PRESenting a Challenge: Posterior Reversible Encephalopathy Syndrome in Pediatric Patients With Guillain-Barré Syndrome: A Case Series and Review of Literature.

BACKGROUND: Guillain-Barré syndrome (GBS) is an autoimmune disorder characterized by demyelination of peripheral nerves. GBS-associated posterior reversible encephalopathy syndrome (PRES) is a rare and potentially life-threatening complication in the pediatric population. We aimed to report and analyze the clinical features, management, and outcomes of three cases of GBS-associated PRES in our setting in the light of the existing literature. METHODS: Medical records of 75 pediatric patients with GBS were reviewed for autonomic changes and GBS-associated PRES. Thirty-one developed dysautonomia while three were identified to have PRES. Clinical, radiological, laboratory, and treatment data were collected and analyzed. RESULTS: All three patients were male and presented with symptoms of acute flaccid paralysis and respiratory distress requiring mechanical ventilation. All three patients experienced various complications, including hypertension, seizures, and hyponatremia, and were subsequently diagnosed with PRES. Multimodal intensive care resulted in patient improvement and discharge in an ambulatory state after an average of 104 days of care. CONCLUSIONS: GBS-associated PRES is a rare and potentially life-threatening complication that can occur in pediatric patients with GBS. Our findings suggest that early recognition, prompt intervention, and multimodal intensive care can improve patient outcomes. Further studies are needed to determine optimal treatment strategies for GBS-associated PRES.

Mimics of Guillain-Barré Syndrome in Pediatric Patients Admitted to the Neuro-Intensive Care Unit of a Tertiary Care Hospital-A Case Series.

Guillain-Barré syndrome is the most common cause of acute flaccid paralysis in children, but several diseases mimic GBS. We aimed to identify and report the clinical pointers and battery of tests required to differentiate Guillain-Barré syndrome from its observed mimics in the pediatric population admitted to our neuro-critical care unit. We conducted a retrospective record analysis of all pediatric patients admitted over ten years from 2008-2018, whose initial presentation was compatible with a clinical diagnosis of GBS. Eighty-three patients were at first treated as GBS, of which seven (8.4%) were found to have an alternate diagnosis-three cases of paralytic rabies, one case each of acute disseminated encephalomyelitis, cervical myeloradiculopathy, neuromyelitis optica, and a case of community-acquired Staphylococcus aureus pneumonia associated sepsis. Neurophysiological and neuro-virological testing, central nervous system imaging, and sepsis screening helped to confirm the alternate diagnosis. Our case series provides knowledge of subtle clinical differences along with the mindful use of diagnostic testing to facilitate the accurate diagnosis of GBS mimics.

Comparison of arterial spin labeling perfusion with dynamic susceptibility contrast perfusion in Moyamoya disease.

Objectives: Moyamoya disease (MMD) leads to frequent ischemic/hemorrhagic manifestations. Our aim was to compare findings of arterial spin labeling (ASL) with dynamic susceptibility contrast (DSC) perfusion in patients of MMD. Materials and Methods: Patients diagnosed as MMD underwent magnetic resonance imaging with ASL and DSC perfusion sequences. Perfusion in bilateral anterior cerebral artery and middle cerebral artery territories at two levels (level of thalami and centrum semiovale) was graded as normal (score 1), or reduced (score 2) on DSC and ASL cerebral blood flow (CBF) maps by comparison with normal cerebellar perfusion. Time to peak (TTP) maps of DSC perfusion were also qualitatively scored as normal (score 1), or increased (score 2) similarly. Correlation between scores of ASL, CBF, DSC, CBF, and DSC, TTP maps was assessed by using Spearman's rank correlation. Results: Among the 34 patients, we did not find any significant correlation between the ASL CBF maps and DSC CBF maps (r = -0.028, P = 0.878), mean matching index 0.39 ± 0.31, whereas significant correlation was noted between the ASL CBF maps and DSC TTP maps (r = 0.58, P = 0.0003), mean matching index 0.79 ± 0.26. ASL CBF underestimated the perfusion compared to DSC perfusion. Conclusion: ASL perfusion CBF maps do not match the DSC perfusion CBF maps and rather match the TTP maps of DSC perfusion. This is explained by inherent problems in estimation of CBF in these techniques because of delay in arrival of label (in ASL perfusion) or contrast bolus (in DSC perfusion) due to the presence of stenotic lesions.

