Contemporary issues in mild traumatic brain injury

OBJECTIVES: To determine (1) minimum criteria in adults for clinical diagnosis of mild traumatic brain injury (TBI) and (2) whether persistent postconcussive syndrome exists as a nosologic entity. DATA SOURCES: PubMed search by MEDLINE of head injuries from January 1977 to July 2002. STUDY SELECTION: All reviews and studies of mild TBI with special reference to those on persistent postconcussive syndrome having a general trauma cohort as a control comparison. DATA EXTRACTION: Review of design and other methodologic issues. Studies dependent on superior strength of evidence (as defined by the American Academy of Neurology) concerning the biologic nature of persistent postconcussive syndrome. DATA SYNTHESIS: A period of altered awareness with amnesia brought on by a direct craniofacial blow is the starting point in determining whether diffuse mild TBI has occurred. An amnestic scale is more helpful than Glasgow Coma Scale score in grading mild injury and in formulating minimum inclusion criteria for mild TBI. Neuropsychologic test results coupled with self-reported symptoms should not be taken as the primary source of evidence for mild TBI. Prolonged cognitive impairment after injury is not unique to brain trauma. CONCLUSIONS: Persistent postconcussive syndrome after mild brain trauma, uncomplicated by focal injury, is biologically inseparable from other examples of the posttraumatic syndrome. To account for the persistent cognitive and behavioral sequelae of posttraumatic states, including persistent postconcussive syndrome, we need further studies on the emerging concept of limbic neuronal attrition occurring as a maladaptive response to pain and stress.     

单光子发射计算机断层成像在轻中型颅脑损伤评估及预后中的应用

目的：探讨单光子发射计算机断层成像（SPECT）在轻、中型颅脑损伤（TBI）早期评估及预后判断方面的价值，为临床功能评估及预后估计提供有价值的依据。方法：24例轻中型颅脑损伤患者受伤2周内行SPECT，CT检查及临床评定，3个月所有患者行脑外伤后综合征的临床测试，并对首检SPECT阳性者复与预后的关系。结果：（1）24例轻中型颅脑损伤首检SPECT阳性率71％，高于CT阳性率46％（P＜0．05），（2）首检SPECT发现阳性病灶48处，高于CT的21处，且分布范围广，（3）首检SPECT阳性预测率59％，阴性预合征；另9例（53％），结论：（1）在轻中型颅脑损伤的早期评估中，SPECT显像较CT扫描更灵敏。（2）SPECT阳性率与脑损害程度相关，（3）首检SPECT阴性提示预后良好，复检SPECT阳性提示多出现脑外伤后综合征。（4）首检SPECT阳性尚不足以估计患者预后。     

Brain SPECT evaluation of amnestic ED patients after mild head trauma

A short period of amnesia is a common complaint after mild head injury. In this study we compare the duration of amnesia after mild head trauma to single photon emission computed tomography (SPECT) perfusion imaging shortly after admission to the emergency department (ED). Sixteen patients consecutively admitted to the ED were prospectively evaluated. The amnesia was scored according to the Extended Glasgow Coma Score. A computed tomography (CT) scan was performed to all patients. All patients had anterograde amnesia. Eleven patients had amnesia of grade 2 (69%) and 5 patients of grade 3 (31%). All patients had a normal CT scan. Twelve of sixteen patients (75%) showed regional perfusion abnormalities on the SPECT study. Decreased perfusion was observed at least in one region (8/12 patients had 2 abnormal regions). The logistic regression analysis showed that SPECT results significantly predicted the severity of amnesia (r = 0.9, P <.0001). Additionally, the SPECT accounted for approximately 84% of the variation in amnesia. We conclude that amnesia after mild head injury is associated with a high incidence of early regional cerebral perfusion abnormalities. Amnesia lasting more than half an hour is associated with bilateral cerebral hypoperfusion. SPECT evaluation in the ED may by a useful additional tool in the objective assessment of posttraumatic amnesia.     

