Diagnosis of Epilepsy: from the Beginning to the New Hybrid PET/MR Technique

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Abstract

The problem of diagnosis and treatment of epilepsy concerns medical society for a several thousands of years. The understanding of the causes and pathological mechanisms of this condition underwent numerous and substantial changes during this time, that allowed reaching significant advances in both the diagnosis or treatment. At the present time, there is a wide spectrum of diagnostic methods that allow localizing the epileptogenic focus, that is essential for planning the surgical treatment in patients with pharmacoresistant epilepsy. The results of the surgical treatment are strongly dependent on the diagnostic accuracy in the detection of one or several epileptogenic foci and on the prognosis of their resection. In this connection, the research on the possibilities and perfection of new diagnostic methods hold the potential to improve the results of the surgical treatment and the life quality in patients with pharmacoresistant epilepsy. This review presents a detailed description of the evolution of epilepsy diagnostics from the first implementation of electroencephalography in the 1920-s to the modern hybrid methods such as SISCOM (Subtraction Ictal SPECT Co-Registered to MRI) and PET-MRI.

About the authors

Igor A. Znamenskiy

Federal Center of Brain Research and Neurotechnologies; The Russian National Research Medical University named after N.I. Pirogov; Scientific and Clinical Center No. 2 of the Petrovsky National Research Centre of Surgery

Email: znamenskiy@fccps.ru
ORCID iD: 0000-0003-0305-6723
SPIN-code: 9835-8594

MD, PhD, Dr. Sci. (Med.), Professor

Russian Federation, Moscow; Moscow; Moscow

Mikhail B. Dolgushin

Federal Center of Brain Research and Neurotechnologies

Email: dolgushin.m@fccps.ru
ORCID iD: 0000-0003-3930-5998
SPIN-code: 6388-9644

MD, PhD, Dr. Sci. (Med.), Professor of the Russian Academy of Sciences

Réunion, Moscow

Anastasiya A. Yurchenko

The Russian National Research Medical University named after N.I. Pirogov

Email: a_a_yurchenko@list.ru
Russian Federation, Moscow

Tatiana M. Rostovtseva

Federal Center of Brain Research and Neurotechnologies

Author for correspondence.
Email: rostovtsevat@mail.ru
ORCID iD: 0000-0001-6541-179X
SPIN-code: 5840-7590
Russian Federation, Moscow

Mariya A. Karalkina

Federal Center of Brain Research and Neurotechnologies

Email: karalkina.m@fccps.ru
ORCID iD: 0000-0002-9267-3602
SPIN-code: 9812-0420

MD, PhD

Russian Federation, Moscow

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2. Fig. 3. A fused SISCOM image (SPECT of the brain performed during a complex partial seizure combined with MRI of the brain) demonstrating hyperperfusion in the basal ganglia and insula of the left hemisphere (courtesy of FSBI «FCMN» FMBA of Russia).

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3. Fig. 1. Ionic currents during the action potential. The cytoplasmic concentration of К+ ions significantly exceeds their extracellular concentration, in contrast to the concentration of Na+ and Ca+. During the propagation of the action potential, Na+ and Ca+ — channels and later К+ channels are opening, that provides a concentration gradient for ions to flow.

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4. Fig. 2. Mechanism for the decrease of the К+ ions’ concentration in the extracellular matrix. The decrease of the К+ ions’ concentration in the extracellular matrix generally results from the effect of 3Na+/2K+ adenosine triphosphatase and inward rectifying potassium channels Kir. Functioning of adenosine triphosphatase requires the presence of adenosine triphosphate in the cytoplasm, whereas the increase of the adenosine triphosphate concentration leads to the decrease of the Kir channels’ activity.

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5. Fig. 4. Combined positron emission tomography combined and fLAIR images obtained in the axial (а) and coronal (б) planes. Significant reduction of the 18F-FDG uptake is noted in the right hippocampus head and corpus (courtesy of FSBI «FCMN» FMBA of Russia).

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