Reversible Lesion Research Articles

Serial brain MRI in TIA patients

Up to 40% of patients with transient ischemic attack (TIA) demonstrate lesions on diffusion-weighted magnetic resonance imaging (DWI). However, the time course of these ischemic lesions is not well known. Some lesions could vanish soon after symptom onset whereas others could be visible only after a certain delay. Based on a population of TIA patients imaged twice with DWI within the first week after onset, our aim was to estimate the rate of patients with DWI reversible ischemic lesion or with delayed DWI positivity. We retrospectively compared DWI at admission (DWI(1), median = 15 hours after TIA) with follow-up DWI (DWI(2), median = 47 hours) in 64 consecutive TIA over a 7-month period. DWI was reviewed in consensus by two readers, blinded to clinical information. Number, extent and arterial distribution of lesions were assessed. DWI(1) and DWI(2) showed similar findings in 55 TIA patients (32 with and 23 without ischemic lesions). In nine (14%) patients, changes were observed on DWI(2): presence of ischemic lesions despite normal DWI(1) (n = 3), increase in lesion size (n = 3), or partial or complete lesion reversibility (n = 3). In most TIA cases, ischemic lesions captured by early DWI and 48-hour DWI are similar. However, some ischemic lesions vanish rapidly while lesion visibility is delayed in other cases.

Dysfunction of default-mode network in encephalopathy with a reversible corpus callosum lesion

Increasing attention has been paid recently to the study of spontaneous brain activity; moreover, particular attention has been paid to the concept of a default-mode network of brain function. Although the functional significance of the default-mode network remains a matter of debate, it has been suggested to be a candidate for the network subserving basic functions related to consciousness. We report the case of a 29-year-old man with encephalopathy and a reversible lesion of the entire corpus callosum. Despite resolution of corpus callosum lesion on magnetic resonance imaging (MRI) within 1week, the patient persistently presented disturbance of consciousness. Resting-state functional MRI revealed that the posterior cingulate cortex/precuneus was functionally disconnected from other brain regions within the default-mode network. Our case report suggests that assessment of the functional connectivity in the resting-state default-mode network could be a useful marker of consciousness disturbance even in the presence of a reversible brain lesion.

Atypical Diffusion-Restricted Lesion in 5-Fluorouracil Encephalopathy: Fig 1.

Central nervous system toxicity of 5-FU could show various manifestations, such as decreased alertness, disorientation, and agitation. It is generally accepted that lesions of 5-FU encephalopathy are mainly in the deep cerebral white matter and corpus callosum on MR imaging. Here we describe a case of 5-FU encephalopathy in gastric cancer with an atypical reversible diffusion-restricted lesion on MR imaging, showing bilateral basal ganglia, thalami, and parasagittal frontal cortex involvement on diffusion and T2-weighted imaging.

Future candidates for indications of Helicobacter pylori eradication: Do the indications need to be revised?

Since the discovery of Helicobacter pylori in 1982, the development of several treatment guidelines has allowed a consensus on the indications for H. pylori eradication. Beyond these currently accepted indications, including various upper gastrointestinal disorders and extragastric diseases, a significant amount of new information regarding H. pylori eradication is emerging. Certain types of acute gastritis, such as nodular gastritis, hypertrophic gastritis, Ménétrier's disease, hemorrhagic gastritis, and granulomatous gastritis are reversible after H. pylori eradication. Further, for chronic gastritis, closed-type atrophic gastritis and complete-type intestinal metaplasia appear to be more reversible after H. pylori eradication than open-type atrophic gastritis and incomplete-type intestinal metaplasia. Eradication can also be considered in subjects younger than 40 years who have a family history of gastric cancer and in subjects with long-term medications that might lead to bleeding (antiplatelet agents) or atrophy (proton pump inhibitors). Emerging evidence indicates that H. pylori eradication could be an effective treatment for some extragastric diseases that are unresponsive to conventional therapy. In such conditions, routine screening for eradication of H. pylori has not previously been recommended; a "test-and-treat" approach is suggested in the aforementioned situations. Given that H. pylori eradication is effective when the gastritis is reversible, future indications should be expanded to include acute gastric lesions that show marked improvement upon H. pylori eradication rather than just focusing on chronic gastric lesions. Future indications for H. pylori eradication should focus more on reversible lesions before preneoplastic conditions develop.

