Classic Magnetic Resonance Imaging Findings Research Articles

L2-hydroxyglutaric aciduria presenting with learning disability and cerebellar signs: A case report

L-2-hydroxyglutaric aciduria (L2HGA) is a rare, autosomal recessive neurometabolic disorder due to variants in the L2HGDH gene, which encodes L-2-hydroxyglutarate dehydrogenase (L2HGDH), an enzyme involved in tricarboxylic acid cycle. Deficiency of L2HGDH causes leukoencephalopathy predominantly affecting the cerebellum. This case presents L2HGA in a 12-year-old Sri Lankan boy born to third-degree consanguineous parents, who also showed learning disability and bilateral cerebellar signs. Magnetic resonance imaging (MRI) of the brain revealed T2/FLAIR hyperintensities in bilateral symmetrical subcortical white matter involving the cerebellum. A diagnosis of 2-hydroxyglutaric aciduria was made after a massive peak of 2-hydroxyglutaric acid (2HG) was observed in the analysis of urine organic acids (UOA) using gas chromatography/mass spectrometry. Genetic variant analysis revealed two heterozygous pathogenic variants in the L2HGDH gene, confirming the genetic diagnosis of autosomal recessive L2HGA. Parental genetic testing confirmed the trans phase of the variants in the index patient and their carrier status of a pathogenic L2HGDH variant. Despite typical clinical features and classical MRI findings, initial clues toward the diagnosis are mainly derived from the UOA analysis. In conclusion, this case underscores the paramount importance of analyzing the UOA profile in the process of identifying rare metabolic causes, such as L2HGA, that contribute to learning disability with neurological involvement in children.

Venous pathology targeted surgical management in Hirayama disease: A comprehensive case series of nine cases exploring this potential etiology.

Hirayama disease is a rare cause of cervical myelopathy predominantly affecting young individuals. The disease is classically characterized by muscle atrophy in the distal upper limbs. While various etiopathogenesis such as dural sac dysplasia, nerve root dysplasia, structural abnormalities of the spinal ligament, and venous dysplasia have been proposed, this study explores the potential role of venous pathology and surgical management on the basis of it. This is a prospective descriptive case series of nine cases. The diagnosis was made based on the Huashan diagnostic criteria which includes clinical manifestation, imaging, and electrophysiology. In cases where magnetic resonance imaging (MRI) failed to demonstrate engorged veins, a computed tomography (CT) venogram of the cervical spine was used as an imaging tool. All patients underwent cervical laminectomy and coagulation of the posterior epidural venous plexus with or without laminoplasty. All the patients were followed up regularly; clinical improvement and neck disability index were assessed. All nine patients were male and exhibited classical clinical features, electrophysiological abnormalities, and MRI findings except, in one patient where a CT venogram helped in establishing the diagnosis as the MRI was inconclusive. Postoperatively, all patients had neurological improvement and stabilization of the disease. All patients who underwent CT venogram and cervical spine X-ray in neutral and dynamic position demonstrated no recurrence of engorged venous plexus or significant instability except one patient developing kyphosis. One patient experiencing symptoms in the other limb underwent a second surgery. This comprehensive case series strongly supports venous pathology as a potential etiology of Hirayama disease. Surgical management with laminectomy and venous coagulation with or without expansile laminoplasty has delivered consistent improvement in neurological outcomes and long-term disease stabilization without the restriction of movements and lesser complications. However, further research is warranted to elucidate the mechanism underlying cervical venous dilatation.

Magnetic Resonance Imaging Findings in Idiopathic Intracranial Hypertension With and Without Pulsatile Tinnitus: An Age-Matched Cohort Study

Many but not all patients with idiopathic intracranial hypertension (IIH) have pulsatile tinnitus (PT). However, little is known about why some patients with IIH develop PT and others do not. The purpose of this study was to determine if any of the classic magnetic resonance imaging (MRI)-detectable markers of IIH differ between patients with and without PT, thereby shedding light on potential pathophysiology. A retrospective age-matched cohort study of patients with documented IIH (diagnosed by neuro-ophthalmologist) was performed. All patients had MRI performed around the time of diagnosis. MRIs were assessed for 16 variables known to be associated with IIH (e.g., pituitary displacement/empty sella, optic nerve tortuosity, transverse sinus stenosis, inferior cerebellar tonsils, arachnoid granulations, slit-like ventricles) by two blinded neuroradiologists. All binary variables were analyzed via χ2 test with Yates correction, or Fisher exact when appropriate. Continuous variables were analyzed via Student t test. Inter-rater reliability for binary variables was assessed by Cohen κ . For continuous variables, intraclass correlation coefficient was calculated. Forty age-matched patients with IIH met the inclusion criteria (20 with PT, 20 without PT). For all known binary MRI findings associated with IIH, there were no statistically significant differences between groups. Likewise, there were no statistically significant differences for continuous variables. The classic MRI findings associated with IIH do not differ between patients with and without PT, suggesting that systemic (rather than localized intrinsic or extrinsic) factors may play a critical role in the pathophysiology.

