Serial Neuroimaging Studies Research Articles

Temporal development of subdural collections in infants with confessed abusive head trauma: a forensic neuroimaging study.

Estimating the age of injury in pediatric abusive head trauma (AHT) is a challenging task but potentially valuable for the identification of perpetrators. The aims of the study are (1) to describe the temporal development of different imaging features of subdural collections (SDCs), and (2) to provide novel age-diagnostic reference data for forensic-radiological expert reports. Using a multi-center approach and a 10-year study period, serial neuroimaging studies of 13 comprehensively investigated AHT cases (8 CT and 26 MRI scans) were analyzed regarding several subdural imaging parameters (SDC appearances, entities, components, and associated findings). Due to confessions by perpetrators, the time points of the trauma were presumed unique and known in all cases facilitating correlation of imaging findings with time. Hyperdense SDCs in CT were found up to 9 d post-injury (p.i.), CSF-like SDCs in CT or MRI as early as from the 3rd hour p.i., and subdural membrane formation as late as from day 283. The heterogeneous variant of the subdural hematohygroma was observed to be the dominant SDC entity between 3 h and 22 d p.i. The tadpole sign was detected in MRI between 3 h and 46 d p.i. Certain subdural imaging findings may be helpful for estimating the age of injury in AHT. Subdural membrane formation is demonstrated to be a late finding and the tadpole sign is an early phenomenon p.i. The data corroborated that the sediment but not the supernatant has the potential for being valuable for age-diagnostic aspects. Question Reliable evidence-based data on the development of SDCs is sparse but required for expert opinions on pediatric AHT. Findings Reference data on the evolution of the imaging appearance of SDCs and associated phenomena in confirmed cases of AHT are provided. Clinical relevance As there is a great need for estimating the age of injury in criminal and civil proceedings, many clinical radiologists are confronted with the diagnostic and forensic aspects of AHT that are addressed in the present study.

Insights from serial magnetic resonance imaging in neonatal encephalopathy in term infants.

Limited serial neuroimaging studies use magnetic resonance imaging (MRI) to define the evolution of hypoxic-ischemic insults to the brain of term infants and encompass both the primary injury and its secondary impact on cerebral development. The optimal timing of MRI to fully evaluate the impact of hypoxic-ischemic encephalopathy on brain development and associated neurodevelopmental sequelae remains unknown. Goals: (a) review literature related to serial neuroimaging in term infants with HIE; (b) describe pilot data in two infants with HIE treated with therapeutic hypothermia who had a brain injury at day 3-5 and underwent four additional MRIs over the next 12 weeks of life and developmental evaluation at 24 months of age. Early MRI defines primary injury on diffusion-weighted imaging, yet the full impact may not be fully apparent until after 1 month of life. The full impact of an ischemic injury on the neonatal brain may not be fully visible until several weeks after the initial insult. This suggests the benefit of obtaining later time points for MRI to fully define the extent of injury and its neurodevelopmental impact. Few studies inform the nature of the evolution of brain injury with hypothermia in HIE, limiting understanding of potential neuroprotection. MRI is the standard of care for prognosis in infants with HIE, however timing for optimal prognostic prediction remains unclear. Insights from MRI after the first week of life may assist in defining the full extent of brain injury and prognostic significance. A pilot study using five MRI timepoints up to 3 months of age, is presented. More data is required with a systematic evaluation of the impact of early brain injury on brain development in term infants with HIE following TH.

Evolution of neuroimaging findings in angioinvasive cerebral aspergillosis in a pediatric patient with leukemia during long-term observation

The central nervous system is one of the most common sites of aspergillosis involvement in immunocompromised people, just after sinopulmonary infections. Neuroimaging modalities are crucial for the diagnosis of cerebral aspergillosis (CA). Here, we describe a rare case of concurrent mixed aspergillosis infection with Aspergillus fumigatus and Aspergillus niger in a 2-year-old leukemic boy. The first neuroimaging finding, which was followed by focal seizures, was recognized as extensive cerebral hemorrhage in the absence of thrombocytopenia and coagulopathy. As the patient survived for more than 4 months after diagnosis, we were able to perform a neuroimaging evaluation during long-term observation. In serial neuroimaging studies, a secondary fungal abscess was observed at the site of hemorrhagic infarctions. Finally, the patient died from bacterial sepsis. In this case study, we try to categorize the neuroimaging findings of CA into distinct phases to better understand how CA changes over time.

