Transient lesion in the splenium of the corpus callosum and antiepileptic drug withdrawal

Cytotoxic Lesions of the Corpus Callosum Associated with Aneurysmal Subarachnoid Hemorrhage May Influence Shunt-Dependent Chronic Hydrocephalus

BACKGROUND

Cytotoxic lesions of the corpus callosum (CLOCCs) are occasionally associated with aneurysmal subarachnoid hemorrhage (aSAH). The effects of aSAH on clinical outcomes in such cases are unclear. The present study aimed to investigate the frequency and characteristics of CLOCCs associated with aSAH to ascertain the predictors of shunt-dependent chronic hydrocephalus (SDCH) after aSAH.

METHODS

We retrospectively investigated cases of aSAH treated by coil embolization. Patients were divided into those with and without CLOCCs. Between-group differences were evaluated, including clinical outcomes and the characteristics of both the patients and the aneurysms. Patients were divided into those with and without SDCH to identify predictive factors of SDCH after aSAH focusing on CLOCCs.

RESULTS

This single-center study included 196 patients with aSAH. All patients received coil embolization between April 2013 and March 2020. CLOCCs were detected in 38 (19.4%) patients. In the group with CLOCCs, male sex, poor severity grade at onset, acute hydrocephalus, SDCH (all P < 0.01), and Fisher group 3 or 4 (P = 0.04) were significantly more common than in the group without CLOCCs. Diabetes and CLOCCs were significant predictors of SDCH after aSAH in multivariate analysis (diabetes: P < 0.01, odds ratio: 6.73, 95% confidence interval: 1.61-28.09; CLOCCs: P < 0.01, odds ratio: 6.86, 95% confidence interval: 2.87-16.38).

CONCLUSIONS

CLOCCs and SDCH were common in patients with poor-grade aSAH, and CLOCCs were independent predictors of SDCH after aSAH. Meticulous follow-up is necessary to detect SDCH after aSAH, especially in patients with poor-grade aSAH and CLOCCs.

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.

Bilateral Structural Network Abnormalities in Epilepsy Associated With Bottom-of-Sulcus Dysplasia

BACKGROUND AND OBJECTIVES

To identify white matter fiber tracts that exhibit structural abnormality in patients with bottom-of-sulcus dysplasia (BOSD) and investigate their association with seizure activity.

METHODS

Whole-brain fixel-based analysis of diffusion MRI data was performed to identify white matter fiber tracts with significant reductions in fiber density and cross-section in patients with BOSD (n = 20) when compared to healthy control participants (n = 40). Results from whole-brain analysis were used to investigate the association of fiber tract abnormality with seizure frequency and epilepsy duration.

RESULTS

Despite the focal nature of the dysplasia, patients with BOSD showed widespread abnormality in white matter fiber tracts, including the bilateral corticospinal, corticothalamic, and cerebellothalamic tracts, superior longitudinal fasciculi, corpus callosum (body), and the forceps major. This pattern of bilateral connectivity reduction was not related to the laterality of the lesion. Exploratory post hoc analyses showed that high seizure frequency was associated with greater reduction in fiber density at the forceps major, bilateral corticospinal, and cerebellothalamic tracts.

DISCUSSION

We demonstrate evidence of a bilaterally distributed, specific white matter network that is vulnerable to disruption in BOSD. The degree of tract abnormality is partly related to seizure activity, but additional contributors such as the genetic background and effects of treatment or environment have not been excluded.

Reversible splenial lesion syndrome with mental disorders as only manifestation

Background

Reversible splenial lesion syndrome (RESLES) was reported to be associated with variable entities. However, much less is known about the cases in which the mental disorders act as the only manifestation.

Method

Total ten patients of RESLES were obtained in this retrospective study from Shenzhen Kangning Hospital. T1-fluid attenuated inversion recovery (T1-FLAIR), T2-weighted images, T2-FLAIR, diffusion-weighted images and apparent diffusion coefficient map were performed on all the patients. Clinical manifestations, laboratory examination results, magnetic resonance imaging (MRI) findings, treatments and outcomes were analyzed.

Result

All patients showed different mental disorders as the only manifestation. There were two cases of alcohol abuse, one of Asperger’s syndrome with malnutrition, one of infection and one of invasive pituitary adenoma. The other cases were diagnosis as major depressive disorder, dissociative and conversion disorders, undifferentiated somatoform disorder, unspecified psychosis and bipolar disorder, respectively. Three patients were completely recovered while the clinical symptoms of rest seven patients partially recovered at the follow-up three months later. Oval-shaped lesion centered on the splenial of corpus callosum (SCC) was observed in all patients using MRI. The lesions of SCC of all patients were completely resolved within five weeks.

Conclusions

We found that RESLES might only showed mental symptoms. On the one hand, for the patients with acute mental disorders, clinicians should be alert to the possibility of RESLES caused by physical disease. On the other hand, we suggest that mental disorder might be a precipitating factor of RESLES.

