Atypical MRI Findings Research Articles

IgG4-related disease with subcutaneous involvement and the associated diagnostic challenges with MRI.

IgG4-related disease is a rare fibroinflammatory disorder characterized by the infiltration of IgG4-rich plasma cells. Herein, we report a case of IgG4-related disease of the subcutaneous tissue with atypical MRI findings and difficulties in the histopathological examination using needle biopsy. Based on the clinical presentation and MRI findings, the patient was diagnosed with a benign myxoid or cystic tumor. Additionally, histopathological findings from a needle biopsy suggested a myxoma. Therefore, the correct diagnosis of IgG4-related disease was not made preoperatively. The resected specimens confirmed IgG4-related disease with an IgG4/IgG ratio > 80%. Previous reports have shown that the MRI findings of IgG4-related disease mimic both malignancy and inflammation; surprisingly, the features of subcutaneous IgG-related disease, including tail sign, unclear border, and heterogeneous enhancement, were similar to those found in sarcoma. Therefore, histopathological findings are needed for a correct diagnosis. Furthermore, careful examination is essential because the neoplasm and inflammation may overlap with IgG4-related disease, and needle biopsy is not fully reflective of the tumor. As is highlighted in the present case, IgG4-related disease is often misdiagnosed; therefore, clinicians should adequately recognize that even if the histopathological findings in biopsy were consistent with those observed in the MRI, misdiagnosis may occur.

Wernicke Encephalopathy: Typical and Atypical Findings in Alcoholics and Non-Alcoholics and Correlation with Clinical Symptoms.

Clinical diagnosis of Wernicke encephalopathy (WE) can be challenging due to incomplete presentation of the classical triad. The aim was to provide an update on the relevance of standard MRI and to put typical and atypical imaging findings into context with clinical features. In this two-center retrospective observational study, the local radiology information system was searched for consecutive patients with clinical or imaging suspicion of WE. Two independent raters evaluated T2-weighted imaging (WI), fluid-attenuation inversion recovery (FLAIR), diffusion WI (DWI), T2*WI and/or susceptibility WI (SWI), and contrast-enhanced (CE)-T1WI, and noted the involvement of typical (i.e., mammillary bodies (MB), periaqueductal grey (PAG), thalamus, hypothalamus, tectal plate) and atypical (all others) lesion sites. Unusual signal patterns like hemorrhages were also documented. Reported clinical features together with the diagnostic criteria of the latest guidelines of the European Federation of Neurological Societies (EFNS) were used to test for relationships with MRI biomarkers. 47patients with clinically confirmed WE were included (Jan '99-Apr '23; mean age, 53yrs; 70% males). Interrater reliability for imaging findings was substantial (κ = 0.71), with lowest agreements for T2WI (κ = 0.85) compared to all other sequences and for PAG (κ = 0.65) compared to all other typical regions. In consensus, 77% (n = 36/47) of WE cases were rated MRI positive, with FLAIR (n = 36/47, 77%) showing the strongest relation (χ2 = 47.0; P < 0.001) compared to all other sequences. Microbleeds in the MB were detected in four out of ten patients who received SWI, not visible on corresponding T2*WI. Atypical findings were observed in 23% (n = 11/47) of cases, always alongside typical findings, in both alcoholics (n = 9/44, 21%) and non-alcoholics (n = 2/3, 67%). Isolated involvement of structures, explicitly PAG (n = 4/36; 11%) or MB (n = 1/36; 3%), was present but observed less frequently than combined lesions (n = 31/36; 86%). Acut-off width of 2.5 mm for the PAG on 2D axial FLAIR was established between cases and age- and sex-matched controls. An independent association was demonstrated only between short-term memory loss and changes in the MB (OR = 2.2 [95% CI: 1.1-4.5]; P = 0.024). In retrospect, EFNS criteria were positive (≥ 2out of4) in every case, but its count (range, 2-4) showed no significant (P = 0.427) relationship with signal changes on standard MRI. The proposed sequence protocol (FLAIR, DWI, SWI and T1WI + CE) yielded good detection rates for neuroradiological findings in WE, with SWI showing microbleeds in the MB with superior detectability. However, false negative results in about aquarter of cases underline the importance of neurological alertness for the diagnosis. Awareness of atypical MRI findings should be raised, not only in non-alcoholics. There is limited correlation between clinical signs and standard MRI biomarkers.

