asymmetry of frontal, but not temporal, activation was correlated with Wada laterality indices. Covert sentence repetition: No correlation was observed. CONCLUSIONS: There was a good congruence between hemispheric dominance for language as assessed with the Wada test and fMRI laterality indices in the frontal but not in the temporal lobes. The story listening and the covert sentence repetition tasks increased the sensitivity of detection of posterior language sites that may be useful for brain lesion surgery.

Cerebral white matter disease in children may be caused by mitochondrial respiratory chain deficiency.

Several mitochondrial diseases are known to occasionally involve the cerebral white matter, namely Leigh syndrome, Kearns-Sayre syndrome, and MELAS syndrome, but in these cases the major finding is alteration in the basal ganglia and brainstem. Here we report on severe diffuse white matter involvement and respiratory chain enzyme deficiency or mitochondrial DNA rearrangement in 5 unrelated families. It is interesting that white matter lesions were the only abnormal neuroradiologic feature in 3 of the 5 families, and multiple small cyst-like white matter lesions were found in 2 of 5 probands. Respiratory chain deficiency should be considered in the diagnosis of severe white matter involvement in childhood.

The noninvasive identification of language function. Neuroimaging and rapid transcranial magnetic stimulation.

Neuroimaging techniques that rely on detecting alterations in blood flow may be used to map the cortical localization of cognitive function during task performance. O-15 water positron emission tomography studies have mapped neural networks that subserve language function. These techniques have been adapted to lateralize and localize language function in patients with intractable epilepsy prior to epilepsy surgery. Functional magnetic resonance (fMR) imaging, relying upon fast MR imaging techniques performed during cognitive tasks, allows localization of language areas in individual adults and children and, because there is no radiation exposure, allows for additional or repeat studies in patients. These noninvasive means of language localization may supplant the invasive means of language lateralization (intracarotid amytal procedure) and localization (corticography), and will allow for the continued study of language organization in health and disease.

Noninvasive assessment of language dominance in children and adolescents with functional MRI: a preliminary study.

BACKGROUND: Assessment of language organization is crucial in patients considered for epilepsy surgery. In children, the current techniques, intra-carotid amobarbital test (IAT) for language dominance, and cortical electrostimulation mapping (ESM), are invasive and risky. Functional magnetic resonance imaging (fMRI) is an alternative method for noninvasive functional mapping, through the detection of the hemodynamic changes associated with neuronal activation. We used fMRI, to assess language dominance in children with partial epilepsy. METHODS: Eleven right handed children and adolescents performed a word generation task during fMRI acquisition focused on the frontal lobes. Areas where the signal time course correlated with the test paradigm (r = 0.7) were considered activated. Extent and magnitude of signal changes were used to calculate asymmetry indices. Seven patients had IAT, ESM, or surgery outcome available for comparison. RESULTS: fMRI language dominance always agreed with IAT (6 cases) and ESM (1 case), showing left dominance in six and bilateral language in one. fMRI demonstrated left dominance in three additional children, and right dominance in one with early onset of left temporal epilepsy. Four children whose initial studies were equivocal due to noncompliance or motion artifacts were restudied successfully. CONCLUSIONS: fMRI can be used to assess language lateralization noninvasively in children. It has the potential to replace current functional mapping techniques in patients, and to provide important data on brain development.

Lead encephalopathy mimicking a cerebellar tumor.

Encephalopathy is a rare but severe complication of lead poisoning, mainly due to cerebral edema. Usually diffuse, symptoms and signs are sometimes focal, suggesting a false diagnosis of tumor, particularly cerebellar tumor. We report such a case diagnosed by MR imaging in which early treatment for edema avoided neurosurgical exploration. Only six cases have been published since Biemond and Van Creveld's first report in 1939. Several data--clinical and experimental--providing specific involvement of cerebellum in lead poisoning are emphasized.

Contribution of MR in the diagnosis of 'occult' posterior laryngeal cleft.

This paper reports three cases of 'occult' submucous posterior laryngeal cleft in which MR examination has visualized the deficiency of the posterior cricoid lamina. Laryngeal cleft is an uncommon anomaly, and its clinical and endoscopic diagnosis is always difficult. To our knowledge, the role of MR in this diagnosis has not yet been emphasized.

[Currarino syndrome: an association not to be overlooked]. / Le syndrome de Currarino: une association à ne pas méconnaître.

The Currarino triad consists of an anorectal malformation, a presacral tumor and a sacrum defect. A new case is reported in a female neonate. The diagnosis was suspected because of delayed emission of meconium associated with an occlusion syndrome. It was confirmed by bone imaging, ultrasonography and magnetic resonance imaging. A colostomy was performed on day 7 then closed on day 43 after several rectal dilation were carried out. A presacral lipoma was operated on at 10 months. The 56 cases reported in the literature are reviewed.

Non-Hodgkin's lymphoma with cardiac presentation: evaluation and follow-up with echocardiography and MR imaging.

Cardiac presentation of non-Hodgkin's lymphoma is rare and usually associated with a short survival. Two cases were documented and followed-up with echocardiography and magnetic resonance imaging (MRI). The tumoral masses were accurately delineated by MRI. A non-delayed diagnosis ensued and, in association with a multiple drug antimitotic therapy, an improved prognosis obtained.