Association of Ischemic Imaging Phenotype With Progression of Brain Atrophy and Cerebrovascular Lesions on MRI: The SMART-MR Study

OBJECTIVE

To investigate the association of silent vascular lesions, imaging negative ischemia, and symptomatic cerebrovascular disease with long-term progression of brain atrophy and cerebrovascular lesions in patients with arterial disease.

METHODS

Within the SMART-MR study, stroke status of participants at baseline was classified as no cerebrovascular disease (reference group, n=829), symptomatic cerebrovascular disease (n=206), silent vascular lesion (n=157), and imaging negative ischemia (n=90) based upon clinical and MRI findings. Using linear mixed models, changes in brain and white matter hyperintensity (WMH) volumes at baseline and during 12 years of follow-up were studied in stroke classifications. Relative risks were estimated for new infarcts during follow-up associated with stroke classifications. Analyses were adjusted for age, sex, cardiovascular risk factors, and medications.

RESULTS

Symptomatic cerebrovascular disease associated with 0.35 SDs (95%CI 0.24-0.47) smaller brain volume and 0.61 SDs (95%CI 0.48-0.74) larger WMH volume at baseline, and increased risk for new infarcts during follow-up (risk ratio (RR) 2.89; 95%CI 2.00-4.16). Silent vascular lesions associated with 0.15 SDs (95%CI 0.01-0.88) smaller brain volume, 0.02 SDs (95%CI 0.01-0.03) steeper brain atrophy slope, and 0.48 SDs (95%CI 0.32-0.64) larger WMH volume at baseline, in addition to increased risk for lacunes (RR 2.08; 95%CI 1.48-2.94). Individuals with imaging negative ischemia had increased risk for cortical infarcts (RR=2.88; 95%CI 2.17-3.82).

CONCLUSIONS

Patients with symptomatic cerebrovascular disease, silent vascular lesions, or imaging negative ischemia have different course of brain volume loss and cerebrovascular lesions development. These findings may have implications for future stroke risk and dementia and need further investigation.

Clinical Features of Cytotoxic Lesions of the Corpus Callosum Associated with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Patients with SAH due to a ruptured intracranial aneurysm occasionally show reversible high-signal lesions in the splenium of the corpus callosum on DWI. These lesions are called cytotoxic lesions of the corpus callosum. This study retrospectively reviewed cases of aneurysmal SAH and investigated clinical features of cytotoxic lesions of the corpus callosum associated with SAH.

MATERIALS AND METHODS

Participants comprised 259 patients with aneurysmal SAH who had undergone curative treatment at our hospital. We examined the following items related to cytotoxic lesions of the corpus callosum: occurrence rate, timing of appearance and disappearance of the lesions, lesion size, aneurysm location, severity of SAH, treatment method, clinical course, and outcome.

RESULTS

Among the 259 cases, DWI detected cytotoxic lesions of the corpus callosum in 33 patients (12.7%). The mean periods from the onset of SAH to detection and disappearance of cytotoxic lesions of the corpus callosum were 6.3 days (range, 0-25 days) and 35.7 days (range, 9-78 days), respectively. Cytotoxic lesions of the corpus callosum were classified into 2 types: a small type localized in the splenium in 26 cases (78.9%) and a large type spread along the ventricle in 7 cases (21.2%). The severity of SAH, coiling, hydrocephalus, and poor mRS score at discharge were significantly higher in the group with cytotoxic lesions of the corpus callosum. However, multivariate analysis did not identify cytotoxic lesions of the corpus callosum as a risk factor for poor outcome.

CONCLUSIONS

Cytotoxic lesions of the corpus callosum appear at a frequency of 12.7% in patients with aneurysmal SAH. Cytotoxic lesions of the corpus callosum associated with SAH take several days to appear and subsequently resolve within about a month. Cytotoxic lesions of the corpus callosum were likely to occur in patients with high-grade SAH but did not represent a predictor of poor outcome.

White Matter Lesions in Adults - a Differential Diagnostic Approach

OBJECTIVE

 Cerebral white matter lesions on MRI in adults are a common finding. On the one hand, they may correspond to a clinically incidental feature, be physiologically or age-associated, or on the other hand they may be the overture to a severe neurological disease. With regard to pathophysiological aspects, practical hints for the differential diagnostic interpretation of lesions in daily clinical practice are presented.

MATERIAL AND METHODS

 With special regard to the vascular architecture and supply of the cerebral white matter, physiological structures are schematically represented and pathophysiological processes are highlighted by comparative image analysis of equally angulated MR sequences.

RESULTS

 The most frequent vascular, inflammatory, metabolic, and neoplastic disease entities are presented on the basis of characteristic imaging findings and corresponding clinical- neurological constellations. The details of signal intensities and localization essential for differential diagnosis are highlighted.