Isolated reversible hypoglossal nerve palsy as the initial manifestation of pre-eclampsia

Isolated hypoglossal nerve lesions often reflect sinister neoplastic or vascular pathology. Rarely, reversible lesions occur, perhaps via mechanisms similar to Bell’s palsy. We report a patient with reversible isolated hypoglossal nerve palsy as the first and predominant early manifestation of pre-eclampsia and speculate on the pathogenesis behind this abnormality.

A case of cerebral amyloid angiopathy with reversible white matter lesions and multiple cerebral microbleeds

A 59-year-old woman presented with a 7-year history of headache. She showed no neurological abnormality. T(2) weighted magnetic resonance (MR) images showed a hyperintense signal in the white matter in the bilateral parieto-occipital lobe without abnormal enhancement. A small amount of prednisolone was administered for rheumatoid arthritis. After prednisolone was discontinued, the T(2) weighted images showed an expansion of the hyperintense signal lesions seen in the white matter, and T(2) weighted image showed multiple foci of petechial bleeding in the cortex and subcortex of the bilateral occipital lobe. A brain biopsy specimen from the right occipital lobe revealed deposition of amyloid in the subarachnoidal and cortical vessel walls and transmural infiltration of a few lymphocytes, eosinophils, and giant histiocytes. Subsequently the patient was diagnosed with central nervous system vasculitis associated with cerebral amyloid angiopathy (CAA). After 5 months, the T(2) weighted images showed a remarkable regression of the hyperintense signal lesions in the white matter of the bilateral parieto-occipital lobe without the administration of any maintenance immunosuppressive agents. However, T(2) weighted image showed an increase of multiple cortico-subcortical foci of petechial bleeding. Her headache did not improve during the illness. Thus, we should consider the diagnosis of CAA when patients present with reversible white matter lesions and multiple cerebral microbleeds simultaneously.

Structural neuroimaging and neuropsychological correlates of a single case of focal central pontine myelinolysis: Intact memory function with decreased intellectual and motor functions

We report on the case of middle-aged right-handed woman with central pontine myelinolysis (CPM) revealed by high resolution structural T2-weighted FLAIR MRI imaging. There was a general flattening of Wechsler Adult Intelligence Scale—Fourth Edition subtest scores which were 1 standard deviation below expected values. In contrast Wechsler Memory Scale—Fourth Edition visual and auditory memory scores remained within the normal range. Verbal working memory appeared mildly impaired while nonverbal working memory was not. Scores on the Advanced Clinical Solution’s Social Perception battery were all in the normal range as were academic skills measured by the Wide Range Achievement Test—Fourth Edition. Performance was impaired on the Delis-Kaplan Executive Function System’s counterpart of the Trail-Making Test: Part B. Similarly, on the Draw-A-Person Test there was a discrepancy in that our patient’s standard score was 76 compared to her estimated premorbid FSIQ in the average range. She also displayed bilateral motor coordination slowing on the Finger Tapping task collectively suggesting damage to pontine motor tracts. The Minnesota Multiphasic Personality Inventory—Second Edition—Restructured Form profile was consistent with a diagnosis of severe anxiety and depression perhaps due to damage to serotoninergic neural tracts originating within the central pons. Finally, the patient displayed severe sleep disturbances and other signs of reticular activating formation injury. CPM may constitute a unique means of studying reversible subcortical lesions in the central pons in otherwise healthy subjects with benign illness. To our knowledge this is among the first patients with CPM without the usual risk factors for the disorder and who was otherwise healthy. Knowledge of the etiology and neuropsychology of such patients might aid in understanding the interaction of the fronto-ponto-cerebellar tracts in executive functions and motor programming.

