Interictal brain SPECT in patients with medically refractory temporal lobe epilepsy

The objective of this study was to evaluate the utility of interictal brain SPECT in localizing the epileptogenic focus in a population of patients of Epilepsy Clinic of Hospital Universitário Clementino Fraga Filho (HUCFF/UFRJ), with medically refractory temporal lobe epilepsy (TLE) and normal computed tomography (CT) scans, studying the correlation between SPECT, electroencephalogram (EEG) and, in 11 cases, brain magnetic resonance imaging (MRI), and to compare the results to the other six literature series. Twelve (52.2%) patients presented abnormal SPECT. Among these, five (41.6% of abnormal SPECTs) presented unilateral SPECT changes at the same side of EEG (hypoperfusion in four and hyperperfusion in one), three (25% of abnormal SPECTs) presented bilateral hypoperfusion and bilateral EEG changes too, and four (33.3%) presented unilateral hypoperfusion and bilateral EEG changes. The statistical analysis was based on fuzzy logic. The correlation index among SPECT X EEG, SPECT X MRI and SPECT X EEG X MRI were highly significant, with significance levels at 0.01, p < 0.0005 and trust interval at 99% in all correlations. The correlation studies between the series presented similar results.     

Single-photon emission computed tomography of brain perfusion: analysis of 60 paediatric cases

Sixty-nine brain perfusion single-photon emission computed tomography (SPECT) scans were performed on 60 paediatric patients with various neurological diagnoses. SPECT was abnormal more frequently in degenerative brain diseases (82 per cent), than in epilepsy (63 per cent), encephalitis (62 per cent), cerebrovascular disease (43 per cent), or other brain disorders (43 per cent). SPECT was more sensitive than EEG, CT and MRI results. SPECT was of considerable value for diagnosis in many cases. It was a decisive aid in two cases, but misleading in another two, so SPECT must be related to findings obtained by clinical and other laboratory methods.     

Chronological changes in brain MRI, SPECT, and EEG in neurosarcoidosis with stroke-like episodes

Abstract  Neurosarcoidosis with recurrent stroke-like episodes has been reported only rarely in the literature. We repeatedly measured brain magnetic resonance images (MRI), SPECT, and electroencephalograms (EEG) in a 32-year-old male patient with this condition. In the acute stage of the episodes, he showed semi-coma followed by severe dysphasia; left-frontal EEG delta wave activities and left-sided hyperperfusion SPECT were noted. Gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) MRI findings were aggravated diffusely in the convalescent stage of the disease rather than in the acute stage. The EEG and SPECT findings were clearly reflective of an early stage of acute encephalomeningitis caused by the neurosarcoidosis, and thus are more useful than MRI for evaluation of the acute inflammatory process in this condition.     

Focal brain dysfunction in a 41-year old man with familial alternating hemiplegia

The acute pathophysiologic changes during hemiplegic spells and the long-term outcome of alternating hemiplegia remain obscure. In a 41-year-old male with familial alternating hemiplegia we found an increase in right frontal cerebral blood flow 3 h into a 5-h left hemiplegic episode. A repeat high-resolution brain SPECT study performed 26 h after the resolution of the left hemiplegia revealed normalization of the frontal blood flow accompanied by hyperperfusion in the right parietal lobe. An interictal SPECT scan several weeks later showed no asymmetries. Head CT and MRI scans were negative. Neuropsychologic assessment and neurologic examination revealed evidence of a diffuse disorder which predominantly involved the right hemisphere. To our knowledge, there are no previous correlative studies of serial highresolution brain SPECT with MRI, or of detailed neuropsychologic assessment, in adult patients with such an advanced course of alternating hemiplegia of childhood.     