CONCLUSION

 By means of comparative image analysis and the recognition of characteristic lesion patterns, taking into account anatomical principles and pathophysiological processes, the differential diagnostic classification of cerebral white matter lesions and associated diseases can be significantly facilitated. The additional consideration of clinical and laboratory findings is essential.

KEY POINTS

  · Cerebral white matter lesions can be a harmless secondary finding or overture to a severe neurological disease.. · The comparative image analysis of different sequences with identical angulation is crucial.. · With special regard to the vascular anatomy, different lesion patterns can be identified.. · The consideration of neurological and laboratory chemical constellations is essential for the differential diagnosis..

CITATION FORMAT

· Weidauer S, Wagner M, Hattingen E. White Matter Lesions in Adults - a Differential Diagnostic Approach. Fortschr Röntgenstr 2020; 192: 1154 - 1173.

Treatment-related transient splenial lesion of the Corpus Callosum in patients with neuropsychiatric disorders: a literature overview with a case report

Introduction: Transient-localized lesions of the splenium of the corpus callosum (SCC) have been described in various clinical conditions, some of them being attributed to the withdrawal of psychotropic drugs. The pathophysiology of the lesion reflects cytotoxic edema and reversible demyelination.Areas covered: The present article aimed at reviewing cases of transient SCC lesion exclusively related to changes in pharmacotherapy. It also reports the original case of a patient receiving a complex psychopharmacological therapy who developed a transient SCC lesion investigated by magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and pharmacogenetic profiling.Expert opinion: To date, only one review on the subject has been published, analyzing 22 cases of transient SCC lesion arising in epileptic patients on antiepileptic therapy. It hypothesized that the nature of the lesion is a cytotoxic edema and the cases described in the subsequent 14 years seem to support this hypothesis. The authors reported the case of an Italian-Egyptian patient who developed a transient SCC lesion after the rapid withdrawal of Carbamazepine and Lurasidone. The lesion completely disappeared from the MRI performed after 1 month. Patient's ethnic group and its pharmacogenetic profile were considered as possible causes of altered drug metabolism and, likely, of the SCC lesion.

Cortical atrophy accelerates as cognitive decline worsens in multiple sclerosis

Objective

To determine which pathologic process could be responsible for the acceleration of cognitive decline during the course of multiple sclerosis (MS), using longitudinal structural MRI, which was related to cognitive decline in relapsing-remitting MS (RRMS) and progressive MS (PMS).

Methods

A prospective cohort of 230 patients with MS (179 RRMS and 51 PMS) and 59 healthy controls was evaluated twice with 5-year (mean 4.9, SD 0.94) interval during which 22 patients with RRMS converted to PMS. Annual rates of cortical and deep gray matter atrophy as well as lesion volume increase were computed on longitudinal (3T) MRI data and correlated to the annual rate of cognitive decline as measured using an extensive cognitive evaluation at both time points.

Results

The deep gray matter atrophy rate did not differ between PMS and RRMS (−0.82%/year vs −0.71%/year, p = 0.11), while faster cortical atrophy was observed in PMS (−0.87%/year vs −0.48%/year, p < 0.01). Similarly, faster cognitive decline was observed in PMS compared to RRMS (p < 0.01). Annual cognitive decline was related to the rate of annual lesion volume increase in stable RRMS (r = −0.17, p = 0.03) to the rate of annual deep gray matter atrophy in converting RRMS (r = 0.50, p = 0.02) and annual cortical atrophy in PMS (r = 0.35, p = 0.01).

Conclusions

These results indicate that cortical atrophy and cognitive decline accelerate together during the course of MS. Substrates of cognitive decline shifted from worsening lesional pathology in stable RRMS to deep gray matter atrophy in converting RRMS and to accelerated cortical atrophy in PMS only.

Transient Lesion of the Splenium of the Corpus Callosum after Acute Ischemic Stroke

Two patients who showed transient lesions in the splenium of the corpus callosum (SCC) secondary to acute ischemic stroke are reported. Both patients had embolic strokes and showed an isolated lesion in the SCC on magnetic resonance imaging (MRI) 1-2 weeks after the onset of stroke, with a hyperintense lesion on diffusion-weighted imaging and decreased apparent diffusion coefficient values, with no symptoms related to the lesion. In both cases, the lesion disappeared on MRI approximately 1 week later. Clinicians should note that transient SCC lesions can occur following acute ischemic stroke and avoid misdiagnosing them and performing unnecessary examinations or treatment.

Circulating cortisol and cognitive and structural brain measures: The Framingham Heart Study

OBJECTIVE

To assess the association of early morning serum cortisol with cognitive performance and brain structural integrity in community-dwelling young and middle-aged adults without dementia.

