Radiographic evolution of myelitis in a case of glial fibrillary acidic protein (GFAP) astrocytopathy.

Autoimmune glial fibrillar acidic protein (GFAP) astrocytopathy is a rare autoimmune neuroinflammatory disorder that affects the central nervous system. We present a case of GFAP astrocytopathy in a middle-aged male who presented with constitutional symptoms, encephalopathy and lower extremity weakness and numbness. Initially MRI of the spine was normal, but he subsequently developed longitudinally extensive myelitis and meningoencephalitis. Workup for infectious aetiologies was negative and the patient's clinical course worsened despite broad antimicrobial coverage. Ultimately, he was found to have anti-GFAP antibodies in his cerebral spinal fluid consistent with GFAP astrocytopathy. He was treated with steroids and plasmapheresis with clinical and radiographic improvement. This case demonstrates the temporal evolution of myelitis on MRI in a case of steroid-refractory GFAP astrocytopathy.

Case 279: Central-Variant Posterior Reversible Encephalopathy Syndrome.

HistoryA 25-year-old woman with recently diagnosed systemic lupus erythematosus and class IV lupus nephritis confirmed with biopsy and treated with mycophenolate mofetil presented with a 2-day history of progressively worsening edema of her face and lower extremities. She had no antecedent infection or vaccination. She was admitted to the hospital and treated with methylprednisolone, furosemide, and C1 esterase inhibitor. On hospital day 2, she experienced a witnessed generalized tonic-clonic seizure. At that time, she became hypoxic and was intubated for airway protection. Her laboratory study results preceding the seizure were remarkable for hyponatremia, with a blood sodium level of 122 mEq/L (122 mmol/L) (normal range, 135-145 mEq/L [134-145 mmol/L]), which was corrected to 137 mEq/L (137 mmol/L) over 48 hours. Same-day cerebrospinal fluid analysis was unremarkable, and unenhanced head CT findings (not shown) were normal, with no evidence of intracranial hemorrhage or edema.Her subsequent hospital course was complicated by renal failure requiring continuous renal replacement therapy, hypertension (systolic blood pressure ranging from 140 to 190 mm Hg), anemia requiring blood transfusions, thrombocytopenia, and pneumonia. She remained intubated with a limited neurologic examination due to sedative medications until hospital day 10. After extubation, she was noted to have a right gaze preference. She was able to speak in short phrases and follow simple commands. Neurologic examination was notable for drowsiness, right gaze deviation, direction-changing torsional nystagmus, horizontal ophthalmoplegia, and generalized symmetric weakness without upper motor neuron signs. The following day (hospital day 11), unenhanced MRI of the brain was performed along with MR angiography of the brain. Biopsy of the temporal artery was normal, without evidence of inflammation.

Case 279.

HistoryA 25-year-old woman with recently diagnosed systemic lupus erythematosus and class IV lupus nephritis confirmed with biopsy and treated with mycophenolate mofetil presented with a 2-day history of progressively worsening edema of her face and lower extremities. She had no antecedent infection or vaccination. She was admitted to the hospital and treated with methylprednisolone, furosemide, and C1 esterase inhibitor. On hospital day 2, she experienced a witnessed generalized tonic-clonic seizure. At that time, she became hypoxic and was intubated for airway protection. Her laboratory study results preceding the seizure were remarkable for hyponatremia, with a blood sodium level of 122 mEq/L (122 mmol/L) (normal range, 135-145 mEq/L [134-145 mmol/L]), which was corrected to 137 mEq/L (137 mmol/L) over 48 hours. Same-day cerebrospinal fluid analysis was unremarkable, and unenhanced head CT findings (not shown) were normal, with no evidence of intracranial hemorrhage or edema.

Three Cases of Trigeminal Neuralgia with Radiographic Absence of Meckel's Cave.

