Gamma Knife surgery for recurrent or persistent Cushing disease: long-term results and evaluation of biological effective dose in a series of 26 patients

INTRODUCTION

Here we report long-term results after stereotactic radiosurgery (SRS) with Gamma Knife (GKRS) for Cushing disease. We further evaluated the potential role of the biological effective dose (BED) in the cure of this disease.

METHODS

A retrospective review of a prospectively collected database (n = 26) was undertaken at Lille University Hospital, France. The mean follow-up period was 66 months (median 80, range 19–108). The mean marginal prescribed dose was 28.5 Gy (median 27.5, range 24–35) and the mean BED was 208.5 Gy2.47 (median 228.1, range 160–248). We divided patients with endocrine remission into a high BED group (160–228 Gy2.47, n = 6) and a low BED group (228–248 Gy2.47, n = 12).

RESULTS

Eighteen (69.2%) patients had endocrine remission in the absence of any pharmacological therapy after a mean of 36 months (median 24, range 6–98). The actuarial probability of endocrine remission was 59% at 3 years and 77.6% at 7 years, which remained stable up to 10 years. There was a tendency to a higher overall probability of biological remission associated with higher BED values (77% versus 66% at last follow-up), although this did not reach statistical significance. Of note, the numbers of patients reflecting this actuarial probability at 12, 24, 36, 51 and 96 months were 21, 15, 11, 7 and 3, respectively. Tumour control was achieved in all cases (mean decrease in size for patients experiencing one was 29.4%, range 0–100%). Seven patients developed new pituitary insufficiency after GKRS.

CONCLUSONS

Gamma Knife radiosurgery offers high rates of tumour control and endocrine remission on a long-term basis for ACTH-secreting pituitary adenomas. In this small series, higher BED values appeared to be associated with better endocrine remission rates. Owing to the limited sample size, such results should be validated in a larger cohort.

Gamma Knife radiosurgery for acromegaly: Evaluating the role of the biological effective dose associated with endocrine remission in a series of 42 consecutive cases

INTRODUCTION

Stereotactic radiosurgery (SRS) is a valuable treatment option for persistent and/or recurrent acromegaly secondary to growth hormone (GH) secreting pituitary adenoma (PA). Here, we assess the role of biological effective dose (BED) received by PA treated with SRS in relation with endocrine remission.

METHODS

Forty-two patients (minimum 6 months follow-up) were included. Mean marginal dose was 27.7 (median 28, 20-35), and mean BED received by tumour was 193.1 Gy_2.47 (median 199.7, 64.1-237.1). Based on the median values, we divided the patients in high tumour BED group (H-BEDtm, 199.7-237.1 Gy_2.47, n = 12) and low BED one (L- BEDtm, 64.1-199.7 Gy_2.47 , n = 10). The two groups did not differ by pretherapeutic IGF-1 levels (p = .1) or by the prescribed dose (p = .6).

RESULTS

Mean follow-up period was 62.5 months (median 60.5, 9-127). Probability of IGF-1 normalization was 65% at 3 years and 72.4% at 4 years, remaining stable until last follow-up. Twenty-two (52.4%) patients had complete endocrine remission in absence of any Somatostatin analogues. Actuarial rates were 33% at 3 years and 57.4% at 7 years, further remaining stable during follow-up course. In univariate analysis, only statistically significant parameter was pretherapeutic serum IGF-1 and IGF-1 index (p = .01). Five patients (5/26, 19.3%) without previous hypopituitarism developed new pituitary insufficiency. H-BEDtm was associated with higher rates of endocrine remission compared with L-BEDtm, with actuarial probability of 70.2% versus 48.2% at 9 years, although this did not reach statistical significance (p > .05).

CONCLUSION

Our study confirms that SRS by Gamma Knife is safe and effective for GH-secreting PA. Pretherapeutic serum levels of IGF-1 were only statistically significant parameter for endocrine remission.

Biometry of the Cerebellar Vermis and Brain Stem in Children: MR Imaging Reference Data from Measurements in 718 Children

BACKGROUND AND PURPOSE

Objective and quantitative data to define cerebellar vermis and/or brain stem hypoplasia in children are lacking. Our aim was to provide MR imaging biometric references for the cerebellar vermis and brain stem from a large cohort of children with normal cerebellums.

MATERIALS AND METHODS

The MR imaging data were retrospectively selected from our hospital data base from January 1, 2014, to December 31, 2017. All MR imaging examinations of children between 1 day and 15 years of age, including midline sagittal sections, were included. Children with a clinical history or MR imaging abnormalities that may affect the posterior fossa were excluded. We manually measured four 2D parameters: vermian height, anterior-posterior diameter of the vermis, anterior-posterior diameter of the midbrain-pons junction, and anterior-posterior midpons diameter. The inter- and intraobserver agreement was evaluated.

RESULTS

Seven hundred eighteen children were included (372 boys and 346 girls), from 1 day to 15 years of age. Normal values (third to 97th percentiles) were provided for each parameter. The vermis parameters showed a rapid growth phase during the first year, a slower growth until the fifth year, and finally a near-plateau phase. The brain stem parameters showed more progressive growth. The intra- and interobserver agreement was excellent for all parameters.

CONCLUSIONS

We provide reference biometric data of the vermis and the brain stem using simple and reproducible measurements that are easy to use in daily practice. The relevance of these 2D measurements should be further validated in diseases associated with cerebellar abnormalities.

Lesions in deep gray nuclei after severe traumatic brain injury predict neurologic outcome

PURPOSE

This study evaluates the correlation between injuries to deep gray matter nuclei, as quantitated by lesions in these nuclei on MR T2 Fast Spin Echo (T2 FSE) images, with 6-month neurological outcome after severe traumatic brain injury (TBI).

MATERIALS AND METHODS

Ninety-five patients (80 males, mean age = 36.7y) with severe TBI were prospectively enrolled. All patients underwent a MR scan within the 45 days after the trauma that included a T2 FSE acquisition. A 3D deformable atlas of the deep gray matter was registered to this sequence; deep gray matter lesions (DGML) were evaluated using a semi-quantitative classification scheme. The 6-month outcome was dichotomized into unfavorable (death, vegetative or minimally conscious state) or favorable (minimal or no neurologic deficit) outcome.