Treatment of Central Nervous System Post-Transplant Lymphoproliferative Disorder in Immunocompromised Patients with Pancreas Transplant– Between the Rock and a Hard Place (P2-13.002)

<h3>Objective:</h3> To describe the clinical presentation and management of two patients who developed pancreatic transplant rejection during treatment of post-transplant CNS lymphoma (PT-CNSL). <h3>Background:</h3> PT-CNSL is a rare neoplasm developing after immunosuppressive therapy following solid-organ transplantation. Treatment involves reducing immunosuppression, which risks graft rejection. In pancreas transplant recipients, this is associated with increased mortality rates with limited therapeutic alternatives. <h3>Design/Methods:</h3> NA <h3>Results:</h3> <h3>Case Description:</h3> <h3>Case 1:</h3> a 43-year-old female status post pancreas-kidney transplant was diagnosed with PT-CNSL in 2022, initially managed by withholding tacrolimus and initiating rituximab therapy at 375 mg/m2 IV (starting weekly for 3 months, then monthly). The lymphoma regressed with treatment until the patient experienced pancreatic graft rejection (lipase peak 1,124 U/L). This was treated by adding on low-dose tacrolimus which resulted in an improvement in graft rejection and allowed ongoing therapy with rituximab, yielding a complete response of the PT-CNSL. <h3>Case 2:</h3> A 55-year-old female status post pancreas-kidney transplant in 2010, was diagnosed with PT-CNSL in 2021. Treatment involved discontinuation of mycophenolate and tacrolimus and initiation of rituximab at 375 mg/m2 IV (starting weekly for six months, then monthly). Although the lymphoma regressed, the patient experienced acute epigastric pain with a lipase peak of 2,715 U/L with CT of the abdomen illustrating acute pancreatitis. Due to concern for transplant rejection, low-dose tacrolimus was initiated along with rituximab, resulting in resolution of elevated lipase. Continued serial neuroimaging studies demonstrated a complete response. <h3>Conclusions:</h3> PT-CNSL increases morbidity and mortality in pancreas transplant patients with limited treatment options. Treatment should balance maintaining CNS response with careful re-initiation of immunosuppression in the setting of graft rejection; however, there is limited knowledge regarding ideal doses of immunosuppression. We demonstrate that low-dose tacrolimus to prevent graft rejection was safe and effective in treating two patients with PT-CNSL, highlighting the need for further investigation into optimal management strategies. <b>Disclosure:</b> Mrs. Haque has nothing to disclose. Prof. ORLANDO has nothing to disclose. Glenn Lesser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cancer Expert Now. Glenn Lesser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for SDP Oncology. Glenn Lesser has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Agios. Glenn Lesser has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Incysus . Glenn Lesser has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for ONO Pharma. Glenn Lesser has received personal compensation in the range of $0-$499 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer. The institution of Glenn Lesser has received research support from Denovo Biopharma. The institution of Glenn Lesser has received research support from Oblato . The institution of Glenn Lesser has received research support from Novocure. The institution of Glenn Lesser has received research support from GBM Agile - GCAR. Dr. Strowd has received personal compensation for serving as an employee of Kaplan. Dr. Strowd has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Monteris Medical, Inc. Dr. Strowd has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novocure. Dr. Strowd has received personal compensation in the range of $5,000-$9,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Academy of Neurology. The institution of Dr. Strowd has received research support from Southeastern Brain Tumor Foundation. The institution of Dr. Strowd has received research support from Jazz Pharmaceuticals. The institution of Dr. Strowd has received research support from National Institutes of Health. The institution of Dr. Strowd has received research support from Alpha Omega Alpha. The institution of Dr. Strowd has received research support from American Board of Psychiatry and Neurology. Dr. Strowd has received publishing royalties from a publication relating to health care. Dr. Strowd has received publishing royalties from a publication relating to health care.