Maple syrup urine disease: magnetic resonance imaging findings in three patients.

Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disorder, caused by branched-chain alpha-ketoacid dehydrogenase (BCKD) deficiency, leading to toxic accumulation of branched-chain amino acids (BCAAs) including leucine, isoleucine and valine and their corresponding a-ketoacids. The diagnosis of MSUD is based on elevated BCAAs and allo-isoleucine in plasma, and branched-chain hydroxyacids and ketoacids in urine. The identification of alloisoleucine >5 µmol/L is considered pathognomonic. Moreover, brain magnetic resonance imaging (MRI) showing atypical signal intensity and oedema is characteristic of MSUD. Recognition of the classical neuro-radiological findings of MSUD is particularly useful in local settings as many healthcare facilities lack the resources to measure Plasma Amino Acids (PAA). We report three cases of MSUD, in whom the disorder was strongly suspected at presentation, based on classical brain MRI findings, which was urgently confirmed by PAA analysis.

Combined Brain/Heart Magnetic Resonance Imaging in Systemic Lupus Erythematosus.

Cardiovascular Disease (CVD) in Systemic Lupus Erythematosus (SLE) and Neuropsychiatric SLE (NPSLE) has an estimated prevalence of 50% and 40%, respectively and both constitute major causes of death among SLE patients. In this review, a combined brain/heart Magnetic Resonance Imaging (MRI) for SLE risk stratification has been proposed.The pathophysiologic background of NPSLE includes microangiopathy, macroscopic infarcts and accelerated atherosclerosis. Classic brain MRI findings demonstrate lesions suggestive of NPSLE in 50% of the NPSLE cases, while advanced MRI indices can detect pre-clinical lesions in the majority of them, but their clinical impact still remains unknown. Cardiac involvement in SLE includes myo-pericarditis, valvular disease/endocarditis, Heart Failure (HF), coronary macro-micro-vascular disease, vasculitis and pulmonary hypertension. Classic and advanced Cardiovascular Magnetic Resonance (CMR) indices allow function and tissue characterization for early diagnosis and treatment follow-up of CVD in SLE.Although currently, there are no clinical data supporting the combined use of brain/heart MRI in asymptomatic SLE, it may have a place in cases with clinical suspicion of brain/heart involvement, especially in patients at high risk for CVD/stroke such as SLE with antiphospholipid syndrome (SLE/APS), in whom concurrent cardiac and brain lesions have been identified. Furthermore, it may be of value in SLE with multi-organ involvement, NPSLE with concurrent cardiac involvement, and recent onset of arrhythmia and/or heart failure.

Intramuscular peripheral nerve sheath tumors: schwannoma, ancient schwannoma, and neurofibroma.

To analyze the prevalence of classic magnetic resonance imaging (MRI) findings of intramuscular peripheral nerve sheath tumors (PNSTs), including schwannoma, ancient schwannoma, and neurofibroma. Thirty pathologically confirmed benign intramuscular PNSTs (24 schwannomas, 3 ancient schwannomas, and 3 neurofibromas) were retrospectively reviewed. Classic MRI findings of PNSTs including split fat sign, fascicular sign, target sign, entering and exiting nerve, and thin hyperintense rim were assessed for each intramuscular PNST. Denervation change of the affected muscle was also assessed. In ancient schwannoma and neurofibroma, the signal intensity (SI) and enhancement pattern were analyzed. All intramuscular schwannomas revealed two more classic MRI findings. Eight of the 24 intramuscular schwannomas revealed affected muscle denervation change. All intramuscular ancient schwannomas showed only split fat sign. All intramuscular ancient schwannomas showed denervation change of the associated muscle. All intramuscular neurofibroma showed split fat sign and one case with target sign was detected. Ancient schwannomas were isointense SI on T1-weighted image (T1WI) and one case had hyperintense foci. They showed heterogeneously hyperintense SI on T2-weighted image (T2WI) with heterogeneous enhancement. Neurofibromas were isointense SI (2/3) and slight hyperintense SI (1/3) on T1WI and heterogeneously hyperintense SI on T2WI with heterogeneous enhancement. One ancient schwannoma showed conglomerated calcifications. Intramuscular schwannomas were easily diagnosed based on MRI. In the case of intramuscular ancient schwannoma and neurofibroma with only split fat sign among the classic MRI findings, they might be distinguished from other intramuscular soft tissue tumors based on muscle denervation change or typical crescent split fat sign.