RESULTS

Sixty-six percent of the patients (63/95) had both satisfactory registration of the 3D atlas on T2 FSE and available clinical follow-up. Patients without DGML had an 89% chance (P = 0.0016) of favorable outcome while those with bilateral DGML had an 80% risk of unfavorable outcome (P = 0.00008). Multivariate analysis based on DGML accurately classified patients with unfavorable neurological outcome in 90.5% of the cases.

CONCLUSION

Lesions in deep gray matter nuclei may predict long-term outcome after severe TBI with high sensitivity and specificity.

Neuropsychological evaluation and follow-up of children with cerebellar cortical dysplasia

AIM

To describe neuropsychological disturbances and the developmental course associated with cerebellar cortical dysplasia (CCD).

METHOD

The neuroimaging findings from 10 children (five males, five females; aged 3-10 y) with CCD were reviewed and classified. These children all underwent clinical neurological examination and neuropsychological assessment (NPA) on admission, then were followed for an average of 6 years using the cognitive Wechsler Scale, Vineland Adaptive Behavior Scales, and Rey-Osterrieth Complex Figure/McCarthy Drawing subtests.

RESULTS

Based on magnetic resonance imaging, CCD was categorized as minor (n = 4), moderate (n = 1), and severe (n = 5). The first NPA disclosed mental retardation* in six (profound, three; moderate, one; mild, two) and normal intelligence in four (low, two; average, one; high, one), but with verbal/performance dissociation in three cases. Socio-adaptive functions were altered in all children except one. Visuospatial abilities were delayed in eight children. In the follow-up, no progression was observed in the three cases with profound mental retardation, whereas the remainder showed homogeneous or disharmonic progression, including improvement or deterioration of verbal/performance function. Cognitive impairment and evolution was not associated with the degree of cerebellar involvement.

INTERPRETATION

The neuropsychological profile and evolution associated with CCD do not appear to be predictable, and some features might improve over time.

Neonatal status epilepticus due to lamination disorder without significant cell death

BACKGROUND

Malformations of the cerebral cortex may be associated with severe epilepsy and status epilepticus. It has been shown that status epilepticus models induce excitotoxic cell death. In humans, very few data are available.

CASE AND RESULTS

We report a case of a multifocal disorder of the lamination diagnosed in a neonate, born at 30 weeks' gestation, who died from a refractory status epilepticus at two months and half. This abnormality was not detected by repeated MRI studies. Only microscopic investigations permitted to identify this disorder of the lamination. We found also little cell death or cell loss.

DISCUSSION

Our report highlights the possible false negative results of MRI in a newborn. We can also discuss that immature human brain maybe less sensitive to neuronal injury than mature as described in animal models.

Natural history of traumatic meningeal bleeding in infants: semiquantitative analysis of serial CT scans in corroborated cases

BACKGROUND

The natural history of posttraumatic meningeal bleeding in infants is poorly documented, and the differences between inflicted head injury (IHI) and accidental trauma (AT) are debated. Autopsy findings have suggested that anoxia also plays a role in bleeding; however, these findings may not reflect what occurs in live trauma patients.

PURPOSE

We studied the natural history of traumatic meningeal bleeding in infants using serial computed tomography (CT) scans in corroborated IHI and AT.

MATERIALS AND METHODS

From our prospective series, we selected corroborated cases (confessed IHI or AT having occurred in public), who underwent at least three CT scans in the acute phase. We performed a semiquantitative analysis of meningeal bleeding using a four-tier scale (absent, faint, frank, and thick) derived from the Fisher grading for aneurysmal bleeding in four regions of interest (convexity, falx cerebri, sagittal sinus, and tentorium cerebelli).

RESULTS

We studied 20 cases: ten IHI and ten AT. Bleeding was maximal at the convexity initially, then increased along the falx and sagittal sinus, and then along the tentorium. Decrease and disappearance of blood was variable according to the site and the initial quantity of blood. We found no difference between IHI and AT.

CONCLUSION

Our findings suggest that the primary site of meningeal bleeding in infantile head trauma is the convexity of the brain; blood cells then migrate toward the midline following the flow of cerebrospinal fluid circulation and inferiorly following gravity. The pattern of bleeding in traumatic cases appears similar in IHI and AT but different from anoxic lesions.

[Structural MRI in adult partial epilepsy]

Magnetic resonance imaging (MRI) is the prominent imaging modality in the field of epilepsy. MRI plays a major role in describing and recognizing the malformations of cortical development and hippocampal sclerosis and has improved epilepsy patient care. MRI is also accurate in detecting the other major epilepsy etiologies (vascular malformations and cicatricial lesions). Presurgical MRI is relevant since it provides a high-resolution study of the brain.

Subdural effusion in a CNS involvement of systemic juvenile xanthogranuloma: a case report treated with vinblastin

Juvenile xanthogranuloma (JXG) is one of the most common non-Langerhans cell histiocytosis in children. Usually cutaneous, there are disseminated forms. However, neurological localization remains exceptional. A 7-month-old boy had been admitted for subdural effusion due to non-accidental head injury and skin nodular lesions. A biopsy of a skin lesion was considered suggestive of JXG. Skin, eyes, brain, lungs, liver, and testicles were involved. Systemic treatment of JXG was begun with vinblastine. It allowed the regression of skin, lung, and CNS lesions. At age of 11 years, he had not reappearance of the xanthogranuloma. This report emphasizes the possible presentation of xanthogranuloma with subdural effusions, the organs which should be examined in case of disseminated forms and the efficiency of vinblastin.

Progressive myelopathy due to meningeal thickening in shunted patients: description of a novel entity and the role of surgery

INTRODUCTION

Spinal cord compression due to meningeal thickening is a rare occurrence in shunted patients. Because of the long delay to clinical onset, this complication has not been identified as yet.