Bickerstaff’s brainstem encephalitis: case report and Tc99m brain SPECT findings

A 21-year-old healthy female suffered from an upper respiratory tract infection and 2 days later developed diplopia, unsteady gait, dysarthria and a profound disturbance of consciousness with rapid development of coma. Brain MRI and Tc99m brain perfusion SPECT, EEG, neurophysiological tests and CSF analysis results were unspecific. The detection of serum anti-GQ1b IgG autoantibodies at high titre led to the diagnosis of Bickerstaff’s brainstem encephalitis (BBE). Clinical symptoms resolved after treatment with plasma exchange and the outcome was good. Brain MRI was normal, and Tc99m brain perfusion SPECT demonstrated hypoperfusion of the whole cerebral hemispheres and basal ganglia with relative sparing of the thalami and the brainstem. Similar to brain MRI, the sensitivity of Tc99m brain perfusion SPECT in detecting brainstem lesions in typical BBE patients seems to be low.     

Fragile X syndrome and cerebral perfusion abnormalities: single-photon emission computed tomographic study

Fragile X syndrome is an inherited disorder caused by a defective gene on the X chromosome. It is associated with developmental or behavioral symptoms and various degrees of mental retardation. Morphologic abnormalities and altered perfusion of various brain areas can underlie these functional disturbances. The aim of this study was to investigate the cerebral perfusion state in patients with fragile X syndrome using single-photon emission computed tomography (SPECT). Structural and functional assessment was also performed by magnetic resonance imaging (MRI) and electroencephalography (EEG). Eight boys with cytogenetically confirmed fragile X syndrome (mean age 8.8 +/- 4.4 years, range 5-18 years), were included. All patients had mental retardation, with a mean IQ of 58.9 +/- 8.8 (range 40-68), and additional neurobehavioral symptoms. SPECT revealed cerebral perfusion abnormalities in six patients (75%), most commonly in the frontoparietotemporal area and prominent in the right hemisphere. The SPECT and EEG findings were concordant: hypoperfused areas in SPECT corresponded to regions of persistent slow-wave paroxysms on EEG. On the other hand, cranial MRI was abnormal qualitatively only in two patients (25%) showing cerebellar and vermal hypoplasia and cerebral hemispheric asymmetry. Our results indicate that cerebral perfusion abnormalities, which are correlated with electrophysiologic findings but not necessarily with anatomic abnormalities, can underlie the pathogenesis of the clinical findings observed in fragile X syndrome.     

Minimally resective epilepsy surgery in MRI‐negative children

Aim. Performing epilepsy surgery on children with non‐lesional brain MRI often results in large lobar or multilobar resections. The aim of this study was to determine if smaller resections result in a comparable rate of seizure freedom. Methods. We reviewed 25 children who had undergone focal corticectomies restricted to one aspect of a single lobe or the insula at our institution within a 5.5‐year period. Data collected in the comprehensive non‐invasive pre‐surgical evaluation (including scalp video‐EEG, volumetric MRI, functional MRI, EEG source localization, and SPECT and PET), as well as from invasive recordings performed in each patient, was reviewed. Data from each functional modality was identified as convergent or divergent with the epileptogenic zone using image coregistration. Specific biomarkers (from extra‐operative and invasive testing) previously indicated to be indicative of focal epileptogenicity were used to further tailor each resection to an epileptogenic epicentre. Tissue pathology and postoperative outcomes were obtained from all 25 patients. Results. Two years postoperatively, 15/25 (60%) children were seizure‐free, three (12%) experienced >90% reduction in seizure frequency, two (8%) had a 50–90% reduction in seizure frequency, and the remaining five (20%) had no change in seizure burden. There was no significant difference in outcome based on numerous pre‐ and postoperative factors including location of resection, the number of preoperative functional tests providing convergent data, and tissue pathology. Conclusion. In MRI‐negative children with focal epilepsy, an epileptogenic epicentre within a larger epileptogenic zone can be identified when specific biomarkers are recognized on non‐invasive and invasive testing. When such children undergo resection of a small, well‐defined epileptogenic epicentre, favourable outcomes can be achieved.     