Concomitant chronic subdural hematomas and arachnoid cysts in young adults.

Objective: This study aimed to evaluate the correlation between arachnoid cysts and chronic subdural hematomas in young adults. Methods: This retrospective study evaluated ten patients having concomitant chronic subdural hematomas and arachnoid cysts. Patients were evaluated with the data of age and gender, location of hematoma and arachnoid cyst, trauma history, symptoms at admission, maximum hematoma diameter, contiguity between arachnoid cyst and hematoma, and treatment methods. Results: We treated 285 patients who were diagnosed with cSDH between January 2013 and December 2019. 22 patients were under the age of 40 years. Ten of them had both cSDH and arachnoid cysts. The mean age of patients was 24.8±3.9 years. Patients with only chronic subdural hematoma had higher mean age than the patients with arachnoid cyst-related chronic subdural hematoma. In four patients, the onset of chronic subdural hematoma was reported after arachnoid cyst diagnosis. Four of the patients did not have causative trauma history, and two patients suffered minor sports-related traumas. All patients had headache, and only two patients had hemiparesis. The location of arachnoid cysts were in the middle fossa in eight patients. All patients had chronic subdural hematomas on the ipsilateral side of arachnoid cyst. Four patients who had smaller than 10 mm maximal cSDH diameter underwent conservative management. They were followed by serial neuroimaging studies and it was noted that the hematoma disappered and the size of the arachnoid cysts decreased over time without any neurological complication. In six cases, craniotomy was required, and all recovered completely. cSDH did not recur during 5-60 months of follow-up period (median 12 months). Conclusions: It seems that presence of an arachnoid cyst in young adults is a predisposing factor for the formation of chronic subdural hematoma. Coincidentally diagnosed arachnoid cyst patients may be followed up with periodical clinical examinations and neuroimaging studies.

Concomitant chronic subdural hematomas and arachnoid cysts in young adults

Objective: This study aimed to evaluate the correlation between arachnoid cysts and chronic subdural hematomas in young adults. Methods: This retrospective study evaluated ten patients having concomitant chronic subdural hematomas and arachnoid cysts. Patients were evaluated with the data of age and gender, location of hematoma and arachnoid cyst, trauma history, symptoms at admission, maximum hematoma diameter, contiguity between arachnoid cyst and hematoma, and treatment methods. Results: We treated 285 patients who were diagnosed with cSDH between January 2013 and December 2019. 22 patients were under the age of 40 years. Ten of them had both cSDH and arachnoid cysts. The mean age of patients was 24.8±3.9 years. Patients with only chronic subdural hematoma had higher mean age than the patients with arachnoid cyst-related chronic subdural hematoma. In four patients, the onset of chronic subdural hematoma was reported after arachnoid cyst diagnosis. Four of the patients did not have causative trauma history, and two patients suffered minor sports-related traumas. All patients had headache, and only two patients had hemiparesis. The location of arachnoid cysts were in the middle fossa in eight patients. All patients had chronic subdural hematomas on the ipsilateral side of arachnoid cyst. Four patients who had smaller than 10 mm maximal cSDH diameter underwent conservative management. They were followed by serial neuroimaging studies and it was noted that the hematoma disappered and the size of the arachnoid cysts decreased over time without any neurological complication. In six cases, craniotomy was required, and all recovered completely. cSDH did not recur during 5–60 months of follow-up period (median 12 months). Conclusions: It seems that presence of an arachnoid cyst in young adults is a predisposing factor for the formation of chronic subdural hematoma. Coincidentally diagnosed arachnoid cyst patients may be followed up with periodical clinical examinations and neuroimaging studies.