Trigeminal neuralgia (TN) is a debilitating but treatable disease. Classic TN has referable vascular compression of the trigeminal nerve, but rarely secondary sources of anatomic compression will present, including vascular malformations, aneurysms, or tumors. Understanding the etiology of the patients' symptoms leads to targeted treatment. Three patients presented with symptoms consistent with TN: shooting, paroxysmal pains in the distribution of the trigeminal nerve. However, imaging revealed no vascular conflict at the root entry zone of the trigeminal nerve. Instead, on the affected side Meckel's cave was absent. No other compressive mass lesion was identified. In all three cases, patients were offered both Gamma Knife Radiosurgery and surgical decompression of Meckel's cave. All 3 patients elected to proceed with stereotactic radiation and reported improvement in pain. Many cases of classic TN can be explained by neurovascular conflict at the trigeminal root entry zone, but secondary sources of compression or restriction along the nerve can result in similar symptomology. In this case series, an absent or hypoplastic ipsilateral Meckel's cave may have produced symptoms consistent with TN. Imaging with fine cuts through Meckel's cave is an important diagnostic tool.

Imaging correlates for the 2016 update on WHO classification of grade II/III gliomas: implications for IDH, 1p/19q and ATRX status.

The 2016 World Health Organization Classification of Tumors of the Central Nervous System incorporates the use of molecular information into the classification of brain tumors, including grade II and III gliomas, providing new prognostic information that cannot be delineated based on histopathology alone. We hypothesized that these genomic subgroups may also have distinct imaging features. A retrospective single institution study was performed on 40 patients with pathologically proven infiltrating WHO grade II/III gliomas with a pre-treatment MRI and molecular data on IDH, chromosomes 1p/19q and ATRX status. Two blinded Neuroradiologists qualitatively assessed MR features. The relationship between each parameter and molecular subgroup (IDH-wildtype; IDH-mutant-1p/19q codeleted-ATRX intact; IDH-mutant-1p/19q intact-ATRX loss) was evaluated with Fisher's exact test. Progression free survival (PFS) was also analyzed. A border that could not be defined on FLAIR was most characteristic of IDH-wildtype tumors, whereas IDH-mutant tumors demonstrated either well-defined or slightly ill-defined borders (p = 0.019). Degree of contrast enhancement and presence of restricted diffusion did not distinguish molecular subgroups. Frontal lobe predominance was associated with IDH-mutant tumors (p = 0.006). The IDH-wildtype subgroup had significantly shorter PFS than the IDH-mutant groups (p < 0.001). No differences in PFS were present when separating by tumor grade. FLAIR border patterns and tumor location were associated with distinct molecular subgroups of grade II/III gliomas. These imaging features may provide fundamental prognostic and predictive information at time of initial diagnostic imaging.

Erratum to: Imaging correlates for the 2016 update on WHO classification of grade II/III gliomas: implications for IDH, 1p/19q and ATRX status.

In the initial online publication, the values in the last two rows in Table 1 were in the wrong rows. The original article has been corrected.

Case 220: Neurocutaneous Melanosis.

History A 3-month-old boy presented with new onset of seizure that subsided when he arrived at our institution. There was no reported fever or family history of seizure. Physical examination did not reveal any neurologic abnormalities. Multiple skin lesions of varying sizes were identified on the scalp, trunk, and extremities and were reported to have been present since birth. Laboratory test results were normal. Magnetic resonance (MR) imaging of the brain was performed.

Cerebral microbleeds and cognitive decline in a hemodialysis patient: Case report and review of literature.

Cerebral microbleeds (CMBs) are small hemosiderin deposits indicative of prior cerebral microscopic hemorrhage and previously thought to be clinically silent. Recent population-based cross-sectional studies and prospective longitudinal cohort studies have revealed association between CMB and cognitive dysfunction. In the general population, CMBs are associated with age, hypertension, and cerebral amyloid angiopathy. In the chronic kidney disease (CKD) population, diminished estimated glomerular filtration rate has been found to be an independent risk factor for CMB, raising the possibility that a uremic milieu may predispose to microbleeds. In the end-stage renal disease (ESRD) population on hemodialysis, the incidence of microbleeds is significantly higher compared with a control group without history of CKD or stroke. We present an ESRD patient on chronic hemodialysis with a history of gradual cognitive decline and progressive CMBs. Through this case and literature review, we illustrate the need to develop detection and prediction models to treat this frequent development in ESRD patients.