Understanding the pathophysiology of reflex epilepsy using simultaneous EEG‐fMRI

Measuring neuro‐haemodynamic correlates in the brain of epilepsy patients using EEG‐fMRI has opened new avenues in clinical neuroscience, as these are two complementary methods for understanding brain function. In this study, we investigated three patients with drug‐resistant reflex epilepsy using EEG‐fMRI. Different types of reflex epilepsy such as eating, startle myoclonus, and hot water epilepsy were included in the study. The analysis of EEG‐fMRI data was based on the visual identi?cation of interictal epileptiform discharges on scalp EEG. The convolution of onset time and duration of these epilepsy spikes was estimated, and using these condition‐specific effects in a general linear model approach, we evaluated activation of fMRI. Patients with startle myoclonus epilepsy experienced epilepsy in response to sudden sound or touch, in association with increased delta and theta activity with a spike‐and‐slow‐wave pattern of interictal epileptiform discharges on EEG and fronto‐parietal network activation pattern on SPECT and EEG‐fMRI. Eating epilepsy was triggered by sight or smell of food and fronto‐temporal discharges were noted on video‐EEG (VEEG). Similarly, fronto‐temporo‐parietal involvement was noted on SPECT and EEG‐fMRI. Hot water epilepsy was triggered by contact with hot water either in the bath or by hand immersion, and VEEG showed fronto‐parietal involvement. SPECT and EEG fMRI revealed a similar fronto‐parietal‐occipital involvement. From these results, we conclude that continuous EEG recording can improve the modelling of BOLD changes related to interictal epileptic activity and this can thus be used to understand the neuro‐haemodynamic substrates involved in reflex epilepsy.     

脑外伤长期昏迷病人促醒治疗

目的 探讨脑外伤长期昏迷病人促醒途径。方法 自1986年5月～1999年12月，对142例严重脑外伤病人集中后续治疗，并进行头颅CT、MRI、脑干诱发电位及脑电功率谱随访研究。结果 102例(71．83％)在经过平均92天的昏迷期(30天～36个月)后恢复意识，其中25例(24．5％)恢复工作或学习，生活自理52例(51％)及25例仍需他人照料。结论 认为脑外伤长期昏迷病人经过积极治疗后，其中部分病人可望恢复意识，头颅CT、MRI、脑干诱发电位及脑电功率谱能从不同角度对脑外伤长期昏迷预后估价提供明确客观指标。     

MRI-SPECT and PET-EEG findings on brain dysfunction in schizophrenia.

1. In this article the author reviews a series of investigations on brain dysfunction in untreated schizophrenics using manumotor and music listening tasks as activation paradigms. Methods involved were EEG mapping, Single Photon Emission Computerized Tomography (SPECT; Xenon-133 inhalation method), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET; 11-2-Deoxyglucose as tracer). 2. Major signs of brain dysfunction yielded a "nonreactivity" on both motor and music stimulation in patients displaying marked negative symptomatology, as shown consistently by EEG Mapping, SPECT and PET. In contrast, first-break patients with predominant "positive" and without underlying negative symptoms showed signs of "normal" to "diffuse hyperactivation" on such stimulations, as demonstrated by EEG and SPECT imaging methods. 3. Interestingly, MRI planimetry of the size of the corpus callosum (CC) corroborated the above findings, showing a significantly larger CC in "positive" than "negative" patients. 4. Together with functional imaging findings of other working groups and recent neuropathological theories we finally raise some speculative neurophysiological hypotheses on brain dysfunction in subgroups of schizophrenics, which might have direct implications for treatment and follow-up of these patients.     

Correlative study of the cognitive impairment, regional cerebral blood flow, and electroencephalogram abnormalities in children with Down's syndrome

The aim of this study was to investigate possible correlations of the cognitive impairment with abnormalities of regional cerebral blood flow and electroencephalogram in children with (Down's Syndrome) DS. Nine patients with DS were evaluated by single photon emission computed tomography (SPECT) in combination with clinical findings, electroencephalography (EEG), and magnetic resonance imaging (MRI). In cases with IQs below 40, there were one or more findings of abnormal EEG/MRI and brain perfusion SPECT. In 6 cases (66.7%) EEG findings were normal, but 3 (33.3%) had abnormal EEG findings. Perfusion abnormalities were most pronounced in the fronto-parieto-temporal region in the form of hypoperfusion (n = 5) and in the right hemisphere (n = 5) than the left hemisphere (n = 1). These findings suggest that the children with DS had varying levels of structural, perfusion, and electrophysiological abnormalities in the brain and these abnormalities were reflected by measurable alterations of the cognitive functions.     