AIMS

We report on nine cases of shunt-related progressive myelopathy due to meningeal thickening (SPMMT).

MATERIALS AND METHODS

We reviewed our database of shunted children, for cases having developed progressive tetraparesis due to cervical meningeal thickening.

RESULTS

We identified nine observations of SPMMT, eight of these with hydrocephalus due to neonatal meningitis; the last case had Dandy-Walker malformation shunted at birth and suffered postoperative meningitis. The age of clinical onset of myelopathy was between 6 and 20 years (median 12.8). All patients presented with slowly progressive walking difficulties with falls and no spinal pain. Magnetic resonance imaging (MRI) showed typically a thickened dura mater with collapse of the arachnoid space, compensatory expansion of the epidural fat, and T2 hyperintensity in the spinal cord. We operated on seven patients for surgical decompression and arachnoidolysis: One died postoperatively because of shunt malfunction, and two others died later of complications of tetraplegia. Three patients were aggravated after surgery, three experienced partial improvement, but one of these subsequently deteriorated again.

CONCLUSION

SPMMT appears to be a novel and well-defined clinical and pathological entity; its pathological and radiological features are stereotyped; however, the diagnosis is delayed because of the slow pace of the disease. Although surgical decompression may be the only option, its results were poor in our experience; earlier surgery might improve this grim prognosis.

Neuropathological and MRI findings in an acute presentation of hemiconvulsion-hemiplegia: a report with pathophysiological implications

The mechanisms underlying the hemiconvulsion-hemiplegia-epilepsy syndrome (HHE) remain unclear. The current proposed pathogenic mechanism is a neuronal injury induced by venous thrombosis and/or hypoxia. Previous abnormalities of the brain were suggested as underlying mechanism.

MATERIALS AND METHODS

We report a patient who presented acutely with hemiconvulsion-hemiplegia (HH) syndrome, but unfortunately died. We discuss the possible pathophysiology of the HH syndrome and possible therapeutic implications utilizing the data from neuroimaging and pathological studies. Post-mortem examination was performed including immunohistochemistry and electron microscopy of the brain tissue.

RESULTS

The abnormalities in diffusion-weighted imaging indicate cytotoxic edema of the epileptic hemisphere. The pathological studies confirmed a right homogenous hemispheric edema without evidence of any malformation, inflammatory, infectious or metabolic disease. We found axonal damages in the right thalamus confirmed by anti-neurofilament staining.

DISCUSSION

The pathological studies suggest that cytotoxic edema is responsible for neuronal damage. In HH syndrome, two mechanisms playing a role in the development of a later epilepsy could suggest delayed cell death induced by cytotoxic edema and/or thalamic dysfunction causing a disruption of thalamo-cortical circuit. In acute presentation, the use of anti-edema therapy should be discussed to prevent the cell injury.

[Main temporal aspects of the MRI signal of subdural hematomas and practical contribution to dating head injury]

BACKGROUND AND PURPOSE

MRI signal of a subdural hematoma (SDH) is often regarded as similar to that of an intracerebral hematoma but no precise study has analyzed the evolution of the signal of subdural hematomas. Their dating is however significant, in particular in the child, within the context of the diagnosis of child abuse. The objective of this study is to compare with MRI a group of adult patients having a subdural and/or intracerebral, in order to study the evolution of the signals of these two types of hematomas.

MATERIAL AND METHODS

This prospective study included patients hospitalized for post-traumatic acute subdural or intracerebral hematoma. The protocol included an emergency brain CT and 4 MRI at fixed times: in emergency (early phase), between the third and the seventh day (early subacute phase), during the third week (late subacute phase), and after four months after the hemorrhage. The protocol included T1-weighted sequences before and after injection of gadolinium, T2-weighted, fluid-attenuated inversion-recovery (FLAIR), gradient echo and diffusion.

RESULTS

Eighteen patients were included and all 72 MRI were interpretable. The time course of the cerebral hematomas was similar to that described in the literature, whereas that of subdural hematomas was different in 15 patients. This distinction was significant in the early phase for subdural hematomas, which displayed hypersignal in T2 and FLAIR, whereas cerebral hematomas showed a hyposignal in the same sequences. The variation was also notable in the early subacute period during which subdural hematomas displayed hypersignal in T1, FLAIR and diffusion, and isosignal in T2, whereas cerebral hematomas showed isosignal in T1, and hyposignal in T2, FLAIR and diffusion.

CONCLUSION

The time course of MRI signal of subdural hematomas is different from that of cerebral hematomas. This difference is significant in T2 sequence and FLAIR, especially in the early subacute period. These radiographic observations in adults can be useful for the MRI dating of subdural hematomas in shaken-baby syndrome.

Traumatic intracranial hemorrhage in newborns

INTRODUCTION

Neonatal traumatic head injuries (NTHI) can be life-threatening and require aggressive treatment. The indications, techniques, and results of brain decompression are not well defined in the literature.

METHODS

We studied prospectively cases of NTHI with intracranial traumatic lesions; skull fractures without underlying lesions were not included. We treated 17 cases of NTHI: 7 patients had a subdural hematoma, 3 had an extradural hematoma, and the others had subarachnoid hemorrhage. Surgical evacuation of intracranial clots was performed in 7 cases, by needle aspiration in 5 and by craniotomy in 2 patients with extradural hematomas.

RESULTS

The outcome was favorable in all but one patient, who had hemophilia A, and died of rebleeding at the age of 2 months.

CONCLUSION

Surgical decompression of intracranial hematomas due to NTHI is often unnecessary; however, it may be required in emergency because of poor clinical tolerance. Whenever possible, percutaneous needle aspiration is the treatment of choice.

Imaging of head injuries in infants: temporal correlates and forensic implications for the diagnosis of child abuse

OBJECT

The dating of inflicted head injuries in infants is a recurrent and difficult problem in the forensic evaluation of child abuse. The dating of hemorrhagic lesions when using magnetic resonance (MR) imaging is delicate because many confusing factors interact. In particular, infants frequently develop subdural hematomas (SDHs), which are generally composed of a supernatant, similar to cerebrospinal fluid (CSF), and a sediment, similar to blood clots. In the absence of a validated theoretical model predicting the evolution of blood signal in head-injured infants, clinical data are much needed; however, reliably dated information regarding head injuries in infants is scarce.