MRI Spectrum of Toxic Encephalopathy-An Institutional Experience.

Background: There are numerous toxins that affect our nervous system, both central and peripheral. Innumerable differentials exist in patients of acute encephalopathy and the list can be narrowed down with appropriate imaging. Specific neuroradiological features point to a particular diagnosis in a substantial number of cases. Objective: Through this study, we aimed to demonstrate the varied imaging findings of toxic encephalopathy on MRI encountered at our institute. Material and Methods: A retrospective analysis of the patients clinically diagnosed as toxic encephalopathy and referred for imaging between March 2015 and December 2019 was done. A total of 25 patients were included. Patient records were reviewed for clinical details, laboratory investigations, and treatment; the institute Picture Archiving and Communication System provided the imaging findings. Results: Patients presenting were aged between 22 and 55 years (mean-34.3 years). Four patients (16%) presented with imaging findings characteristic of Marchiafava-Bignami disease and six patients (24%) had MRI findings of Wernicke encephalopathy. Three patients (12%) had methanol poisoning sequelae while imaging findings of nitroimidazole drug toxicity were observed in another three patients (12%). Two patients (8%) each of carbon monoxide poisoning and lead toxicity were seen. We had one patient (4%) each of isoniazid, methyl iodide, dextropropoxyphene toxicity, chronic toluene abuse, and hyperglycemia-induced hemiballismus-hemichorea. Conclusion: Our study illustrates the amalgamated spectrum of MRI appearances in various subgroups of toxic encephalopathies. Imaging substantiated by relevant history and clinical manifestations can accurately diagnose the possible causative agent in the majority of the cases.

Subacute Sclerosing Panencephalitis: Restricted Diffusion and Clinical Evolution.

Background: Subacute sclerosing panencephalitis (SSPE) is a rare entity characterized by a protracted course and progressive neurological deterioration. Objective: We present patterns of diffusion restriction in eight cases of SSPE, a seldom described imaging attribute. Methods: A retrospective analysis was performed on the clinical and neuroimaging data obtained from records of patients with proven SSPE. Patients whose magnetic resonance imaging (MRI) showed evidence of diffusion restriction were included in the analysis. MRI was performed on 3 T and 1.5-T clinical MR systems. Imaging characteristics were reviewed and tabulated by two neuroradiologists. Results: Eight SSPE patients (seven men, one woman; age range: 5-15 years; mean age: 11 years) diagnosed and managed at our institute were included in the analysis. Restricted diffusion was evident in the basal ganglia (n = 3), corpus callosum (n = 2), white matter (n = 2) and in bilateral middle cerebellar peduncles (MCP) (n = 2). One patient had diffusion restriction in the genu of the corpus callosum and bilateral frontal cortical white matter. None of the diffusion-restricted lesions showed contrast enhancement or susceptibility. Six cases fulfilled the diagnostic criteria for fulminant SSPE (fSSPE). The extent of neuroparenchymal involvement was greater in this subset of patients. Conclusions: Restricted diffusion in SSPE, hitherto infrequently described, can indeed occur in both grey and white matter structures and in both supratentorial and infratentorial compartments. Parenchymal diffusion restriction in SSPE possibly reflects an early time point in the clinical evolution. A greater extent of parenchymal diffusion restriction may portend a rapid downhill course, possibly qualifying for fSSPE.

"Trapped labelled spins"-related signal on arterial spin labelling in the assessment of flow-diverted aneurysms: preliminary experience.

