PiDeeL: metabolic pathway-informed deep learning model for survival analysis and pathological classification of gliomas.

MOTIVATION: Online assessment of tumor characteristics during surgery is important and has the potential to establish an intra-operative surgeon feedback mechanism. With the availability of such feedback, surgeons could decide to be more liberal or conservative regarding the resection of the tumor. While there are methods to perform metabolomics-based tumor pathology prediction, their model complexity predictive performance is limited by the small dataset sizes. Furthermore, the information conveyed by the feedback provided on the tumor tissue could be improved both in terms of content and accuracy. RESULTS: In this study, we propose a metabolic pathway-informed deep learning model (PiDeeL) to perform survival analysis and pathology assessment based on metabolite concentrations. We show that incorporating pathway information into the model architecture substantially reduces parameter complexity and achieves better survival analysis and pathological classification performance. With these design decisions, we show that PiDeeL improves tumor pathology prediction performance of the state-of-the-art in terms of the Area Under the ROC Curve by 3.38% and the Area Under the Precision-Recall Curve by 4.06%. Similarly, with respect to the time-dependent concordance index (c-index), PiDeeL achieves better survival analysis performance (improvement of 4.3%) when compared to the state-of-the-art. Moreover, we show that importance analyses performed on input metabolite features as well as pathway-specific neurons of PiDeeL provide insights into tumor metabolism. We foresee that the use of this model in the surgery room will help surgeons adjust the surgery plan on the fly and will result in better prognosis estimates tailored to surgical procedures. AVAILABILITY AND IMPLEMENTATION: The code is released at https://github.com/ciceklab/PiDeeL. The data used in this study are released at https://zenodo.org/record/7228791.

Targeted metabolomics analyses for brain tumor margin assessment during surgery.

MOTIVATION: Identification and removal of micro-scale residual tumor tissue during brain tumor surgery are key for survival in glioma patients. For this goal, High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) spectroscopy-based assessment of tumor margins during surgery has been an effective method. However, the time required for metabolite quantification and the need for human experts such as a pathologist to be present during surgery are major bottlenecks of this technique. While machine learning techniques that analyze the NMR spectrum in an untargeted manner (i.e. using the full raw signal) have been shown to effectively automate this feedback mechanism, high dimensional and noisy structure of the NMR signal limits the attained performance. RESULTS: In this study, we show that identifying informative regions in the HRMAS NMR spectrum and using them for tumor margin assessment improves the prediction power. We use the spectra normalized with the ERETIC (electronic reference to access in vivo concentrations) method which uses an external reference signal to calibrate the HRMAS NMR spectrum. We train models to predict quantities of metabolites from annotated regions of this spectrum. Using these predictions for tumor margin assessment provides performance improvements up to 4.6% the Area Under the ROC Curve (AUC-ROC) and 2.8% the Area Under the Precision-Recall Curve (AUC-PR). We validate the importance of various tumor biomarkers and identify a novel region between 7.97 ppm and 8.09 ppm as a new candidate for a glioma biomarker. AVAILABILITY AND IMPLEMENTATION: The code is released at https://github.com/ciceklab/targeted_brain_tumor_margin_assessment. The data underlying this article are available in Zenodo, at https://doi.org/10.5281/zenodo.5781769. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Pituitary Abscess: A Challenging Preoperative Diagnosis-A Multicenter Study.

Background and Objectives: Pituitary abscess (PA) is a rare occurrence, representing less than 1% of pituitary lesions, and is defined by the presence of an infected purulent collection within the sella turcica. Pas can be classified as either primary, when the underlying pituitary is normal prior to infection, or secondary, when there is associated a pre-existing sellar pathology (i.e., pituitary adenoma, Rathke's cleft cysts, or craniopharyngioma), with or without a recent history of surgery. Preoperative diagnosis, owing to both non-specific symptoms and imaging features, remains challenging. Treatment options include endonasal trans-sphenoidal pus evacuation, as well as culture and tailored antibiotic therapy. Methods: A retrospective multicenter study, conducted on a prospectively built database over a 20-year period, identified a large series of 84 patients harboring primary sellar abscess. The study aimed to identify crucial clinical and imaging features in order to accelerate appropriate management. Results: The most common clinical presentation was a symptom triad consisting of various degrees of asthenia (75%), visual impairment (71%), and headache (50%). Diagnosis was achieved in 95% of cases peri- or postoperatively. Functional recovery was good for visual disturbances and headache. Pituitary function recovery remained very poor (23%), whereas the preoperative diagnosis represented a protective factor. Conclusions: In light of the high prevalence of pituitary dysfunction following the management of PAs, early diagnosis and treatment might represent a crucial issue. Currently, there are no standard investigations to establish a conclusive preoperative diagnosis; however, new, emerging imaging methods, in particular nuclear imaging modalities, represent a very promising tool, whose potential warrants further investigations.

