C4-T3 Replacement Laminoplasty and Microsurgical Resection of Ependymoma: 2-Dimensional Operative Video

Spinal ependymomas are the most common intramedullary spinal cord tumors in adults.1-4 They are benign histologically, and maximum safe surgical resection should be pursued with the goal of maintaining neurological integrity.4 Spinal ependymoma resections have been described in the operative video literature, including those using techniques of laminoplasty to prevent postlaminectomy kyphosis.1-3,5 Defining the planes between tumor and normal spinal cord is critical to achieving safe maximum resection.3 This video will illustrate the microsurgical techniques used in the resection of a large spinal cord ependymoma in a patient who presented with progressive lower extremity paraparesis and incontinence and was found to have a large intradural, intramedullary C4-T3 lesion with a rostral glial tumor cyst. The patient consented to surgical intervention. The patient was placed prone in MAYFIELD 3-point pin fixation (Integra LifeSciences, Plainsboro Township, New Jersey). Intraoperative neurophysiological electrodes were placed for somatosensory evoked potentials, motor evoked potentials, and D-wave monitoring of corticospinal tracts.6,7 C3-T4 replacement laminoplasties were performed. A midline dural incision spanning C4-T4 was made. A midline myelotomy preserving the pial venous plexus was performed with a 69 Beaver blade.2 The attachments of the tumor to the normal white matter of the spinal cord were microsurgically defined, coagulated, and divided. Tumor debulking was performed with an ultrasonic aspirator. Once gross total resection was achieved, the pial edges of the spinal cord were reapproximated. The dura was closed in a watertight fashion. The patient recovered from surgery well with preservation of her motor function with a continued T7 sensory level.

Two Classes of T1 Hypointense Lesions in Multiple Sclerosis With Different Clinical Relevance

Background: Hypointense lesions on T1-weighted images have important clinical relevance in multiple sclerosis patients. Traditionally, spin-echo (SE) sequences are used to assess these lesions (termed black holes), but Fast Spoiled Gradient-Echo (FSPGR) sequences provide an excellent alternative.Objective: To determine whether the contrast difference between T1 hypointense lesions and the surrounding normal white matter is similar on the two sequences, whether different lesion types could be identified, and whether the clinical relevance of these lesions types are different.Methods: Seventy-nine multiple sclerosis patients' lesions were manually segmented, then registered to T1 sequences. Median intensity values of lesions were identified on all sequences, then K-means clustering was applied to assess whether distinct clusters of lesions can be defined based on intensity values on SE, FSPGR, and FLAIR sequences. The standardized intensity of the lesions in each cluster was compared to the intensity of the normal appearing white matter in order to see if lesions stand out from the white matter on a given sequence.Results: 100% of lesions on FSPGR images and 69% on SE sequence in cluster #1 exceeded a standardized lesion distance of Z = 2.3 (p < 0.05). In cluster #2, 78.7% of lesions on FSPGR and only 17.7% of lesions on SE sequence were above this cutoff value, meaning that these lesions were not easily seen on SE images. Lesion count in the second cluster (lesions less identifiable on SE) significantly correlated with the Expanded Disability Status Scale (EDSS) (R: 0.30, p ≤ 0.006) and with disease duration (R: 0.33, p ≤ 0.002).Conclusion: We showed that black holes can be separated into two distinct clusters based on their intensity values on various sequences, only one of which is related to clinical parameters. This emphasizes the joint role of FSPGR and SE sequences in the monitoring of MS patients and provides insight into the role of black holes in MS.

Pelizaeus-Merzbacher Disease: A Case Report

Pelizaeus-Merzbacher Disease (PMD), as a rare genetically x-linked leukodystrophy, is a disorder of proteolipid protein expression in myelin formation. This disorder is clinically presented by neurodevelopmental delay and abnormal pendular eye movements. The responsible gene for this disorder is the proteolipid protein gene (PLP1). Our case was a oneyear-old boy referred to the radiology department for evaluating the Central Nervous System (CNS) development by brain Magnetic Resonance Imaging (MRI). Clinically, he demonstrated neuro-developmental delay symptoms. The brain MRI results indicated a diffuse lack of normal white matter myelination. This case report should be considered about the possibilityof PMD in the brain MRI of patients who present a diffuse arrest of normal white matter myelination.