PURPOSE: To investigate ASL-MRI features of flow-diverted aneurysms, review their haemodynamic surrogates, and discuss their pertinent clinical implications. METHODS: Retrospective single institutional analysis was performed on the clinical and imaging data of patients who underwent digital subtraction angiography (DSA) and ASL-MRI after endovascular flow diversion for cerebral aneurysms. Pseudo-continuous ASL-MRI was performed with post-label delays of 1525-1800 ms. Intra-aneurysmal "trapped labelled spins" (TLS)-related hypersignal, as seen on cerebral blood flow (CBF)-weighted maps of ASL-MRI, was investigated. Intermodality equivalence with DSA [O'Kelly-Marotta (OKM) grading for occlusion], 3D-TOF-MRA, and 3D spin-echo T1-weighted ("black-blood") images was assessed. RESULTS: Ten cases were included. "TLS" signal was demonstrable in 7/8 (87.5%) of the DSA-visible flow-diverted aneurysms (OKM grade B3, n = 6; OKM grade A3, n = 2). No TLS was seen in both OKM-D (excluded) aneurysms. TLS was not visualised in an OKM-B3 aneurysm with < 3 mm opacifying remnant. 3D-TOF-MRA and ASL-MRI were discordant at 5 instances (45.4%; TOF-MRA false negative, n = 4; false positive, n = 1). Loss of flow void on black-blood images corresponded to the absence of TLS and vice versa in all cases but one. CONCLUSION: "Trapped labelled spins"-related signal on ASL-MRI occurs in patent large aneurysms that have undergone successful endovascular flow diversion. This phenomenon likely represents an interplay of a multitude of haemodynamic factors including decelerated intra-aneurysmal inflow and outflow restriction. Serial intra-saccular TLS signal changes may hold diagnostic value, including contexts where 3D-TOF-MRA interpretation becomes dubious. "Trapped labelled spins"-related signal as a non-invasive proxy marker of aneurysm patency can possibly obviate unnecessary DSA.

Abusive head trauma in India: imaging raises the curtain.

The purpose of the study was to identify children at our institute who possibly suffered abusive head trauma (AHT). A retrospective study of CT imaging of children between one month to three years of age between January 2013 and May 2021 was carried out at a dedicated neurocentre in Southern India. We identified 48 cases of possible AHT. The demographics, clinical features at presentation, imaging and fundus findings were analyzed. Imaging revealed subdural hemorrhage (SDH) in 42 and sub dural effusion (SDE) in 5 cases, one case had only hypoxia. The location of SDH was studied as was hypoxia underlying SDH, global hypoxia and ischemia. Cases of subarachnoid hemorrhage (SAH), parenchymal hematoma & intraventricular hemorrhage (IVH) were also noted. Skeletal survey, chest X-ray and CT spine were reviewed. AHT needs to be paid attention to in the Indian scenario. An extensive work up is required to substantiate the claim and to work on prevention & management of these cases subsequently.

Persistent Primitive Olfactory Artery: Three Cases.

ABSTRACT: The persistent primitive olfactory artery is a very rare arterial variant with a little over a score of cases reported in literature so far. We present 3 cases illustrating this entity, which were incidentally diagnosed while imaging for other indications.

Pediatric spinal cord infarct: a rare cause of a rare disorder, (wo)man in barrel syndrome.

The "man in barrel syndrome" is a condition which resembles the aspect of patient being constrained in a barrel in which patient presents with bilateral upper limb weakness. It has classically been attributed to supratentorial lesions in watershed zones. We present such a case in a 12-year-old child who presented with bibrachial weakness and was noted to have cervical cord infarct on imaging. Spinal cord infarct is a rare cause of this syndrome, and until now only 20 cases have been described in which cervical cord infarct led to this presentation, all of them being adults. We describe first case report of bibrachial diplegia due to cord infarct in a child. Our case adds to the limited literature of cervical cord ischemia as a cause of "(wo) man in barrel syndrome" and re-iterates the fact that imaging of cervical cord should be considered while evaluating these cases.

Anterior Cranial Fossa Dural Arteriovenous Fistulae - Angioarchitecture and Intervention.