Analysis of Metabolic Pathways by 13C-Labeled Molecular Probes and HRMAS Nuclear Magnetic Resonance Spectroscopy: Isotopologue Identification and Quantification Methods for Medical Applications.

The use of 13C-labeled molecular probes is essential to explore altered metabolic pathways in human pathologies. The analysis of the different 13C isotopologues resulting from these changes in metabolic pathways is essential to understand the different biological processes involved. We propose an NMR methodology consisting of eight different NMR experiments performed under HRMAS conditions to explore metabolic pathways in unprocessed pathological cells and tissues. This methodology has the potential to study human pathologies in the medical field and to enable the analysis of the mode of action of therapeutic treatments.

Local recurrence and cerebral progression-free survival after multiple sessions of stereotactic radiotherapy of brain metastases: a retrospective study of 184 patients : Statistical analysis.

PURPOSE: Forty to sixty percent of patients treated with focal therapy for brain metastasis (BM) will have distant brain recurrence (C-LR), while 10-25% of patients will have local recurrence (LR) within 1 year after stereotactic radiotherapy (SRT). The purpose of this study was to analyze cerebral progression-free survival (C-PFS) and LR of BM among patients treated with repeated courses of radiotherapy in stereotactic conditions. METHODS AND MATERIALS: We retrospectively reviewed data from 184 patients treated for 915 BMs with at least two courses of SRT without previous WBRT. Initial patient characteristics, patient characteristics at each SRT, brain metastasis velocity (BMV), delay between SRT, MRI response, LR and C­LR were analyzed. RESULTS: In all, 123 (66.9%), 39 (21.2%), and 22 (12%) patients received 2, 3, or 4 or more SRT sessions, respectively. Ninety percent of BMs were irradiated without prior surgery, and 10% were irradiated after neurosurgery. The MRI response at 3, 6, 12 and 24 months after SRT was stable regardless of the SRT session. At 6, 12 and 24 months, the rates of local control were 96.3, 90.1, and 85.8%, respectively. In multivariate analysis, P­LR was statistically associated with kidney (HR = 0.08) and lung cancer (HR = 0.3), ECOG 1 (HR = 0.5), and high BMV grade (HR = 5.6). The median C­PFS after SRT1, SRT2, SRT3 and SRT4 and more were 6.6, 5.1, 6.7, and 7.7 months, respectively. C­PFS after SRT2 was significantly longer among patients in good general condition (HR = 0.39), patients with high KPS (HR = 0.91), patients with no extracerebral progression (HR = 1.8), and patients with a low BMV grade (low vs. high: HR = 3.8). CONCLUSION: Objective MRI response rate after repeated SRT is stable from session to session. Patients who survive longer, such as patients with breast cancer or with low BMV grade, are at risk of local reirradiation. C­PFS after SRT2 is better in patients in good general condition, without extracerebral progression and with low BMV grade.

Metabolomic Profile of Aggressive Meningiomas by Using High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

Meningiomas are in most cases benign brain tumors. The WHO 2016 classification defines three grades of meningiomas. This classification had a prognosis value because grade III meningiomas have a worse prognosis value compared to grades I and II meningiomas. However, some benign or atypical meningiomas can have a clinical aggressive behavior. There are currently no reliable markers which allow distinguishing between the meningiomas with a good prognosis and those which may recur. High-resolution magic angle spinning (HRMAS) spectrometry is a noninvasive method able to determine the metabolite profile of a tissue sample. We retrospectively analyzed 62 meningioma samples by using HRMAS spectrometry (43 metabolites). We described a metabolic profile defined by a high concentration for acetate, threonine, N-acetyl-lysine, hydroxybutyrate, myoinositol, ascorbate, scylloinositol, and total choline and a low concentration for aspartate, glucose, isoleucine, valine, adenosine, arginine, and alanine. This metabolomic signature was associated with poor prognosis histological markers [Ki-67 ≥ 40%, high histological grade and negative progesterone receptor (PR) expression]. We also described a similar metabolomic spectrum between grade III and grade I meningiomas. Moreover, all grade I meningiomas with a low Ki-67 expression and a positive PR expression did not have the same metabolomic profile. Metabolomic analysis could be used to determine an aggressive meningioma in order to discuss a personalized treatment. Further studies are needed to confirm these results and to correlate this metabolic profile with survival data.