Patients with chronic migraine without history of medication overuse are characterized by a peculiar white matter fiber bundle profile

Background: We investigated intracerebral fiber bundles using a tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) data to investigate microstructural integrity in patients with episodic (MO) and chronic migraine (CM).Methods: We performed DTI in 19 patients with MO within interictal periods, 18 patients with CM without any history of drug abuse, and 18 healthy controls (HCs) using a 3T magnetic resonance imaging scanner. We calculated diffusion metrics, including fractional anisotropy (FA), axial diffusion (AD), radial diffusion (RD), and mean diffusion (MD).Results: TBSS revealed no significant differences in the FA, MD, RD, and AD maps between the MO and HC groups. In comparison to the HC group, the CM group exhibited widespread increased RD (bilateral superior [SCR] and posterior corona radiata [PCR], bilateral genu of the corpus callosum [CC], bilateral posterior limb of internal capsule [IC], bilateral superior longitudinal fasciculus [LF]) and MD values (tracts of the right SCR and PCR, right superior LF, and right splenium of the CC). In comparison to the MO group, the CM group showed decreased FA (bilateral SCR and PCR, bilateral body of CC, right superior LF, right forceps minor) and increased MD values (bilateral SCR and right PCR, right body of CC, right superior LF, right splenium of CC, and right posterior limb of IC). Conclusion: Our results suggest that chronic migraine can be associated with the widespread disruption of normal white matter integrity in the brain.

Patients With Chronic Migraine Without History of Medication Overuse Are Characterized by a Peculiar White Matter Fiber Bundle Profile

Background: We investigated intracerebral fiber bundles using a tract-based spatial statistics (TBSS) analysis of diffusion tensor imaging (DTI) datato investigate microstructural integrity in patients with episodic (MO) and chronic migraine (CM).Methods: We performed DTI in 19 patients with MO within interictal periods, 18 patients with CM without any history of drug abuse, and 18 healthy controls (HCs) using a 3T magnetic resonance imaging scanner. We calculated diffusion metrics, including fractional anisotropy (FA), axial diffusion (AD), radial diffusion (RD), and mean diffusion (MD).Results: TBSS revealed no significant differences in the FA, MD, RD, and AD maps between the MO and HC groups. In comparison to the HC group, theCM group exhibited widespread increased RD (bilateral superior [SCR] and posterior corona radiata [PCR], bilateral genu of the corpus callosum [CC], bilateral posterior limb of internal capsule [IC], bilateral superior longitudinal fasciculus [LF]) and MD values (tracts of the right SCR and PCR, right superior LF, and right splenium of the CC). In comparison to theMO group, theCM group showed decreased FA (bilateral SCR and PCR, bilateral body of CC, right superior LF, right forceps minor) and increased MD values (bilateral SCR and right PCR, right body of CC, right superior LF, right splenium of CC, and right posterior limb of IC). Conclusion: Our results suggest that chronic migraine can be associated withthe widespread disruption of normal white matter integrity in the brain.

Role of Diffusion Weighted Imaging in Characterization of Intracranial Rim Enhancing Lesions

Introduction: The differentiation of rim enhancing abscess from high grade necrotic lesions is difficult in conventional imaging. Our purpose was to assess the role of diffusion weighted imaging of intracranial rim enhancing lesions to differentiate the etiologies. Methods: Fifty one patients, 32 male and 19 female with mean age of 48.47 years and with rim enhancing intracranial lesions in magnetic resonance imaging, who underwent surgery from January 2012 to December 2012, were studied for different characteristics of the lesions in DWI and pathologically correlated the observed findings. Results: Out of 58 rim enhancing lesions 21 were primary brain tumor, 18 abscess, 14 metastasis and 5 neurocysticercosis. Twenty lesions had restricted diffusion in center, 22 lesions had thin smooth enhancing rim and 23 lesions were with low T2 complete rim. Diffusion restriction at non enhancing center of the lesion and thin smooth enhancing rim have sensitivity and specificity of 88.89% and 90.24% (p <0.0001) for brain abscess and 83.33% and 80.49% (p <0.0001) for other lesions. ADC ratio of center to that of normal white matter showed sensitivity and specificity of 88.9% and 90% respectively (p <0.0001) at cut off point of 1.09. Lesions with thin smooth rim enhancement with diffusion restriction in nonenhancing center are 100% specific for brain abscess. Conclusions: On studying the different MRI characteristics of rim enhancing lesions, combining enhancement characteristic with DWI is more helpful in coming to the proper diagnosis.

Progressive Multiple Sclerosis Transcriptome Deconvolution Indicates Increased M2 Macrophages in Inactive Lesions

Accumulating evidence suggests M2 macrophages contribute to tissue reparation and limit inflammation in multiple sclerosis (MS). However, most studies have focused on murine models without substantial support through human MS observations. The present study aimed to quantify the relative abundances of M2 macrophages in different lesion types excised from human MS patients. CIBERSORTx, an established RNA deconvolution algorithm, was applied on bulk RNA-sequencing data developed from 98 lesions from 10 progressive MS patients and 5 neuropathological control donors. A validated gene signature matrix for 22 human hematopoietic cell subsets was used to infer the relative proportions of immune cells that were present in the original lesion. Deconvolution of the bulk gene expression data showed that inactive lesions contained significantly more M2 macrophages compared to normal white matter control samples. The findings suggest that M2 macrophages may play a role during lesion inactivity in MS.