Revisiting classic MRI findings of venous malformations: Changes in protocols may lead to potential misdiagnosis.

Introduction Magnetic resonance imaging (MRI) is most sensitive and specific for characterizing venous malformations (VMs). VMs typically demonstrate central enhancement on delayed-contrast imaging. Fluid-fluid levels (FFLs) are uncommon in VMs and common in lymphatic malformations (LMs). Technology has advanced since the initial description of these findings. Rates of detection of these MRI findings in VMs may have changed as MRI technology and techniques have evolved. Methods and methods A prospectively maintained database from a multidisciplinary vascular anomalies clinic was reviewed to identify patients with final diagnosis of VM or LM. Patients with reviewable contrast-enhanced MRIs were selected, reviewing the oldest MRI studies in the database against the newest MRI studies to identify equal numbers of patients from the temporal extremes. Imaging was reviewed to assess for presence of FFLs. Enhancement was quantified by measuring signal in the same location of the lesion both on pre- and postcontrast sequences Results Forty patients were identified for analysis. Twenty studies with sufficient archived imaging for review were performed between 1995 and 2006; 20 such studies were performed between 2011 and 2012. The new imaging cohort had higher rates of FFL visualization ( p = 0.001). Correlation was found between time to imaging following contrast and degree of enhancement ( p < 0.001). Inverse correlation was found between scan date and time to contrast ( p = 0.001) and scan date and enhancement ( p = 0.021). Conclusion FFLs should no longer be considered exclusionary for the diagnosis of VMs. Timing following contrast administration should be maximized to increase degree of enhancement to confirm the diagnosis of VMs.

Joubert syndrome: Case report of three affected siblings

Joubert syndrome (JS) is a rare autosomal recessive disorder that has variable phenotype but characteristic magnetic resonance imaging (MRI) findings. “Molar tooth” appearance of cerebellar peduncles and “bat-wing” appearance of the fourth ventricle are the classically described MRI findings. Herein, we describe JS in three siblings, products of a second-degree consanguineous marriage, who presented with developmental delay, abnormal eye movements, and impaired vision. The axial MRI in all three siblings revealed the classic MRI findings described in the JS.

Wernicke Encephalopathy in a Nonalcoholic

Wernicke encephalopathy (WE) is characterized by altered levels of consciousness and disturbances in eye movements and gait changes. The condition is caused by thiamine deficiency. The imaging findings are classic; however, it mimicking as a third ventricular tumor with obstructive hydrocephalus is rare. We report an elderly nonalcoholic patient who presented with altered mental status and gait disturbances. Computed tomography scan revealed a mass lesion in the area of third ventricle with obstructive hydrocephalus, but magnetic resonance imaging (MRI) of the brain revealed classic findings of WE. She was treated for that and a shunt procedure was avoided. WE is an uncommon neurological disorder with classic MRI findings. MRI also helps us to avoid confusing this condition with a third ventricular tumor and consequently avoids a shunt procedure. However, when diagnosed and treated in time the recovery is dramatic.

New Variant Creutzfeldt-Jacob Disease Presenting With Catatonia: A Rare Presentation

New Variant Creutzfeldt-Jacob Disease Presenting With Catatonia: A Rare Presentation

Hirayama′s disease

Hirayama's disease is a form of juvenile muscular atrophy affecting young individulas in their second to third decade. The underlying pathogenetic mechanism is believed to be an imbalanced growth between the individuals' vertebral column and the spinal canal contents, which causes abutment of the anterior spinal cord against the vertebral column and detachment of the posterior dura, leading to microcirculatory disturbances and ischemic changes in the cord. This mechanism is exiquisitely demonstrated on magnetic resonance imaging (MRI), but requires additional imaging, with the neck in the flexed position. Neurphysiological imaging studies have provided supporting evidence by demonstrating changes in the N13 potential, with neck flexion. Nonetheless, few studies have also reported contradictory findings with MRI and somatosensory evoked potentials, in Hirayamas Disease. This condition is underdiagnosed because most clinicians are not familiar with this disorder and do not request a flexion MRI. Early recognition of this entity and differentiation from other causes of focal cord atrophy is important, because limitation of neck flexion by using a simple neck collar can prevent its further progression. We report the classical MRI findings in a young patient with Hirayama's disease with neutral and flexion MRI.