1. Shije J, Brannagan TH. Chronic Inflammatory Demyelinating Polyradiculoneuropathy. Semin Neurol. 2019;39(05):596-607. doi:10.1055/s-0039-1693008
Nice review article on an entitiy whos diagnosis is primarily electrodiagnostic, but MR has a solid secondary role.
Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a relatively common autoimmune disorder affecting the peripheral nerves and nerve roots, often causing progressive or recurrent weakness with diminished reflexes. Electrodiagnostic (EDx) studies, cerebral spinal fluid (CSF) analysis, and nerve biopsy may help provide supportive evidence for the diagnosis.
Cranial neuropathies, and respiratory and/or autonomic dysfunction may be present, although they are infrequent. Cranial nerve involvement, including oculomotor, facial, or bulbar, have been reported in 7% to 16% of cases. Respiratory failure is rare in CIDP. Some CIDP patients have an acute-onset presentation that is clinically indistinguishable from acute inflammatory demyelinating polyradiculoneuropathy (AIDP) or Guillain–Barre Syndrome (GBS) early in the disease course.
CIDP prevalence ranging from 0.8/100,000 (Tottori Prefecture, Japan) to 8.9/100,000 (Olmsted County, Minnesota) have been reported. The annual incidence may range from 0.15 to 1.6/100,000. CIDP can affect age groups from childhood to beyond the eighth decade of life. The highest prevalence reported is in the seventh decade of life, although the mean age of onset may be around the fourth to fifth decade of life; men are more likely to be affected than women.
Most cases have a favorable response to one of the three first-line treatments: corticosteroids, IV immunoglobulin (IVIG) and plasmapheresis. Responses to these treatments may vary among individual patients. There is evidence that a small percentage of CIDP patients with IgG class 4 (IgG4) autoantibodies to paranodal proteins have characteristic clinical features and poorer response to IVIG. Chemotherapy and other immunomodulatory agents, as well as hematopoietic stem cell transplantation, may be considered in refractory cases.
European Federation of Neurologic Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria for CIDP have imaging as a supportive diagnostic tool:
Supportive criteria: 1) CSF protein elevated with <10 WBC. 2) MRI contrast enhancement or hypertrophy of the nerve roots or plexus. 3) Sensory conduction velocity slowing, 4) Objective clinical improvement after immunomodulatory treatment. 5) Nerve biopsy showing unequivocal evidence of demyelination/remyelination.
2. Jokinen H, Koikkalainen J, Laakso HM, et al. Global Burden of Small Vessel Disease–Related Brain Changes on MRI Predicts Cognitive and Functional Decline. Stroke. 2020;51(1):170-178. doi:10.1161/STROKEAHA.119.026170
Magnetic resonance imaging scans of 560 older individuals from LADIS (Leukoaraiosis and Disability Study) were analyzed using automated atlas- and convolutional neural network–based segmentation methods yielding volumetric measures of white matter hyperintensities, lacunes, enlarged perivascular spaces, chronic cortical infarcts, and global and regional brain atrophy. The subjects were followed up with annual neuropsychological examinations for 3 years and evaluation of instrumental activities of daily living for 7 years.
WMH, lacunes, infarcts, and enlarged perivascular spaces were segmented using U-shaped convolutional neural networks on fluid-attenuated inversion recovery and T2 and T1 sequences. The segmentation was performed using 10-fold cross-validation. The ground truth segmentations required for training were generated using manual and semiautomatic methods. An automated postprocessing of the convolutional neural networks results was performed to remove possible erroneous segmentations utilizing spatial information from the multiatlas segmentation and intensity information from a probabilistic intensity atlas.
The strongest predictors of cognitive performance and functional outcome over time were the total volumes of white matter hyperintensities, gray matter, and hippocampi. In a multivariable linear mixed model, volumes of white matter hyperintensities, lacunes, gray matter, and hippocampi remained as independent predictors of cognitive impairment.
They conclude that the global burden of small vessel disease–related brain changes as quantified by an image segmentation tool is a powerful predictor of long-term cognitive decline and functional disability.
2 figures, 3 tables
3. Lester A, McDonald KL. Intracranial ependymomas: molecular insights and translation to treatment. Brain Pathol. 2020;30(1):3-12. doi:10.1111/bpa.12781
This review summarizes the advances made in the molecular characterization of intracranial ependymomas, outlines the progress made in establishing preclinical models and proposes strategies for moving toward subgroup-specific preclinical investigations and treatment.