Late-onset leukoencephalopathy induced by long-term chemotherapy with capecitabine and cyclophosphamide for liver metastasis from breast cancer

A 55-year-old woman with a 3-year and 4-month history of liver metastasis from breast cancer underwent chemotherapy with capecitabine and cyclophosphamide for following 10-months. She did not have hypertension and was not pregnant. She showed dysarthria and mild somnolence, and her conscious level developed to semicoma after 6 days. She had pyrexia. Cerebrospinal fluid (CSF) demonstrated increased cell-count and elevated protein but no evidence of positive cytological finding and cultivation of bacteria was found in the CSF. Brain magnetic resonance imaging (MRI) revealed multiple lesions with hyperintensity in the brain stem, bilateral middle cerebellar peduncles, left splenium of corpus callosum, bilateral basal ganglia, bilateral thalami, bilateral corona radiata, and bilateral subcortical white matters of parietal lobes on the T(2) weighted and fluid attenuated inversion recovery (FLAIR) images. These lesions demonstrated mild hyperintensity on the diffusion weighted images but did not demonstrate hypointensity on the T(1) weighted images. Capecitabine and cyclophosphamide were discontinued at 4th day after onset of symptoms, and her conscious disturbance showed improvement slowly since day 12 after cessation of these drugs and hyperintensity areas detected on FLAIR image of MRI showed decreasing intensity after three weeks of onset. Capecitabine is an oral prodrug converted to 5-fluorouracil (5-FU). 5-FU and cyclophosphamide are known to induce leukoencephalopathy. Reversible multiple lesions with leukoencephalopathy on brain MRI which is called as a posterior reversible encephalopathy syndrome (PRES). Capecitabine is also reported to induce PRES in rare cases. Combination of these drugs was considered for the possible cause to induce leukoencephalopathy like PRES. Usually leukoencephalopathy occurs in relatively early time after start of chemotherapy with capecitabine or cyclophosphamide, but we consider that late-onset leukoencephalopathy can be induced by long-term chemotherapy with these drugs. It is necessary to observe leukoencephalopathy by brain MRI regularly when these drugs are used.

Apparent diffusion coefficient restriction in the white matter: going beyond acute brain territorial ischemia

BackgroundReduction of apparent diffusion coefficient (ADC) values in white matter is not always ischaemic in nature.MethodsWe retrospectively analysed our MRI records featuring reduced ADC values in the centrum semiovale without grey matter involvement or significant vasogenic oedema.ResultsSeveral conditions showed the aforementioned MR findings: moose-horn lesions on coronal images in X-linked Charcot-Marie-Tooth disease; small fronto-parietal lesions in Menkes disease; marked signal abnormalities in the myelinised regions in the acute neonatal form of maple syrup urine disease; strip-like involvement of the corpus callosum in glutaric aciduria type 1; persistent periventricular parieto-occipital abnormalities in phenylketonuria; diffuse signal abnormalities with necrotic evolution in global cerebral anoxia or after heroin vapour inhalation; almost completely reversible symmetric fronto-parietal lesions in methotrexate neurotoxicity; chain-like lesions in watershed ischaemia; splenium involvement that normalises in reversible splenial lesions or leads to gliosis in diffuse axonal injury.ConclusionNeuroradiologists must be familiar with these features, thereby preventing misdiagnosis and inappropriate management.

Abstract 17786: Presence of an Esophageal Temperature Probe During Pulmonary Vein Isolation: Is There an Increased Risk for Esophageal Lesion Development?