Concomitant chronic subdural hematomas and arachnoid cysts in young adults

Objective: This study aimed to evaluate the correlation between arachnoid cysts and chronic subdural hematomas in young adults. Methods: This retrospective study evaluated ten patients having concomitant chronic subdural hematomas and arachnoid cysts. Patients were evaluated with the data of age and gender, location of hematoma and arachnoid cyst, trauma history, symptoms at admission, maximum hematoma diameter, contiguity between arachnoid cyst and hematoma, and treatment methods. Results: We treated 285 patients who were diagnosed with cSDH between January 2013 and December 2019. 22 patients were under the age of 40 years. Ten of them had both cSDH and arachnoid cysts. The mean age of patients was 24.8±3.9 years. Patients with only chronic subdural hematoma had higher mean age than the patients with arachnoid cyst-related chronic subdural hematoma. In four patients, the onset of chronic subdural hematoma was reported after arachnoid cyst diagnosis. Four of the patients did not have causative trauma history, and two patients suffered minor sports-related traumas. All patients had headache, and only two patients had hemiparesis. The location of arachnoid cysts were in the middle fossa in eight patients. All patients had chronic subdural hematomas on the ipsilateral side of arachnoid cyst. Four patients who had smaller than 10 mm maximal cSDH diameter underwent conservative management. They were followed by serial neuroimaging studies and it was noted that the hematoma disappered and the size of the arachnoid cysts decreased over time without any neurological complication. In six cases, craniotomy was required, and all recovered completely. cSDH did not recur during 5–60 months of follow-up period (median 12 months). Conclusions: It seems that presence of an arachnoid cyst in young adults is a predisposing factor for the formation of chronic subdural hematoma. Coincidentally diagnosed arachnoid cyst patients may be followed up with periodical clinical examinations and neuroimaging studies.

Concomitant chronic subdural hematomas and arachnoid cysts in young adults.

Objective: This study aimed to evaluate the correlation between arachnoid cysts and chronic subdural hematomas in young adults. Methods: This retrospective study evaluated ten patients having concomitant chronic subdural hematomas and arachnoid cysts. Patients were evaluated with the data of age and gender, location of hematoma and arachnoid cyst, trauma history, symptoms at admission, maximum hematoma diameter, contiguity between arachnoid cyst and hematoma, and treatment methods. Results: We treated 285 patients who were diagnosed with cSDH between January 2013 and December 2019. 22 patients were under the age of 40 years. Ten of them had both cSDH and arachnoid cysts. The mean age of patients was 24.8±3.9 years. Patients with only chronic subdural hematoma had higher mean age than the patients with arachnoid cyst-related chronic subdural hematoma. In four patients, the onset of chronic subdural hematoma was reported after arachnoid cyst diagnosis. Four of the patients did not have causative trauma history, and two patients suffered minor sports-related traumas. All patients had headache, and only two patients had hemiparesis. The location of arachnoid cysts were in the middle fossa in eight patients. All patients had chronic subdural hematomas on the ipsilateral side of arachnoid cyst. Four patients who had smaller than 10 mm maximal cSDH diameter underwent conservative management. They were followed by serial neuroimaging studies and it was noted that the hematoma disappered and the size of the arachnoid cysts decreased over time without any neurological complication. In six cases, craniotomy was required, and all recovered completely. cSDH did not recur during 5-60 months of follow-up period (median 12 months). Conclusions: It seems that presence of an arachnoid cyst in young adults is a predisposing factor for the formation of chronic subdural hematoma. Coincidentally diagnosed arachnoid cyst patients may be followed up with periodical clinical examinations and neuroimaging studies.

Current Opportunities for Clinical Monitoring of Axonal Pathology in Traumatic Brain Injury.

