Multinodular and Vacuolating Neuronal Tumor-like Lesion of the Spinal Cord: Two Case Reports.

We describe 2 cases of a spinal cord lesion with imaging features closely resembling those described in supratentorial multinodular and vacuolating neuronal tumor (MVNT) or infratentorial multinodular and vacuolating posterior fossa lesions of unknown significance. Multiple well-delineated nonenhancing T2-hyperintense intramedullary cystic ovoid nodules were visualized within the white matter of the spinal cord, including some immediately abutting the gray matter. No alterations in signal intensity or morphology were detected in a follow-up. Moreover, no relevant clinical symptoms attributable to the lesions were present. We describe these lesions as presumed MVNT, and we therefore use the term MVNT-like spinal cord lesions.

Microstructural Changes in the Spinothalamic Tract of CPSS Patients: Preliminary Results from a Single-Center Diffusion-Weighted Magnetic Resonance Imaging Study.

INTRODUCTION: Chronic pain after spinal surgery (CPSS), formerly known as failed back surgery syndrome, encompasses a variety of highly incapacitating chronic pain syndromes emerging after spinal surgery. The intractability of CPSS makes objective parameters that could aid classification and treatment essential. In this study, we investigated the use of cerebral diffusion-weighted magnetic resonance imaging. METHODS: Cerebral 3T diffusion-weighted (DW-) MRI data from adult CPSS patients were assessed and compared with those of healthy controls matched by age and gender. Only imaging data without relevant artefacts or significant pathologies were included. Apparent diffusion coefficient (ADC) maps were calculated from the b0 and b1000 values using nonlinear regression. After skull stripping and affine registration of all imaging data, ADC values for fifteen anatomical regions were calculated and analyzed with independent samples T-tests. RESULTS: A total of 32 subjects were included (sixteen CPSS patients and sixteen controls). The mean ADC value of the spinothalamic tract was found to be significantly higher in CPSS patients compared with in healthy controls (p = 0.013). The other anatomical regions did not show statistically different ADC values between the two groups. CONCLUSION: Our results suggest that patients suffering from CPSS are subject to microstructural changes, predominantly within the cerebral spinothalamic tract. Additional research could possibly lead to imaging biomarkers derived from ADC values in CPSS patients.

Imaging in Whiplash-Associated Disorders.

"Whiplash," a term describing the severe acceleration and deceleration forces applied to the head, craniocervical junction (CCJ), and cervical spine during trauma, is one of the most frequent mechanisms of injury to the CCJ. The CCJ is a complex region at the transition of the cranium and the cervical spine, essential for maintaining craniocervical stability. In whiplash injuries, the CCJ may be compromised due to underlying ligamentous or, less frequently, osseous, intravertebral disk and/or muscular lesions. Imaging is crucial in detecting acute lesions but may also play a role in the follow-up of chronic pathology because soft tissue lesions and progressive disk pathology could contribute to a whiplash-associated disorder.

The current role and future directions of imaging in failed back surgery syndrome patients: an educational review.

BACKGROUND: Failed back surgery syndrome (FBSS) is an umbrella term referring to painful sensations experienced by patients after spinal surgery, mostly of neuropathic nature. Adequate treatment of FBSS is challenging, as its etiology is believed to be multifactorial and still not fully clarified. Accurate identification of the source of pain is difficult but pivotal to establish the most appropriate treatment strategy. Although the clinical utility of imaging in FBSS patients is still contentious, objective parameters are highly warranted to map different phenotypes of FBSS and tailor each subsequent therapy. MAIN BODY: Since technological developments have weakened the applicability of prior research, this educational review outlined the recent evidence (i.e., from January 2005 onwards) after a systematic literature search. The state of the art on multiple imaging modalities in FBSS patients was reviewed. Future directions related to functional MRI and the development of imaging biomarkers have also been discussed. CONCLUSION: Besides the fact that more imaging studies correlated with symptomatology in the postoperative setting are warranted, the current educational review outlined that contrast-enhanced MRI and MR neurography have been suggested as valuable imaging protocols to assess alterations in the spine of FBSS patients. The use of imaging biomarkers to study correlations between imaging features and symptomatology might hold future potential; however, more research is required before any promising hypotheses can be drawn.

