Metabolic changes assessed by 1H MR spectroscopy in the corpus callosum of post-COVID patients.

OBJECTIVE: Many patients with long COVID experience neurological and psychological symptoms. Signal abnormalities on MR images in the corpus callosum have been reported. Knowledge about the metabolic profile in the splenium of the corpus callosum (CCS) may contribute to a better understanding of the pathophysiology of long COVID. MATERIALS AND METHODS: Eighty-one subjects underwent proton MR spectroscopy examination. The metabolic concentrations of total N-acetylaspartate (NAA), choline-containing compounds (Cho), total creatine (Cr), myo-inositol (mI), and NAA/Cho in the CCS were statistically compared in the group of patients containing 58 subjects with positive IgG COVID-19 antibodies or positive SARS-CoV-2 qPCR test at least two months before the MR and the group of healthy controls containing 23 subjects with negative IgG antibodies. RESULTS: An age-dependent effect of SARS-CoV-2 on Cho concentrations in the CCS has been observed. Considering the subjective threshold of age = 40 years, older patients showed significantly increased Cho concentrations in the CCS than older healthy controls (p = 0.02). NAA, Cr, and mI were unchanged. All metabolite concentrations in the CCS of younger post-COVID-19 patients remained unaffected by SARS-CoV-2. Cho did not show any difference between symptomatic and asymptomatic patients (p = 0.91). DISCUSSION: Our results suggest that SARS-CoV-2 disproportionately increases Cho concentration in the CCS among older post-COVID-19 patients compared to younger ones. The observed changes in Cho may be related to the microstructural reorganization in the CCS also reported in diffusion measurements rather than increased membrane turnover. These changes do not seem to be related to neuropsychological problems of the post-COVID-19 patients. Further metabolic studies are recommended to confirm these observations.

Ideational Slippage in Middle-Aged and Older Adults: A Preliminary Study.

Ideational slippage-characterized by incorrect word usage and strained logic during dialogue-is common in aging and, at greater frequency, is an indicator of pre-clinical cognitive decline. Performance-based assessment of ideational slippage may be useful in the study of cognitive aging and Alzheimer's-disease-related pathology. In this preliminary study, we examine the association between corpus callosum volume and a performance-based assessment of ideational slippage in middle-aged and older adults (age 61-79 years). Ideational slippage was indexed from cognitive special scores using the Rorschach Inkblot Method (RIM), which are validated indices of deviant verbalization and logical inaccuracy (Sum6, WSum6). Among middle-aged and older adults, smaller splenium volume was associated with greater ideational slippage (ηp2 = 0.48), independent of processing speed and fluid intelligence. The observed negative associations are consistent with visuospatial perception and cognitive functions of the splenium. The effect was strongest with the splenium, and volumes of the genu and total white matter had small effects that were not statistically significant. Conclusions: Results are discussed with future application of RIM special scores for the assessment of pre-clinical cognitive decline and, based on observed effect sizes, power analyses are reported to inform future study planning.

A rare cause of dysarthria: Legionnaires' disease.

PURPOSE/AIM OF THE STUDY: A case admitted with dysarthria and syncope and hyperintense lesion in the splenium of the corpus callosum, diagnosed as Legionnaires' disease by detecting Legionella antigen in the urine, and recovered only with antibiotic treatment is presented because it is rare in the literature. MATERIALS AND METHODS: When a 64-year-old female patient was admitted to the emergency department with complaints of sudden loss of consciousness and fainting at home, she had speech impairment, and her pulse oxygen saturation in room air was 88%. In the neurological examination, there was no pathological finding except dysarthria in the patient with no motor deficit. The patient had no respiratory complaints and had a recent travel history. In laboratory examinations, hyponatremia was detected with increased C-reactive protein and liver enzymes. Consolidation was observed in the lower right zone on chest computed tomography. Ampicillin + sulbactam (4x1 gr, intravenous) and clarithromycin (2 × 500 mg orally) were initiated. On cranial magnetic resonance, a hyperintense lesion was observed in the splenium of the corpus callosum in the oval T2 sequence. Legionella pneumophila serogroup 1 antigen in urine was reported as positive. On the fourth day of her hospitalization, the patient, whose CRP and liver enzyme values regressed, her hyponatremia improved, her pulse oxygen saturation increased to 92% in room air, and her speech became comprehensible, was discharged after oral antibiotic treatment was arranged. On the 12th day, the speech ability of the patient completely returned to normal. CONCLUSION: Legionella infection should be suspected in the presence of pneumonia and corpus callosum splenium lesion.