METHODS

The authors prospectively studied infants who presented with dated and corroborated head injury to investigate the temporal modifications of computerized tomography (CT) and MR imaging in relation to the delay since trauma. In cases of SDH, the authors distinguished between sediment and supernatant based on their CT scanning appearance. They then studied the MR imaging signal of these two components in T1- and T2-weighted, fluid-attenuated inversion recovery (FLAIR), and gradient-echo sequences. Whereas the signal of the supernatant showed little difference from that of the CSF and did not yield information about the date of trauma, the signal in the sediment, especially on the T1-weighted and FLAIR sequences, showed time-related modifications that could be used to date the trauma.

CONCLUSIONS

The authors propose a method by which to develop a time scale for the dating of head injuries in infants based on the modifications of signal and location of blood on CT and MR images.

Cavernous malformations after cerebral irradiation during childhood: report of nine cases

INTRODUCTION

Cavernous hemangioma is increasingly recognized as a late complication of cerebral irradiation (CI); however, the significance of the problem, especially the risk of hemorrhage, is not documented in the literature. In order to discover this, we reviewed our experience of radiation-induced cavernous hemangiomas (RICH) in patients who had received CI during childhood.

METHODS

We reviewed retrospectively our pediatric database of 965 brain tumors, 419 of which were irradiated between 1964 and 2003. We collected nine cases of RICH diagnosed in patients who had received CI during childhood.

RESULTS

The CI dosage ranged between 25 and 55 Gy. The interval between CI and the diagnosis of RICH ranged from 4 to 22 years. The RICH was the cause of brain hemorrhage in five cases, three of which required surgical evacuation.

DISCUSSION

Radiation-induced cavernous hemangiomas are an underestimated problem, and systematic screening of irradiated patients with gradient-echo MRI will probably yield more asymptomatic cases. We think that not all RICH require surgery, but only those responsible for intracerebral hemorrhage or that show radiological progression.

CONCLUSION

With respect for the long interval between CI and diagnosis of RICH, we advise control with MRI, including gradient-echo sequence, as late as 15 years after CI, and closer monitoring of asymptomatic RICH.

Imagerie par résonance magnétique du retard mental non spécifique

Mental retardation is considered idiopathic or not otherwise specified when no etiological diagnosis can be identified in spite of comprehensive history, physical examination and metabolic or genetic investigations. In such cases, brain MRI is indicated for patients with abnormal head size or shape, craniofacial malformation, somatic anomalies, neurocutaneous findings, seizures, focal neurological findings or behavioral and/or developmental problems. Brain anomalies are now considered a main category for the etiology of mental retardation. MRI evaluation should include axial images of the entire brain, sagittal images through the midline structures, and coronal images of the posterior fossa or entire brain. MRI allows detection of major and or minor cerebral anomalies or malformations, sometimes multiple. In the literature, the most frequently involved structures include: 1/ corpus callosum (hypoplasia, short corpus callosum and verticalized splenium), 2/ septum pellucidum (cavum septum pellucidum or cavum vergae), 3/ ventricles (ventriculomegaly), 4/ cerebral cortex (cortical dysplasia), 5/ cerebellum (hypoplasia), and 6/ extra-axial CSF spaces (enlargement). In our patient population, dysplasia involving the cerebellum and vermis have been identified, a finding that has not yet been described in the literature. MRI allows detection of multiple minor morphological anomalies. Most have classically been considered as normal variants but they may in fact be markers of cerebral dysgenesis and are currently the only anomaly detected in the work-up of patients with mental retardation. Their role in the pathogenesis of mental retardation is under evaluation.

[Management of patients after a first seizure]

Neuroimaging evaluation in patients after a first seizure could be easily determined on the basis of seizure history, neurological examination, blood sample analysis and electroencephalography. The main objectives of the initial work-up are to differentiate a true seizure event from seizure-like symptoms, to exclude a single seizure as a manifestation of non organic cause and finally to consider the seizure as a result of cerebral lesion or inaugurate epilepsy. When a new onset seizure is diagnosed, urgent neuroimaging is recommended only in patients with focal neurological deficit, persistent or worsening alteration in the level of consciousness and when clinical and biological data lead to a suspected vascular or infectious etiology. Brain CT scan is usually more available in emergency to identify the cause of seizure. It may have an important role for the therapeutic strategy and may defer MRI investigation. Nevertheless, brain MRI must be performed in emergency when CT scan is not conclusive despite a severe clinical condition or in case of cerebral venous thrombosis. Imaging modalities depend on clinical data, patient age and suspected epilepsy type.

IRM des malformations de l’hippocampe dans l’épilepsie temporale réfractaire

OBJECTIVE

In some patients with temporal lobe epilepsy, recent MRI studies have revealed several morphological features indicative of discrete hippocampal malformation (HM). Its prevalence is unknown and the relationship between the HM and the origin of seizures has never been investigated. Our purpose is to define the MRI findings of this new entity and to determine its incidence in a group of patients and in a control group in order to evaluate its clinical significance.

MATERIALS AND METHODS

MR imaging findings in 97 patients suffering from medically intraceable temporal epilepsy were prospectively evaluated during the preoperative evaluation of surgical candidates. The MR-imaging protocol included oblique coronal slices perpendicular to the temporal lobes using high resolution T2 weighted (HR TSE T2), Fluid attenuated inversion recovery (FLAIR) and inversion-images. This protocol has been completed by axial FLAIR images and axial and sagittal IR images of the whole brain. Coronal HR TSE T2 images were performed in 50 healthy control subjects. Cerebral lesion and hippocampal morphology were evaluated in both groups.