Traumatic brain injury (TBI) is a multidimensional and highly complex disease commonly resulting in widespread injury to axons, due to rapid inertial acceleration/deceleration forces transmitted to the brain during impact. Axonal injury leads to brain network dysfunction, significantly contributing to cognitive and functional impairments frequently observed in TBI survivors. Diffuse axonal injury (DAI) is a clinical entity suggested by impaired level of consciousness and coma on clinical examination and characterized by widespread injury to the hemispheric white matter tracts, the corpus callosum and the brain stem. The clinical course of DAI is commonly unpredictable and it remains a challenging entity with limited therapeutic options, to date. Although axonal integrity may be disrupted at impact, the majority of axonal pathology evolves over time, resulting from delayed activation of complex intracellular biochemical cascades. Activation of these secondary biochemical pathways may lead to axonal transection, named secondary axotomy, and be responsible for the clinical decline of DAI patients. Advances in the neurocritical care of TBI patients have been achieved by refinements in multimodality monitoring for prevention and early detection of secondary injury factors, which can be applied also to DAI. There is an emerging role for biomarkers in blood, cerebrospinal fluid, and interstitial fluid using microdialysis in the evaluation of axonal injury in TBI. These biomarker studies have assessed various axonal and neuroglial markers as well as inflammatory mediators, such as cytokines and chemokines. Moreover, modern neuroimaging can detect subtle or overt DAI/white matter changes in diffuse TBI patients across all injury severities using magnetic resonance spectroscopy, diffusion tensor imaging, and positron emission tomography. Importantly, serial neuroimaging studies provide evidence for evolving axonal injury. Since axonal injury may be a key risk factor for neurodegeneration and dementias at long-term following TBI, the secondary injury processes may require prolonged monitoring. The aim of the present review is to summarize the clinical short- and long-term monitoring possibilities of axonal injury in TBI. Increased knowledge of the underlying pathophysiology achieved by advanced clinical monitoring raises hope for the development of novel treatment strategies for axonal injury in TBI.

Peritoneal dialysis impairs nitric oxide homeostasis and may predispose infants with low systolic blood pressure to cerebral ischemia

Background & purposeInfants on chronic peritoneal dialysis (PD) have an increased risk of developing neurological morbidities; however, the underlying biological mechanisms are poorly understood. In this clinical study, we investigated whether PD-mediated impairment of nitric oxide (NO) bioavailability and signaling, in patients with persistently low systolic blood pressure (SBP), can explain the occurrence of cerebral ischemia. Methods & resultsRepeated blood pressure measurements, serial neuroimaging studies, and investigations of systemic nitrate and nitrite levels, as well as NO signaling, were performed in ten pediatric patients on PD. We consistently observed the loss of both inorganic nitrate (−17 ± 3%, P < 0.05) and nitrite (−34 ± 4%, P < 0.05) during PD, which may result in impairment of the nitrate-nitrite-NO pathway. Indeed, PD was associated with significant reduction of cyclic guanosine monophosphate levels (−59.4 ± 15%, P < 0.05). This reduction in NO signaling was partly prevented by using a commercially available PD solution supplemented with l-arginine. Although PD compromised nitrate-nitrite-NO signaling in all cases, only infants with persistently low SBP developed ischemic cerebral complications. ConclusionsOur data suggests that PD impairs NO homeostasis and predisposes infants with persistently low SBP to cerebral ischemia. These findings improve current understanding of the pathogenesis of infantile cerebral ischemia induced by PD and may lead to the new treatment strategies to reduce neurological morbidities.

Antithrombotic Therapy for Secondary Stroke Prevention in Bacterial Meningitis in Children