Background: Luminal esophageal temperature (LET) measurement is investigated as a tool to decrease risk of esophageal lesion formation during pulmonary vein isolation using radiofrequency (RF) current. However, recent evidence from duty-cycled phased RF ablation revealed a possible contributing role of the esophageal probe to lesion formation by direct tissue heating or interaction with the ablation device. Whether the presence of a LET probe may increase lesion formation during conventional irrigated RF ablation has not yet been investigated. Methods and Results: 62 patients (65% male, age 63±11 years, LA 44±10 mm) with drug-resistant atrial fibrillation underwent circumferential pulmonary vein isolation (PVI) using irrigated RF energy and a 3D-mapping system. A maximum power of 30 Watts was applied at the left atrial posterior wall (LAPW). In 30 patients a LET probe with 5 metal electrodes (3 thermistors) was placed in the esophagus and continuously adjusted to the level of the target pulmonary vein (group 1). LET measurement was observational only and no temperature cutoff was used. In the remaining 32 patients, no LET probe was placed (group 2). All patients underwent gastro-esophagoscopy 2±1 days after the procedure. The cumulative RF energy applied to the LAPW was 21368±9449 Joules (group 1) and 18092±8143 Joules (group 2, p=0,15). Esophageal lesions were found in 12 patients (40%) of group 1 (ulcerations: 4, erythema: 8), and 11 patients (34%) of group 2 (ulcerations: 5, erythema: 4); p=0,65. Lesions healed without clinical sequelae on proton pump inhibitor therapy in all patients. Within group 1, maximum LET in patients with and without lesions was 45,7±3,7 °C and 43,8±3,9 °C, respectively (p=0,20). Conclusion: The incidence of reversible esophageal lesions after circumferential PVI using irrigated RF energy was similar whether or not a temperature probe was present in the esophagus when no temperature cutoff was used.

Benign paroxysmal positional vertigo showing sequential translations of four types of nystagmus

We report a case of benign paroxysmal positional vertigo (BPPV) showing sequential translation of four types of nystagmus and discuss its pathophysiology. The case was 65-year-old female. We analyzed her nystagmus three-dimensionally. At the first visit, she showed vertical-torsio nystagmus of the posterior canal type of BPPV (P-BPPV) and subsequently showed recently reported geotropic nystagmus with a long time constant. Two weeks later, she showed apogeotropic nystagmus of the horizontal canal type of BPPV (AH-BPPV) and subsequently a geotropic nystagmus with a short time constant of the horizontal canal type of BPPV (GH-BPPV). Three kind of nystagmus, namely P-BPPV, AH-BPPV and GH-BPPV can be explained by the otoconial debris hypothesis of the same ear. Finally, the recently reported geotropic nystagmus with a long time constant may be explained by a reversible lesion such as the denatured cupula or utricular imbalance of the same ear.

Tratamiento de las vasculitis de grandes vasos

Large vessels vasculitis: Giant cells arteritis (GCA), and Takayasu's arteritis (TA) are a pair of systemic chronic inflammatory diseases characterized by specific involvement of large caliber, elastic-layered arteries. Presently, and derived from the paucity of clinical controlled trials approaching the issue, the management of GCA and TA is largely based on the clinical judgment of the treating physician. Glucocorticoids and immunosuppressive drugs are used when clear evidence of inflammatory activity is observed. The traditional management approach is to start with systemic glucocorticoid therapy at immunosuppressive dose, followed by cytotoxic immunosuppressive drugs (methotrexate, azatioprine, cyclophosphamide or mycofenolate mofetil) aimed at maintaining remission and decreasing corticosteroid therapy time. Recently, based on the potential pathogenic role of tumor necrosis factor α in these diseases, a series of reports addressing the benefic effect of αTNF-blockers in patients who have been resistant to the traditional management approach have been published. Non- reversible vascular lesions (such as occlusion or stenosis) may require surgical treatment (stent or bypass), however this must be done only when a complete control of the inflammatory activity has been reached.

Does magnetic resonance represent the gold-standard of imaging for the follow-up of arthritis?