Age-related changes to the craniocervical ligaments in asymptomatic subjects: a prospective MR study.

PURPOSE: The craniocervical junction (CCJ) is a complex of bony and ligamentous structure stabilizing CCJ. Nearly one-third of all traumatic injuries to the cervical spine involve the CCJ. Only little literature is available on this topic, and most of the studies are focused on anatomy, biomechanics or ligamentous injury in whiplash-associated disorders. We conducted a prospective study to investigate age-related changes in the craniocervical ligaments. METHODS: We included asymptomatic volunteers between 16 and 99 years old who had no history of whiplash or other cervical trauma. Volunteers underwent a three-dimensional turbo spin-echo proton density-weighted sequence with variable flip-angle distribution focused on the craniocervical ligaments. The six main ligaments of the craniocervical junction were evaluated for grade of degeneration on a four-point scale by two independent readers, blinded for age and sex. RESULTS: We included 102 volunteers. The mean age was 50.03 (16-94). Fifty-nine (58%) patients showed degeneration of at least one ligament of the CCJ. High-grade anomalous changes and multiligamentous involvement had a positive correlation with age (p < 0.001). The inter-rater agreement was fair to moderate, and the intra-rater agreement was moderate to substantial. CONCLUSION: The craniocervical ligaments show a variable degree of signal intensity and thickness in asymptomatic adults. We postulate that these changes can be due to normal aging or due to repetitive microtrauma. We propose a new grading system to evaluate changes to the craniocervical ligaments in asymptomatic volunteers. These slides can be retrieved under Electronic Supplementary Material.

Epilepsy and migraine in a patient with Urbach-Wiethe disease.

We report the clinical, neuroradiological, and molecular genetic findings in a patient with lipoid proteinosis or Urbach-Wiethe disease. Interestingly, in this patient epilepsy and migraine were the symptoms leading to the diagnosis of the disease, contrary to most patients in whom skin abnormalities are the first recognized symptoms.

Spectrum of nonterminal myelocystoceles.

OBJECTIVE: To present the magnetic resonance imaging features, clinical findings, and possible embryologic bases for nonterminal myelocystoceles, a distinct subset of closed spinal dysraphisms. METHODS: We retrospectively analyzed imaging series and clinical records from five newborns and one older child with skin-covered soft tissue masses along the posterior midline spine. Spinal (6 patients) and brain (5 patients) magnetic resonance imaging was performed before surgical repair and compared with clinical findings, observations at surgery, and final lesion histology. RESULTS: The lesions affected the cervical (n = 3), thoracic (n = 2), and lumbar (n = 1) regions. In each case, the dome of the mass was covered by thickened, dystrophic epithelium with no subcutaneous fat, whereas the base and lateral walls of the mass were covered by normal skin. All patients were neurologically intact at presentation. In three cases, a stalk emanated from the dorsal normal spinal cord, crossed a narrow posterior bony spina bifida, and coursed through a posterior meningocele to attach to the inner aspect of its dome. The other three cases showed dissection of a hydromyelic cavity into the stalk, converting it into a second "cyst" within the meningocele. Concurrent anomalies included focal hydromyelia immediately cranial to the origin of the posterior stalk (n = 2), mild Chiari II malformation (n = 3), triventricular hydrocephalus from aqueductal stenosis (n = 1), filar lipoma (n = 1), and presumed neurenteric cyst (n = 1). At surgery, the sac was resected in all cases, but intradural exploration and untethering was performed in only three children. Embryologic considerations indicate that the spectrum of these lesions likely arises from partial limited closure of the neural tube, failed disjunction of the cutaneous ectoderm, and variable degrees of hydromyelia. CONCLUSION: The nonterminal myelocystocele is a distinct form of closed spinal dysraphism characterized by a skin-covered meningocele, which is either crossed by a fibroneurovascular stalk that extends from the dorsal aspect of the spinal cord to attach to the dome of the meningocele (abortive form, or myelocystocele manqué) or contains a hydromyelic cavity that is continuous with the ependymal canal of the spinal cord (complete form).