A metabolic database for biomedical studies of biopsy specimens by high-resolution magic angle spinning nuclear MR: a qualitative and quantitative tool.

PURPOSE: The aim of this study is to generate a metabolic database for biomedical studies of biopsy specimens by high-resolution magic angle spinning (HRMAS) nuclear MR (NMR). METHODS: Seventy-six metabolites, classically found in human biopsy samples, were prepared in aqueous solution at a known concentration and analyzed by HRMAS NMR. The spectra were recorded under the same conditions as the ones used for the analysis of biopsy specimens routinely performed in our hospital. RESULTS: For each metabolite, a complete set of NMR spectra (1D 1 H, 1D 1 H-CPMG, 2D J-Resolved, 2D TOCSY, and 2D 1 H-13 C HSQC) was recorded at 500 MHz and 277 K. All spectra were manually assigned using the information contained in the different spectra and existing databases. Experiments to measure the T1 and the T2 of the different protons present in the 76 metabolites were also recorded. CONCLUSION: This new HRMAS metabolic database is a useful tool for all scientists working on human biopsy specimens, particularly in the field of oncology. It will make the identification of metabolites in biopsy specimens faster and more reliable. Additionally, the knowledge of the T1 and T2 values will allow to obtain a more accurate quantification of the metabolites present in biopsy specimens.

Muscle fluorodeoxyglucose uptake assessed by positron emission tomography-computed tomography as a biomarker of inflammatory myopathies disease activity.

OBJECTIVE: To devise a simple PET-CT score for measurement of muscle disease activity in patients with inflammatory myopathies (IMs) and to assess its validity. METHODS: A total of 44 PET-CT examinations in 34 IM patients (performed during cancer screening) and 20 PET-CT examinations in matched controls (investigated for pulmonary nodules with a conclusion of benignity) were analysed. Maximal standardized uptake values (SUVmax) were recorded bilaterally in eight proximal muscles. The muscle SUVmax (mSUVmax) was defined as the average of the 16 muscle SUVmax values, normalized on the liver mean SUV. Reliability, validity and responsiveness were evaluated. RESULTS: The mSUVmax was increased in IM patients compared with controls. This index allowed the identification of patients with high vs low muscle disease activity using the myositis intention to treat activity index as the gold standard. In patients with subsequent examinations, our method showed good accuracy to detect changes in muscle disease activity [area under the curve 0.96 (95% CI 0.84, 1)]. Responsiveness was strong. Interrater reliability was excellent. CONCLUSION: PET-CT, a non-invasive tool useful for cancer screening, is also valuable to measure muscle disease activity and its evolution in IM patients.

An integrated genomic and metabolomic approach for defining survival time in adult oligodendrogliomas patients.

INTRODUCTION: The identification of frequent acquired mutations shows that patients with oligodendrogliomas have divergent biology with differing prognoses regardless of histological classification. A better understanding of molecular features as well as their metabolic pathways is essential. OBJECTIVES: The aim of this study was to examine the relationship between the tumor metabolome, six genomic aberrations (isocitrate dehydrogenase1 [IDH1] mutation, 1p/19q codeletion, tumor protein p53 [TP53] mutation, O6-methylguanin-DNA methyltransferase [MGMT] promoter methylation, epidermal growth factor receptor [EGFR] amplification, phosphate and tensin homolog [PTEN] methylation), and the patients' survival time. METHODS: We applied 1H high-resolution magic-angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy to 72 resected oligodendrogliomas. RESULTS: The presence of IDH1, TP53, 1p19q codeletion, MGMT promoter methylation reduced the relative risk of death, whereas PTEN methylation and EGFR amplification were associated with poor prognosis. Increased concentration of 2-hydroxyglutarate (2HG), N-acetyl-aspartate (NAA), myo-inositol and the glycerophosphocholine/phosphocholine (GPC/PC) ratio were good prognostic factors. Increasing the concentration of serine, glycine, glutamate and alanine led to an increased relative risk of death. CONCLUSION: HRMAS NMR spectroscopy provides accurate information on the metabolomics of oligodendrogliomas, making it possible to find new biomarkers indicative of survival. It enables rapid characterization of intact tissue and could be used as an intraoperative method.