RESULTS

Fourteen patients (14%) showed hippocampal morphological modification. The most frequent and specific findings were lack of visualization of the internal hippocampal (lack of linear T2 hypointensity within the hippocampus) and the abnormal shape (pyramidal, vertically oriented or globular-shaped). Other signs were: abnormal position of the hippocampus (medically located hippocampus) and vertical collateral sulcus. Cases without visualization of the internal structure of the hippocampus were considered as a complete form of HM and were correlated with temporal epilepsy. A vertical collateral sulcus was observed in some control group subjects.

CONCLUSION

Complete forms of HM could be considered as epileptogenic lesions. Nevertheless, interpretation of the incomplete form is delicate: the abnormal angle of the collateral sulcus can be encountered in healthy subjects and could therefore be considered a normal variant.

[Subdural hematomas in children: role of cerebral and spinal MRI in the diagnosis of child abuse]

PURPOSE

To determine if the presence of multiple subdural hematomas (SH) of varying signal intensities at MRI was suggestive of repeated injuries allowing a diagnosis of non accidental head injury (NAHI).

MATERIAL AND METHODS

We included 13 patients (9 boys/4 girls; mean age 15.3 weeks) with suspected NAHI and bilateral SH. Six patients had MRI during acute admission (first week) and seven patients between 10 and 30 days after head trauma (mean 12.6 days). A total of 8/13 patients had spinal MRI. We assessed the distribution and signal intensity of SH, brain, epidural and spinal cord abnormalities. Our findings were compared to medico-legal investigations in 7/13 patients to evaluate the correlation between the age of SH on MRI and the date of injuries.

RESULT

Lesions detected included cerebral edema, ischemia, contusions and cranio-cervical axonal injury and 2/8 patient had spinal epidural hematomas. Multiple SH with varying signal intensities were seen. The commonest location was the frontoparietal areas (100%) and suboccipital region (77%). In 5/6 cases, MRI during the acute admission revealed multiple and small SH having the same signal intensity. When MRI was performed later multiple SH of varying signal intensity were found in 54% of cases. We found a good correlation between the age of the SH and the date of suspected injuries in all cases. Nevertheless, in 5 patients, other SH of various ages were present suggesting rebleeding.

CONCLUSION

Our findings confirm the value of MRI in the detection of brain and spinal cord lesions and SH of varying signal intensities in non accidental head injury. MRI is not able to predict whether different signal intensities correspond to spontaneous repeated bleedings or repeated injuries. The presence of these lesions without clinical evidence of accidental trauma justifies a medico-legal evaluation to confirm the diagnosis of child abuse and to protect these patients.

MRI in children with mental retardation

BACKGROUND

In mental retardation (MR) an aetiological diagnosis is not always obtained despite a detailed history, physical examination and metabolic or genetic investigations. In some of these patients, MRI is recommended and may identify subtle abnormal brain findings.

OBJECTIVE

We reviewed the cerebral MRI of children with non-specific mental retardation in an attempt to establish a neuroanatomical picture of this disorder.

MATERIALS AND METHODS

Thirty children with non-specific MR were selected to undergo cerebral MRI. The examination included supratentorial axial slices, mid-sagittal images and posterior fossa coronal images. Brain malformations, midline and cerebellar abnormalities were studied.

RESULTS

In 27 of 30 patients, the neuroimaging evaluation revealed a relatively high incidence of cerebral and posterior fossa abnormalities. The most frequent were: dysplasia of the corpus callosum (46%; hypoplasia, short corpus callosum and vertical splenium), partially opened septum pellucidum and/or cavum vergae (33%), ventriculomegaly (33%), cerebral cortical dysplasia (23%), subarachnoid space enlargement (16.6%), vermian hypoplasia (33%), cerebellar and/or vermian disorganised folia (20%), and subarachnoid spaces enlargement in the posterior fossa (20%). Other anomalies were: enlarged Virchow-Robin spaces (10%), white matter anomalies (10%) and cerebellar or vermian atrophy.

CONCLUSIONS

MRI has shown a high incidence of subtle cerebral abnormalities and unexpected minor forms of cerebellar cortical dysplasia. Even if most of these abnormalities are considered as subtle markers of brain dysgenesis, their role in the pathogenesis of mental retardation needs further investigation.

[Neurenteric cyst: an unusual congenital malformation of the spinal canal]

Neurenteric cyst is a rare congenital anomaly, which is included in the split notochord syndrome. The cyst arises from abnormal persistence of the neurenteric canal at about three weeks of gestation. The most common locations are extramedullary intradural. They can extend anywhere along the neuraxis. The intermittent, polymorphic and misleading clinical symptoms may result in a delay in diagnosis. Magnetic resonance imaging is the gold standard in the diagnosis of this anomaly. Surgical treatment allows total recovery in most cases.

[Acute spinal epidural and subdural hematomas]

Acute spinal epidural and subdural hematomas are rare entities. The clinical presentation is similar in both cases. MR imaging is the most appropriate imaging technique. On axial images, epidural hematoma has a biconvex shape. It is separated from the spinal cord by the hypointense dura on T2-weighted images. Conversely, subdural hematoma has a crescentic shape on axial images and is located medially to the dura. In the latter case, the epidural fat is not involved. There is no surgical indication for patients with early and rapid regressive symptoms. In other cases the surgical treatment consists of hematoma evacuation.

[Wernicke-Korsakoff syndrome: diagnostic contribution of magnetic resonance imaging]

Data regarding the magnetic resonance imaging (MRI) features in Wernicke-Korsakoff syndrome (WKS) are scarce. WKS usually combines a cerebellar syndrome, oculomotor disorder and confusion. The aim of this study was to determine more precisely the clinical presentation of WKS and the frequency and topography of MRI abnormalities. Furthermore, we try to assess the prognostic value of both clinical signs and MRI abnormalities. We retrospectively studied 25 patients with WKS in which an MRI was available. We assessed the initial clinical presentation and the outcome. We also analyzed the frequency and the location of MRI lesions. We then correlated clinical and MRI data with the clinical outcome. Eleven patients (44 p. 100) had the full WKS. Fourteen of the 25 patients (56 p. 100) had a poor evolution. The occurrence of full WKS was correlated with a poor outcome (p < 0.02). Signal abnormalities on T2-weighted images were found in the periacqueducal region, in the thalami or in the mamillar bodies in 16 cases (64 p. 100). There was a correlation between an hypersignal in at least one region and a poor clinical outcome (p < 0.02). Our study demonstrates the high frequency of brain MRI lesions in WKS and the correlation of both initial clinical signs and MRI abnormalities with a poor clinical outcome.