METHODS

We evaluated dementia-free Framingham Heart Study (generation 3) participants (mean age 48.5 years, 46.8% men) who underwent cognitive testing for memory, abstract reasoning, visual perception, attention, and executive function (n = 2,231) and brain MRI (n = 2018) to assess total white matter, lobar gray matter, and white matter hyperintensity volumes and fractional anisotropy (FA) measures. We used linear and logistic regression to assess the relations of cortisol (categorized in tertiles, with the middle tertile as referent) to measures of cognition, MRI volumes, presence of covert brain infarcts and cerebral microbleeds, and voxel-based microstructural white matter integrity and gray matter density, adjusting for age, sex, APOE, and vascular risk factors.

RESULTS

Higher cortisol (highest tertile vs middle tertile) was associated with worse memory and visual perception, as well as lower total cerebral brain and occipital and frontal lobar gray matter volumes. Higher cortisol was associated with multiple areas of microstructural changes (decreased regional FA), especially in the splenium of corpus callosum and the posterior corona radiata. The association of cortisol with total cerebral brain volume varied by sex (p for interaction = 0.048); higher cortisol was inversely associated with cerebral brain volume in women (p = 0.001) but not in men (p = 0.717). There was no effect modification by the APOE4 genotype of the relations of cortisol and cognition or imaging traits.

CONCLUSION

Higher serum cortisol was associated with lower brain volumes and impaired memory in asymptomatic younger to middle-aged adults, with the association being evident particularly in women.

Reversible lesions of the corpus callosum with initially restricted diffusion in a series of Caucasian children

BACKGROUND

Reversible lesions of the corpus callosum with initial restricted diffusion on diffusion-weighted imaging (DWI) are rare and mainly described in the south Asiatic population.

OBJECTIVE

The purpose of this study was to describe the clinical presentation, imaging findings, prognosis and etiology of transient restricted diffusion lesions of the corpus callosum in a series of Caucasian children.

MATERIALS AND METHODS

Seven children presenting with a transient restricted DWI lesion of the corpus callosum were included. Their clinical presentations and paraclinical examinations were investigated in addition to their MRI findings during the acute phase and at follow-up.

RESULTS

Five patients initially presenting with prodromal flu-like symptoms were diagnosed with mild encephalopathy with reversible corpus callosum lesions, three of which were due to the influenza virus. For two patients (twins) with a stroke-like presentation and without febrile illness, a central nervous system manifestation of X-linked Charcot-Marie-Tooth disease with connexin 32 mutation was diagnosed. All patients had a good clinical prognosis without clinical sequelae or residual MRI lesion for all patients at follow-up.

CONCLUSION

A transient lesion of the corpus callosum with restricted diffusion should prompt the radiologist to suggest an infectious trigger in children. The prognosis of these patients was good with normalization of clinical symptoms and MRI without any specific treatment.

Transient Splenial Lesion of the Corpus Callosum Related to Migraine with Aura in a Pediatric Patient

BACKGROUND

Transient splenial lesions of the corpus callosum are rare radiological findings first described in association with epilepsy, antiepileptic drugs and viral encephalitis. However, subsequently more cases were described associated with diverse clinical conditions.

CASE REPORT

We describe a 13-year-old girl suffering from migraine with aura presenting with headache, right-sided hemiparesis and encephalopathy. Brain magnetic resonance imaging revealed an ovoid lesion in the splenium of the corpus callosum. The patient's neurological symptoms resolved within 3 days without therapy and the lesion disappeared in follow up magnetic resonance images obtained 3 weeks after the onset of the symptoms.

RESULTS

Migraine with aura was considered to be the cause of the lesion. To our knowledge the present case is the first report of a pediatric patient with a diagnosis of migraine with aura presenting with hemiparesis and encephalopathy.

CONCLUSIONS

A diagnosis of transient lesion of the corpus callosum should be suspected in patients with migraine with aura presenting with hemiparesis and encephalopathy. A mild course and a good prognosis might be expected in the presence of a splenial lesion of the corpus callosum.

Rotavirus-associated mild encephalopathy with a reversible splenial lesion (MERS)-case report and review of the literature

Background

Rotavirus is the most common cause of severe gastroenteritis in children under the age of 5 years worldwide. It is well recognised that rotavirus can cause signs and symptoms beyond the gastrointestinal tract, including neurological manifestations such as encephalopathy. Mild encephalopathy with a reversible splenial lesion (MERS) is a clinico-radiological syndrome that has been associated with rotavirus. We report a case of a 4-year-old boy with clinically mild encephalopathy, who had an isolated splenial lesion in the corpus callosum on neuroimaging, and rotavirus RNA detected in faeces. We use this case as an opportunity to review the literature on rotavirus-associated MERS.