Ependymomas are rare neuroepithelial tumors, accounting for only 6.9% of primary central nervous system (CNS) tumors diagnosed annually. However, they are the third most common pediatric CNS tumor, constituting 10% of primary intracranial tumors. Ependymomas typically arise from the ependymal lining of the ventricles and central canal of the spinal cord, although they can also arise in the cerebral hemispheres. More than 60% of all ependymomas arise in the posterior fossa, with approximately 30% in the supratentorial region, and the remaining 10% in the spine. However, the location varies by age, with 90% of ependymomas in pediatric patients arising in the brain and the majority of tumors in adults arising in the spine.
WHO classification of CNS tumors categorizes ependymal tumors into five subtypes across three grades. Grade I comprises subependymomas and myxopapillary ependymomas, which are considered benign and rarely transform into grade II or III tumors. However, there are reports of a small number of myxopapillary ependymomas which contain anaplastic features and display malignant behavior. Grade II and III tumors are referred to as ependymomas and anaplastic ependymomas. However, the grading of these tumors, has been criticized for its subjective criteria and lack of reproducibility among pathologists. Further, due to tumor heterogeneity, there is little correlation between tumor grade and patient outcome in pediatric cases. These issues are acknowledged in the 2016 WHO classification, which notes histopathological grading may soon become obsolete.
Approximately 72% of supratentorial ependymomas contain RELA gene fusions. These tumors are more common in children over the age of 4 and adults and have one of the poorest prognoses. Much more in this review on various genetics which are going to have preeminence in this tumor classification in the near future.
2 tables
4. Iverson GL, Gardner AJ, Shultz SR, et al. Chronic traumatic encephalopathy neuropathology might not be inexorably progressive or unique to repetitive neurotrauma. Brain. 2019;142(12):3672-3693. doi:10.1093/brain/awz286
In the 20th century, chronic traumatic encephalopathy (CTE) was conceptualized as a neurological disorder affecting some active and retired boxers who had tremendous exposure to neurotrauma. In recent years, the two research groups in the USA who have led the field have asserted definitively that CTE is a delayed-onset and progressive neurodegenerative disease, with symptoms appearing in midlife or decades after exposure. Between 2005 and 2012 autopsy cases of former boxers and American football players described neuropathology attributed to CTE that was broad and diverse. This pathology, resulting from multiple causes, was aggregated and referred to, in toto, as the pathology ‘characteristic’ of CTE. Preliminary consensus criteria for defining the neuropathology of CTE were forged in 2015 and published in 2016. Most of the macroscopic and microscopic neuropathological findings described as characteristic of CTE, in studies published before 2016, were not included in the new criteria for defining the pathology. In the past few years, there has been steadily emerging evidence that the neuropathology described as unique to CTE may not be unique. CTE pathology has been described in individuals with no known participation in collision or contact sports and no known exposure to repetitive neurotrauma. This pathology has been reported in individuals with substance abuse, temporal lobe epilepsy, amyotrophic lateral sclerosis, multiple system atrophy, and other neurodegenerative diseases. Moreover, throughout history, some clinical cases have been described as not being progressive, and there is now evidence that CTE neuropathology might not be progressive in some individuals. Considering the current state of knowledge, including the absence of a series of validated sensitive and specific biomarkers, CTE pathology might not be inexorably progressive or specific to those who have experienced repetitive neurotrauma.
21 pages! 3 information boxes, 1 figure, 1 table
5. Graff-Radford J, Gunter JL, Jones DT, et al. Cerebrospinal fluid dynamics disorders. Neurology. 2019;93(24):e2237-e2246. doi:10.1212/WNL.0000000000008616
The combination of high-convexity tight sulci (HCTS), defined as compression of sulci at the vertex, enlarged CSF spaces in the Sylvian fissure, and ventriculomegaly, is an established neuroimaging phenotype of a CSF dynamics disorder (CDD) called disproportionately enlarged subarachnoid space hydrocephalus (DESH). Although DESH was originally identified in individuals with symptomatic, normal-pressure hydrocephalus (NPH), recent population studies suggest that features of DESH are more common with advancing age and occur more frequently among persons without obvious symptoms than previously believed.
In HCTS, the ventricles and Sylvian fissures can enlarge and mimic atrophy (i.e., neurodegeneration). The authors therefore hypothesized that this pattern could be overrepresented among persons with normal tau levels and abnormal neurodegeneration (T−[N]+). An additional objective was to determine the frequency of HCTS and to categorize persons with the HCTS pattern of structural imaging abnormalities within the amyloid-tau-neurodegeneration biomarker framework.