Infantile subdural hematomas due to traffic accidents

The most common cause of subdural hematomas (SDH) in infants is shaken-baby syndrome (SBS). The pathogenesis and natural history of infantile SDH (ISDH) are poorly documented, because in SBS, the date of shaking is usually imprecise and the assault is often repeated. Victims of traffic accidents (TA) form a study group close to experimental conditions, because the trauma is unique, witnessed and dated. We reviewed 18 cases of SDH due to TA in infants under the age of 24 months. Our goal was to investigate the clinical and radiological data and natural history of SDH. A subdural collection was found on the day of trauma in 7 cases. In 3 of these, the collection was already hypodense. The perifalcine region was the most frequent site of intracranial bleeding. Blood hyperdensity was always found on CT scans performed during the first week, and turned hypodense on about the 9th day. Three patients had retinal hemorrhage, of a type distinct from that found in SBS. Drainage of the SDH was required in 14 cases after a mean delay of 13.5 +/- 5.8 days after trauma. Four patients also required a ventriculoperitoneal shunt because of associated hydrocephalus. Our data suggest that impaired CSF drainage plays a large role in the pathogenesis of ISDH. The fact that a single and recent trauma can result in mixed-density ISDH can be of great importance in forensic medicine.

Intracerebral medulloepithelioma with a long survival

This report concerns a 3-month-old boy where neuroimaging examination showed a large, well-circumscribed, mildly heterogeneous tumor arising in the left ventricle. Pathological findings were compatible with a medulloepithelioma. A survey of published cases of medulloepitheliomas showed this tumor to be highly malignant, possibly displaying the entire range of differentiation from embryonal primitive neuroepithelium to mature cells and usually involving the cerebral hemispheres with a very poor prognosis in this location. On the other hand, medulloepitheliomas occurring in the eye or the orbit generally benefit from a gross-total resection and may present a good prognosis. Curiously, the patient reported here is doing well 7 years after the resection without any postoperative treatment. The exclusive intraventricular location of the tumor and its gross-total resection clearly seems to have contributed to this unusual recovery.

Neuropathologic and MR imaging correlation in a neonatal case of cerebellar cortical dysplasia

Little documentation of the correlation between MR imaging findings in isolated cerebellar cortical dysplasia (CCD) and its neuropathologic characteristics exists in the recent literature. We documented a postmortem neuropathologic study of a clinically and radiologically well-documented case of CCD in a neonate with severe hypotonia and status epilepticus. MR imaging revealed a global vermian hypoplasia with marked cortical dysplasia. CCD was associated with a voluminous heterotopic mass. The postmortem neuropathologic study confirmed vermian hypoplasia and CCD, which consisted of right cerebellar cortical polymicrogyria with subcortical heterotopia. CCD is a pathologic entity that could be well diagnosed with MR imaging even in the neonatal period.

[Pituitary adenomas and pregnancy: morphological MRI features]

The authors present the clinical aspects and changes of the pituitary gland and adenomas in pregnant women by MRI. A number of physiological morphologic changes are seen during pregnancy. Moreover, the hormonal milieu affects patients with adenomas which could evolve leading to severe complications as hypertrophy, necrosis, and hemorrhage. An increase in the volume and T1 hyperintensity of the anterior pituitary, is normally seen. These changes are explained by an increase in lactotrops and prolactin production. Tumoral complications are more frequent with macroadenomas, and are suggestive of a sellar mass or apoplexy. Nevertheless, other differential diagnoses must be suggested in pregnancy and post-partum including hypophysitis and Sheehan syndrome.

MRI protocol technique in the optimal therapeutic strategy of non-functioning pituitary adenomas

OBJECTIVES AND DESIGN

We performed a prospective study using magnetic resonance imaging (MRI) at regular post-operative intervals in non-irradiated patients with non-functioning pituitary adenomas (NFAs) to assess the frequency of tumoral regrowth and recurrences, in order to define the indications of post-operative radiotherapy.

PATIENTS AND METHODS

Fifty-one patients aged 25--80 years (mean, 55.6plus minus12.3 years) were included. Post-operative MRIs were performed 3--12 months (mean, 5.2plus minus1.7 months) after surgery, 6 months later and then, every 12--18 months for at least 2 years. The mean post-operative follow-up was 67.7plus minus31.8 months (range, 24--144 months).

RESULTS

In 17 patients (33%, group I) no tumoral residue was observed on post-operative MRIs and no tumoral recurrence was diagnosed. Tumour regrowth was detected in 13 of the 34 patients (38.2%) with post-operative tumoral residue (group II), 7--66 months (mean, 27.3plus minus17.3 months) after surgery. In this group, Kaplan--Meier analysis showed 78.8% recurrence free survival at 2 years and 60.9% at 5 years. Patients with tumoral regrowth had higher mean residual tumoral volume than patients without any tumoral regrowth in the group II (258plus minus165 vs 163plus minus165 mm(3), P=0.05).

CONCLUSIONS

We suggest a MRI protocol that includes, a 4- to 6-, 12- and 24-month post-operative MRI for every patient. When no tumoral residue is seen, pituitary radiotherapy is useless. MRI must be repeated 3, 5 and 10 years after surgery to eliminate late recurrence. The observed frequency of tumoral regrowth in patients with tumoral residue does not justify systematic post-operative radiotherapy. It should be performed only when tumoral regrowth is proved by a yearly MRI survey.