PURPOSE: Anterior cranial fossa (ACF) dural arteriovenous fistulae (DAVF) are rare, unique, and ominous. While surgical disconnection is considered as the favored management option, endovascular treatment has lately gained importance. We present a single institution experience of seven cases. METHOD: A retrospective analysis was performed on the institutional patient database. Features analyzed were demographic details, symptoms, angioarchitecture, treatment course, angiographic results, procedural complications, and follow-up. RESULTS: This study included seven patients. The age at presentation ranged from 5-67 years. Clinical symptomatology was as intracranial hemorrhage in 4 patients and headache, chemosis and seizures in one patient each. The fistulae were paramedian at the ACF base. All DAVFs were Cognard type 4. The arterial feeders were from the anterior ethmoidal branches of the ophthalmic artery in all cases (bilateral in n = 5), frontal branches of the middle meningeal artery (MMA) (n = 6), and multiple ECA branches. The arterial route was the choice for access. Complete fistula obliteration was achieved in all but one patient. A traversed vein underwent rupture in one patient. One patient suffered postsurgical hemorrhage. No clinical or angiographic recurrence was noted. CONCLUSION: The DAVFs of the ACF are inherently high-grade lesions. Transorbital ECA-ICA branch anastomoses may be recruited as feeders. They may be best managed by multidisciplinary means personalized on an angioarchitectural basis. Endovascular embolization is safe and efficacious when performed through a navigable feeder from the frontal division of the MMA, which according to our interpretation is in anastomosis with the anterior falcine branch of the anterior ethmoidal artery.

Dissecting aneurysms of the posterior cerebral artery - A retrospective review of imaging, angiographic characteristics, endovascular management and outcome.

PURPOSE: To review management, clinical and imaging outcomes of dissecting posterior cerebral artery (PCA) aneurysms with emphasis on endovascular management in the form of parent vessel occlusion (PVO) at a tertiary care center. METHODS: Thirty-six dissecting PCA aneurysms (19 ruptured) encountered at our center between January 2013 and November 2019 were reviewed for aneurysm location/size/presence of fetal PCA/management. Postprocedural imaging of patients who underwent endovascular intervention was reviewed for PCA territory infarcts and clinical records assessed for presence of neuro-deficits and outcome. None of the patients underwent a balloon test occlusion (BTO) prior to PVO. RESULTS: The location of the aneurysms was as follows-P1 = 8/P1-P2 = 11/P2 = 5/P2-P3 = 10/P3 = 2. The mean size was 11.7x6.8 mm. Endovascular intervention was carried out in 20 patients in the form of PVO with coiling in 16 patients, coiling alone in 3 patients, and reconstruction of the left PCA with flow diverter deployment in one patient. Postprocedural PCA territory infarct was seen in 5 cases of PVO out of which 4 had a good functional recovery. Overall, 15/16 patients (93.7%) who underwent PVO had mRS ≤ 2 on follow-up. The single case with flow diverter also developed an infarct and had adverse outcome on follow up. CONCLUSION: Among the various management strategies for dissecting PCA aneurysms, PVO is feasible and relatively safe even in absence of BTO in scenarios like critically ill patients with ruptured aneurysms, difficult access and financial constraints. Thromboembolic complications and antiplatelet therapy is a concern in reconstructive strategies.

Pial arteriovenous fistula: A clinical and neuro-interventional experience of outcomes in a rare entity.

PURPOSE: Pial arteriovenous fistulae (PAVF) are rare intracranial vascular malformations, predominantly seen in children and distinct from arteriovenous malformations and dural arteriovenous fistulae. PAVF often leads to high morbidity and mortality. The aim of our study was to describe the clinical features and endovascular management of PAVF at various intracranial locations; to analyze the use of liquid embolic agents and coils alone or in combination in the treatment of PAVF and to analyze the outcome of embolization. MATERIALS AND METHODS: Retrospective review of diagnostic angiography and neurointerventional database of our institution identified a cohort of 15 patients with non-galenic PAVF from 2008 to 2014 out of 6750 patients. Fourteen patients were treated endovascularly with coils and liquid embolic materials in combination or alone. Patients were followed up for evaluation of prognosis. RESULTS: Age of the patients ranged from 3 to 37 years. Most patients were male and most common presentation was headache followed by seizure. Most common location of fistula was frontal lobe. The most common type was single artery single hole fistula with venous varix. Satisfactory obliteration was seen in all cases. One patient developed intraparenchymal hematoma on the first post procedural day and outcome was poor. CONCLUSIONS: PAVF are rare intracranial vascular malformations which can effectively be managed endovascularly with liquid embolic, coils alone, or in combination. Complete occlusion of the fistula can be achieved in most cases in a single sitting with a reasonable morbidity related to the procedure, compared with the natural history of this disease.

Tumors masquerading as neurological diseases: A caution for clinicians in planning diagnosis and treatment.