Imaging in spinal trauma.

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.

MR angiography of the intracranial vessels: technical aspects and clinical applications.

Evaluation of the intracranial circulation provides valuable information in the diagnosis and prognosis of various intracranial abnormalities and may influence patient management. Technical advances in magnetic resonance angiography (MRA) have improved the accuracy of this technique in various clinical situations, such as aneurysms, arterial and venous steno-occlusive diseases, vascular malformations, inflammatory arterial diseases, preoperative assessment of the patency of dural sinuses, and congenital vascular abnormalities. In many centers, MRA has replaced conventional digital subtraction angiography in screening for intracranial vascular disease, because of its non-invasive and non-ionizing character. Several MRA techniques have been developed for the imaging of the intracranial vascular system, such as time-of-flight MRA (TOF MRA), phase-contrast MRA (PC MRA), and more recently contrast-enhanced MRA (CE MRA). In the evaluation of steno-occlusive disease, the three-dimensional (3D) TOF-MRA technique is recommended for arterial evaluation, and the 2D TOF or 2D PC-MRA technique for venous evaluation. For the evaluation of aneurysms and arteriovenous malformations (AVMs), we recommend the 3D CE-MRA technique, especially dynamic sequences in case of AVM. In this review, the technical aspects, limitations, and optimization of these MRA techniques will be discussed together with their indications in intracranial disease.

Cortical hypoxic-ischemic brain damage in shaken-baby (shaken impact) syndrome: value of diffusion-weighted MRI.

Shaken-baby syndrome (SBS) is a type of child abuse caused by violent shaking of an infant, with or without impact, and characterized by subdural hematomas, retinal hemorrhages, and occult bone fractures. Parenchymal brain lesions in SBS may be missed or underestimated on CT scans, but can be detected at an earlier stage with diffusion-weighted MRI (DW-MRI) as areas of restricted diffusion. We demonstrate the value of DW-MRI in a 2-month-old baby boy with suspected SBS. The pattern of diffusion abnormalities indicates that the neuropathology of parenchymal lesions in SBS is due to hypoxic-ischemic brain injuries, and not to diffuse axonal injury.

Brainstem hemorrhage in descending transtentorial herniation (Duret hemorrhage).

OBJECTIVES: To review clinical and radiological findings in patients with Duret hemorrhages and to discuss the pathophysiology and differential diagnosis of these lesions. PATIENTS AND METHODS: We reviewed the case records of four patients with Duret hemorrhages who had been admitted to the neurological intensive care unit with supratentorial mass lesions. RESULTS: Descending transtentorial and subfalcine herniations were present in all cases. Three patients were admitted with acute subdural hematoma and one with intraparenchymal hemorrhage. Computed tomography revealed the presence of blood in the mesencephalon and upper pons. Three patients died; one survived with severe disabilities. DISCUSSION: Duret hemorrhages are typically located in the ventral and paramedian aspects of the upper brainstem (mesencephalon and pons). The pathophysiology of Duret hemorrhage remains under debate: arterial origin (stretching and laceration of pontine perforating branches of the basilar artery), versus venous origin (thrombosis and venous infarction). Multifactorial causation seems likely. CONCLUSION: Duret hemorrhages are delayed, secondary brainstem hemorrhages. They occur in craniocerebral trauma victims with rapidly evolving descending transtentorial herniation. Diagnosis is made on computed tomography of the brain. In most cases the outcome is fatal. On the basis of our observations we believe that arterial hypertension and advanced age are risk factors for the development of Duret hemorrhage.