Synovial chondromatosis: Rare involvement of metacarpophalangeal joint and diagnostic challenges in MR imaging.

Synovial chondromatosis (SC) is a rare benign tumor of the cartilaginous tissue that frequently affects large joints intra-articularly. Characteristic imaging findings were reported for the diagnosis of SC. Herein, we report a case of SC of the metacarpophalangeal joint with atypical MRI findings. Considering the clinical presentation, erosion, absence of calcification on X-ray and CT, and low intensity on short tau inversion recovery (STIR), tenosynovial giant cell tumor was the initially diagnosis. However, histopathological findings revealed SC with fibrosis, which was confirmed using Elastica Van Gieson (EVG) staining. In general, low intensity on STIR in SC indicate calcification; however, it can also represent fibrosis in SC. In this case, the diagnosis of SC using MRI was limited highlighting the importance of histopathological findings for an accurate diagnosis of SC.

Double inversion recovery MRI of subcortical band heterotopia and its variations.

Subcortical band heterotopia (SBH) is a malformation of cortical development diagnosed via MRI. Currently, patients with SBH are classified according to Di Donato's classification. We aimed to show a variation of SBH and the usefulness of double inversion recovery (DIR) images. We retrospectively reviewed the MRI findings of 28 patients with SBH. The patients were classified according to Donato's classification by using conventional MR images, and their DIR findings were reviewed. Of 28 patients, 20 were grade 1 and 8 were grade 2 according to Di Donato's classification. In 15 of 28 patients, the following four types of atypical MRI findings were detected: asymmetry distribution (four cases), coexistence of thin and thick SBH (five cases), and DIR faint abnormal signal intensity in subcortical white matter (five cases) and in deep white matter (five cases). The latter two types were detected on DIR alone and have not been reported. Additionally, these were identified only in the mild group (Di Donato's classification 1-1 or 1-2). DIR is a useful MRI sequence for detecting faint white matter signal abnormalities, and it can aid in the accurate classification of SBH and identification of its variations, which may reflect the pathology of SBH.

Magnetic resonance imaging characteristics of pediatric pilocytic astrocytoma.

MRI has an important role in diagnosing pilocytic astrocytoma and post-surgical follow-up since the surgical approach has a leading role in its treatment. The purpose of our study is to provide an overview of the typical and atypical MRI findings in a series of pediatric patients with isolated-not NF1-related-pilocytic astrocytomas and to correlate specific MRI patterns with clinical variables. This is a cross-sectional retrospective study providing the analysis of several clinical and neuroradiological findings from a cohort of pediatric pilocytic astrocytoma, starting from the data collected in the Fondazione IRCCS Istituto Neurologico Carlo Besta (FINCB) internal Cancer Registry during an 11-year time period (January 2008-January 2019). Fifty-six patients were included in the study. Median age at diagnosis was 9.4 years; a slight female prevalence was noticed (m/f ratio 44.6%/55.4%). The majority of pPAs had well-defined contours: 51 (91.1%), 47 (88.7%) were hypointense on T1-wi, all of them were hyperintense on T2-wi, 46 (90.2%) were hyperintense on FLAIR, and 48 (85.7%) were heterogeneous on T1-wi and T2-wi sequences. We found positive correlation between pPAs location and age (r = 0.017), and small degree of connection between pPAs location and gender (Cramer's V = 0.268). We presented typical and atypical pPAs MRI findings. Age and tumor location were positevely correlated, while degree of connection between gender and pPAs location was small. All of this may aid clinicians, most of all neuroradiologists, neurosurgeons, and neurologists in proper diagnoses and follow-up of these specific patient population.