Decreased Cerebral Blood Flow in Neuro-Behcet''s Syndrome Patients With Neuropsychiatric Manifestations and Normal Magnetic Resonance Imaging—A Preliminary Report

Involvement of the brain is one of the most important complications of Behcet's disease, but its diagnosis is difficult because of the lack of effective imaging tools. Therefore, technetium‐99m ethyl cysteinate dimer (Tc‐99m ECD) single‐photon emission computed tomography (SPECT) of the brain was used to detect abnormal regional cerebral blood flow in patients with neuro‐Behcet's syndrome (NBS). Tc‐99m ECD brain SPECT was per‐formed to detect hypoperfusion areas of the brain in 10 NBS patients with definite neuropsychiatric symptoms or signs and normal brain magnetic resonance imaging (MRI) findings. Tc‐99m ECD brain SPECT demonstrated hypoperfusion areas of the brain in all of the 10 NBS patients. The parietal lobes were the most common areas with hypoperfusion lesions. Tc‐99m ECD brain SPECT is a more sensitive and useful tool than brain MRI for detecting hypoperfusion areas of the brain in NBS patients.     

Cobalt-55 positron emission tomography in traumatic brain injury: a pilot study.

Traumatic brain injury is usually assessed with the Glasgow coma scale (GCS), CT, or MRI. After such injury, the injured brain tissue is characterised by calcium mediated neuronal damage and inflammation. Positron emission tomography with the isotope cobalt-55 (Co-PET) as a calcium tracer enables imaging of affected tissue in traumatic brain injury. The aim was to determine whether additional information can be gained by Co-PET in the diagnosis of moderate traumatic brain injury and to assess any prognostic value of Co-PET. Five patients with recent moderately severe traumatic brain injury were studied. CT was performed on the day of admission, EEG within one week, and MRI and Co-PET within four weeks of injury. Clinical assessment included neurological examination, GCS, neuropsychological testing, and Glasgow outcome scale (GOS) after one year. Co-PET showed focal uptake that extended beyond the morphological abnormalities shown by MRI and CT, in brain regions that were actually diagnosed with EEG. Thus Co-PET is potentially useful for diagnostic localisation of both structural and functional abnormalities in moderate traumatic brain injury.     

“Paradoxical” EEG response to propofol may differentiate post‐cardiac arrest non‐convulsive status epilepticus from diffuse irreversible cerebral anoxia

Current EEG criteria for the diagnosis of non‐convulsive status epilepticus in critically ill patients with repetitive generalised or focal epileptiform discharges primarily rely on a widely accepted low cut‐off frequency limit of 2.5–3 Hz for non‐evolving patterns, or on discharge evolution of frequency, location or mophology. The secondary criterion is a significant clinical or EEG improvement following acute administration of a rapidly acting antiepileptic drug, such as lorazepam. We describe a comatose patient after out‐of‐hospital cardiac arrest, in whom very slow (1‐Hz), non‐evolving generalised periodic epileptiform discharges against an almost completely depressed background would suggest substantial anoxic damage and poor neurological outcome. Yet, reloading with propofol for diagnostic purposes completely dispersed generalised periodic epileptiform discharges and revealed previously absent biological activity, raising the possibility of non‐convulsive status epilepticus that was subsequently confirmed. Brain MRI showed no significant anoxic brain damage and EEG improved, but the patient died from severe cardiopulmonary complications. These observations suggest that in rare cases, slow, non‐evolving generalised periodic epileptiform discharges may reflect non‐convulsive status epilepticus rather than diffuse irreversible cerebral anoxia, while reloading with propofol can be used as an additional secondary diagnostic criterion.     

