ORIGINAL ARTICLE Magnetic Resonance Imaging Abnormalities in the Corpus Callosum of a Patient With Neuropsychiatric Lupus Brent Fogel, MD, PhD, Doris Cardenas, MD, and Bruce Ovbiagele, MD Background: Systemic lupus erythematosus (SLE) is a multisystem autoimmune disorder which can present with a variety of neurologic and psychiatric complications. Currently, there are no consensus neuroimaging findings associated with neuropsychiatric SLE. Case Summary: We describe the unusual neuroimaging findings in a patient with SLE and a history of epilepsy who presented to a tertiary care emergency department with features of neuropsychiatric lupus, as well as recent seizures. Magnetic resonance imaging of the brain revealed an isolated lesion with T2 signal hyperintensity and restricted diffusion in the midline splenium of the corpus callosum. Conclusions: While establishing the precise etiology underlying the clinical and radiographic observations in this case is difficult, several possibilities are discussed, including acute ischemia and epileptic sequelae. The location of the patient’s lesion in a region potentially associated with pure psychotic disorders raises the possibility that such a lesion may be sufficient to produce acute behavior changes and psychotic features in certain patients. Key Words: lupus, magnetic resonance imaging, corpus callosum, splenium, psychosis (The Neurologist 2006;12: 271–273) S ystemic lupus erythematosus (SLE) is a multisystem autoimmune disorder which can cause diverse neurologic symptoms, including behavioral changes, psychosis, and encephalopathy.1,2 While the precise mechanisms behind these complications are unclear, both direct and indirect immunemediated effects on the cerebral vasculature and the brain itself have been implicated.2 Currently there are no consensus neuroimaging findings associated with the neuropsychiatric manifestations of SLE.1 Here, we describe a patient with SLE and a history of epilepsy who presented with neuropsychiatric lupus, characterized by behavioral changes and psychosis, and was found to have an isolated lesion with increased T2 signal intensity and restricted diffusion in the midline sple- From the Department of Neurology, UCLA Medical Center, Los Angeles, California. Reprints: Brent Fogel, MD, PhD, Department of Neurology, University of California at Los Angeles, 710 Westwood Plaza, Los Angeles, CA 90095. E-mail: bfogel@ucla.edu. Copyright © 2006 by Lippincott Williams & Wilkins ISSN: 1074-7931/06/1205-0271 DOI: 10.1097/01.nrl.0000237119.00864.d7 The Neurologist • Volume 12, Number 5, September 2006 nium of the corpus callosum on magnetic resonance imaging (MRI), a region potentially associated with pure psychotic disorders.3 CASE REPORT A 44-year-old Hispanic female with a history of SLE, as well as a known seizure disorder, was brought to the emergency room by her family following 2 days of behavioral changes and 1 generalized seizure. She had recently discontinued all regular medications, including prednisone, azathioprine, and phenytoin. On examination, the patient was fully alert but had difficulties with all aspects of orientation, including self, and was unable to follow complex commands. Her behavior included agitation, combativeness, and overt psychosis with disorganized thinking, visual hallucinations, and paranoid delusions. The remainder of her neurologic examination was nonfocal. She was afebrile. Computed tomography imaging of the brain showed an old left lacunar infarct but no masses or hemorrhage. Lumbar puncture revealed a CSF opening pressure of 180 mm H2O, glucose 64 mg/dL, protein 36 mg/dL, 0 white blood cells, and a negative gram stain. Her basic chemistries, liver enzymes, and complete blood count were normal. Partial thromboplastin time and erythrocyte sedimentation rate were elevated at 116 seconds and 94 mm/h respectively. Phenytoin was undetectable but approximately 1 week prior had been mildly elevated at 25 ␮g/mL. MRI of the brain performed approximately 24 hours following presentation revealed a focal hyperintensity in the midline splenium of the corpus callosum on T2 and fluid-attenuated inversion recovery (FLAIR) images (Fig. 1). This lesion showed restricted diffusion on diffusion weighted imaging (DWI) and was hypointense on apparent diffusion coefficient (ADC) sequences (Fig. 1). There were no other acute findings noted on MRI. Magnetic resonance angiography of the brain and neck was unremarkable. Transthoracic echocardiogram showed no thrombus and a normal ejection fraction. Electroencephalogram demonstrated diffuse slowing but no epileptiform activity. Based on the overall clinical presentation, the patient was diagnosed with neuropsychiatric lupus using established criteria.1 Treatment was initiated with intravenous corticosteroids, cyclophosphamide, and anticoagulation. Five days post-treatment, the patient was much improved, with full orientation, following 2-step commands, and stable behavior without overt psychotic features. Subsequent neurologic examination showed no clear evidence of hemispheric disconnection. 