A Rare Case of Bilateral Globus Pallidus Enhancement in a Patient with Clinical Wernicke Encephalopathy (P4-4.003)

<h3>Objective:</h3> To describe a case of Wernicke encephalopathy with atypical MRI findings showing enhancement involving bilateral globi pallidi. <h3>Background:</h3> Thiamine deficiency, commonly as a result of malnourishment associated with alcohol dependence, can cause Wernicke encephalopathy, a neuropsychiatric syndrome that presents with a triad of ophthalmoplegia, altered mental status, and ataxia. Brain MRI typically shows contrast enhancement of the thalamus and mammillary bodies. <h3>Design/Methods:</h3> Case Study <h3>Results:</h3> In March 2022, a 55-year-old man with a history of alcohol dependence, hypertension, atrial fibrillation, kidney failure, sleep apnea, and obesity presented to our neurology clinic for initial evaluation and follow-up of a previous hospitalization in October 2021 for symptoms of Wernicke encephalopathy. Brain MRI obtained at his hospitalization showed edema and contrast enhancement with restricted diffusion involving the bilateral globi pallidi. He had been drinking 750 mL of bourbon every other day for about 10 years. He noted that his symptoms had improved with thiamine supplementation but still endorsed left unilateral gait instability. He denied carbon monoxide poisoning, exposure to insecticides/pesticides or other toxins. Lab results confirmed this and showed no evidence of exposure to toxins that are known to be associated with insults involving the globus pallidus. His review of systems was positive for weakness and confusion. Physical examination was notable for some impairment of finger-to-nose test, difficulty in sustaining rapid alternating movements, and a broad-based but stable gait. We recommended that the patient continues thiamine supplementation and physical therapy. <h3>Conclusions:</h3> Wernicke encephalopathy is associated with atrophic changes involving the mammillary bodies and thalamus, but current literature does not show evidence of changes involving the globus pallidus. The atypical involvement of the bilateral globi pallidi seen in this case demonstrates a need for further research into the role of globus pallidus in the pathogenesis of Wernicke encephalopathy. <b>Disclosure:</b> Miss Karim has nothing to disclose. Mr. Jin has nothing to disclose. Dr. Bagga has nothing to disclose. Dr. Mehrizi has nothing to disclose.

Adult-Onset Acute Flaccid Myelitis with White Matter-predominant Longitudinally Extensive Transverse Myelitis Following Coxsackie B5 Enterovirus Infection: a case report (P8-10.001)

<h3>Objective:</h3> To describe an adult-onset case of transverse myelitis associated with enterovirus (Coxsackie B5) infection. <h3>Background:</h3> Both Acute Flaccid Myelitis (AFM) and longitudinally-extensive transverse myelitis (LETM) are more commonly associated with pediatric enteroviral infections than adult infections. However, we present an adult case of AFM due to Coxsackie B5 virus with an atypical pattern on spinal imaging. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> A 55-year-old male presented with acute urinary retention and lower extremity flaccid paraplegia two weeks after gastrointestinal illness. Neurologic exam revealed flaccid paralysis of bilateral lower extremities with absent lower extremity reflexes, and a sensory level to pinprick at T5. Vibration was diminished up to the ankle and proprioception was absent at the toes bilaterally. MRI thoracic spine showed T2 hyperintensity of ventral and bilateral lateral columns spanning T4-T10 levels, with notable sparing of central gray matter. MRI brain revealed four periventricular and subcortical T2/FLAIR hyperintense lesions as well as one cortical lesion. Cerebrospinal Fluid (CSF) studies demonstrated 16 WBC, 63 Glucose, and 56 Protein with one unique oligoclonal band. CSF PCR panel was positive for Enterovirus Coxsackie B5. Of note spinal angiogram, NMO, MOG, other rheumatologic and infectious usual myelitis workup was negative. The patient was treated with two days of IV steroids, five days of IV immunoglobulin therapy (IVIG), and five PLEX sessions with minimal improvement. <h3>Conclusions:</h3> We describe an adult patient presenting with Coxsackie B5-associated AFM with LETM. This patient demonstrated atypical MRI findings of T2 hyperintensity of the ventral and bilateral lateral columns spanning T4-T10 with notable sparing of central gray matter along with abnormal EMG suggesting anterior horn cell involvement. This case report highlights the importance of consideration of enterovirus as an etiology of atypical AFM with LETM in the adult population. <b>Disclosure:</b> Ms. Manouvakhova has nothing to disclose. Dr. Moghavem has nothing to disclose. Dr. Pulst-Korenberg has nothing to disclose.