Diffusion Restriction in the Splenium: A Comparative Study of Cytotoxic Lesions of the Corpus Callosum (CLOCCs) versus Lesions of Vascular Etiology.

Cytotoxic lesions of the corpus callosum (CLOCCs) have broad differential diagnoses. Differentiating these lesions from lesions of vascular etiology is of high clinical significance. We compared the clinical and radiological characteristics and outcomes between vascular splenial lesions and CLOCCs in a retrospective cohort study. We examined the clinical and radiologic characteristics and outcomes in 155 patients with diffusion restriction in the splenium of the corpus callosum. Patients with lesions attributed to a vascular etiology (N = 124) were older (64.1 vs. 34.6 years old, p < 0.001) and had >1 vascular risk factor (91.1% vs. 45.2%, p < 0.001), higher LDL and A1c levels, and echocardiographic abnormalities (all p ≤ 0.05). CLOCCs (N = 31) more commonly had midline splenial involvement (p < 0.001) with only splenial diffusion restriction (p < 0.001), whereas vascular etiology lesions were more likely to have multifocal areas of diffusion restriction (p = 0.002). The rate of in-hospital mortality was significantly higher in patients with vascular etiology lesions (p = 0.04). Across vascular etiology lesions, cardio-embolism was the most frequent stroke mechanism (29.8%). Our study shows that corpus callosum diffusion restricted lesions of vascular etiology and CLOCCs are associated with different baseline, clinical, and radiological characteristics and outcomes. Accurately differentiating these lesions is important for appropriate treatment and secondary prevention.

Marchiafava-Bignami disease: Case presentation and radiological imaging.

Marchiafava-Bignami disease (MBD) is a rare vitamin B deficiency classically associated with alcoholism. MBD damages the corpus callosum and presents with nonspecific neurological symptoms. Radiological imaging is critical for diagnosing MBD and commencing subsequent treatment, which often consists of vitamin B supplementation. We present a case of MBD in a 56-year-old male with alcohol use disorder, epilepsy, schizophrenia, post-traumatic stress disorder, and cardiovascular risk factors. The patient presented with general neurological symptoms, and there were several potential diagnoses to consider based on the patient's history. Radiological imaging was necessary for diagnosis. This case demonstrates the role radiological imaging plays in the workup of MBD.

Morphometric Shape Analysis of Corpus Callosum in Children With Down Syndrome.

Down syndrome (DS) is characterized by varying degrees of mental retardation and delay in neurocognitive functions. Herein, we analyzed the morphometric shape of the corpus callosum (CC) in children with DS. Twenty-three DS cases underwent magnetic resonance imaging and have grossly normal CC, and 23 control group cases were included in this retrospective study (2012-2020). The CC was obtained from T2-weighted mid-sagittal images, and certain anatomical points were marked on the CC. Statistical geometric shapes and deformations of CC were evaluated for both groups. The age range of patients with DS and control group was 6 to 42 months. A statistically significant difference was found in the shape of CC between the groups (P < .001). Deformation was most evident in the splenium in the DS group.

Concurrent bacterial liver abscess and mild encephalitis/encephalopathy with reversible splenial lesion in a patient with poorly controlled type 2 diabetes.

A 34-year-old man with poorly controlled type 2 diabetes was admitted to our hospital because of fever, headache, vomiting, and impaired consciousness. His hemoglobin A1c level was as high as 11.0%. Abdominal computed tomography revealed a bacterial liver abscess, while head magnetic resonance imaging simultaneously showed a high-signal lesion on diffusion-weighted imaging and a low-signal lesion on the apparent diffusion coefficient map of the splenium of the corpus callosum. No significant findings were detected in the cerebrospinal fluid. The latter findings led to a diagnosis of mild encephalitis/encephalopathy with reversible splenial lesions. His impaired consciousness resolved on Day 5 after treatment with ceftriaxone and metronidazole infusion and intensive insulin therapy; magnetic resonance imaging on Day 20 showed that the lesion in the splenium of the corpus callosum had disappeared. We propose that when a person with poorly controlled diabetes develops a bacterial infection and presents with impaired consciousness and headache, clinicians should consider the complications of mild encephalitis/encephalopathy with reversible splenial lesion.

Splenium tract projections of the corpus callosum to the parietal cortex classifies Alzheimer's disease and mild cognitive impairment.

