BACKGROUND AND PURPOSE:Prior studies regarding acute toxic leukoencephalopathy (ATL) are either small, or preliminary. Our aim was to evaluate etiologies of and differences in imaging severity and outcomes among various etiologies of ATL. MATERIALS AND METHODS:MRIs of patients with suspected ATL over 15 years were retrospectively reviewed; inclusion criteria were: MRI Ͻ3 weeks of presentation with both DWI and FLAIR. These were jointly graded by two neuroradiologists via a previously described score of severity. Clinical outcome was evaluated via both modified Rankin (mRS) and ATL outcome (ATLOS) scores, each being correlated with the DWI and FLAIR scores. Etiologic subgroups of n Ͼ 6 patients were statistically compared. RESULTS:Of 101 included patients, the 4 subgroups of n Ͼ 6 were the following: chemotherapy (n ϭ 35), opiates (n ϭ 19), acute hepatic encephalopathy (n ϭ 14), and immunosuppressants (n ϭ 11). Other causes (n ϭ 22 total) notably included carbon monoxide (n ϭ 3) metronidazole (n ϭ 2), and uremia (n ϭ 1). The mean DWI/FLAIR severity scores were 2.6/2.3, 3.3/3.3, 2.1/2.1 and 2.0/2.5 for chemotherapeutics, opiates, AHE and immunosuppressants, respectively, with significant differences in both imaging severity and outcome (P ϭ .003-.032) among subgroups, particularly immunosuppressant versus chemotherapy-related ATL and immunosuppressants versus opiates (P ϭ .004 -.032) related ATL. DWI and FLAIR severity weakly correlated with outcome ( ϭ 0.289 -.349, P Ͻ .005) but correlated stronger in the chemotherapy ( ϭ 0.460 -.586, P Ͻ .010) and opiate ( ϭ.472-.608, P Ͻ .05) subgroups, which had the worst outcomes. ATL clinically resolved in 36%, with severe outcomes in 23% (coma or death, 9/16 deaths from fludarabine). Notable laboratory results were elevated CSF myelin basic protein levels in 8/9 patients and serum blood urea nitrogen levels in 24/91. CONCLUSIONS:Clinical outcomes of ATL vary on the basis of etiology, being worse in chemotherapeutic-and opiate-related ATL. Uremia may be a predisposing or exacerbating factor. ABBREVIATIONS:AHE ϭ acute hepatic/hyperammonemic encephalopathy; ATL ϭ acute toxic leukoencephalopathy; ATLOS ϭ acute toxic leukoencephalopathy outcome score; CTL ϭ chronic toxic leukoencephalopathy; MBP ϭ myelin basic protein; NAWMϭ normal appearing white matter; PRES ϭ posterior reversible encephalopathy syndrome; PVWM ϭ periventricular white matter Indicates open access to non-subscribers at www.ajnr.org Indicates article with on-line appendix. http://dx.

BACKGROUND AND PURPOSE Posterior reversible encephalopathy syndrome is a clinicoradiologic syndrome. Literature regarding associated factors and the prognostic significance of contrast enhancement in posterior reversible encephalopathy syndrome is sparse. This study set out to evaluate an association between the presence of enhancement in posterior reversible encephalopathy syndrome and various clinical factors in a large series of patients with this syndrome. MATERIALS AND METHODS From an MR imaging report search that yielded 176 patients with clinically confirmed posterior reversible encephalopathy syndrome between 1997 and 2014, we identified 135 patients who had received gadolinium-based contrast. The presenting symptoms, etiology, clinical follow-up, and maximum systolic and diastolic blood pressures within 1 day of MR imaging were recorded. MRIs were reviewed for parenchymal hemorrhage, MR imaging severity, and the presence and pattern of contrast enhancement. Statistical analyses evaluated a correlation between any clinical features and the presence or pattern of enhancement. RESULTS Of 135 included patients (67.4% females; age range, 7–82 years), 59 (43.7%) had contrast enhancement on T1-weighted MR imaging, the most common pattern being leptomeningeal (n=24, 17.8%) or leptomeningeal plus cortical (n=21, 15.6%). Clinical outcomes were available in 96 patients. No significant association was found between the presence or pattern of enhancement and any of the variables, including sex, age, symptom, MR imaging severity, blood pressure, or outcome (all P >.05 after Bonferroni correction). CONCLUSIONS The presence or pattern of enhancement in posterior reversible encephalopathy syndrome is not associated with any of the tested variables. However, an association was found between MR imaging severity and clinical outcome.

BACKGROUND AND PURPOSE:Because intramedullary spinal cord metastasis is often a difficult diagnosis to make, our purpose was to perform a systematic review of the MR imaging and relevant baseline clinical features of intramedullary spinal cord metastases in a large series.

Interlaminar lumbar puncture and cervical puncture may not be ideal in all circumstances. Recently, we have used a transforaminal approach in selected situations. Between May 2016 and December 2017, twenty-six transforaminal lumbar punctures were performed in 9 patients (25 CT-guided, 1 fluoroscopy-guided). Seven had spinal muscular atrophy and were referred for intrathecal nusinersen administration. In 2, CT myelography was performed via transforaminal lumbar puncture. The lumbar posterior elements were completely fused in 8, and there was an overlying abscess in 1. The L1-2 level was used in 2; the L2-3 level, in 10; the L3-4 level, in 12; and the L4-5 level, in 2 procedures. Post-lumbar puncture headache was observed on 4 occasions, which resolved without blood patching. One patient felt heat and pain at the injection site that resolved spontaneously within hours. One patient had radicular pain that resolved with conservative treatment. Transforaminal lumbar puncture may become an effective alternative to classic interlaminar lumbar puncture or cervical puncture.

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