An automatic MEG low-frequency source imaging approach for detecting injuries in mild and moderate TBI patients with blast and non-blast causes

Traumatic brain injury (TBI) is a leading cause of sustained impairment in military and civilian populations. However, mild (and some moderate) TBI can be difficult to diagnose because the injuries are often not detectable on conventional MRI or CT. Injured brain tissues in TBI patients generate abnormal low-frequency magnetic activity (ALFMA, peaked at 1-4 Hz) that can be measured and localized by magnetoencephalography (MEG). We developed a new automated MEG low-frequency source imaging method and applied this method in 45 mild TBI (23 from combat-related blasts, and 22 from non-blast causes) and 10 moderate TBI patients (non-blast causes). Seventeen of the patients with mild TBI from blasts had tertiary injuries resulting from the blast. The results show our method detected abnormalities at the rates of 87% for the mild TBI group (blast-induced plus non-blast causes) and 100% for the moderate group. Among the mild TBI patients, the rates of abnormalities were 96% and 77% for the blast and non-blast TBI groups, respectively. The spatial characteristics of abnormal slow-wave generation measured by Z scores in the mild blast TBI group significantly correlated with those in non-blast mild TBI group. Among 96 cortical regions, the likelihood of abnormal slow-wave generation was less in the mild TBI patients with blast than in the mild non-blast TBI patients, suggesting possible protective effects due to the military helmet and armor. Finally, the number of cortical regions that generated abnormal slow-waves correlated significantly with the total post-concussive symptom scores in TBI patients. This study provides a foundation for using MEG low-frequency source imaging to support the clinical diagnosis of TBI.     

Positron emission tomography and epilepsy.

PURPOSE: This review examines the current role of positron emission tomography (PET) in the investigation and management of patients with epilepsy. PROCEDURES: A literature review utilizing MEDLINE(R) and other sources was undertaken. For the comparison of the accuracy of PET with magnetic resonance imaging (MRI) for seizure focus localization, only publications since 1994 were examined. Individual patient data was tabulated to provide figures for seizure focus localization rates for different types of focal epilepsy and the prognostic value of PET findings for epilepsy surgery outcome. RESULTS: The majority of PET studies used 2-deoxy-2-[18F]fluoro-D-glucose (FDG). The epileptogenic sites typically show reduced FDG uptake (hypometabolism). In patients with intractable temporal lobe epilepsy (TLE), unilateral temporal lobe hypometabolism (UTH) corresponding to the seizure focus was seen in 86% of patients. In the same population, MRI demonstrated relevant abnormalities in 76%. UTH contralateral to the seizure focus was rarely seen (3%). Following temporal lobectomy, 86% of patients with ipsilateral UTH had a good outcome. When MRI was normal, UTH predicted a good outcome in 82%. Fifty percent with bitemporal hypometabolism had independent bilateral foci, and in those who proceeded to surgery only 50% had a good result. In extratemporal epilepsy, hypometabolism relevant to the focus was seen in 67% but, as in TLE, it was often more extensive than pathological abnormality. Recently evidence of a role for 11C-Flumazenil has emerged with reduced binding in the primary epileptogenic site. 11C-Flumazenil abnormalities appear more restricted to abnormal cortex and may be a better guide to the extent of resection required for surgical success. CONCLUSIONS: FDG-PET has a key role in the evaluation of patients with intractable partial epilepsy, particularly when surgery is a treatment option. Development and application of more specific biochemical probes may further improve the clinical value of PET for the understanding and treatment of epilepsy.     

Single-photon emission computed tomography for cerebral blood flow in school phobia

To investigate the correlation between abnormalities of regional cerebral blood flow and psychosomatic symptoms in school phobia, we examined cerebral blood flow in 55 patients with school phobia using single-photon emission computed tomography (SPECT) with 111 MBq ¹²³I-iodoamphetamine. The relationship between neuropsychological examination scores and SPECT findings was also examined. None of our patients exhibited evidence of focal structural abnormalities on magnetic resonance imaging. Blood flow, expressed as the corticocerebellar ratio (CCR) in the frontal, temporal, and occipital lobes, was markedly lower in patients with general fatigue, headache, and memory disturbance than in healthy adult subjets studied by another investigator and used as reference values in this study. However, parietal CCRs were higher in children with school phobia than in adult volunteers. These findings suggest that in patients with school phobia, the clinical psychosomatic symptoms may be closely related to decrease cerebral blood flow, especially in the frontal lobe. The relationship between symptoms of depression in our patients, measured using the self-rating depression scale score, and CCR was not significant.     