Case presentation

A previously healthy 4-year-old boy presented with a 2-day history of vomiting, diarrhoea, and fever, complicated by reduced level of consciousness. Magnetic resonance imaging of the brain showed a marked hyperintensity in the splenium of the corpus callosum on T2 and diffusion-weighted images. Rotavirus genome was detected by polymerase chain reaction in a stool specimen, but not in the cerebrospinal fluid. The genotype was identified as G1P8. His clinical condition improved with gradual resolution of his symptoms. No neurological complications were evident upon discharge and the patient had no recurring symptoms or significant residual defects when followed up 2 months later.

Conclusion

MERS is a novel clinic-radiological syndrome first described in Japan. A transient splenial lesion with reduced diffusion that appears as a high signal intensity in diffusion-weighted MRI is the main diagnostic feature. Rotavirus is one of the most common agents associated with MERS, although to our knowledge only one previous case has been reported from Europe. The majority of patients appear to achieve full recovery following rotavirus-associated MERS, irrespective of treatment. This case, together with other published reports, supports the hypothesis that rotavirus-associated MERS is unlikely to be the result of direct viral invasion of the CNS. It has been suggested that MERS may be caused by intra-myelinic axonal oedema or local inflammatory cell infiltration; however, the pathogenesis remains incompletely understood.

Salivary cortisol, brain volumes, and cognition in community-dwelling elderly without dementia

OBJECTIVE

We investigated the associations of morning and evening salivary cortisol levels with regional brain volumes and cognitive functioning in community-dwelling older persons without dementia.

METHOD

From the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study, we included 4,244 persons without dementia (age 76 ± 5 years, 58% women) who had 1.5T brain MRI, assessment of cognitive functioning, and saliva collected at home 45 minutes after awakening and at night. Linear regression analysis was used to estimate the cross-sectional relationship among cortisol levels, brain volumes, and cognitive functioning, adjusting for covariates.

RESULTS

Higher evening cortisol was associated with smaller total brain volume (highest vs lowest tertile -16.0 mL; 95% confidence interval -19.7 to -12.2 mL, adjusted for age, sex, education, intracranial volume, smoking, steroid use, white matter lesions, and brain infarcts on MRI). The smaller volumes were observed in all brain regions, but were significantly smaller in gray matter than in white matter regions. Poorer cognitive functioning across all domains was also associated with higher evening cortisol. Higher levels of morning cortisol were associated with slightly greater normal white matter volume and better processing speed and executive functioning, but not with gray matter volume or with memory performance.

CONCLUSIONS

In older persons, evening and morning cortisol levels may be differentially associated with tissue volume in gray and white matter structures and cognitive function. Understanding these differential associations may aid in developing strategies to reduce the effects of hypothalamic-pituitary-adrenal axis dysfunction on late-life cognitive impairment.

Postictal MRI abnormalities and seizure-induced brain injury: notions to be challenged

OBJECTIVE

This was a bibliographic search to address the quality of evidence in clinical reports supporting the assertion that brain MRI signal abnormalities are a direct consequence of seizures.

METHODS

The search on PubMed was performed by applying the following inclusion criteria: a) original case reports, b) in humans, c) as single case reports or series of patients, d) of visually detected acute MRI signal abnormalities, e) attributable directly to seizures, and f) published in English. Bibliographic references of initially selected publications were reviewed for additional articles. Full texts of selected publications were read for information regarding clinical, EEG, and MRI features. Moreover, claimed evidence supporting seizure-induced excitotoxicity was assessed.

RESULTS

The search resulted in 91 publications corresponding to 413 cases. There was a wide range of clinical features and EEG and MRI abnormalities. Premorbid or comorbid conditions were present in many cases, and some of them are potential causes of MRI changes. Claimed evidence for MRI signal abnormalities as a direct consequence of ictal activity was mostly based on the similarity with previous reports, animal models, reversibility, congruent EEG, MRI changes not respecting vascular territories, and ruling out other etiologies.

CONCLUSIONS

Evidence supporting the notion of seizure-induced excitotoxicity is questionable in the studied reports of postictal MRI abnormalities.

Clinical and Neuroimaging Profile of Children with Lesions in the Corpus Callosum

PURPOSE

T2-hyperintense signal changes in corpus callosum (CC) have been described in epilepsy and encephalitis/encephalopathy. Little is known about their pathophysiology. The aim of this study was to examine the clinical presentation and evolution of CC lesions and relationship to seizures.

METHODS

We identified 12 children among 29,634 patients from Radiology Database. We evaluated following characteristics: seizures and accompanying medical history, antiepileptic drug usage, presenting symptoms, and radiological evolution of lesions.

RESULTS

CC lesions were seen in patients with prior diagnosis of epilepsy (n = 5) or in those with new onset seizures (n = 3), or with encephalitis/encephalopathy without history of seizures (n = 4). Seizure clustering or disturbances of consciousness were the main presenting symptoms. No relationship was observed between CC lesion and AEDs. On imaging, ovoid lesions at presentation resolved on follow up imaging and linear lesions persisted. DTI showed that the fibers passing through splenial lesions originated from the posterior parietal cortex and occipital cortex bilaterally.