Several studies suggest that MRI is between 2 and 10 times superior to conventional radiology in the visualization of erosions. This higher sensibility is dependent on the specific joint assessed, the precocity of the disease, and the timing of follow-up. In addition, MRI can depict bone oedema, which is an early and reversible bone lesion, and evaluate the degree of inflammation of the synovial membrane. A single examination could therefore evaluate disease activity and damage. The sensitivity to change of articular MRI is good, as demonstrated by a number of follow-up studies. In view of these advantages, it may be surprising that MRI has not yet become the gold standard of imaging of the arthritic joint. The three main reasons are low availability of high field machines, examination's costs, and lack of standardization of the technique. Low field extremity-dedicated MRI machines are probably the answer to the first two concerns. They have been shown to obtain reliable results for the clinician, and to be relatively cheap and patient-friendly, allowing repeated follow-up examinations. As far as standardization is concerned, there are many studies addressing the problem, with OMERACT as the driving force. MRI is likely to represent the future of the follow up of arthritis for the evaluation of its pace of progression and the effect of treatment. The advent of new and potent biologic therapies has incremented the need for more sensible imaging methods and will probably drive their diffusion in clinical practice.

Pathomorphology of the Heart Conduction System: Comparative Study during Increase in Left or Right Ventricular Afterload

Pathomorphology of the peripheral compartments of the heart conduction system under conditions of increased left or right ventricular afterload is characterized by interstitial edema, hemorrhages, and reversible and irreversible focal lesions. The percentage of damaged conduction cardiomyocytes increases in the wall of hemodynamically overloaded ventricle and in the ventricular septum. These changes are more pronounced in cases when the afterload increase is complicated by heart failure development. Acute dilatation of the heart and distention of the myocardium are events of great specific significance in the genesis of the conduction system disorders developing under conditions of increased right ventricular afterload in comparison with those developing under conditions of increase left ventricular afterload. These data attest the presence of a pathomorphological base for the appearance of arrhythmias during the acute phase of pressure overload of the heart, especially in cases when it is aggravated by heart failure.

Acute Marchiafava-Bignami Disease With Selective Involvement of the Precentral Cortex and Splenium

Marchiafava-Bignami disease (MBD) is defined pathologically as callosal degeneration associated with chronic alcoholism. We report a patient with MBD with acute lesions confined in the precentral cortex and splenium. Various magnetic resonance imaging (MRI) modalities were performed sequentially to elucidate the pathophysiology. A 52-year-old man with chronic alcoholism developed acute confusion and dysarthria. He improved incompletely with nutritional supplementation. Diffusion-weighted imaging MRI disclosed the presence of reversible lesions with low apparent diffusion coefficient values in the precentral cortex and splenium. Perfusion-weighted imaging revealed that the cerebral blood volume and flow decreased and subsequently increased, and the mean transit time and time to peak were persistently prolonged. On magnetic resonance spectroscopy, choline was initially normal and became elevated during the recovery period, whereas N-acetylaspartate was low initially and after the resolution of the lesion on conventional MRI. The precentral cortex and splenium are the most vulnerable areas in acute MBD. The lesions have reversible restricted diffusivity and hypoperfusion. The magnetic resonance spectroscopy findings correlate well with the clinical status.

Reversible Diffuse White Matter Lesion in Alagille Syndrome

A boy with genetically confirmed Alagille syndrome was incidentally found to manifest striking diffuse hyperintensity of the white matter on T(2)-weighted cranial magnetic resonance images. He never exhibited signs of hepatic encephalopathy. For his progressive liver failure, he underwent a live-donor liver transplant at age 2 years, which unexpectedly resulted in a near-complete resolution of the diffuse white matter lesion. Reversible white matter lesions attributed to cerebral edema were reported in adult patients with liver cirrhosis, but not in the pediatric population. The diffuse reversible white matter lesion in the present case demonstrated T(2) hyperintensity, coupled with restricted diffusion confirmed by apparent diffusion coefficient, and was suggestive of etiologies such as ischemia or cytotoxic edema rather than vasogenic edema.

Acute encephalopathy with a lesion of the splenium of the corpus callosum – A report of two cases

We report two cases of encephalopathy following a short febrile illness. Case one was a five year old child whose magnetic resonance imaging (MRI) of the brain showed a reversible discrete lesion in the splenium of the corpus callosum (SCC) and a ten year old boy who had extensive hyperintensity of the SCC. As these children have presented while there was an outbreak of influenza in our locality and since the second child tested positive for H1N1 antigen on PCR test, we feel that as previous authors have pointed out, these cases are cases of possible influenza encephalopathy. This awareness needs to be disseminated as this specific MRI finding should prompt one to test for H1N1 antigen and offer specific antiviral agent. Case one showed signs that support the existence of a splenial syndrome.