The corpus callosum (CC) is the largest bundle of white matter tracts in the brain connecting the left and right cerebral hemispheres. The posterior region of the CC, known as the splenium, seems to be relatively preserved throughout the lifespan and is regularly examined for indications of various pathologies, including Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). However, the splenium has rarely been investigated in terms of its distinct inter-hemispheric tract bundles that project to bilateral occipital, parietal and temporal areas of the cortex. The aim of the present study was to determine if any of these sub-splenium tract bundles are specifically affected by individuals with AD and MCI compared to normal controls. Diffusion Tensor Imaging was used to directly examine the integrity of these distinct tract bundles and their diffusion metrics were compared between groups of MCI, AD, and control individuals. Results revealed that differences between MCI, AD, and controls were particularly evident at parietal tracts of the CC splenium and were consistent with an interpretation of compromised white matter integrity. Combined parietal tract diffusivity and density information strongly discriminated between AD patients and controls with an accuracy (AUC) of 97.19%. Combined parietal tract diffusivity parameters correctly classified MCI subjects against controls with an accuracy of 74.97%. These findings demonstrated the potential of examining the CC splenium in terms of its distinct inter-hemispheric tract bundles for the diagnosis of AD and MCI.

Mild Encephalopathy With Partial Reversible Splenium Lesion Associated With SARS-CoV-2 Infection.

Viral-associated encephalitis/encephalopathy includes a wide spectrum of syndromes reported often in children. A rare form presents with mild encephalitis/encephalopathy and reversible splenial lesion(s). This report describes a case of this rare presentation associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a 68-year-old woman. The patient presented to the hospital with altered mental status. Examination revealed mild encephalopathy with disorientation to date and time. Initial laboratory workup was significant for mild hypernatremia and acute kidney injury, and a polymerase chain reaction (PCR) test for SARS-CoV-2 was positive. MRI of the brain revealed an area of hyperintensity and water restriction in the corpus callosum. The patient was treated with tocilizumab, dexamethasone, and remdesivir. MRI of the brain five weeks later revealed partial resolution of the hyperintensity, and complete resolution of the restricted diffusion previously seen in the corpus callosum, which confirmed the diagnosis of mild encephalitis/encephalopathy with a reversible splenial lesion. We highlight the importance of recognizing this phenomenon in association with SARS-CoV-2 infection.

Reversible splenial lesion after surgery for distant arteriovenous malformation: a case report.

Isolated lesions of the corpus callosum are rare and may represent permanent but also transient responses to various pathology termed "reversible splenial lesion syndrome" (RESLES) when in light of relevant clinical presentation. We present the first case of the RESLES after elective surgery for distant arteriovenous malformation (AVM), followed by a slight speech disturbance and MRI verified small, oval, well-circumscribed area of apparent cytotoxic edema in the center of the corpus callosum splenium, which completely resolved within 15 days. Surgery for AVM is followed by the complex adaptation to a new vascular pattern, RESLES might develop, and should be suspected.

A case of intravascular lymphoma presenting with a lesion in the splenium of the corpus callosum.

Intravascular lymphoma (IVL) is difficult to diagnose because its clinical presentation and laboratory and imaging findings are nonspecific. Herein, we report a case of IVL presenting as a lesion in the splenium of the corpus callosum. A 52-year-old man attended the emergency department with a 2-week history of progressively worsening abnormal behavior and gait disturbance. Magnetic resonance imaging on admission revealed an oval lesion in the splenium of the corpus callosum. The follow-up magnetic resonance imaging performed 2 months after disease onset revealed multiple high-signal areas in the bilateral cerebral white matter on T2-weighted images and diffusion-weighted images. The blood test results showed an elevated level of lactate dehydrogenase and serum-soluble interleukin-2 receptor. These findings were compatible with the diagnosis of IVL. IVL is often difficult to diagnose due to a wide variety of clinical presentations and imaging findings.

Unusual Lesion in the Splenium of the Corpus Callosum and COVID-19 Infection: A Case Report.

The novel coronavirus (SARS-CoV-2) causing the recent pandemic outbreak may result in brain injuries. The disease has a high prevalence for thromboembolic complications and a massive release of cytokines. We report a case of CLOCCS, one of the rare neurological complications of SARS-CoV-2 infection. Teaching Point: The imaging features of the cytotoxic lesion of the corpus callosum (CLOCCS) on magnetic resonance imaging should be known by every radiologist, to make the positive diagnosis and prevent misdiagnosis, especially in the setting of a COVID-19 infection.