INTRODUCTION: Neurological diseases can be due to direct diseases of the central nervous system (CNS) or peripheral nervous system (PNS) or be a bystander syndrome of systemic diseases. Treatment options depend on the cause. Toxic, metabolic and nutritional, and immune-mediated consequences of clinically occult neoplasms produce a spectrum of neurological diseases, recognition of which has therapeutic and prognostic importance. PATIENTS AND METHODS: Children, as well as adults who presented to the authors in the last 5 years with neurological diseases and later their diseases could be diagnosed or attributed to neoplasms which were occult, were included for the study. OBSERVATION: 28 patients were seen by the authors in the last 5 years with neurological manifestation and hidden tumor. Maximum incidence was in the age of above 60 years followed by the age group of 21-40 years. The commonest neurological presentation was muscle and nerve in adults and seizure in children. DISCUSSION: Short duration, rapid progression, severe weight loss, and poor response to treatment given for nontumor associated neurological syndrome are the red flags which point to the diagnosis. CONCLUSION: Seizures and psychosis formed the commonest features in children, muscle and nerve in adults. Short duration, rapid progression, and resistance to treatment are the markers for possible underlying neoplasm.

MOG antibody seropositive aseptic meningitis: A new clinical phenotype.

The spectrum of myelin oligodendrocyte glycoprotein antibody (MOG-Ab) associated demyelination is evolving. Our case report describes a unique clinical presentation of aseptic meningitis with demyelinating lesions of the brain resembling acute disseminated encephalomyelitis and MOG-Ab seropositivity. A 22-year-old lady presented with history of fever of one week duration followed by headache, vomiting and neck stiffness. She had bilateral papilledema and signs of meningeal irritation. Neuroimaging revealed T2 and FLAIR hyperintense lesions in the right caudate, temporal lobe and left insula with enhancement on gadolinium contrast along with leptomeningeal enhancement. An extensive search for infectious and inflammatory etiology was negative while serum was positive for MOG-Abs tested twice at an interval of 12 days. She showed remarkable clinical-radiological resolution with steroids and has remained symptom free on follow up.

Spinal Cord Infarction: Clinical and Radiological Features.

INTRODUCTION: Spinal cord infarction is an uncommon disease varying in its clinical presentation. This study describes the clinical and radiological presentation of spinal cord infarcts in 17 consecutive patients. MATERIAL AND METHODS: Clinical and MR imaging data of 17 patients were reviewed. Inclusion criteria were acute or subacute presentation (peak within 72 hours) and MRI showing typical signal changes on T2WI compatible with spinal cord infarct. Exclusion criteria were clinical or MRI findings suggesting other etiologies. RESULTS: Clinical presentation included dissociative anesthesia, weakness of limbs, back or neck pain, and autonomic symptoms with symptom onset to peak time ranging from few minutes to 48 hours in patients with anterior spinal artery infarct (n = 16), and weakness and sensory loss in ipsilateral upper limb in patient with posterior spinal artery infarct (n = 1). One patient presented with "man-in-the-barrel syndrome (MIB)." MRI findings in anterior spinal artery infarcts included pencillike hyperintensities on T2 sagittal (n = 16, 100%) and "owl eye" appearance on T2 axial (n = 6, 37.5%) images. Diffusion restriction was noted in 8 cases and enhancement was noted in 2 cases. The posterior spinal artery infarct showed T2 hyperintensity in left posterior paramedian triangular distribution in cervical cord (C2-C7). Follow-up was available for 9 patients (period ranging from 15-41 months). Four patients had a favorable outcome who could walk independently, 1 patient could walk with support, and 2 patients were wheelchair bound. Two patients died. CONCLUSION: Spinal cord infarction is a rare but important cause of acute spinal syndrome. Typical distribution and appropriate imaging can help in timely diagnosis.

Imaging of dentate nucleus pathologies; a pictorial essay.

Dentate nucleus is affected in a wide variety of conditions. Magnetic resonance imaging of the brain is the diagnostic modality of choice for delineating the signal characteristics, which helps in narrowing down a vast list of differentials for conditions affecting the dentate. Computed tomography plays an important role, especially for pathologies associated with calcification of dentate nucleus.