Metabolomic characterization of human hippocampus from drug-resistant epilepsy with mesial temporal seizure.

OBJECTIVE: Within a complex systems biology perspective, we wished to assess whether hippocampi with established neuropathological features have distinct metabolome. Apparently normal hippocampi with no signs of sclerosis (noHS), were compared to hippocampal sclerosis (HS) type 1 (HS1) and/or type 2 (HS2). Hippocampus metabolome from patients with epilepsy-associated neuroepithelial tumors (EANTs), namely, gangliogliomas (GGs) and dysembryoplastic neuroepithelial tumors (DNTs), was also compared to noHS epileptiform tissue. METHODS: All patients underwent standardized temporal lobectomy. We applied 1 H high-resolution magic angle spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy to 48 resected human hippocampi. NMR spectra allowed quantification of 21 metabolites. Data were analyzed using multivariate analysis based on mutual information. RESULTS: Clear distinct metabolomic profiles were observed between all studied groups. Sixteen and 18 expected metabolite levels out of 21 were significantly different for HS1 and HS2, respectively, when compared to noHS. Distinct concentration variations for glutamine, glutamate, and N-acetylaspartate (NAA) were observed between HS1 and HS2. Hippocampi from GG and DNT patients showed 7 and 11 significant differences in metabolite concentrations when compared to the same group, respectively. GG and DNT had a clear distinct metabolomic profile, notably regarding choline compounds, glutamine, glutamate, aspartate, and taurine. Lactate and acetate underwent similar variations in both groups. SIGNIFICANCE: HRMAS NMR metabolomic analysis was able to disentangle metabolic profiles between HS, noHS, and epileptic hippocampi associated with EANT. HRMAS NMR metabolomic analysis may contribute to a better identification of abnormal biochemical processes and neuropathogenic combinations underlying mesial temporal lobe epilepsy.

Positional Brain Single-Photon Emission Computed Tomography Findings in a Case of Limb-Shaking Syndrome.

An 84-year-old man, who presented lower limbs limb-shaking syndrome at orthostatism lasting a few seconds, was referred in our stroke unit. Magnetic resonance imaging showed an acute infarction in the right thalamus and the insular cortex, left extracranial carotid stenosis at 80%, and low flow in the right middle cerebral artery but did not explain limb-shaking syndrome symptomatology. We performed comparative positional brain perfusion single-photon emission computed tomography (SPECT), in the upright and in the supine position, to explore and localize hypoperfusion-endangered brain structures that may be involved in the presenting symptoms. Brain perfusion SPECT showed deep hypoperfusion in bilateral carotid territories in the upright position in favor of a hemodynamic mechanism, on which blood pressure was maintained higher to avoid hypoperfusion and the patient remained supine for a longer period of time than in the usual support. Late postoperative brain perfusion SPECT after left endarterectomy did not show significant abnormalities. Limb-shaking syndrome may be related to a transient decrease in blood pressure and cerebral blood flow caused by postural changes. Positional brain perfusion SPECT seems to be helpful to improve clinical care. Positional brain perfusion SPECT should be discussed in the acute phase of stroke and if there are involuntary movements.

A Hangover Under 177 Lu-PSMA-617 Therapy : A Red Flag for Brain 68 Ga-PSMA-11 PET/MRI?

ABSTRACT: Leptomeningeal carcinomatosis in prostate cancer is extremely rare. Because of the low overall penetration of drugs into the brain and the prolonged survival of castration-resistant prostate cancer (CRPC) patients, a special attention should be paid to the appearance of neurological symptoms in long-term CRPC survivors. A patient suffering from a CRPC with bone metastases underwent 4 cycles of 177 Lu-PSMA (prostate-specific membrane antigen)-617. Starting from the third cycle, he reported an increasing feeling of a permanent hangover. A 68 Ga-PSMA-11 brain PET/MRI was carried out after the fourth cycle. It revealed intraparenchymatous brain metastases with intense uptake and evidences of leptomeningeal carcinomatosis.