The authors analyzed 684 participants ≥50 years of age who were enrolled in the prospective population based Mayo Clinic Study of Aging and underwent structural MRI, amyloid PET imaging, and tau PET imaging. A fully automated machine-learning algorithm that had been developed previously in house was used to detect neuroimaging features of high-convexity tight sulci. On the basis of PET and MRI measures, participants were classified as having normal (A−) or abnormal (A+) amyloid, normal (T−) or abnormal (T+) tau, and normal (N−) or abnormal (N+) neurodegeneration. The neuropsychological battery assessed domain-specific and global cognitive scores. Gait speed also was assessed.
Of 684 participants, 45 (6.6%) were classified with high-convexity tight sulci according to the automated algorithm. Patients with HCTS were older than patients without HCTS. More were cognitively impaired after age and sex adjustment. Amyloid PET status was similar with and without HCTS, but tau PET standard uptake value ratio (SUVR) was lower for those with HCTS after age and sex adjustment.
The HCTS pattern represents a definable subgroup of non-AD pathophysiology (i.e., T−[N]+) that is associated with cognitive impairment. HCTS may confound clinical and biomarker interpretation in AD clinical trials.
2 figures, 1 table, including MR
6. Law ZK, Ali A, Krishnan K, et al. Noncontrast Computed Tomography Signs as Predictors of Hematoma Expansion, Clinical Outcome, and Response to Tranexamic Acid in Acute Intracerebral Hemorrhage. Stroke. 2020;51(1):121-128. doi:10.1161/STROKEAHA.119.026128
Hematoma expansion complicates up to 38% of patients with acute intracerebral hemorrhage (ICH) within the first few hours of onset and leads to higher mortality and morbidity. However, given that the majority of patients with ICH do not have hematoma expansion, identifying patients at risk of hematoma expansion may be important in clinical trials testing hemostatic therapies to selectively target patients who are most likely to benefit.
Several noncontrast CT (NCCT) signs of heterogeneous density and irregular shape have been identified as predictors of hematoma expansion in ICH. The blend sign, black hole sign, swirl sign, fluid level, and hypodensities are signs of heterogeneous density; another, the island sign, reflects irregular shape. Heterogeneous density represents areas of hyperdense mature blood and hypodense fresh blood indicating ongoing bleeding, while island sign may represent multifocal bleeding points. The universal availability of NCCT in patients with ICH and the reportedly excellent interrater reliability amongst trained assessors makes these signs an attractive alternative to CTA spot sign. These signs have a sensitivity of 31.9% to 44.7% and specificity of 94.7% to 98.2% for prediction of hematoma expansion. However, many source studies were small single-center studies. One exception was the Antihypertensive Treatment of Acute Cerebral Hemorrhage II, which found NCCT signs to be useful predictors of hematoma expansion. Several metaanalyses have found substantial heterogeneity between the studies. Therefore, further studies are needed to evaluate the value of NCCT signs.
This study looked at 2077 patients, where baseline and 24-hour computed tomography scans of trial participants were analyzed. Hematoma expansion was defined as an increase in hematoma volume of >33% or >6 mL on 24-hour computed tomography. Poor functional outcome was defined as modified Rankin Scale of 4 to 6 at day 90. Multivariable logistic regression was performed to identify predictors of hematoma expansion and poor functional outcome.
Blend sign is defined as an area of hypodensity adjacent to the hyperdense area of hematoma. The margin should be well-defined with a difference of at least 18 Hounsfield units between the 2 areas. Black hole sign is an area of hypodensity that is completely encapsulated by an adjacent hyperdense area within a hematoma. The difference between the 2 areas should be at least 28 Hounsfield units. Black hole sign is a subset of hypodensities, which can be of any Hounsfield unit and have distinct or indistinct border, as long as it is completed encapsulated by hyperdense area. The island sign is characterized by presence of ≥3 separate small hematomas adjacent to the main hematoma or ≥4 small bubble- or sprout-like hematomas that are partially connected to the main hematoma.
They conclude that the blend sign, black hole sign, and hypodensities predict hematoma expansion while black hole sign, hypodensities, and island signs predict poor functional outcome.