[Imaging pathologies of the corpus callosum]. / Pathologien des Corpus callosum in der Bildgebung.

The corpus callosum is the largest fiber bundle in the cerebral white matter in the human brain. A multitude of disorders including congenital malformations, acute and chronic traumatic lesions, ischemia, neoplasms, secondary manifestations of metabolic, toxic or degenerative diseases as well as chronic inflammatory and demyelinating diseases can primarily or secondarily affect the corpus callosum. This article presents magnetic resonance imaging (MRI) characteristics of the most relevant diseases affecting the corpus callosum.

Case report: Clinically mild encephalitis/encephalopathy with a reversible splenial lesion: an autopsy case.

Clinically mild encephalitis/encephalopathy with a reversible splenial lesion is a clinicoradiological syndrome characterized by transient neuropsychiatric symptoms and hyperintensity of the splenium of the corpus callosum on diffusion-weighted MRI. Although intramyelinic edema and inflammatory cell infiltration can be predicted by MRI, the pathology of the splenium of the corpus callosum remains unknown. We encountered a case of clinically mild encephalitis/encephalopathy with a reversible splenial lesion and hypoglycemia in a patient who died of sepsis, and an autopsy was performed. The postmortem pathological findings included intramyelinic edema, myelin pallor, loss of fibrous astrocytes, microglial reactions, and minimal lymphocytic infiltration in the parenchyma. Based on these findings, transient demyelination following cytotoxic edema in the splenium of corpus callosum was strongly considered a pathogenesis of "clinically mild encephalitis/encephalopathy with a reversible splenial lesion" associated with hypoglycemia, and it could be generalized for the disease associated with the other causes. As cytotoxic edema could be the central pathology of the disease, the recently proposed term cytotoxic lesions of the corpus callosum may be applicable to this syndrome.

Mild Encephalopathy With Reversible Splenial Lesion (MERS) in a Child With Influenza.

Mild encephalopathy with reversible splenial lesion (MERS) is a rare clinical-radiological syndrome with a favorable prognosis that typically presents with central nervous system symptoms such as altered mental status, delirious behavior, seizures, muscle weakness, ophthalmoplegia, and headache. The diagnosis of MERS is based on a constellation of central nervous system symptoms within one week of fever, a lesion in the splenium of the corpus callosum, and complete resolution without sequelae. Both clinical and imaging findings generally resolve within a few months. Treatment is largely supportive care and/or treatment of the primary cause.

Imaging of the neurological manifestations of dengue: A case series.

Dengue fever, the most common arboviral tropical disease, has shown a rapid increase in incidence over the last few decades. Increasing evidence of the various neurological manifestations in dengue has been documented in the literature. Patients positive for dengue on serology and with neurological manifestations were analysed and included in the present case series and brief review. The cases reveal a spectrum of neurological findings in dengue infection and include dengue haemorrhagic encephalitis, acute disseminated encephalomyelitis (ADEM), reversible splenial lesion syndrome (RESLES), intracranial haematoma, and posterior reversible encephalopathy syndrome (PRES), with a focus on the relevant imaging features. Contribution: The present case series emphasises the importance of understanding the relevant imaging findings and potential aetiopathogenesis of neurological involvement in dengue infected patients in order to make the correct diagnosis for effective treatment and improved outcome.

Restricted diffusion of the callosal splenium is highly specific for seizures in neonates.

BACKGROUND: To determine whether restricted diffusion of the callosal splenium is specific for seizure activity in neonates. METHODS: We performed a retrospective chart review of 123 neonates who had a diagnosis of hypoxic ischemic encephalopathy (HIE) who underwent therapeutic cooling and had magnetic resonance imaging (MRI) within the first 10 days of life. The regions examined for injury include the callosal splenium, cortex, deep gray matter, and subcortical white matter. Neurodevelopmental outcomes were secondarily assessed using the Bayley Scales of Infant Development at 12 to 18 months of age and > 18 months of age. APGAR scores and pH, two important markers of hypoxia/ischemia and encephalopathy, were also analyzed in relation to these outcomes. RESULTS: Approximately 41% of the neonates had at least one abnormal region on brain MRI, and 21% had abnormal signal in the splenium. Clinical and/or electrographic seizures were documented in 32%. Changes in the splenium had a sensitivity of 54%, specificity of 94%, and positive predictive value of 81% for seizure presence. The presence of seizures and splenium lesion was associated poor developmental outcomes at 12 to 18 months of age. APGAR scores at 10 minutes, but not lowest pH was associated with splenial changes. CONCLUSIONS: Restricted diffusion of the callosal splenium is specific for recent seizures in neonates with HIE. Seizures and splenial lesion represent risk factors for poor neurodevelopmental outcomes. Child neurologists and neonatologists should consider splenial signal abnormality in their assessment of neonates at risk for seizures and counsel families about likely outcomes accordingly.