18FDG PET/CT Tumoral and Neurologic Therapeutic Response in a Case of Anti-GABABR Paraneoplastic Limbic Encephalitis.

ABSTRACT: A 70-year-old man with a history of small cell lung carcinoma 2 years earlier was addressed for the suspicion of a paraneoplastic limbic encephalitis. Brain 18FDG PET/CT revealed a bilateral amygdalian and hippocampal hypermetabolism, confirming a limbic encephalitis, and concurrent whole-body 18FDG PET/CT showed a small cell lung carcinoma plurifocal metastatic recurrence, consistent with a paraneoplastic limbic encephalitis. 18FDG PET/CT follow-up under chemotherapy revealed an almost complete normalization of brain metabolism and a partial metabolic response of the metastatic recurrence, consistent with the good clinical neurological evolution of the patient. This case highlights the clinical-metabolic imaging correlation in paraneoplastic limbic encephalitis.

68Ga-DOTATOC PET in Extracranial Hepatic and Bone Metastasis of Atypical Refractory Meningioma: A Case Report.

ABSTRACT: A falcine meningioma was diagnosed in a 66-year-old woman and was treated by surgery and 2 times by radiotherapy during 9 years of follow-up with the diagnosis of atypical meningioma. Three months after the last radiotherapy, incidental liver lesions were detected on chest CT realized for suspected pneumonia. In view of the predisposing factors for meningioma metastases, 68Ga-DOTATOC hepatic and cerebral PET/MRI was performed and completed by total body PET/CT demonstrating a somatostatin receptor 2 overexpression of the multiple liver lesions and several bone lesions. Biopsies from the liver and iliac bone confirmed the metastatic origin of meningioma.

Sequential Brain Perfusion Findings in a Case of Osmotic Demyelination Syndrome.

ABSTRACT: A 60-year-old man with chronic alcoholism for 30 years was admitted to the hospital for an acute alcoholic syndrome with global confusional state, cognitive disorders, and ataxia. MRI detected bilateral mamillary bodies T 2 hypersignal related to Wernicke encephalopathy. It was treated by oral thiamine supplementation with clinical improvement. Two months later, he was rehospitalized for rapidly progressive dementia symptoms. Brain perfusion scintigraphy revealed pontine hyperperfusion and right hippocampal hypoperfusion. One month after IV thiamine supplementation, brain perfusion scintigraphy showed normalization of perfusion abnormalities in the pons and right hippocampus, leading to the diagnosis of alcoholic-related osmotic demyelination syndrome.

18 F-FDOPA and MRI Findings in a Case of Multiple Sclerosis.

ABSTRACT: A 39-year-old woman with no significant medical history underwent a brain MRI because of headaches and dysarthria having lasted 3 weeks. A tumor lesion was suspected. PET imaging was decided. She underwent FDG and FDOPA PET, leading to the diagnosis of low-grade glioma. Three months later, a new imaging assessment was organized. It showed a decrease in the hypermetabolism of the lesion and the appearance of a second lesion questioning the diagnosis. Further assessment led to the conclusion of a multiple sclerosis. This case illustrates that FDOPA PET uptake should be interpreted with caution in patients with suspected primary brain tumors.

Progression of Nigrostriatal Denervation in Cerebellar Multiple System Atrophy: A Prospective Study.