Periodic lateralized epileptiform discharges in multiple sclerosis: a case report.

The occurrence of epileptiform abnormalities on the EEG in patients with multiple sclerosis (MS) is rare. The following case correlates the clinical, EEG, MRI, and single photon emission computed tomographic (SPECT) findings in a patient with a long history of MS and acute onset of focal motor seizures and confusion. Two routine EEGs, brain MRI, and brain SPECT were performed. The patient was a 44-year-old woman with a long history of clinically definite MS of the relapsing-remitting and secondary progressive form with three events of focal motor seizures followed by generalized tonic-clonic seizures and postictal confusion. The first EEG done during admission showed periodic lateralized epileptiform discharges in the right temporal region. Brain MRI done several weeks later showed scattered T2 hyperintensities in several locations, including the periventricular and subcortical white matter bilaterally. Brain SPECT using Tc99-Neurolite demonstrated decreased perfusion on the right parietal and temporal lobes. This case suggests that focal motor seizures and a transient state of altered consciousness can be the result of an exacerbation of MS. The neurophysiologic expression of these clinical manifestations may present as periodic lateralized epileptiform discharges on the EEG and decreased regional perfusion on brain SPECT.     

A comprehensive clinico‐pathological and genetic evaluation of bottom‐of‐sulcus focal cortical dysplasia in patients with difficult‐to‐localize focal epilepsy

Aims. We comprehensively studied the clinical presentation, stereo‐EEG and MRI findings, histopathological diagnosis, and brain somatic mutations in a retrospective series of drug‐resistant patients with difficult‐to‐localize epilepsy due to focal cortical dysplasia at the bottom of a sulcus (BOS‐FCD). Methods. We identified 10 patients with BOS‐FCD from the Cleveland Clinic epilepsy surgery database submitted for intracranial video‐EEG monitoring. Brain MRI, including voxel‐based morphometric analysis and surgical tissue submitted for histopathology, was reviewed. Paraffin tissue samples from five patients were made available for targeted next‐generation sequencing. Postsurgical follow‐up was available in nine patients. Results. BOS‐FCD was identified in the superior frontal sulcus in six patients, inferior frontal sulcus in one patient, central sulcus in one patient, and intraparietal sulcus in two patients. All patients had stereotyped seizures. Intracranial EEG recordings identified ictal onset at the BOS‐FCD in all 10 patients, whereas ictal scalp EEG had a localizing value in only six patients. Complete resection was achieved by lesionectomy or focal corticectomy in nine patients. Histopathologically, six patients had FCD type IIb and three had FCD type IIa. Next‐generation sequencing analysis of DNA extracted from lesion‐enriched (micro‐dissected) tissue from five patients with FCD type II led to the identification of a germline frameshift insertion in DEPDC5, introducing a premature stop in one patient. Eight out of nine patients with available follow‐up were completely seizure‐free (Engel Class IA) after a mean follow‐up period of six years. Conclusion. Our results confirm previous studies classifying difficult‐to‐localize BOS‐FCD into the emerging spectrum of FCD ILAE type II mTORopathies. Further studies with large patient numbers and ultra‐deep genetic testing may help to bridge the current knowledge gap in genetic aetiologies of FCD.     

Lateralization of epileptiform discharges in patients with epilepsy and precocious destructive brain insults

Unilateral destructive brain lesions of early development can result in compensatory thickening of the ipsilateral cranial vault. The aim of this study was to determine the frequency of these bone changes among patients with epilepsy and precocious destructive lesions, and whether a relationship exists between these changes and epileptiform discharges lateralization. Fifty-one patients had their ictal / interictal scalp EEG and skull thickness symmetry on MRI analyzed. Patients were divided into three main groups according to the topographic distribution of the lesion on the MRI: hemispheric (H) (n=9); main arterial territory (AT) (n=25); arterial borderzone (Bdz) (n=17). The EEG background activity was abnormal in 26 patients and were more frequent among patients of group H (p= 0.044). Thickening of the skull was more frequent among patients of group H (p= 0.004). Five patients (9.8%) showed discordant lateralization between epileptiform discharges and structural lesion (four of them with an abnormal background, and only two of them with skull changes). In one of these patients, ictal SPECT provided strong evidence for scalp EEG false lateralization. The findings suggest that compensatory skull thickening in patients with precocious destructive brain insults are more frequent among patients with unilateral and large lesions. However, EEG lateralization discordance among these patients seems to be more related to EEG background abnormalities and extent of cerebral damage than to skull changes.     

