By Reha Tolun
The history of diagnostic neuroradiology begins with the invention of x-ray and its application as craniography in the very early 20th century. A famous neurosurgeon, Dandy, was the first to perform pneumoencephalography in 1918. Drainage of spinal fluid and injection of the same amount of air in about a total of 50ml of volume was performed through lumbar puncture in a patient in the sitting position and craniograms were obtained that showed the ventricular system and subarachnoid spaces with this technique. A version of this technique is the ventriculogram where contrast material, either air or iodinated contrast material was injected through a cannula inserted in one of the lateral ventricles. In 1923 Siccard introduced myelography through the lumbar route. Egas Moniz, a neurologist from Portugal, was the first to perform cerebral angiography in 1927 by injecting iodinated contrast material into the surgically exposed cervical carotid arteries. One of the first six patients died due to the toxic effects of the iodinated contrast agents. The technique was abandoned for a few years and then restarted as less toxic iodinated contrast materials were developed. Diagnostic angiography gained more importance after Seldinger technique was developed in 1952 that enabled catheterization of both carotid and vertebral arteries by a single puncture of one femoral artery. As years passed less toxic iodinated contrast agents, less traumatic and thinner catheterization materials and better x-ray equipments were developed. All these techniques showed brain or spinal cord indirectly through filling the ventricles, subarachnoid spaces or vessels by contrast materials. As can be observed from the above information the pioneers of neuroradiology in the world were mainly neurologists and neurosurgeons.
Then came the era of visualizing neural or other soft tissues directly by the invention of computed tomography (CT) in 1972 by an English electronic engineer, Godfrey Hounsfield. This revolutionary radiologic invention was followed by magnetic resonance imaging (MRI) developed by Lauterburg and Damadian in the early 1980s. MRI can roughly be defined as a more sophisticated and refined form of CT. Interest of radiologists for neuroradiologic examinations grew after invention of “remote systems” such as CT and MRI.
In late 1950s and early 1960s a few neurosurgeons and neurologists in Turkey began performing pneumoencephalograpy, ventriculography, myelography or direct puncture carotid angiography.
The first modern neuroradiologist who began performing catheter-based 4 vessel angiography was Dr.Gençay Gürsoy from Istanbul University who was trained by a famous European neuroradiologist Amundsen from Norway. Dr.Gürsoy was trained in Norway through 1968-1970 and through 1972-1974. In the same years Dr.Okay Sarıbaş and Dr.Mesude Duyguner from Hacettepe University in Ankara were the other pioneers of modern neuroradiology in Turkey. After Dr.Gürsoy left for Norway for the second time Dr.Reha Tolun from the same Neurology Department of Istanbul University Istanbul Medical Faculty began performing neuroradiologic examinations. Dr.Tolun was trained by Dr.Jean Jacques Merland in Paris University Hospital Lariboisiére between 1979-1980 in spinal and therapeutic angiography. Dr.Tolun was the pioneer of therapeutic neuroangiography in Turkey. Dr.Tolun and his neurologist colleagues Dr.Sara Bahar, Dr.Halil Atilla İdrisoğlu, Dr.Rezzan Tunçay and Dr.Oğuzhan Çoban ran the Diagnostic and Therapeutic Neuroradiology Section of Neurology Department of Istanbul Medical Faculty for more than a decade. This section was a referance center in Turkey throughout 1980s. Dr.Gürsoy rejoined the department in 1989 after 7 years of exile from political reasons. Another neurologist Dr.Gazi Özdemir and his neurology colleagues from Osmangazi Univesity in Eskişehir were routinely performing neuroangiography for more than 2 decades.
A radiologist from Istanbul University Cerrahpaşa Medical Faculty, Dr.Cıvan Işlak, after being trained in therapeutic neuroangiography in France, was the pioneer of interventional neuroradiology as a radiologist and began his hometown practice in early 1990s in Istanbul.
In 1989 a Department of Neuroradiology was founded at the Istanbul Medical Faculty and Dr.Reha Tolun from the Neurology and Dr.Cahit Babuna from the Radiology departments were assigned as faculty. This department was abolished by the Higher Interuniversity Council (YÖK), and Neuroradiology was tied to the Radiology Department of Istanbul Medical Faculty as a section. The old equipments in the Neurology’s Neuroradiology section finally collapsed and the new equipments were installed in the Radiology Department where Dr.Özenç Minareci from Radiology Department began heading the Neuroradiology Section. As can be seen neuroradiology was taken over by radiologists in Turkey and also in the world.
Surprisingly some neurologists, after completing certain endovascular neurosurgery fellowship programs began practicing interventional neurology (therapeutical neuroangiography) in the early 2000s. The Turkish Society of Neurology founded in 2009 “The Working Group of Neuroradiology” and Dr.Tolun was assigned as moderator.The group’s name was changed to “The Working Group of Interventional Neurology” in 2011.
In the early 2000s Dr.Gomez and Dr.Adnan Qureshi from the USA were the pioneers of interventional neurology. Now there are about 100 interventional neurologists in the USA. Together with even more endovascular neurosurgeons most of the interventional neuroradiologic procedures are now performed by physicians from neuroscience origin in the USA.
Dr.Adnan Qureshi attended the 45. National Congress of Neurology in 2009 at Antalya as invited speaker of the Working Group of Neuradiology. Dr Qureshi invited Dr.Tolun as invited speaker to the First International Congress of Interventional Neurology held in 2011 at Minneapolis, and then to the two successive yearly congresses.
Dr. Özcan Özdemir from Eskişehir, Dr.Semih Giray from Adana and Dr.Erdem Gürkaş from Ankara have been practicing interventional neurology since 2010 in their departments of neuroangiography. Dr.Yakup Krespi joined Dr. Reha Tolun as a interventional neurologists. The number of interventional neurologists nowadays in Turkey has reached 10 with other young neurologists that joined the above mentioned centers.
As for interventional neurology in the other European countries there are probably very few interventional neurologists, the number maybe reaching 10, in some countries like Spain, France and Poland.
There are probably even fewer neurosurgeons in Europe practicing endovascular neurosurgery.
It seems reasonable to us that similar to cardiologist who medically take care of their patients and also perform their interventional cardiac procedures neurologists and neurosurgeons should perform neurointerventinal procedures of their patients.
We believe that the number of endovascular neurointerventionists, either from neurology or neurosurgery origins, will rise in the near future in Europe.
Dr. Reha Tolun is presently working at the Istanbul Memorial Hospital, and is heading the “Acute Ischemic Stroke Treatment Unit”.