Functional analysis of missense DARS2 variants in siblings with leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation.

Biallelic pathogenic variants in the nuclear gene DARS2 (MIM# 610956), encoding the mitochondrial enzyme aspartyl-tRNA synthetase (MT-ASPRS) cause leukoencephalopathy with Brain Stem and Spinal Cord Involvement and Lactate Elevation (LBSL) (MIM# 611105), a neurometabolic disorder characterized by progressive ataxia, spasticity, developmental arrest or regression and characteristic brain MRI findings. Most patients exhibit a slowly progressive disease course with motor deterirartion that begins in childhood or adolescence, but can also occasionaly occur in adulthood. More severe LBSL presentations with atypical brain MRI findings have been recently described. Baker's yeast orthologue of DARS2, MSD1, is required for growth on oxidative carbon sources. A yeast with MSD1 knockout (msd1Δ) demonstrated a complete lack of oxidative growth which could be rescued by wild-type MSD1 but not MSD1 with pathogenic variants. Here we reported two siblings who exhibited developmental regression and ataxia with different age of onset and phenotypic severity. Exome sequencing revealed 2 compound heterozygous missense variants in DARS2: c.473A>T (p.Glu158Val) and c.829G>A (p.Glu277Lys); this variant combination has not been previously reported. The msd1Δ yeast transformed with plasmids expressing p.Glu259Lys, equivalent to human p.Glu277Lys, showed complete loss of oxidative growth and oxygen consumption, while the strain carrying p.Gln137Val, equivalent to human p.Glu158Val, showed a significant reduction of oxidative growth, but a residual ability to grow was retained. Structural analysis indicated that p.Glu158Val may interfere with protein binding of tRNAAsp, while p.Glu277Lys may impact both homodimerization and catalysis of MT-ASPRS. Our data illustrate the utility of yeast model and in silico analysis to determine pathogenicity of DARS2 variants, expand the genotypic spectrum and suggest intrafamilial variability in LBSL.

Neurosyphilis-the great imitator in disguise

Neurosyphilis is a great imitator and has varied presentations. We report a case presenting as corticobasal syndrome and its atypical MRI findings are described.

Adult‐onset medulloblastoma presenting with atypical MRI findings

AbstractWe report an extremely rare case of an 18‐year‐old girl with chronic progressive speech and gait disturbances due to abnormalities around the fourth ventricle, diagnosed as classic medulloblastoma with WNT signaling dysregulation by brain biopsy. Brain MRI showed atypical findings of symmetrical midline located adult medulloblastoma with no mass effect. PET‐CT scans revealed marked uptake of only 11C‐methionine. Medulloblastoma with atypical MRI findings should be considered in the differential diagnosis of tumors around the fourth ventricle in adults, even approximately symmetrical midline tumors with no mass effect. 11C‐methionine PET‐CT may be superior in detecting adult medulloblastomas with unique characteristics.

Investigations of Huntington's Disease and Huntington's Disease-Like Syndromes in Indian Choreatic Patients.