CONCLUSION

In patients with seizures, no clear relationship was demonstrated between seizure characteristics or AED use with CC lesions. Ovoid lesions resolved and may have different pathophysiologic mechanism when compared to linear lesions that persisted.

Reversible Splenial Lesion Following Rapid Withdrawal of Carbamazepine

A 19-year-old man with paroxysmal kinesigenic dyskinesia (PKD) taking 200mg carbamazepine per day for six years was admitted to our hospital because of a medical certificate for soldiers. The dyskinesias were usually precipitated by sudden movements and these attacks occurred several times a day and had a brief duration (less than one minute). The drug was abruptly withdrawn seven days before the brain imaging and video-electroencephalography monitoring. Magnetic resonance imaging showed cytotoxic edema in the splenium, which were completely resolved three months later (Figure).

Differential diagnosis of white matter lesions: Nonvascular causes-Part II

The knowledge of characteristic lesion patterns is important in daily practice imaging, as the radiologist increasingly is required to provide precise differential diagnosis despite unspecific clinical symptoms like cognitive impairment and missed elaborated neurological workup. This part II dealing with nonvascular white matter changes of proven cause and diagnostic significance aimed to assist the evaluation of diseases exhibiting lesions exclusively or predominantly located in the white matter. The etiologies commented on are classified as follows: (a) toxic-metabolic, (b) leukodystrophies and mitochondriopathies, (c) infectious, (d) neoplastic, and (e) immune mediated. The respective mode of lesion formation is characterized, and typical radiological findings are displayed. More or less symmetrical lesion patterns on the one hand as well as focal and multifocal ones on the other are to be analyzed with reference to clinical data and knowledge of predilection sites characterizing major disease categories. Complementing spinal cord imaging may be useful not only in acute and relapsing demyelinating diseases but in certain leukodystrophies as well. In neuromyelitis optica (NMO), the detection of a specific antibody and some recently published observations may lead to a new understanding of certain deep white matter lesions occasionally complicating systemic autoimmune disease.

Corpus callosum and epilepsies

Introduction.Corpus callosum (CC) is the largest forebrain commissure. Structural anomalies and accompanying clinical symptoms are not in the focus of neurologists, epileptologists or neurosurgeons.

Aim and method.Anatomy, embryological development, normal functions, structural abnormalities, additional malformations, clinical symptoms and seizure disorders with CC anomalies are reviewed from the literature.

Review.The detection of callosal anomalies increased rapidly with widespread use of brain imaging methods. Agenesis or dysgenesis of corpus callosum (AgCC) might be considered an accidental finding. Epileptic seizures occur in up to 89% of patients with AgCC. The causal relationship correctly is questioned. However, additional causative malformations of midline and/or telencephalic structures can be demonstrated in most seizure patients. The interruption of bilateral spread of seizure activities acts as the concept for callosotomy as epilepsy surgery. Indications are drug-resistant generalized, diffuse, or multifocal epilepsies. A resectable seizure onset zone should be excluded. Most treated patients are diagnosed as Lennox-Gastaut or Lennox-like syndrome.

Conclusions.In cases with callosal abnormalities and clinical symptoms additional malformations are frequently observed, especially with seizure disorders. Callosotomy is the most effective option against drop attacks. The method probably is underused. After callosotomy a circumscript seizure focus might be unveiled and a second step of resective epilepsy surgery can be successful.

MRI evaluation of pathologies affecting the corpus callosum: A pictorial essay

The corpus callosum is a midline cerebral structure and has a unique embryological development pattern. In this article, we describe the pathophysiology and present imaging findings of various typical/atypical conditions affecting the corpus callosum. Since many of these pathologies have characteristic appearances on magnetic resonance imaging (MRI) and their therapeutic approaches are poles apart, ranging from medical to surgical, the neuroradiologist should be well aware of them.

Boomerang sign: Clinical significance of transient lesion in splenium of corpus callosum

Transient signal abnormality in the splenium of corpus callosum on magnetic resonance imaging (MRI) is occasionally encountered in clinical practice. It has been reported in various clinical conditions apart from patients with epilepsy. We describe 4 patients with different etiologies presenting with signal changes in the splenium of corpus callosum. They were diagnosed as having progressive myoclonic epilepsy (case 1), localization-related epilepsy (case 2), hemicrania continua (case 3), and postinfectious parkinsonism (case 4). While three patients had complete involvement of the splenium on diffusion-weighted image (“boomerang sign”), the patient having hemicrania continua showed semilunar involvement (“mini-boomerang”) on T2-weighted and FLAIR image. All the cases had noncontiguous involvement of the splenium. We herein, discuss these cases with transient splenial involvement and stress that such patients do not need aggressive diagnostic and therapeutic interventions. An attempt has been made to review the literature regarding the pathophysiology, etiology, and outcome of such lesions.