To assess the safety and efficacy of antithrombotic therapy (ATT) for secondary stroke prevention of childhood bacterial meningitis. A retrospective study of cases of stroke associated with bacterial meningitis in 2 pediatric hospitals during a period of 15years. Patients were included in the study if they were between 28days and 18years of age and had at least 2 serial neuroimaging studies during the acute phase of their illness. The safety of ATT was assessed by the presence or absence of intracranial hemorrhage. Efficacy was assessed by the failure in preventing stroke recurrence. Neurologic outcome was determined by the last documented Pediatric Stroke Outcome Measure score. Twenty-two cases of childhood bacterial meningitis complicated by stroke were identified. Six cases were treated with heparin after either initial or recurrent infarction. None of the cases receiving heparin had further recurrence. Aspirin (acetylsalicylic acid [ASA]) was started after the initial or after recurrent infarction in 10 cases. Four (40%) had infarctions on ASA; 3 of these patients subsequently received heparin. In the 14 cases in which no ATT was begun, 8 (57%) had further recurrence of infarction. None of the patients, whether receiving heparin or ASA, had intracranial hemorrhage. In this small sample, heparin and ASA appeared to be safe in childhood bacterial meningitis complicated by stroke and may be effective in improving outcome. Heparin may be more effective than aspirin in preventing recurrent infarction.

Serial neuroimaging in infants with abusive head trauma: timing abusive injuries

The appearance and evolution of neuroimaging abnormalities following abusive head trauma (AHT) is important for establishing the time frame over which these injuries might have occurred. From a legal perspective this frames the timing of the abuse and therefore identifies and excludes potential perpetrators. A previous pilot study involving 33 infants with AHT helped to refine the timing of these injuries but was limited by its small sample size. In the present study, the authors analyzed a larger group of 210 cases involving infants with AHT to chronicle the first appearance and evolution of radiological (CT, MRI) abnormalities. All children younger than 24 months admitted to the Penn State Hershey Medical Center with AHT over a 10-year period were identified from a medical record review; the time of injury was determined through an evaluation of the clinical records. All imaging studies were analyzed, and the appearance and evolution of abnormalities were chronicled on serial neuroimaging studies obtained in the days and weeks after injury. One hundred five infants with specific injury dates and available imaging studies were identified; a subset of 43 children additionally had documented times of injury. In infants with homogeneously hyperdense subdural hematomas (SDHs) on initial CT scans, the first hypodense component appeared within the SDH between 0.3 and 16 days after injury, and the last hyperdense subdural component disappeared between 2 and 40 days after injury. In infants with mixed-density SDHs on initial scans, the last hyperdense component disappeared between 1 and 181 days. Parenchymal hypodensities appeared on CT scans performed as early as 1.2 hours, and all were visible within 27 hours after the injury. Rebleeding into SDHs was documented in 17 cases (16%) and was always asymptomatic. Magnetic resonance imaging of the brain was performed in 49 infants. Among those with SDH, 5 patterns were observed. Patterns I and II reflected homogeneous SDH; Pattern I (T1 hyperintensity and T2/FLAIR hypointensity, "early subacute") more commonly appeared on scans performed earlier after injury compared with Pattern II (T1 hyperintensity and T2/FLAIR hyperintensity, "late subacute"), although there was considerable overlap. Patterns III and IV reflected heterogeneous SDH; Pattern III contained relatively equal mixtures having different intensities, whereas Pattern IV had fluid that was predominantly T1 hypointense and T2/FLAIR hyperintense. Again, Pattern III more commonly appeared on scans performed earlier after injury compared with Pattern IV, although there was significant overlap. These data extend the preliminary data reported by Dias and colleagues and provide a framework upon which injuries in AHT can be timed as well as the limitations on such timing estimates.

Early Spinal Cord and Brainstem Involvement in Infantile Leigh Syndrome Possibly Caused by a Novel Variant

Leigh syndrome, due to a dysfunction of mitochondrial energy metabolism, is a genetically heterogeneous and progressive neurologic disorder that usually occurs in infancy and childhood. Its clinical presentation and neuroimaging findings can be variable, especially early in the course of the disease. This report presents a patient with infantile Leigh syndrome who had atypical radiologic findings on serial neuroimaging studies with early and severe involvement of the cervical spinal cord and brainstem and injury to the thalami and basal ganglia occurring only late in the clinical course. Postmortem microscopic examination supported this timing of injury within the central nervous system. In addition, mitochondrial deoxyribonucleic acid sequencing showed a novel homoplasmic variant that could be responsible for this unique lethal form of Leigh syndrome.