Mumps Virus Encephalitis with Symmetric Claustrum Lesions: Fig 1.

Bilateral symmetric claustrum lesions shown on MR imaging are rarely reported, especially transient and reversible lesions associated with seizures, such as herpes simplex encephalitis,[1][1] unidentified encephalopathy,[2][2] and acute encephalitis with refractory repetitive partial seizures.[3][3

Oxidative stress in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS)

We examined oxidative stress markers, tau protein and cytokines in the cerebrospinal fluid (CSF) in six patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS). In the CSF, 8-hydroxy-2′-deoxyguanosine (8-OHdG) and hexanoyl-lysine adduct levels increased over the cutoff index in four and one out of six MERS patients, respectively. The CSF IL-6 and IL-10 levels were increased in three out of six patients, two of which had extended lesion of the cerebral white matter. The CSF value of tau protein, marker of the axonal damage, was not increased, and neuron specific enolase (NSE) in the CSF was not increased. The increased 8-OHdG levels in the CSF, DNA oxidative stress marker, in four MERS patients, suggesting involvement of oxidative stress in MERS. MERS is occasionally accompanied with hyponatremia, although our patients lacked hyponatremia. It is possible that the disequilibrium of systemic metabolism including electrolytes may lead to facilitation of oxidative stress and reversible white matter lesion in MERS. The increase of cytokine production seems to be involved in the distribution of lesions in MERS.

Lesion evidence for the critical role of the intraparietal sulcus in spatial attention

Based on lesion mapping studies, the inferior parietal lobule and temporoparietal junction are considered the critical parietal regions for spatial-attentional deficits. Lesion evidence for a key role of the intraparietal sulcus, a region featuring prominently in non-human primate studies and human functional imaging studies of the intact brain, is still lacking, probably due to the exceptional nature of isolated intraparietal sulcus lesions. We combined behavioural testing and functional imaging in two patients with a focal intraparietal sulcus lesion sparing the inferior parietal lobule and temporoparietal junction to examine the critical contribution of the intraparietal sulcus to spatial attention. Case H.H. had a focal ischaemic lesion (1.8 cm3) that was confined to the posterior segment of the left intraparietal sulcus, whereas Case N.V. had a partially reversible lesion of the middle segment of the right intraparietal sulcus extending into the superior parietal lobule (13.8 cm3). The performance of these cases was contrasted with five cases with a classical inferior parietal lesion, as well as with a group of 31 age-matched controls. In the behavioural study, the patients performed an orientation discrimination task on a peripheral target (eccentricity 7.6°) that was preceded by a central spatial cue. We manipulated both the cue validity (17% trials with an invalid spatial cue) and the presence of a competing distracter in the visual field contralateral to the target (17% double stimulation trials). The ability of the patients with an intraparietal sulcus lesion to reorient their spatial focus of attention and to select between competing stimuli was impaired for contralesional targets compared with controls, similarly to what we saw in the inferior parietal group. Furthermore, we could observe that the deficit in Case N.V. resolved with regression of the lesion. To further evaluate the correspondence between spatial-attentional deficits and the intraparietal sulcus lesions, we ascertained the functional integrity of the inferior parietal lobule and temporoparietal junction in Case H.H. using event-related functional magnetic resonance imaging with the same task as in the behavioural study. The intraparietal sulcus lesion of this patient did not affect the task-related activation of the inferior parietal lobule or temporoparietal junction. Additionally, a resting-state functional magnetic resonance imaging study in Case H.H. and 62 controls revealed that the lesion in Case H.H. did not affect the topology of the ventral attention network nor the strength of its main inter- and intrahemispheric connections. Our findings demonstrate that the human superior parietal cortex critically contributes to spatially selective attention.