Comparison of SPECT findings and neuropsychological sequelae in carbon monoxide and organophosphate poisoning

Abnormal regional cerebral blood flow in patients with acute carbon monoxide (CO) and organophosphate (OP) poisoning was examined using (99m)Tc-hexamethylpropylene amine oxime (HMPAO) brain single photon emission computed tomography (SPECT) in fourteen patients. We evaluated the predictive significance of acute phase brain SPECT findings for long-term neuropsychological sequelae. Changes were found in the frontal, temporal, parietal lobes within the first week after both types of poisoning. The distribution of the hypoperfused cerebral areas as demonstrated by (99m)Tc-HMPAO imaging was similar in the two groups during the acute phase. Neuropsychological sequelae developed in five patients poisoned with OP and six with CO. Patients who had SPECT findings heterogeneously or in the temporal or frontal lobes displayed disorientation. Those with fronto-parietal and frontal lobe changes displayed mental confusion. Parkinsonism also was observed in patients with parieto-occipital, parietal and frontal lobe lesions. The distribution of these lesions appears to predict the long term sequelae of these poisonings, though additional studies with larger numbers of patients are needed to confirm the role of SPECT imaging in both OP and CO poisonings.     

Functional Imaging in Temporal Lobe Epilepsy

This article highlights the importance of functional imaging methods in the diagnosis and preoperative planning in temporal lobe epilepsy TLE). It starts with a discussion of the role of ictal and interictal single-photon emission computed tomography (SPECT) and interictal positron emission tomography (PET) in lateralizing TLE. The next section discusses the role of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) and perfusion MRI, particularly for lateralization of language and memory in TLE patients. The final section explores the relatively new role that the emerging technique of diffusion tensor imaging (DTI) is playing in the evaluation of TLE.     

"Benign" imaging abnormalities in children and adolescents with headache

OBJECTIVE: To study the frequency of "benign" abnormalities on brain imaging in children with headache, compare it with the frequency of imaging findings that dictate a change in patient management, and determine the association of benign findings with headache. METHODS: A database of 681 headache patients from the pediatric outpatient neurology department over 2 years was reviewed. Patients with benign imaging abnormalities were compared to those with nonbenign findings. Benign abnormalities were defined as those that did not result in a change in patient management. Using literature review, we discuss the benign findings and their possible association with headache. RESULTS: Two-hundred and forty-one patients (35.4%) had imaging at our facility. Two-hundred and eighteen had brain magnetic resonance imaging and 23 had brain computed tomography (CT) only. Twenty-two patients had CT of the sinuses in addition to brain imaging. Forty-six (19.1%) were found to have 50 benign abnormalities including 13 sinus disease, 11 Chiari I malformations, 7 nonspecific white matter abnormalities, 5 venous angiomas, 5 arachnoid cysts, 4 enlarged Virchow-Robin spaces, 2 pineal cysts, 1 mega cisterna magna, 1 fenestration of the proximal basilar artery, and 1 periventricular leukomalacia. Twenty-three patients (9.5%) had findings requiring a change in management. These included 5 sinus disease, 4 tumors, 4 old infarcts, 3 Chiari I, 2 moyamoya, 1 intracranial vascular stenosis, 1 internal jugular vein occlusion, 1 arteriovenous malformation, 1 demyelinating disease, and 1 intracerebral hemorrhage. When excluding sinusitis, which was evident clinically prior to imaging, 3 patients had absence of abnormal neurologic symptoms and signs and imaging findings that resulted in a change in management. CONCLUSIONS: Approximately 20% of pediatric headache patients with brain imaging have benign abnormalities that do not result in a change in headache management. Imaging findings that require a change in management are rare in patients with an absence of abnormal neurologic symptoms and signs, occurring in 1.2% of patients imaged in this study.     

