Characteristics and Surgical Outcomes of Patients With Refractory Magnetic Resonance Imaging–Negative Epilepsies

Bien, Christian G.; Szinay, Miriam; Wagner, Jan; Clusmann, Hans; Becker, Albert; Urbach, Horst

doi:10.1001/archneurol.2009.283

Cited by 206 publications

(185 citation statements)

References 23 publications

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“…[5][6][7][8] Despite substantial efforts, the lack of a lesion on MRI has consistently been shown to be one of the predictors for surgical failure. 9,10 Therefore, MRI-negative patients are usually considered unfavorable surgical candidates 4 and are often denied epilepsy surgery. Yet, surgical resection can be effective in well-selected patients with no visible MRI abnormality.…”

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confidence: 99%

The pathology of magnetic-resonance-imaging-negative epilepsy

et al. 2013

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Patients with magnetic-resonance-imaging (MRI)-negative (or 'nonlesional') pharmacoresistant focal epilepsy are the most challenging group undergoing presurgical evaluation. Few large-scale studies have systematically reviewed the pathological substrates underlying MRI-negative epilepsies. In the current study, histopathological specimens were retrospectively reviewed from MRI-negative epilepsy patients (n ¼ 95, mean age ¼ 30 years, 50% female subjects). Focal cortical dysplasia cases were classified according to the International League Against Epilepsy (ILAE) and Palmini et al classifications. The most common pathologies found in this MRI-negative cohort included: focal cortical dysplasia (n ¼ 43, 45%), gliosis (n ¼ 21, 22%), hamartia þ gliosis (n ¼ 12, 13%), and hippocampal sclerosis (n ¼ 9, 9%). The majority of focal cortical dysplasia were ILAE type I (n ¼ 37) or Palmini type I (n ¼ 39). Seven patients had no identifiable pathological abnormalities. The existence of positive pathology was not significantly associated with age or temporal/extratemporal resection. Follow-up data post surgery was available in 90 patients; 63 (70%) and 57 (63%) attained seizure freedom at 6 and 12 months, respectively. The finding of positive pathology was significantly associated with seizure-free outcome at 6 months (P ¼ 0.035), but not at 12 months. In subgroup analysis, the focal cortical dysplasia group was not significantly correlated with seizure-free outcome, as compared with the negative-pathology groups at either 6 or 12 months. Of note, the finding of hippocampal sclerosis had a significant positive correlation with seizurefree outcome when compared with the negative-pathology group (P ¼ 0.009 and 0.004 for 6-and 12-month outcome, respectively). Absence of a significant histopathology in the resected surgical specimen did not preclude seizure freedom. In conclusion, our study highlights the heterogeneity of epileptic pathologies in MRInegative epilepsies, with focal cortical dysplasia being the most common finding. The existence of positive pathology in surgical specimen may be a good indication for short-term good seizure outcome. There is a small subset of cases in which no pathological abnormalities are identified.

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confidence: 99%

The pathology of magnetic-resonance-imaging-negative epilepsy

et al. 2013

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“…In addition, various neuro-radiological imaging techniques are employed to further identify the structural or functional epileptogenic lesion(s). Multiple studies have shown that the prognosis of epilepsy surgery varies depending on the etiology and location of the epileptogenic zone [43][44][45][46][47][48][49][50][51][60][61][62][63][64]. Radiographically identifiable epileptogenic lesions provide information about the etiology and localization of epilepsy, and can provide prognostic information for focal respective epilepsy surgery.…”

Section: Non-pharmacological Treatmentmentioning

confidence: 99%

“…Radiographically identifiable epileptogenic lesions provide information about the etiology and localization of epilepsy, and can provide prognostic information for focal respective epilepsy surgery. Identifying a structural lesion on MRI provides an excellent prognosis from epilepsy surgery, with 60-90% freedom from disabling seizures [43][44][45][46][47][48][49][50][51][60][61][62][63][64]. Temporal lobe epilepsy is the most common type of epilepsy, and mesial temporal sclerosis (MTS) is the most common temporal lobe epilepsy [65].…”

Section: Non-pharmacological Treatmentmentioning

confidence: 99%

Review of Epilepsy - Etiology, Diagnostic Evaluation and Treatment

Shin¹,

Jewells²,

Hadar³

et al. 2014

Int J Neurorehabilitation Eng

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Epilepsy is the fourth most common neurological disorder in the US, affecting nearly 2.5 million Americans. The economic impact of epilepsy represents estimated direct and indirect costs of 12.5 billion dollars per year. Patients with this disorder experience increased morbidity and mortality with long term fatality rates of 24%. Multiple diagnostic tools are used to identify and classify the seizure type/syndrome, etiology and localization of seizures, including electroencephalogram (EEG), magnetic resonance imaging (MRI), positron emission tomography (PET), and single photon emission computed tomography (SPECT), magneto encephalogram (MEG), and neuropsychiatric testing. Despite 29 different antiepileptic medications that are available in the US, one third of patients remain refractory to pharmacological treatment. In these intractable epilepsy patients, non-pharmacological treatments can be considered. Commonly used non-pharmacological treatment options for epilepsy include epilepsy surgery, neurostimulation therapy, and diet therapy. Review of Epilepsy -Etiology, Diagnostic Evaluation and Treatment

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“…It is increasingly recognized that in many NLNE cases, an EZ with underlying focal cortical dysplasia (FCD) may be missed by routine MRI [17,18]. Since nonlesional epilepsy is associated with a poor surgical outcome compared to lesional epilepsy, the use of multimodal imaging for localization of lesions not seen on MRI is essential to identify candidates for epilepsy surgery who are refractory to AED therapy.…”

Section: Introductionmentioning

confidence: 99%