Statistical Analysis of the Apparent Diffusion Coefficient in Patients with Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion Indicates That the Pathology Extends Well beyond the Visible Lesions

Cytotoxic Lesions beyond the Corpus Callosum Following Acute Meningoencephalitis and Mycoplasma Pneumoniae Infection: A Case Report and Literature Review

Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated with a variety of clinical causes. The presence of a small and reversible lesion in the splenium of corpus callosum with restricted diffusion on cranial magnetic resonance imaging is the defining feature. The clinical-radiological manifestations have been documented as mild and reversible. Severer presentations were scarcely reported. In this report, we described a 25-year-old man with preceding fever, worsening somnolence, and convulsions. He was diagnosed with acute meningoencephalitis and Mycoplasma pneumoniae infection after workups. After medical treatments, he had neurological deterioration and progressing CLOCCs from a small oval lesion in the center of splenium extending to the whole corpus callosum and bilaterally adjacent white matter. The patient received intravenous methylprednisolone and immunoglobulin successively, and his neurological conditions improved. The CLOCCs, not always mild and reversible, could present with severe clinicoradiological features.

Intracranial Abnormalities with Diffusion Restriction

Multiple pathologic conditions can cause changes in the random movement of water, which can be detected with diffusion-weighted imaging (DWI). DWI plays a powerful clinical role in detecting restricted diffusion associated with acute brain infarction. Other disorders can also result in restricted diffusion. This article focuses on showing examples of common and uncommon disorders that have restricted diffusion secondary to cytotoxic and/or intramyelinic edema. These disorders include ischemia, infection, noninfectious demyelinating diseases, genetic mutations affecting metabolism, acquired metabolic disorders, toxic or drug exposures, neoplasms and tumorlike lesions, radiation treatment, trauma, and denervation.

A case of reversible splenial lesion syndrome secondary to Fanconi syndrome with white matter swelling as the main manifestation

Reversible splenial lesion syndrome (RESLES) is a rare clinical imaging syndrome that is characterized by magnetic resonance imaging (MRI) findings of reversible abnormal signals in the splenium of the corpus callosum (SCC). There are a variety of pathogenic causes, including infection, metabolic disturbances, and antiepileptic drug use. Moreover, the disease is clinically rare and easily misdiagnosed. Here, we report a unique case of a 32-year-old man with Fanconi syndrome who had an intensified signal in the SCC and diffuse white matter swelling on MRI. We believe this to be the first adult case of RESLES as a manifestation of Fanconi syndrome, which further expands the disease spectrum leading to RESLES. The imaging features of this case included extensive lesions, symmetrical diffuse restricted signals, and reversibility. The identification of these features improves our understanding of the imaging characteristics of RESLES, thus enabling clinicians to better understand this disease, correctly establish its diagnosis, and improve its prognosis in this kind of patient.

Acute toxic encephalopathy following bromadiolone intoxication: a case report

Background

Clinically, bromadiolone poisoning is characterized by severe bleeding complications in various organs and tissues. Bromadiolone-induced toxic encephalopathy is extremely rare. Here, we report a special case of bromadiolone-induced reversible toxic encephalopathy in a patient who had symmetrical lesions in the deep white matter.

Case presentation

A 23-year-old woman mainly presented with dizziness, fatigue, alalia and unsteady gait after the ingestion of bromadiolone. The laboratory examinations showed normal coagulation levels. Brain magnetic resonance imaging (MRI) showed apparent diffusion restriction in the bilateral deep white matter. The clinical manifestations and MRI alterations were reversible within one month of treatment with vitamin K. The neuropsychological assessment showed no neurodegenerative changes at the 2-year follow-up.

Conclusion

With the increased use of bromadiolone as a rodenticide, more cases of ingestion have been reported annually over the past several years. Bromadiolone-induced toxic encephalopathy has no special clinical manifestations and is potentially reversible with timely treatment. Because of the reversible restricted diffusion on diffusion-weighted images (DWI) and low apparent diffusion coefficient (ADC) values, transient intramyelinic cytotoxic oedema is thought to be the cause rather than persistent ischaemia. The underlying pathophysiological mechanism is still unknown and may be coagulant-independent. This clinical case extends the current knowledge about neurotoxicity in cases of bromadiolone poisoning and indicates that MRI is useful for the early detection of bromadiolone-induced toxic encephalopathy.

Reversible splenial lesion syndrome in children: clinical analysis and summary of a case series

Objective

Methods

Results

Conclusions

Reversible lesion in the splenium of the corpus callosum

AIM OF REVIEW

The presence of isolated, reversible lesions in the splenium of the corpus callosum (SCC) is essential to confirm the diagnosis of mild encephalitis/encephalopathy. The lesions usually heal within a month after the onset of neurological symptoms. Magnetic resonance imaging (MRI) has increasingly been used as a diagnostic tool, which has led to the publication of an increasing number of case reports. These have highlighted some inconsistencies about encephalitis/encephalopathy. First, the condition is not always mild and may be severe. Second, reversible lesions in the SCC have been identified in various diseases and conditions other than viral encephalitis/encephalopathy. Third, lesions in SCC are not always completely reversible. On this note, this review describes the specific clinical and radiological features of encephalitis/encephalopathy.

FINDINGS

The reversible lesion in SCC is an MRI finding observable in a wide variety of diseases and conditions. Thus, it should be considered as a secondary change rather than a peculiar feature associated with mild encephalitis/encephalopathy. If reversible lesions are present in the SCC, the symptoms and prognosis are not necessarily favorable, with manifestations of encephalitis/encephalopathy varying from absent to severe. Neuroradiological features that appear as isolated high-intensity signals on diffusion-weighted images and a decreased apparent diffusion coefficient of the lesion might indicate a diagnosis of cytotoxic edema. Findings of previous studies suggest that cytokine-mediated cytotoxic edema of the SCC may be an important pathophysiological manifestation of this condition.

CONCLUSION

The reversible lesions in the SCC found on MRI are not exclusive to encephalitis/encephalopathy but may be secondary to other disorders.