Correlations of interictal FDG-PET metabolism and ictal SPECT perfusion changes in human temporal lobe epilepsy with hippocampal sclerosis

BACKGROUND: The pathophysiological role of the extensive interictal cerebral hypometabolism in complex partial seizures (CPS) in refractory mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE-HS) is poorly understood. Our aim was to study ictal-interictal SPECT perfusion versus interictal fluorodeoxyglucose (FDG)-PET metabolic patterns. METHODS: Eleven adults with refractory unilateral mTLE-HS, who were rendered seizure free after epilepsy surgery, were included. All had an interictal FDG-PET and an interictal and ictal perfusion SPECT scan. FDG-PET data were reconstructed using an anatomy-based reconstruction algorithm, which corrected for partial volume effects, and analyzed semi-quantitatively after normalization to white matter activity. Using Statistical Parametric Mapping (SPM), we compared interictal metabolism of the patient group with a control group. We correlated metabolic with ictal perfusion changes in the patient group. RESULTS: Global cerebral grey matter glucose metabolism in patients was decreased 10-25% compared with control subjects. Interictal PET hypometabolism and ictal SPECT hypoperfusion were maximal in the ipsilateral frontal lobe. Ictal frontal lobe hypoperfusion was associated with crossed cerebellar diaschisis. The ipsilateral temporal lobe showed maximal ictal hyperperfusion and interictal hypometabolism, which was relatively mild compared with the degree of hypometabolism affecting the frontal lobes. CONCLUSION: Interictal hypometabolism in mTLE-HS was greatest in the ipsilateral frontal lobe and represented a seizure-related dynamic process in view of further ictal decreases. Crossed cerebellar diaschisis suggested that there is a strong ipsilateral frontal lobe inhibition during CPS. We speculate that surround inhibition in the frontal lobe is a dynamic defense mechanism against seizure propagation, and may be responsible for functional deficits observed in mTLE.     

I-124-PET/US Fusion Imaging in Comparison to Conventional Diagnostics and Tc-99m Pertechnetate SPECT/US Fusion Imaging for the Function Assessment of Thyroid Nodules

The purpose of this study is to investigate I-124 positron emission tomography (PET)/ultrasound (US) fusion imaging for function assessment of thyroid nodules. In 70 patients, 201 lesions were examined with conventional diagnostics (CD) (thyroid US, laboratory findings and Tc-99m pertechnetate scintigraphy), Tc-99m pertechnetate single photon emission computed tomography (SPECT) and I-124 PET/computed tomography (CT). Subsequently, US fusion imaging (SPECT/US and PET/US) was performed by three experienced investigators. Patients referred for thyroid diagnostics in a clinical routine setting were included in this study if CD produced equivocal results. PET/US was superior to CD and SPECT/US in 96% and 86%, respectively, and ambiguous findings in CD were clarified by PET/US in 96% of the 70 patients. Regarding nodule-based function assessment, 10% (66%), 39% (14%) and 71% (4%) of the 201 lesions were rated with absolute certainty (equivocal or uncertain) using CD, SPECT/US and PET/US, respectively (p < 0.001). PET/US has the potential to improve the function assessment of thyroid nodules in comparison to CD.     

Olfactory hallucinations during migraine in an adolescent with an MRI temporal lobe lesion

OBJECTIVE: To report the first example of an abnormal magnetic resonance imaging (MRI) test in a patient with migraine and olfactory hallucinations and to provide additional evidence for a possible role of the temporal lobe in migraine. BACKGROUND: The relationship between the temporal lobe and migraine with or without hallucinations is unclear and continues to evolve. Clinical and functional neuroimaging studies (positron emission tomography/single photon emission computed tomography) have lent support to the possibility of a relationship. Anatomical neuroimaging with computed tomography has previously been normal. METHODS: The history and findings of an adolescent with migraine and olfactory hallucinations is reported. RESULTS: Brain MRI demonstrated a mass in the temporal lobe. CONCLUSIONS: Magnetic resonance imaging should be considered in patients with olfactory hallucinations and migraine. In addition, the role of the temporal lobe in migraine warrants further study.     

颞叶癫痫的质子磁共振波谱与PET/CT及术后病理对照研究

目的：对颞叶癫痫患者术前的质子磁共振波谱（1H MRS）与正电子发射断层扫描（PET/CT）、脑电图（EEG）及术后病理进行对照研究，评价1H MRS对颞叶癫痫的诊断价值。方法：16例颞叶癫痫病人，术前均做发作期间脑电图和/或长程脑电图监测及PET/CT检查。对28例健康志愿者和16例患者分别进行双侧海马的1H MRS采集，定量分析N-乙酰天门冬氨酸（NAA）、肌酸（Cr）和胆碱（Cho）代谢物的变化。3例患者手术切除致痫灶送病检。结果：病侧组、对侧组和对照组的NAA/Cr、Cho/Cr和NAA/（Cho+Cr）值之间的差异均有统计学意义（P<0.05）。16例患者中5例为单侧异常，11例为双侧异常，14例可确定异常侧，定位敏感度87%。结论：患者1H MRS示病侧与EEG、PET和病理改变有较好的对应性，1H MRS不仅可以发现双侧病变，而且可以指出病变严重的一侧，为术前致痫灶的定位提供可靠的依据。     