3 figures, 3 tables (1 figure of CT images)
7. Michelozzi C, Darcourt J, Guenego A, et al. Flow diversion treatment of complex bifurcation aneurysms beyond the circle of Willis: complications, aneurysm sac occlusion, reabsorption, recurrence, and jailed branch modification at follow-up. J Neurosurg. 2019;131(December):1-12. doi:10.3171/2018.7.jns18654
The use of flow diverter (FD) stents has been largely approved for the treatment of carotid intracranial aneurysms. Recently, their use has been extended to include distal intracranial localizations. Nevertheless, their use on bifurcation aneurysms beyond the circle of Willis—i.e., at the middle cerebral artery (MCA) bifurcation and at the anterior communicating artery (ACoA) complex—is still debated. Only a few articles with relatively small series and short follow-up times have been published, some with contradictory results.
The purpose of this study is to present the authors’ medium-term results, with special emphasis on complications, occlusion rate of the aneurysm sac (digital subtraction angiography [DSA] and MRI), and the fate of cortical branches and perforating arteries covered (“jailed”) by the flow diverter (FD) stent.
Between January 2010 and September 2017, 29 patients (14 female) with 30 aneurysms were treated with an FD stent. Twenty-one aneurysms were at the middle cerebral artery bifurcation, 8 were in the anterior communicating artery region, and 1 was a pericallosal artery bifurcation. Thirty-five cortical branches were covered. A single FD stent was used in all patients.
Permanent morbidity was 3.4% (1/29), due to a jailed branch occlusion, with a modified Rankin Scale (mRS) score of 2 at the last follow-up. Mortality and permanent complication with poor prognosis (mRS score > 2) rates were 0%. The mean follow-up time for DSA and MRI was 21 ± 14.5 months and 19 ± 16 months, respectively. The mean time to aneurysm sac occlusion (available for 24 patients), including stable remodeling, was 11.8 ± 6 months. The overall occlusion rate was 82.1% (23/28), and it was 91.7% (22/24) in the group of patients with at least 2 DSA control sequences. One recanalization occurred at 41 months posttreatment. At the time of publication, at the latest follow-up, 7 (20%) of 35 covered branches were occluded.
MRI revealed asymptomatic and symptomatic ischemic events in perforator territories in 7/28 (25%) and 4/28 (14.3%) patients, respectively, which were reversible within 24 hours.
They conclude that flow diversion of bifurcation aneurysms is feasible, with low rates of permanent morbidity and mortality and high occlusion rates; however, recurrence may occur. Caliber reduction and asymptomatic occlusion of covered cortical branches as well as silent perforator stroke are common. Ischemic complications may occur with no identified predictable factors.
3 tables, 5 figures….2 with angio and MR images
8. Picillo M, Tepedino MF, Abate F, et al. Midbrain MRI assessments in progressive supranuclear palsy subtypes. J Neurol Neurosurg Psychiatry. 2019;91:98-103. doi:10.1136/jnnp-2019-321354
A number of midbrain-based MRI morphometric measures have shown good sensitivity and specificity for differentiating PSP Richardson’s syndrome (classic version) from other parkinsonian disorders, such as the mid-sagittal midbrain area, the pons area to midbrain area ratio (P/M) and the MR Parkinsonism Index (MRPI). The latter appears to have diagnostic value supporting the clinical diagnosis of PSP-RS compared with multiple system atrophy parkinsonian variant as well as Parkinson’s disease (PD).
The authors explored the role of the available midbrain-based MRI morphometric assessments in differentiating among progressive supranuclear palsy (PSP) subtypes (PSP Richardson’s syndrome (PSP-RS), PSP with predominant parkinsonism (PSP-P) and the other variant syndromes of PSP (vPSP)), and (2) supporting the diagnosis of PSP subtypes compared with Parkinson’s disease (PD) and healthy controls (HC).
Seventy-eight patients with PSP (38 PSP-RS 21 PSP-P and 19 vPSP), 35 PD and 38 healthy controls were included in the present analysis. Available midbrain-based MRI morphometric assessments were calculated for all participants.
While brainstem measures proved able to differentiate PSP-RS from PD and HC, none of them showed an adequate sensitivity and specificity profile in differentiating MDS PSP subtypes. Furthermore, the inclusion of the supratentorial ventricle width into the recent MR Parkinsonism Index 2.0 and the pons area to midbrain area ratio 2.0 did not significantly improve overall diagnostic accuracy and balance between sensitivity and specificity of such measures.
4 figures, 4 tables