Mild Encephalopathy/Encephalitis With a Reversible Splenial Lesion (MERS) and Longitudinally Extensive Transverse Myelitis (LETM) in Influenza B: Neurotropic Mechanisms and Diagnostic Challenges.

Mild encephalopathy/encephalitis with a reversible splenial lesion (MERS) and longitudinally extensive transverse myelitis (LETM) are neuroinflammatory conditions related to the brain and spinal cord, respectively. Most cases of MERS and LETM are related to a secondary autoimmune process in response to an initial insult (i.e., infection, immunization, etc.). The case of an 18-year-old female who developed a three-day history of fever, quadriplegia, cough, and mild encephalopathy is reported here. The patient tested positive for influenza B by nasopharyngeal swab with polymerase chain reaction (PCR). Initial magnetic resonance imaging (MRI) revealed the presence of a diffusion-restricted non-enhancing lesion confined to the splenium of the corpus callosum (MERS type I) and longitudinally extensive non-enhancing T2 hyperintensities from C1 to C5. The patient was managed with a five-day course of 1,000 mg of intravenous methylprednisolone (IVMP). Additionally, five days of therapeutic plasmapheresis (PLEX) was completed. The patient showed significant improvement with medical management and physical therapy. At the one-year follow-up, her motor symptoms had resolved and endorsed only mild paresthesia in the upper extremities. A repeat MRI revealed a reversal of the splenium lesion and moderate improvement in T2 hyperintensities of the cervical cord. Assessing neuroinvasion of the influenza virus is difficult, and diagnostic challenges arise in determining primary infectious versus autoimmune-mediated neuroinflammation. A review of the literature on influenza infection with radiographic findings of MERS and LETM is included.

Time course of right-hemisphere recruitment during word production following left-hemisphere damage: A single case of young stroke.

Our understanding of post-stroke language function is largely based on older age groups, who show increasing age-related brain pathology and neural reorganisation. To illustrate language outcomes in the young-adult brain, we present the case of J., a 23-year-old woman with chronic aphasia from a left-hemisphere stroke affecting the temporal lobe. Diffusion MRI-based tractography indicated that J.'s language-relevant white-matter structures were severely damaged. Employing magnetoencephalography (MEG), we explored J.'s conceptual preparation and word planning abilities using context-driven and bare picture-naming tasks. These revealed naming deficits, manifesting as word-finding difficulties and semantic paraphasias about half of the time. Naming was however facilitated by semantically constraining lead-in sentences. Altogether, this pattern indicates disrupted lexical-semantic and phonological retrieval abilities. MEG revealed that J.'s conceptual and naming-related neural responses were supported by the right hemisphere, compared to the typical left-lateralised brain response of a matched control. Differential recruitment of right-hemisphere structures (330-440 ms post-picture onset) was found concurrently during successful naming (right mid-to-posterior temporal lobe) and word-finding attempts (right inferior frontal gyrus). Disconnection of the temporal lobes via corpus callosum was not critical for recruitment of the right hemisphere in visually guided naming, possibly due to neural activity right lateralising from the outset. Although J.'s right hemisphere responded in a timely manner during word planning, its lexical and phonological retrieval abilities remained modest.

A Reversible Lesion of the Corpus Callosum Associated With Bacterial Meningitis.

We report the rare case of a 22-year-old female admitted for headaches, nausea, and an isolated lesion of the splenium of the corpus callosum (SCC) found on brain magnetic resonance imaging (MRI). A lumbar puncture test was performed, and Pseudomonas aeruginosa meningitis was found. Twenty days before the symptoms, she had spinal anesthesia for a cesarean section. As soon as the diagnosis was made, antibiotic therapy was initiated. Nonetheless, no signs or symptoms were related to this lesion, which spontaneously disappeared within one month on the control MRI. Pseudomonas aeruginosa is a gram-negative bacillus and may cause rare and severe meningitis. Therefore, a history of a neurosurgical procedure or spinal anesthesia should be sought in the anamnesis.