Abnormal electron beam computed tomography results: the value of repeating myocardial perfusion single-photon emission computed tomography in the ongoing assessment of coronary artery disease

OBJECTIVE: To determine whether asymptomatic patients with atherosclerosis, indicated by the presence of coronary artery calcium on electron beam computed tomography, are at enough risk for progression of disease to justify a repeated stress single-photon emission computed tomography (SPECT) examination after an initial normal to low-risk perfusion study. PATIENTS AND METHODS: We retrospectively identified patients who had abnormal results on electron beam computed tomography (coronary artery calcium score > 0) and normal to low-risk results on SPECT (defined as a summed stress score of 0-3) within a 3-month period from January 1, 1995, to October 31, 2002. Of the 504 identified patients, 285 remained after exclusion criteria were applied. Of the 285 patients, 69 (mean +/- SD age, 58.2 +/- 7.6 years; 91% male) underwent at least 1 repeated myocardial perfusion SPECT imaging study within 4 years of their initial assessment as normal or at low risk without recurrence of symptoms. The value of repeated SPECT imaging was assessed by detection of a substantial change in the repeated SPECT study and by documentation of a clinical event (death, nonfatal myocardial infarction, or revascularization). Follow-up was 100% complete at a mean of 4.3 +/- 1.6 years. RESULTS: Only 4 patients (6%) had a substantial progression in their SPECT risk category; substantial changes on the SPECT scans occurred only in patients with a coronary artery calcium score greater than 100. Three patients underwent revascularization, yielding a 5-year rate for survival free of revascularization of 94% (95% confidence interval, 88%-100%). No deaths or nonfatal myocardial infarctions were reported. CONCLUSION: The principal findings of this study indicate that asymptomatic patients with initial normal or low-risk results from stress SPECT performed because of abnormal coronary artery calcium scores who remain asymptomatic are at low risk of death, myocardial infarction, or coronary revascularization. Three patients underwent revascularization by percutaneous coronary intervention despite the absence of symptoms. A substantial change in SPECT results (defined as progression from normal or low-risk summed stress score to intermediate- or high-risk summed stress score) affected 6% of patients and was not associated with any adverse hard events (nonfatal myocardial infarction or death).     

Advances in neuroimaging research on Asperger syndrome

Autism spectrum disorder (ASD) (i.e., autism and Asperger syndrome) is a neurodevelopmental disorder, although its etiology is still unclear. Neuroimaging studies have attempted to identify the neurobiological basis of ASD. This article reviews recent progress in ASD research using magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), and positron emission tomography (PET). MRI studies documented structural and functional abnormalities in cerebella, the frontal lobes, the temporal lobes, and limbic systems of individuals with ASD. SPECT and PET studies suggested that abnormalities of the serotonergic system, in addition to decreased regional cerebral blood flow in the frontal and temporal lobes, are implicated in the pathophysiology of ASD.     

SPECT/CT融合显像术前定位诊断异位胃黏膜

目的 探讨SPECT/CT显像术前对异位胃黏膜病灶的定位诊断价值。方法 对25例异位胃黏膜患儿进行SPECT/CT检查,对动态平面显像20 min内腹部有固定异常放射性浓聚灶者,于20 min末行SPECT/CT断层扫描并进行同机断层融合,评价断层融合显像对病灶的定位结果与术中所见的一致性。结果 25例平面显像阳性,其中断层融合显像阳性17例,阴性8例。14例（14/17,82.35%）断层融合显像所示病灶位置与术中所见相同,一致性高（Kappa=0.746,P<0.05）。结论 异位胃黏膜SPECT/CT融合显像可准确定位病灶,有较高的应用价值。     