OBJECTIVES: Nigrostriatal dopaminergic denervation (NSDD) remains poorly characterized in cerebellar multiple system atrophy (MSA-C). We aimed to study NSDD progression in MSA-C and evaluate the capacity for [123I]-FP-CIT-SPECT and parkinsonism to differentiate MSA-C from idiopathic late-onset cerebellar ataxia (ILOCA). METHODS: We included 85 patients successively referred for sporadic late-onset cerebellar ataxia (SLOCA). Every 6 months, SARA, UPDRS-III, and SDFS scores were measured, and MSA-C diagnostic criteria were searched for. Striatal/occipital dopaminergic binding ratio was evaluated every year with [123I]-FP-CIT-scintigraphy. RESULTS: After a mean follow-up of 33.8 months, 33 patients had probable MSA-C, 8 possible MSA-C, and 44 ILOCA. SARA and UPDRS-III scores worsened faster in the probable MSA-C group (p < 0.01) compared with the ILOCA group. The baseline striatal/occipital ratio was lower (2.3 vs 2.97; p < 0.01) and more decreasing among patients with probable MSA-C (p < 0.01). Weighting dysautonomia and parkinsonism and/or NSDD as additional and principal criterion, respectively, in the possible MSA-C diagnostic criteria slightly improved their specificity (81.6% vs 76.9%) and sensitivity (77.8% vs 72.2%) to predict a final diagnosis of probable MSA-C. DISCUSSION: Rapid symptom worsening and NSDD existence and progression predict MSA-C among patients with SLOCA. Parkinsonism, NSDD, and dysautonomia should be considered equivalent for possible MSA-C diagnosis.

Evolution of Neuroimaging Findings in Severe COVID-19 Patients with Initial Neurological Impairment: An Observational Study.

BACKGROUND AND OBJECTIVES: Cerebral complications related to the COVID-19 were documented by brain MRIs during the acute phase. The purpose of the present study was to describe the evolution of these neuroimaging findings (MRI and FDG-PET/CT) and describe the neurocognitive outcomes of these patients. METHODS: During the first wave of the COVID-19 outbreak between 1 March and 31 May 2020, 112 consecutive COVID-19 patients with neurologic manifestations underwent a brain MRI at Strasbourg University hospitals. After recovery, during follow-up, of these 112 patients, 31 (initially hospitalized in intensive care units) underwent additional imaging studies (at least one brain MRI). RESULTS: Twenty-three men (74%) and eight women (26%) with a mean age of 61 years (range: 18-79) were included. Leptomeningeal enhancement, diffuse brain microhemorrhages, acute ischemic strokes, suspicion of cerebral vasculitis, and acute inflammatory demyelinating lesions were described on the initial brain MRIs. During follow-up, the evolution of the leptomeningeal enhancement was discordant, and the cerebral microhemorrhages were stable. We observed normalization of the vessel walls in all patients suspected of cerebral vasculitis. Four patients (13%) demonstrated new complications during follow-up (ischemic strokes, hypoglossal neuritis, marked increase in the white matter FLAIR hyperintensities with presumed vascular origin, and one suspected case of cerebral vasculitis). Concerning the grey matter volumetry, we observed a loss of volume of 3.2% during an average period of approximately five months. During follow-up, the more frequent FDG-PET/CT findings were hypometabolism in temporal and insular regions. CONCLUSION: A minority of initially severe COVID-19 patients demonstrated new complications on their brain MRIs during follow-up after recovery.

Inferior Colliculus's Hypermetabolism: A New Finding on Brain FDG PET and Perfusion MRI in a Patient With COVID-19.

ABSTRACT: We present the case of a 64-year-old man presenting an episode of confusion during SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection with a positive oropharyngeal swab polymerase chain reaction test. He was hospitalized for dyspnea related to pneumonia demonstrated on chest CT. FDG PET performed after the confusion phase, but still in the COVID-19 (coronavirus disease 2019)-positive phase, showed high glucose metabolism of the inferior colliculi. Morphological MRI was normal. The first-pass perfusion MRI shows hyperperfusion of the inferior colliculi, corresponding to FDG PET hypermetabolism.

Three Different FDG Patterns in Periventricular Nodular Heterotopia Correlated to Video Stereoelectroencephalography.

ABSTRACT: A 40-year-old woman with a drug-resistant focal epilepsy underwent cerebral FDG PET in phase 1 presurgical epilepsy study. MRI essentially showed multiple periventricular nodular heterotopias. The stereoelectroencephalography coupled to MRI and FDG PET helped to define the anatomofunctional correlation of the epileptogenic zone network. This procedure brought to light 3 distinct patterns of FDG consumption, corresponding to different anatomoelectroclinical features. This pattern was already found in a previous FDG PET reflecting a "stable" permanent intralesional intercritical stereoelectroencephalography activity, an electrical "signature" of the lesion. Finally, functional imaging improved thermocoagulation in this patient and emphasized the use of FDG in drug-resistant epilepsy.