Neurovascular changes in prolonged migraine aura in FHM with a novel ATP1A2 gene mutation

ObjectivesTo report cerebral blood flow changes during attacks of hemiplegic migraine with prolonged aura (HMPA) longer than 24 h in patients with familial hemiplegic migraine (FHM) with a novel gene...

Hydrocephalus and Chiari type 1 malformation in macrocephaly-cutis marmorata telangiectatica congenita: a case-based update

Macrocephaly-cutis marmorata telangiectatica congenita (M-CMTC) is a newly described condition characterized by macrocephaly (megalencephaly), cutis marmorata telangiectatica congenita, macrosomia and/or asymmetric growth, central nervous system abnormalities and neurological manifestations. This condition is usually documented in the Genetics' literature but it has been scarcely disseminated among neurosurgeons. Sudden death of uncertain origin has been reported in children with M-CMTC. Hydrocephalus and tonsillar herniation often occur in this syndrome. The appearance of symptoms and signs of intracranial hypertension or of brain stem compression in M-CMTC patients may herald the development of irreversible neurological damage or death. We report two children diagnosed with M-CMTC and hydrocephalus who were given a ventriculo-peritoneal shunt. In addition, one of them exhibited tonsillar herniation. Given the high incidence of hydrocephalus and/or tonsillar herniation that occurs in M-CMTC, serial neuroimaging studies and neurosurgical referral seem to be warranted in children with this syndrome.

Germ cell tumors in the basal ganglia: problems of early diagnosis and treatment

Intracranial germ cell tumors (GCTs) originating in the basal ganglia are rare. The authors investigated factors related to the diagnosis of these lesions as well as outcome in order to help decrease the time to diagnosis and improve treatment efficacy. The authors reviewed the clinical features of 142 cases of intracranial GCT in their institute. Fourteen cases of basal ganglia GCT were identified. The symptoms, neuroimaging findings, delay between symptom onset and diagnosis or treatment, initial and further treatment, and outcome were investigated. Major symptoms were motor weakness and precocious puberty. Gadolinium-enhanced T1-weighted MR images showed enhancement in 8 of 11 patients examined, but only slight hyperintensity without enhancement in 2 patients. Ipsilateral peduncle and hemispheric atrophy were found in 3 and 4 patients, respectively. Cases of basal ganglia GCT were characterized by a longer delay from the initial neuroimaging examination to diagnosis compared with GCT in other regions. Five patients had aggravated hemiparesis in the extremities due to the delay in diagnosis. Despite good response to the initial therapy, 5 patients experienced recurrence; 2 of these 5 had malignant GCTs, and 3 had been treated only with chemotherapy or radiochemotherapy with insufficient radiation dose and field. Finally, the 2 patients with malignant GCTs died of the disease, and 1 died of aspiration pneumonia due to dissemination around the brainstem. Early diagnosis requires MR imaging with administration of contrast medium in young patients presenting with motor weakness and/or precocious puberty. Serial neuroimaging studies should be performed if any tiny lesion is detected in the basal ganglia. Since insufficient treatment resulted in early recurrence, radiation therapy with adequate dose and field is essential.

Massive plexiform neurofibromas in childhood: natural history and management issues

The authors review their experience with massive plexiform neurofibromas (PNs) in patients with pediatric neurofibromatosis Type 1 (NF1) to better characterize the natural history and management of these complex lesions. The authors performed a retrospective review of data obtained in seven patients with NF1 in whom massive PNs were diagnosed at The Hospital for Sick Children in Toronto, Ontario, Canada. These patients attended routine follow-up examinations conducted by a number of specialists, and serial neuroimaging studies were obtained to monitor disease progression. The most common presenting feature of PN was that of a painful, expanding lesion. Furthermore, two patients harbored multiple, distinct PNs affecting different body sites. With respect to management, two patients were simply observed, undergoing serial neuroimaging studies; two patients underwent biopsy sampling of their plexiform lesions; two patients underwent attempted medical treatment (farnesyl transferase inhibitor, R11577, and cyclophosphamide chemotherapy); and three patients required surgical debulking of their PNs because the massive growth of these tumors caused functional compromise. Ultimately, one patient died of respiratory complications due to progressive growth of the massive PN lesion. In this review of their experience, the authors found certain features that underscore the presentation and natural history of PNs. The management of these complex lesions, however, remains unclear. Slow-growing PNs may be observed conservatively, but the authors' experience suggests that resection should be considered in selected cases involving significant deterioration or functional compromise. Nevertheless, patients with massive PNs will benefit from close surveillance by a team of specialists to monitor for ongoing disease progression.