Comparison of MRI, EEG, EPs and ECD-SPECT in Wilson's disease

OBJECTIVES: The purpose of this study is to evaluate the efficiency of a few methodologies in detecting anatomo-functional brain abnormalities in patients with Wilson's disease. MATERIALS AND METHODS: Twenty-three patients with Wilson's disease underwent almost simultaneously brain magnetic resonance imaging (MRI), computerized electroencephalography (EEG), multimodal evoked potentials (EPs) and ECD single photon computerized tomography (SPECT) evaluation. The clinical picture was of the neurologic type in 8 patients and of the hepatic type in 15. RESULTS: MRI was abnormal in 7 patients with neurological manifestations. The EPs proved pathologic in 7 neurologically symptomatic patients and in 4 cases with hepatic form. These results agree with those reported in other case studies. The EEG records were abnormal only in 3 cases. Nevertheless, the most interesting finding of this study is the particular frequency (86%) of diffuse or focal decrease of ECD uptake shown by brain SPECT. CONCLUSION: We highlight the use of this interesting procedure in the therapeutic monitoring of this disease.     

CORRELATIVE STUDY OF THE COGNITIVE IMPAIRMENT,REGIONAL CEREBRAL BLOOD FLOW,AND ELECTROENCEPHALOGRAM ABNORMALITIES IN CHILDREN WITH DOWN’S SYNDROME

The aim of this study was to investigate possible correlations of the cognitive impairment with abnormalities of regional cerebral blood flow and electroencephalogram in children with (Down's Syndrome) DS. Nine patients with DS were evaluated by single photon emission computed tomography (SPECT) in combination with clinical findings, electroencephalography (EEG), and magnetic resonance imaging (MRI). In cases with IQs below 40, there were one or more findings of abnormal EEG/MRI and brain perfusion SPECT. In 6 cases (66.7%) EEG findings were normal, but 3 (33.3%) had abnormal EEG findings. Perfusion abnormalities were most pronounced in the fronto-parieto-temporal region in the form of hypoperfusion (n = 5) and in the right hemisphere (n = 5) than the left hemisphere (n = 1). These findings suggest that the children with DS had varying levels of structural, perfusion, and electrophysiological abnormalities in the brain and these abnormalities were reflected by measurable alterations of the cognitive functions.     

低血糖脑病的临床及脑部磁共振特征

目的探讨低血糖脑病的临床及脑部磁共振特征。方法回顾分析69例低血糖昏迷患者的临床、脑磁共振（MRI）成像资料。结果低血糖昏迷诱因较为复杂,常见的为进食减少、腹泻、上呼吸道感染、降糖药物应用不当等。临床表现复杂多样,除意识障碍外,还可表现为偏瘫、四肢瘫、凝视麻痹等,多数伴有Babinski征。69例患者中有18例出现脑MRIDWI异常高信号病灶,病灶主要累及海马、基底节、大脑皮质以及皮质下白质,多为对称性损害。3个月后随访,不伴有脑部MRI损害的患者预后良好率明显高于伴有脑部MRI损害的患者（94．12％对22．22％;P=0．0011）。伴有脑部MRI损害者有10例患者预后不良,其中9例（90％）发生于皮质受累患者。结论低血糖脑病临床表现不具有特异性,对于昏迷患者,应当考虑到低血糖的可能。降糖药物应用不当为低血糖脑病的主要诱发因素。脑部MRI要优于脑部CT检查,其中DWI序列对于检测低血糖所致的脑部损害有着非常重要的意义。皮质受累者预后不良。