Melanotic neuroectodermal tumour of the pineal region

We describe CT and MR findings in a 23-month-old infant with a melanotic neuroectodermal tumour of the pineal gland. The tumour has been stereotactically biopsied and surgically resected. The pathological diagnosis was made on the resected piece. Embryology of the pineal gland and the histology of melanotic neuroectodermal tumour of infancy are discussed.

Subduroperitoneal drainage for subdural hematomas in infants: results in 244 cases

OBJECT

Subduroperitoneal drainage (SDPD) is commonly used in the treatment of infantile subdural hematomas (SDHs). Few studies have focused on this technique and most series have included SDHs of various origins in children of different ages. The surgical procedure is not standardized and results achieved using this technique have not been well documented. The authors reviewed their cases of traumatic SDH treated with SDPD in infants (< 2 years of age). Their standard technique includes bilateral SDPD whenever the SDH is bilateral, placement of a free shunt, and systematic removal of the drainage unit after a few months.

METHODS

The authors performed SDPD in 244 infants with traumatic SDH. The patients' SDHs were controlled by SDPD in 241 cases, and 78.9% of the patients recovered to live a normal life. Complications of SDPD occurred in 38 patients (15.6%): obstruction in 22 cases (9%), infection in eight cases (3.28%), and internal hydrocephalus in eight cases (3.28%). Early complications could be ascribed to surgical technique, delayed complications were associated with the severity of the initial clinical presentation, and late complications were time dependent and unrelated to initial clinical severity. Poor clinical outcome was correlated to the severity of the initial presentation, but not to complications of surgery.

CONCLUSIONS

Because of its efficacy and low complication rate, SDPD is the procedure of choice when subdural taps fail to control SDH. The authors prefer bilateral drainage because of the low rate of complications. Drains should be systematically removed after a few months to prevent long-term complications.

Report of eight cases of occipital dermal sinus: an update, and MRI findings

OBJECTIVE

We report our experience with 8 patients who were ultimately diagnosed as having occipital dermal sinuses. Clinical presentation, imaging findings and outcome are discussed, along with a review of the literature.

STUDY DESIGN

In eight patients with occipital dermal sinuses, we retrospectively collected the following data: time to diagnosis, presenting signs, dermal anomalies, location of bone defects, intraparenchymal extension, surgical techniques and clinical outcome. Conventional radiography was performed in all patients; computerized tomography (CT) scans and magnetic resonance imaging (MRI) in all but two.

RESULTS

Time to diagnosis ranged from 3 months to 9 years. Presenting symptoms were: infection of a cutaneous mass (n = 4), occipital mass (n = 2), intracranial hypertension related to intra-cerebral abscess (n = 2). In all patients, dermal sinus was located near the external protuberance of the occipital bone. In all patients but one, a cutaneous orifice was associated. Other cutaneous anomalies were: hairy nevus (n = 2) and subcutaneous cysts (n = 4). One patient had associated cranio-facial malformations. Plain skull films revealed linear bony defects in all cases but one; CT scans revealed linear bony defects in all cases, osteitis and intra-parenchymal abscesses if present but they did not allow the delineation of the sinus tract. MRI performed in six patients allowed a better appreciation of the malformation revealing intracranial abscess (n = 1), the sinus tract (n = 2), inclusion cysts (n = 2), and associated venous anomalies (n = 1). Surgery was performed in all patients: a complete removal of the dermal sinus was obtained in all patients but one; inclusion cysts were found in six patients. Total recovery without sequelae was obtained in all patients, except one who suffered from developmental delay and a polymalformative syndrome.

CONCLUSIONS

In newborns, a meticulous visual exploration of the midline skin along the craniospinal axis is necessary to detect congenital dermal abnormalities. Early surgery is required to prevent severe intracranial infection. MRI could help to determine the surgical approach by delineation of the sinus tract, its extension into deeper tissues and its association with cysts, abscesses or venous anomalies.

Occipital dermal sinuses: report of nine pediatric cases and review of the literature

Occipital dermal sinuses (ODS) are rare dysraphic lesions resulting from defective separation of the ectoderm and neuroderm. These lesions are often diagnosed at birth and should be treated early because of potentially life-threatening complications. However, the pathogenesis of these rare lesions is still poorly understood, and there is no consensus about the optimal timing of surgery. We reviewed 9 pediatric cases of ODS operated in our department since 1982 and 79 other cases published in the literature during the last 50 years. Thirty-eight percent of these had neurological infection (meningitis or abscess), 22% had purely local infection and 40% were uncomplicated at the time of diagnosis. The incidence of infection was low during the first year of life. MRI was highly valuable to study the extent of the sinus and the content of the cyst. The outcome was regularly favorable after surgery. Surgery should however be undertaken with caution on account of the intimate relationship with venous structures, aggravated by postinfectious scarring when the patient is operated late. Considering the risks associated with surgery in neonates and the low incidence of infection during the first year, we advise performing surgery at around 6 months.

[Cerebellar pilocytic astrocytomas in children. Report of 72 cases]

BACKGROUND AND PURPOSE

Cerebellar pilocytic astrocytoma (CPA) bears a well-deserved reputation of benignity. However, these tumors infiltrate the brainstem in a number of cases, and total removal may cause morbidity, whereas subtotal removal can lead to recurrence.

MATERIAL AND METHODS

To define guidelines for tumor removal, management of tumor remnants and recurrence, we reviewed 72 cases of CPA of childhood operated on in our department since the introduction of CT.

RESULTS

Surgical removal was total in 57 cases, had to be withheld because of brainstem infiltration in nine cases, and was revealed subtotal by postoperative imaging in six cases. Two of the latter were reoperated on; six had only radiological controls and did not progress. Early in the series, eight children had external irradiation because of subtotal removal or recurrence. Three children were reoperated on for tumor recurrence, between six and eight years after complete removal. We had no tumor-related mortality; long-term disability could be related to previous mental retardation, the severity of clinical state at presentation, and complications of surgery and irradiation.

CONCLUSION

The goal of surgery is to cure the patient with minimal morbidity, however, total removal is not always possible. In our experience: i) tumor remnants can be surveyed radiologically, and reoperated only in case of progression; ii) the indications for radiotherapy should be the exception; iii) clinical and radiological follow-up should be protracted beyond entry into adulthood.