Multimodality evoked potential testing in acute mild closed head injury

Multimodality evoked potential (MEP) testing, including brainstem auditory, visual, and somatosensory evoked potentials, have been reported to be useful in predicting outcome in severe closed head injury. Brainstem auditory evoked potentials have been demonstrated to be abnormal in 10% to 40% of acute mild head injury. A prospective study of 18 patients with mild closed head injury was undertaken to determine the usefulness of MEP screening within two weeks of the acute event. Long latency event-related potentials (P300s), in response to auditory stimuli with an oddball paradigm, were included in the screening. The subjects had several symptoms consistent with the postconcussive syndrome at the time of the evoked potential testing. Only one patient had an abnormal evoked potential response (greater than three standard deviations from the mean) from all the testing done. The standard methods of MEP testing were insensitive to quantifying the possible physiologic changes that are associated with memory deficits, lethargy, and emotional irritability after mild closed head injury.     

Current concepts: diffuse axonal injury-associated traumatic brain injury

OBJECTIVES: To review the probable physical, physiologic mechanisms that result in the medical and neuropsychologic complications of diffuse axonal injury (DAI)-associated traumatic brain injury (TBI). DATA SOURCES: Various materials were accessed: MEDLINE, textbooks, scientific presentations, and current ongoing research that has been recently reported. STUDY SELECTION: Included were scientific studies involving TBI, particularly direct injury to the axons and glia of the central nervous system (CNS) in both in vitro and in vivo models. These studies include pathologic findings in humans as well as the medical complications and behavioral outcomes of DAI. Studies that addressed animal models of DAI as well as cellular and/or tissue models of neuronal injury were emphasized. The review also covered work on the physical properties of materials involved in the transmission of energy associated with prolonged acceleration-deceleration injuries. DATA EXTRACTION: Studies were selected with regard to those that addressed the mechanism of TBI associated with DAI and direct injury to the axon within the CNS. The material was generally the emphasis of the article and was extracted by multiple observers. Studies that correlate the above findings with the clinical picture of DAI were included. DATA SYNTHESIS: Concepts were developed by the authors based on the current scientific findings and theories of DAI. The synthesis of these concepts involves expertise in physical science, basic science concepts of cellular injury to the CNS, acute medical indicators of DAI, neuropsychologic indicators of DAI, and rehabilitation outcomes from TBI. CONCLUSIONS: The term DAI is a misnomer. It is not a diffuse injury to the whole brain, rather it is predominant in discrete regions of the brain following high-speed, long-duration deceleration injuries. DAI is a consistent feature of TBI from transportation-related injuries as well as some sports injuries. The pathology of DAI in humans is characterized histologically by widespread damage to the axons of the brainstem, parasagittal white matter of the cerebral cortex, corpus callosum, and the gray-white matter junctions of the cerebral cortex. Computed tomography and magnetic resonance imaging scans taken initially after injury are often normal. The deformation of the brain due to plastic flow of the neural structures associated with DAI explains the micropathologic findings, radiologic findings, and medical and neuropsychologic complications from this type of injury mechanism. There is evidence that the types of cellular injury in TBI (DAI, anoxic, contusion, hemorrhagic, perfusion-reperfusion) should be differentiated, as all may involve different receptors and biochemical pathways that impact recovery. These differing mechanisms of cellular injury involving specific biochemical pathways and locations of injury may, in part, explain the lack of success in drug trials to ameliorate TBI.     

Persistent aura without infarction: decription of the first case studied with both brain SPECT and perfusion MRI

To the best of our knowledge, persistent visual symptoms, lasting months or years without evidence of infarction, a rare complication of migraine with aura, has been reported in only 20 patients. We report the case of a 43-year-old woman with a 31-year history of migraine with typical visual aura. At presentation, she experienced a visual aura in her right hemifield followed by a pulsating headache. The visual symptoms persisted. There were no abnormal findings on neurological and ophthalmological examinations, EEG, visual evoked potentials (VEPs), brain computed tomography and magnetic resonance imaging (MRI). Both brain single photon emission computed tomography (SPECT) and brain perfusion MRI revealed decreased left fronto-parieto-occipital and right occipital blood perfusion. A perfusion MRI, performed 7 months after symptom onset and almost complete extinction of symptoms, was normal. As previously reported, we demonstrated a cortical hypoperfusion by SPECT in a case of persistent visual aura. For the first time this finding was confirmed by perfusion MRI.