271 The Neurologist • Volume 12, Number 5, September 2006 Fogel et al FIGURE 1. Acute focal lesion in the midline splenium of the corpus callosum in a patient with neuropsychiatric lupus. Restricted diffusion is noted on (A) diffusion-weighted imaging with hyperintensity on (B) fluid-attenuated inversion recovery and (C) T2-weighted imaging, but hypointensity on (D) apparent diffusion coefficient imaging. The lesion is indicated by arrows. DISCUSSION Here we report an unusual focal lesion in the splenium of the corpus callosum found on diffusion-weighted MRI in a patient with neuropsychiatric lupus and a history of epilepsy. Establishing a unifying hypothesis for the precise etiology underlying the clinical and radiographic observations in this case is difficult, given the unclear pathogenesis of neuropsychiatric lupus, her comorbid epilepsy, and the variety of differential diagnoses for hyperintense lesions on T2 and DWI. For instance, although such imaging findings are often consistent with acute ischemia, the location of the lesion within the brain in our patient is atypical for infarction. In general, the corpus callosum is quite resistant to ischemia due to its high degree of vascularity and collateral flow from the opposing circulation.4,5 Indeed, ischemic lesions in the corpus callosum involving the splenium are most often associated with large posterior cerebral artery infarcts.4 Another pathophysiological consideration could be that of an acute demyelinating process. Demyelinating disease can produce similar hyperintense lesions, but these are not typically seen this early after symptom onset and frequently are not in isolation.5 Additionally, hyperintense T2-weighted MRI involvement of the splenium can be seen unilaterally with traumatic injury due to sheer forces or bilaterally in Marchiafava-Bignami disease due to acute demyelination 272 secondary to alcohol abuse5; however, this patient denied recent trauma or excessive alcohol intake. Hyperintense T2-weighted MRI splenial lesions have been described in epileptic patients3,6–10 and have been speculated to result from antiepileptic drug toxicity,7 rapid antiepileptic drug withdrawal,8 or from the seizures themselves.3,6,9,10 DWI hyperintensity has also been described in 2 such patients following seizures.10 The precise mechanism underlying these changes remains unclear but perhaps may reflect an inherent sensitivity of the splenium for either transient demyelination or focal edema due to changes in ion transport or other metabolic processes.3,6 –10 Given the mildly elevated phenytoin level in our patient followed by an abrupt discontinuation of this medication and a history of recent seizures, we believe this may be the most likely basis for the abnormal MRI findings observed. This notwithstanding, it is interesting to note that in animal models, immunofluorescence has demonstrated binding of anticardiolipin antibodies purified from SLE patient sera to brain tissue, notably the corpus callosum.11 One intriguing possibility is that SLE patients may have an inherently increased predisposition to corpus callosal injury. On a broader note, a recent study summarized the current literature, examining 69 patients with splenial changes noted on MRI and reporting that 60% of the patients showed altered mental status, while 7% reported hallucinations, reflecting psy© 2006 Lippincott Williams & Wilkins The Neurologist • Volume 12, Number 5, September 2006 chosis.3 The precise degree of association between the lesions and psychosis is unclear, however, as psychiatric findings may have been underreported in previously published cases.3 Furthermore, the specificity of the lesions for psychosis is also unclear because, although all patients had splenial MRI changes, many had additional acute MRI findings,3 which were not fully detailed. Still, involvement of the corpus callosum has been implicated previously in pure psychotic disorders, most notably schizophrenia.3,12–14 Studies of schizophrenic patients have found changes within the corpus callosum relative to normal controls both pathologically and on MRI neuroimaging, including size differences, decreased white matter density, and microstructural changes, suggesting a component of interhemispheric disconnectivity may be involved in the pathogenesis of schizophrenia.3,12–14 A recent review by Shenton et al14 reports that of 27 MRI imaging studies specifically examining the corpus callosum, 63% detected abnormalities in schizophrenics. Many of these studies did not fully examine the entire corpus callosum, so the true incidence may be even greater.14 Complete agenesis of the corpus callosum has also been noted in patients with psychiatric disorders, including 2 children with behavioral problems and psychosis,15 as well as in a set of adult twins with schizophrenia.16 Our patient was found to have a single isolated midline splenial lesion on MRI, suggesting that such a lesion may be sufficient to produce acute behavior changes and psychotic features in certain patients. Future studies should attempt to further examine the relationship between isolated splenial lesions and acute psychosis, particularly in patients with SLE who may have a predisposition to corpus callosal injury. ACKNOWLEDGMENT The authors thank Drs Ron Cummings and Jeremy Rudnick for helpful comments concerning this manuscript. REFERENCES 1. American College of Rheumatology. 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