Cerebellar atrophy after severe traumatic head injury in children

OBJECT

The purpose of this study was to describe late neuropathological MRI findings in pediatric severe head injury and to explore the relationship between these lesions and cognitive sequelae.

METHODS

Thirteen infants with severe head trauma (Glasgow 6) were included in this investigation. Clinical examination, a battery of tests designed to assess neurophysiological status, and MRI investigations of the brain were obtained in periods ranging between 8 and 20 months after the accident. Hemosiderin deposits, encephalomalacia, and cerebellar atrophy were the most frequent traumatic sequelae. The lesions were located in frontal lobes, the basal ganglia, and the cerebellum. Six patients had cerebellar atrophy associated with frontal or temporal postraumatic lesions. Cerebellar clinical dysfunction was observed in only 3 of these patients. Performance on tests evaluating frontal lobe functions was depressed in 5 of them.

CONCLUSIONS

Late MRI after severe head trauma in our pediatric population showed unexpected cerebellar atrophy. Its correlation with prefrontal dysfunction is difficult to confirm because of its association with other parenchymal post-traumatic lesions. Further research involving a larger sample of patients with brain injury of varying severity is in progress, to investigate whether cerebellar atrophy could be a consequence of severe head trauma.

Supratentorial ependymoma in children

The clinical and pathological characteristics of supratentorial ependymomas (STE) in children are not well identified in the literature, because most series deal with ependymomas regardless of their location or the age of the patient. As a result, the pathological description of the disorder is still debated. We therefore reviewed our cases of children operated for STE and compared them with cases of infratentorial ependymomas (ITE) to provide a better characterization of STE and suggest guidelines for treatment. From 1985 to 1999, we operated 18 children for STE, almost half of which developed with no connection to the ventricular system. Intraoperative bleeding and infiltration of the basal ganglia prevented total removal in 4 cases and were the main causes of operative mortality and morbidity. The 5-year overall survival and recurrence-free survival rates were 54 and 37%, respectively, and were highly affected by the extent of resection, but not by histological grade. Because of the high recurrence rate, we recommend systematic postoperative irradiation limited to the tumor site for all high-grade tumors in older children, and reoperation after subtotal removal and for recurrences.

[Cytomegalovirus rhombencephalomyelitis in an immunocompetent subject]

We report the clinical and MRI findings of a 31-year-old healthy immuno-competent patient who presented following 48 hours of diffuse headache with progressive and severe rhombencephalomyelitis signs. Cerebral and medullar MRI confirmed the central nervous system improvement. Serology showed relation with cytomegalovirus infection. Spontaneous improvement was observed and favoured by ganciclovir administration.

Cerebellar gliomas in infants: specificity, pathology, and outcome

Cerebellar gliomas (CGs) in children are generally associated with a favorable outcome; however, data regarding these tumors in very young children are scarce. We report on our experience with CGs in children less than 3 years old at surgery, compared with a second group older than 3 years. From 1991 to 1996, we operated on 7 children with CGs in the first group and 43 in the second. Psychomotor delay and regression were the first symptoms in 3 cases, and 3 had macrocrania. The tumor was totally removed in all cases. One child died intraoperatively of air embolism and subdural bleeding. Three had malignant tumors (grade 3 or 4). There was no operative mortality or malignancy in the second group of patients. With a mean follow-up of 33 months, all survivors in the first group are disease-free, with no or minimal symptoms, and attend normal schools. The clinical, surgical, and pathological features suggest that children under 3 years of age represent a specific subgroup of CGs.

Cerebellar cortical dysplasia: MR findings in a complex entity

BACKGROUND AND PURPOSE

MR imaging findings of cerebellar cortical dysplasia have been described as a new cerebellar malformation. The purpose of this study was to assess the association of cerebellar cortical dysplasia with other cerebral malformations.

METHODS

We retrospectively reviewed 46 MR examinations of patients presenting with developmental delay, hypotonia, and facial deformities to identify abnormal folia or fissures or both within cerebellar hemispheres or vermis suggesting cortical dysplasia.

RESULTS

Cerebellar cortical dysplasia was diagnosed in 17 patients. In two patients, it was isolated. In the remaining 15 patients, the malformation was associated with vermian malformation (n=11), cerebral cortical dysplasias (n=8), dysplasia of corpus callosum (n=6), and heterotopia (n=5). A widespread malformation of the posterior fossa was observed in eight patients (Dandy-Walker, Chiari II and III, and hypoplasia of brain stem). One patient with hypertrophied cerebellar hemisphere had minor enlargement of the right cerebral hemisphere and lateral ventricle. He also had nodular heterotopia, suggesting unilateral megalencephaly.

CONCLUSION

Our study suggests that cerebellar cortical dysplasias are common in cases with more widespread cerebral malformations. Technical progress providing high-quality tridimensional MR imaging of the cerebellum may explain its recent descriptions.

Cerebellar gliomas in children with NF1: pathology and surgery

Cerebellar gliomas associated with NF1 (CGNF1) are rarely reported in the literature, and they are considered to be malignant in a high proportion of cases. In an attempt to improve the definition of this disease and clarify its management, we reviewed our patients with CGNF1 and compared their tumors with sporadic cerebellar gliomas (SGC). We operated on six children with CGNF1, all but one of whom were asymptomatic. They represented one-tenth of all pediatric cerebellar gliomas, and one third of NF1-associated gliomas seen in our institution. CGNF1 appeared at a later age than SCG. They are seated near the roof of the IV ventricle and are not related to white matter hypersignal hamartomas. Most of these tumors showed radiological progression. They were four pilocytic astrocytomas, one ganglioglioma, and one malignant astrocytoma. One patient had tumor recurrence after 8 years, and the others are still disease free. The overall outcome appeared to be better for GCNF1 than for SCG. On account of the regular growth, uncertain pathology, and good surgical outcome, we advocate systematic resection of these tumors.