The diagnostic workup for choreiform movement disorders including Huntington's disease (HD) and those mimicking HD like phenotype is complex. The aim of the present study was to genetically define HD and HD-like presentations in an Indian cohort. We also describe HTT-CAG expansion manifesting as neuroferritinopathy-like disorder in four families from Punjab in India. 159 patients clinically diagnosed as HD and HD-like presentations from various tertiary neurology clinics were referred to our centre (CSIR-IGIB) for genetic investigations. As a first tier test, CAG-TNR for HTT was performed and subsequently HD-negative samples were screened for JPH3 (HDL2), TBP (SCA17), ATN1 (DRPLA), PPP2R2B (SCA12) and GGGGCC expansion in C9orf72 gene. Four families presenting as neuroferritinopathy-like disorder were also investigated for HTT-CAG expansion. 94 of 159 (59%) patients were found to have expanded HTT-CAG repeats. Pathogenic repeat expansion in JPH3, TBP, ATN1 and C9orf72 were not found in HD negative cases. Two patients were positive for SCA12-CAG expansion in pathogenic length, whereas 5 cases harboured TBP-CAG repeats falling in reduced penetrance range of 41- 48 repeats for SCA17. Four unrelated families, presented with atypical chorea and brain MRI findings suggestive of basal ganglia abnormalities mimicking neuroferritinopathy were found to harbour HTT-CAG expansion. We present SCA12 as a new reported phenocopy of HD which should be considered for diagnostic workout along with SCA17 for HD-like syndromes. This study also illustrates the necessity, to consider evolving HD like phenotype, as a clinical diagnosis for cases with initial manifestations depicting neuroferritinopathy.

Atypical Pediatric Demyelinating Diseases of the Central Nervous System

Pediatric central nervous system demyelinating diseases include multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and acute disseminated encephalomyelitis (ADEM). As diagnostic criteria become more inclusive, the risk of misdiagnosis of atypical demyelinating diseases of rheumatologic, infectious, and autoimmune etiology increases. We review mimics of multiple sclerosis, neuromyelitis optica spectrum disorder, and acute disseminated encephalomyelitis, including rheumatologic diseases: systemic lupus erythematosus and neuro-Behçet disease; infectious diseases: human immunodeficiency virus, progressive multifocal leukoencephalopathy, and subacute sclerosis panencephalitis; and autoimmune diseases including X-linked Charcot-Marie-Tooth disease, chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) and autoimmune glial fibrillary acidic protein (GFAP) encephalopathy. Atypical demyelinating disease may mimic classic neuroinflammatory diseases of the central nervous system. Imaging may meet criteria for a diagnosis of multiple sclerosis, or patients may present with optic neuritis and transverse myelitis consistent with neuromyelitis optica spectrum or myelin oligodendrocyte glycoprotein (MOG) antibody disorders. Through careful history-taking and review of atypical MRI findings, we may avoid misdiagnosis and mistreatment.

Herpes simplex virus infection presenting as stroke-like symptoms with atypical MRI findings

Herpes simplex virus infection presenting as stroke-like symptoms with atypical MRI findings

Alcohol Induced Wernicke Encephalopathy with Atypical MRI Findings

Wernicke encephalopathy is a neurological complication of thiamine deficiency, usually in the setting of poor diet, classically with alcoholism. Patients present with acute onset of encephalopathy, oculomotor dysfunction, gait ataxia and memory impairment. If untreated, the disorder can result in severe morbidity and possibly death; patient outcomes are entirely dependent on prompt diagnosis and administration of parenteral thiamine. Although diagnosed clinically, the radiologist may be able to alert the referring clinician to the possibility of the disease when imaging features are observed, thereby improving the chance of treatment success. Although various imaging features have been ascribed to alcohol and non-alcohol related forms of Wernicke encephalopathy, recent literature suggests that such a distinction is not reliable, and that the causes of Wernicke encephalopathy are not readily distinguishable on MRI, as in the index case presented here.