Moyamoya following cranial irradiation for primary brain tumors in children

To study the risk factors for the development of moyamoya syndrome after cranial irradiation for primary brain tumors in children. We reviewed neuroimaging studies and dosimetry data for 456 children who were treated with radiation for a primary brain tumor and who were prospectively evaluated with serial neuroimaging studies and neurologic evaluations. A total of 345 patients had both adequate neuroimaging and radiation dosimetry data for further analysis. We used survival analysis techniques to examine the relationship of clinically important variables as risk factors for the development of moyamoya over time. Overall, 12 patients (3.5%) developed evidence of moyamoya. The onset of moyamoya was more rapid for patients with neurofibromatosis type 1 (NF1) (median of 38 vs 55 months) and for patients who received >5,000 cGy of radiation (median of 42 vs 67 months). In a multiple Cox proportional hazards regression analysis controlling for age at start of radiation, each 100-cGy increase in radiation dose increased the rate of moyamoya by 7% (hazard ratio [HR] = 1.07, 95% CI: 1.02 to 1.13, p = 0.01) and the presence of NF1 increased the rate of moyamoya threefold (HR = 3.07, 95% CI: 0.90 to 10.46, p = 0.07). Moyamoya syndrome is a potentially serious complication of cranial irradiation in children, particularly for those patients with tumors in close proximity to the circle of Willis, such as optic pathway glioma. Patients who received higher doses of radiation to the circle of Willis and with neurofibromatosis type 1 have increased risk of the development of moyamoya syndrome.

Rapamycin causes regression of astrocytomas in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the formation of hamartomas in multiple organs. Five to 15% of affected individuals display subependymal giant cell astrocytomas, which can lead to substantial neurological and postoperative morbidity due to the production of hydrocephalus, mass effect, and their typical location adjacent to the foramen of Monro. We sought to see whether therapy with oral rapamycin could affect growth or induce regression in astrocytomas associated with TSC. Five subjects with clinically definite TSC and either subependymal giant cell astrocytomas (n = 4) or a pilocytic astrocytoma (n = 1) were treated with oral rapamycin at standard immunosuppressive doses (serum levels 5-15 ng/ml) from 2.5 to 20 months. All lesions demonstrated growth on serial neuroimaging studies. Magnetic resonance imaging scans were performed before and at regular intervals following initiation of therapy. All lesions exhibited regression and, in one case, necrosis. Interruption of therapy resulted in regrowth of subependymal giant cell astrocytomas in one patient. Resumption of therapy resulted in further regression. Treatment was well tolerated. Oral rapamycin therapy can induce regression of astrocytomas associated with TSC and may offer an alternative to operative therapy of these lesions.

Dorsal Midbrain Syndrome due to Mesencephalic Hemorrhage Case Report with Serial Imaging

Spontaneous, nontraumatic, nonhypertensive, midbrain hemorrhage is an uncommon cause of the dorsal midbrain syndrome. We describe a patient with this syndrome in whom the initial neuroimaging studies failed to clearly identify the lesion. Subsequent magnetic resonance imaging studies disclosed a dorsal midbrain hemorrhage. The patient experienced gradual spontaneous resolution of her dorsal midbrain signs and symptoms over several months. The evolution on serial neuroimaging studies of the dorsal midbrain hemorrhage in this patient is described.