A case of reversible splenial lesions in late postpartum preeclampsia

There have been reports of various etiologies associated with reversible splenial lesions manifested as obviously restricted diffusion. We describe for a 27-year-old woman suffering from late postpartum preeclampsia associated with reversible splenial lesions. This association has not been reported to date. Awareness that profound late postpartum preeclampsia can rarely result in abnormalities of the splenium of the corpus callosum (SCC) may help clinicians avoid unnecessary diagnostic procedures and therapeutic interventions. Moreover, it must be stated that prediction of the clinical course based on DWI and ADC values should be used with caution.

Transient splenial lesion after recovery of cerebral vasoconstriction and posterior reversible encephalopathy syndrome: a case report of eclampsia

We describe a 34-year-old eclamptic woman with transient splenial lesion (TSL) after reversible cerebral vasoconstriction (RCV) and posterior reversible encephalopathy syndrome (PRES). She developed a headache, generalized convulsion and severe hypertension at an uncomplicated virginal delivery. Brain MRI disclosed T2-hyperintensity lesions in the posterior circulation territories. Two weeks later, T2-hyperintensity lesions had vanished. MR angiography (MRA) revealed segmental vasoconstriction in the right posterior, left internal and middle cerebral arteries. At one month after onset, MRA was normalized. T2-weighted imaging depicted asymptomatic isolated TSL. These radiological changes of the present patient highlighted the serial relationship between PRES, RCV and TSL in eclampsia.

Neuroimaging of pediatric brain infections

Neuroimaging plays an important and growing role in the diagnosis and therapeutic management of pediatric brain infections. This article describes the spectrum of imaging findings associated with major pediatric viral and bacterial brain infections, outlining the role of current imaging technology in the differential diagnoses of brain injury, detection of complications and therapy monitoring. MRI is the tool of choice in the evaluation of brain infections and particular attention is devoted to the role of diffusion-weighted imaging and magnetic resonance spectroscopy. This article considers viral and bacterial infection in their different modalities of presentation as congenital, acute and subacute/chronic disease. With regard to congenital infections, the growing role of fetal MRI as a valuable complement to ultrasound in the prenatal assessment of brain damage is emphasized.

[Transient splenial lesion in influenza A H1N1 2009 infection]

Severe neurologic complications have been rarely reported during novel pandemic influenza A(H1N1) virus infections. We describe the case of an 10-year-old boy with new onset seizures and proven influenza A(H1N1) 2009 infection showing a reversible hyperintense lesion in the splenium of the corpus callosum on T2-weighted and FLAIR magnetic resonance images without contrast enhancement. Transient splenial lesions have been described in the context of virus encephalopathy and do not require specific treatment.

Secondary Corpus Callosum Abnormalities Associated with Antiepileptic Drugs in Temporal Lobe Epilepsy

Epilepsy is more than a grey-matter disorder affecting large white matter connections of the brain with seizure generation and propagation. The mechanism for such changes remains unclear. The purpose of this study was to investigate the microstructural changes in the corpus callosum in temporal lobe epilepsy (TLE) patients and whether these abnormalities are related to antiepileptic drug (AED) therapy. Ten TLE patients receiving AED therapy, ten TLE patients with no therapy and ten controls were included in the study. The regions of interest in the corpus callosum were outlined to each Witelson region (WR). Fractional anisotrophy (FA), apparent diffusion coefficient (ADC), three main diffusivity values (λ1, λ2, λ3) and tractography were acquired from each WR. DTI indices of these tracts and each WR were compared between the three subject groups and correlates examined with clinical variables that included duration of epilepsy, gender, AED type and AED therapy exposure. In TLE subjects with receiving AED therapy significantly (p<0.05) decreased FA and increased ADC values of corpus callosum were obtained when compared to the other groups. There was no significant relationship between AED type and DTI indices. Analysis of eigen values in the splenium of corpus callosum (WR7) showed λ1 values were significantly decreased in relation to AED medication duration (p<0.05). FA values of rostrum and corpus showed a reduction with duration of epilepsy. TLE is associated with abnormal integrity of corpus callosum white matter tracts. AED therapy may cause additional damage on secondary degeneration and medication time effects especially on the splenium of corpus callosum.

[Transient lesion in the splenium of the corpus callosum and a sudden antiepileptic drugs withdrawal: a case with focal epilepsy in presurgical evaluation]

INTRODUCTION

A sudden withdrawal of antiepileptic drugs gives higher rate of epileptic seizures in the settings of video electroencephalography (vEEG), monitoring that is a subject to further registration and analysis. A very rare complication of this method is transient lesion of the splenium of corpus callosum (SCC) detected with brain MRI.