Unusual movement disorders and atypical MRI findings in patients with West Nile Encephalitis: A case series of two patients with evidence of clinical and imaging resolution with IVIG (P4.9-033)

Unusual movement disorders and atypical MRI findings in patients with West Nile Encephalitis: A case series of two patients with evidence of clinical and imaging resolution with IVIG (P4.9-033)

Bilateral Medial Medullary Syndrome with Atypical Clinical Presentation and Brain MRI Findings (P5.3-065)

Bilateral Medial Medullary Syndrome with Atypical Clinical Presentation and Brain MRI Findings (P5.3-065)

Multiple sclerosis with atypical MRI presentation: Results of a nationwide multicenter study in 57 consecutive cases

BackgroundThe recent 2017 modification have increased the sensitivity of McDonald criteria for MS. Nevertheless, some MS patients with atypical MRI findings have been identified, leading to prolonged delay to diagnosis and high costs to look for alternative diagnoses. ObjectiveTo describe a series of MS patients with atypical MRI presentation. Material and methodsPatients with atypical MS were identified through a nationwide retrospective study. We established a five groups classification: tumefactive demyelinating lesion (TDL)-onset MS, acute disseminated encephalomyelitis (ADEM)-like MS, cavitary MS and leukodystrophy-like MS. All the patients meeting our radiological criteria for atypical MS were included. ResultsA total of 57 patients met the inclusion criteria. 7 cases were classified in the TDL-onset group, 10 in the ADEM-like group, 26 in the cavitary group and 14 in the leukodystrophy-like group. Overall risk of conversion to MS after an isolated TDL was around 30% at five years. Patients in the TDL-onset and ADEM-like groups globally presented an acute onset and a relapsing-remitting evolution. Conversely, patients in the cavitary and leukodystrophy- groups largely evolved with a progressive and severe course. ConclusionA significant number of MS patients can have a striking atypical presentation and may be misdiagnosed. This preliminary analysis helps to refine the spectrum of atypical MS patients.

Atypical MRI presentation of posterior reversible encephalopathy syndrome with predominant brainstem involvement

We report here the case of a 80-year-old woman for the assessment of an acute confusional state since 2 days asssociated with diffuse and gradual headache. Brain MRI disclosed isolated hyperintense signal on fluid-attenuated inversion recovery sequence involving the medulla and the right inferior cerebellar peduncle with moderate swelling, consistent with vasogenic oedema, without abnormalities on diffusion-weighted imaging sequence. PRES diagnosis was suspected and antihypertensive therapy was introduced to achieve a blood pressure goal < 140/90mmHg, allowing a quickly favourable clinical course. Three months later, brain MRI demonstrated a complete clearance of the abnormalities, confirming the PRES diagnosis. Atypical MRI findings are possible with involvement of basal ganglia, brainstem or cerebellum, but in these cases, oedema is most of the time accompanied by the classical parieto-occipital region involvement. Vasogenic oedema strictly unilateral or involving exclusively the brainstem or the cerebellum are very rare and should prompt suspicion for an alternative diagnosis. That constitutes a crucial diagnosis challenge in neurology.

Primary central nervous system lymphoma presenting as Parkinsonism with atypical MRI findings and elevated 14-3-3 protein (P6.083)

Primary central nervous system lymphoma presenting as Parkinsonism with atypical MRI findings and elevated 14-3-3 protein (P6.083)

Different Magnetic Resonance Imaging Manifestations of Diabetic Chorea in a Case with Hyperglycemia and Another One with Hypoglycemia

Diabetic chorea (DC) is a rare complication of diabetes. Here we describe two cases of DC; patient 1 was an 87-year-old woman with chronic kidney disease and was administered with sulphonylurea and dipeptidylpeptodase-4 inhibitor. She showed right side hemiballismus and head magnetic resonance imaging T1-weighted images revealed a high intensity area in the putamen and caudate nucleus. Patient 2 was a 51-year-old woman who was diagnosed with diabetic ketoacidosis. She showed right side hemiballism and multiple, small hyperintense regions in both the periventricular sides in diffusion weighted images. Based on the hemiballism, we concluded a diagnosis of DC in the diabetic patient, although the case presentation is rare or has atypical MRI findings.