Analyzing nasal septal deviations to develop a new classification system: a computed tomography study using MATLAB and OsiriX.

IMPORTANCE Accurately characterizing nasal septal deviations is valuable for surgical planning, classifying nasal septal deviations, providing a means to accurately perform outcomes research, and understanding the causes of chronic conditions. OBJECTIVE To determine and quantify regions of septal deformity that can be used to develop a comprehensive classification system. DESIGN, SETTING, AND PARTICIPANTS A retrospective case series study was conducted at an academic tertiary care hospital. Sixty-four participants were selected based on a convenience sample of computed tomography (CT) scans of the paranasal sinuses and midface available between June 29, 2011, and August 16, 2012. Exclusion criteria consisted of incomplete or inadequate CT series. The most recent CT scans were chosen for analyses regardless of the indication for imaging. Digital Imaging and Communications in Medicine format bitmap file­formatted data were obtained and analyzed using MATLAB and OsiriX. The line to curve ratio, deviation area, and root mean square (RMS) values of the septal contour vs the ideal straight septum fit were calculated. Analysis was performed to detect significant differences (P < .05) using the 3 measures.MAIN OUTCOMES AND MEASURES Quantitative analysis of nasal septal deviation.RESULTS The population consisted of 50 male and 14 female patients aged 3 to 83 years(mean, 42 years). Mean line to curve ratios, areas, and RMS values were highest in contours that intersected the perpendicular plate­vomer junction, with a mean line to curve ratio of1.04 and mean deviated area of 627.16 arbitrary units (P = .02). Maximal deviation areas were also seen midway from the perpendicular plate­vomer junction to the nasal spine with a mean area of 577.31 arbitrary units (P = .01). The RMS values were significantly elevated along the crista galli and perpendicular plate­vomer junction (P < .05).CONCLUSIONS AND RELEVANCE Maximum septal deviation is seen at the perpendicular plate­vomer junction and in the regions near the crista galli and anterior nasal spine.Deviation area and RMS values are important measures to characterize septal deviations.Understanding septal deviations can aid in developing a functional classification system of nasal septal deviations for clinical use and a means to better record and compare surgical outcomes.

Cryptogenic stroke and the left atrial septal pouch: a case report.

The left atrial septal pouch (LASP) is an anatomic variant of the interatrial septum and may be a nidus for thromboembolism. We present the case of a 49 year-old man without known vascular risk factors who experienced bi-hemispheric strokes over the course of 10 days, suggestive of multiple emboli. Transesophageal echocardiography revealed a prominent LASP. We suggest that presence of LASP was a likely cause of stroke in this patient and that further study of a possible association between LASP and ischemic stroke in younger individuals may be warranted.

Sequence-specific MR imaging findings that are useful in dating ischemic stroke.

Patients may present to the hospital at various times after an ischemic stroke. Many present weeks after a neurologic deficit has occurred, as is often the case with elderly patients and those in a nursing home. The ability to determine the age of an ischemic stroke provides useful clinical information for the patient, his or her family, and the medical team. Many times, perfusion imaging is not performed, and pulse sequence-specific magnetic resonance (MR) imaging findings may help determine the age of the infarct. The findings seen at apparent diffusion coefficient mapping and diffusion-weighted, fluid-attenuated inversion recovery (FLAIR) and unenhanced and contrast material-enhanced T1- and T2-weighted gradient-echo and susceptibility-weighted MR imaging may help determine the relative age of a cerebral infarct. Strokes may be classified and dated as early hyperacute, late hyperacute, acute, subacute, or chronic. Recent data indicate that in many patients with restricted diffusion and no change on FLAIR images, it is more likely than was initially thought that the stroke is less than 6 hours old. The time window to administer intravenous tissue plasminogen activator is currently 4.5 hours from the time when the patient was last seen to be normal, and for anterior circulation strokes, the time window for administering intraarterial tissue plasminogen activator is 6 hours from when the patient was last seen to be normal. For this reason, accurate dating is important in patients with ischemic stroke.