CASE REPORT

We presented a patient with a 5-year history of pharmacoresistant epilepsy admitted to the Institute of Neurology (August, 2008) for vEEG monitoring. Interictal epileptic discharges but none seizure were recorded after the sudden withdrawal of antiepileptic medications, during 5 days of vEEG monitoring Initial brain MRI three days after vEEG monitoring revealed focal lesion in SCC, hyperintense on T2 and FLAIR sequence. A longitudinal radiological follow-up (7 and 49 days after initial acquisition) confirmed transient nature of the lesion without diffusion coefficient changes.

CONCLUSION

SCC lesion, reversible and harmless, may occur after a sudden antiepileptic withdrawal. Its early detection makes further extensive neuroradiological and clinical examinations unnecessary.

[Corpus callosum. Landmark of the origin of cerebral diseases]

Diseases of the corpus callosum include developmental disorders, immunomodulated CNS diseases, vascular malformations, disturbances of metabolism including the electrolyte homeostasis, secondary degenerations and mechanical injuries. This report provides information on the differential diagnosis of reversible and irreversible pathological changes of the corpus callosum with special focus on the localization, which often allows conclusions on the pathogenesis to be drawn.

Blood pressure and progression of cerebral atrophy in patients with vascular disease

BACKGROUND

Cerebral atrophy on brain magnetic resonance imaging (MRI) has been associated with vascular risk factors including hypertension. Progression of cerebral atrophy and its risk factors have not been studied in vascular disease patients. This study aimed to assess the progression of cerebral atrophy and to evaluate possible associations with blood pressure (BP) in patients with pre-existing vascular disease.

METHODS

A total of 331 patients with manifest vascular disease from the Second Manifestations of ARTerial Disease (SMART) Study underwent baseline and follow-up MRI scanning (mean follow-up 4.1 +/- 0.3 years). The annual change in brain and ventricular volume was calculated with an automated quantitative volumetric method. Associations between BP and change in brain and ventricular volumes and between BP and the occurrence of lacunar infarcts were analyzed.

RESULTS

At baseline mean age was 58 +/- 9 years and mean BP was 138/80 mm Hg. Mean annual decrease in brain tissue volume was 6.5 +/- 3.8 ml and mean annual increase in ventricular volume was 1.0 +/- 1.0 ml. There was no association observed between BP and annual change in brain or ventricular volume, but a clear association was found between BP and incident lacunar infarcts (odds ratio 1.57; 1.11-2.22 per s.d. increase in systolic BP (SBP)).

CONCLUSIONS

The magnitude of changes in brain tissue and ventricular volume in patients with vascular disease was comparable to the physiological changes described in normal people at a much higher age. Progression of cerebral atrophy in this population may be associated with advanced physiological aging, but is probably not caused by elevated BP.

Two newly proposed infectious encephalitis/encephalopathy syndromes

Two newly proposed infectious encephalitis/encephalopathy syndromes, in which magnetic resonance imaging (MRI) is essential for the diagnosis, have been reviewed. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is reported only in East Asian infants, characterized by a febrile seizure (usually >30 min) as the initial neurological symptom on day 1, followed by secondary seizures at day 4 to 6; affected children display variable levels of neurological sequelae. MRI shows no acute abnormality during the first two days; reduced diffusion appears in the frontal or fronto-parietal subcortical white matter during days 3 to 9, then disappears between days 9 and 25. Excitotoxic injury with delayed neuronal death is hypothesized as a possible mechanism based on MR spectroscopic findings. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is characterized by a reversible lesion with homogeneously reduced diffusion in the corpus callosum (at least involving the splenium), sometimes associated with symmetrical white matter lesions. The most common neurological symptom is delirious behavior, followed by consciousness disturbance, and seizures, all of which completely recover within a month. The reason for the transiently reduced diffusion within the lesions is unknown; possibilities that have been postulated include intramyelinic edema, interstitial edema in tightly packed fibers, and a transient inflammatory infiltrate.

Delirious behavior in influenza is associated with a reversible splenial lesion

Delirious behavior is one of the main clinical features in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion. On the other hand, it has been reported that more than 10% of patients with influenza in Japan develop delirious behavior. Magnetic resonance imaging (MRI) studies in patients with influenza-associated delirious behavior were examined to determine how often a reversible splenial lesion is associated with this symptom. All patients who presented to Kameda Medical Center between November 2007 and March 2008 with delirious behavior associated with influenza were studied using MRI and EEG. Of the 370 patients with influenza, 11 had delirious behavior, lasting for less than 12h. MRI revealed a reversible splenial lesion with homogeneously reduced diffusion in 5 patients. Transient EEG abnormalities (occipital slow waves during wakefulness) were observed in 4 of the 9 patients examined. A reversible splenial lesion with reduced diffusion should be considered as an underlying condition in patients with delirious behavior associated with influenza.