Ayub K. Ommaya
Encyclopedia
Ayub Khan Ommaya, MD, ScD (h.c.), FRCS, FACS (April 14, 1930, Mian Channu - July 11, 2008, Islamabad) was a Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

i neurosurgeon and the inventor of the Ommaya reservoir
Ommaya reservoir
An Ommaya reservoir is an intraventricular catheter system that can be used for the aspiration of cerebrospinal fluid or for the delivery of drugs into the cerebrospinal fluid. It consists of a catheter in one lateral ventricle attached to a reservoir implanted under the scalp...

. The reservoir is used to provide chemotherapy
Chemotherapy
Chemotherapy is the treatment of cancer with an antineoplastic drug or with a combination of such drugs into a standardized treatment regimen....

 directly to the tumor site for brain tumors. Ommaya was also a leading expert in traumatic brain injuries.

Professional history

Dr. Ommaya received his M.D. from King Edward Medical College in Pakistan
Pakistan
Pakistan , officially the Islamic Republic of Pakistan is a sovereign state in South Asia. It has a coastline along the Arabian Sea and the Gulf of Oman in the south and is bordered by Afghanistan and Iran in the west, India in the east and China in the far northeast. In the north, Tajikistan...

 in 1953 and completed his graduate work in Physiology, Psychology, and Biochemistry at the University of Oxford (Balliol College) as a Rhodes Scholar (M.A.) in 1956. Dr. Ommaya received his honorary Doctor of Science degree from Tulane University, School of Engineering Sciences in 1981.

From 1960 to 1980, he joined the staff of the National Institute of Health and became Chief of Neurosurgery, studying treatment of malignant neoplasms, the biomechanics and mechanisms of brain injury, and memory. He has also served as Chief Medical Advisor to the U.S. Department of Transportation (National Highway Traffic Safety Administration
National Highway Traffic Safety Administration
The National Highway Traffic Safety Administration is an agency of the Executive Branch of the U.S. government, part of the Department of Transportation...

) from 1980 until 1985. He was a clinical professor at George Washington University from 1980 until 2003.

He had patents in devices for drug delivery to the brain, protective systems for neck and head injuries and an artificial organ for treatment of diabetes.

He was Hunterian Professor of the Royal College of Surgeons of England
Royal College of Surgeons of England
The Royal College of Surgeons of England is an independent professional body and registered charity committed to promoting and advancing the highest standards of surgical care for patients, regulating surgery, including dentistry, in England and Wales...

.

Dr. Ommaya published over 150 articles, chapters, and books. His research focused on cancer treatment, traumatic brain injury, a CSF artificial organ, and philosophy of mind. Through discussions with Cong. William Lehman
William Lehman (Florida politician)
William H. Lehman was a United States Representative from Florida.Born in Selma, Alabama, he graduated from Dallas Academy and Selma High School, 1930. He received a B.S...

 Chair of the House Appropriations Committee responsible for the Department of Transportation, he developed CDC's National Center for Injury Prevention and Control
National Center for Injury Prevention and Control
CDC's National Center for Injury Prevention and ControlThe U.S. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control's mission is to provide leadership in preventing and controlling injuries, i.e., reducing the incidence, severity, and adverse outcomes of...

, which as part of its mission focuses on traumatic brain injury
Traumatic brain injury
Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...

. As part of this effort Ommaya commissioned the IOM report Injury in America. The report called for the creation of the CDC center. Dr. Ommaya was consistently ranked as a leading neurosurgeon and often was called in to perform difficult cases.

Dr. Ommaya’s research provided the experimental data needed to model traumatic brain injury. His Centripetal theory was foundational to the biomechanics of traumatic brain injury. This work allowed for improved modeling of brain injury by engineers in their design of safety equipment in automobiles. His sustained interest in traumatic injury also lead to the creation of the National Center for Injury Prevention and Control through his friendship with Congressman Lehman, then chair of the House Appropriations Subcommittee on Transportation.

Dr. Ommaya also did early work with the Computed Tomography Scanner. His work with Sir Godfrey Hounsfield to determine the spatial resolution of the CT scanner opened the door for its use in stereotactic surgery. Spinal angiography was also pioneered by Ommaya, Di Chiro, and Doppman. This work allowed for the visualization of arteries and veins and allowed for understanding of spinal cord arteriography. The same team reported the treatment of spinal cord AVMs by percutaneous embolization of an intercostal artery using stainless steel pellets. This was one of the first reports of interventional neuroradiology. Dr. Ommaya made several significant contributions to many areas that concern Neurological surgeons, treatment of cancer, hydrocephalus, traumatic brain injury, and Arterio-Venous Malformations.

Early life

Dr. Ayub K. Ommaya, the youngest son of four children, was born on April 14, 1930 in Mian Channu
Mian Channu
Mian Channu is a city in Punjab province, Pakistan .In the year 1919, it was declared as a notified area Committee and in 1938 as a Town Committee. Its limits were last extended in the year 1950. Since then no extension has been made and the development in the Town from 1947 to 1961 remained slow...

, British India (now Pakistan). His father Nadir Khan was a Jemadar in the British Indian Calvary (Bengal Lancers) and his mother Ida was a housewife. Ayub’s father fought in France during World War I, and was determined to find a wife there. He met Ayub’s mother in Eu, France in 1922. Ayub’s father died when he was 13, his oldest brother Jan joined the Army to help support the family and eventually rose to the rank of Brigadier General. Finances were a challenge to the family after Ayub’s father died.

Dr. Ommaya completed his premedical studies at Gordon College, Rawalpindi
Rawalpindi
Rawalpindi , locally known as Pindi, is a city in the Pothohar region of Pakistan near Pakistan's capital city of Islamabad, in the province of Punjab. Rawalpindi is the fourth largest city in Pakistan after Karachi, Lahore and Faisalabad...

, Pakistan, and his medical studies at King Edward Medical College in Lahore. While at medical school he received the Harper-Nelson Gold Medal for outstanding academic achievement. In addition to his medical studies, Dr. Ommaya found time to establish himself as a champion debater, boxer, and swimmer. Dr. Ommaya won a regional swimming competition and then won the national competition in 1953. He also developed a remarkable tenor voice, and briefly studied opera in Venice, Italy, prior to taking a Rhodes scholarship at Balliol College, Oxford. During his stay at Oxford in addition to a developing interest in mechanisms of brain injury he won the James Willis Kirkaldy Oxford University Prize in 1956. He was also awarded the Hunterian Professorship at the Royal College of Surgeons in 1964.

Neurosurgical career

Dr. Ommaya completed his neurosurgical training under Dr. Joseph Pennybacker at Nuffield College of Surgical Sciences in London and at the Radcliffe Infirmary in Oxford. After his neurosurgical training, Dr. Ommaya came to America and began working as a researcher and clinician at the Surgical Neurology Branch of the NIH. His good friend Dr. Baruch Blumberg, who later received the Nobel Prize, arranged for his invitation to NIH. He also was a clinical professor at George Washington University.

Dr. Ommaya was well known for his surgical skill and in 1977 he completed a difficult removal of a spinal Arterio-Venous Malformation (AVM) which received attention in the lay press.8 During the 18 hour operation the patient was placed in total body hypothermia and total circulatory arrest for 45 minutes. The hypothermia was needed to slow metabolism and protect the brain and organs from reduced oxygen supply while Dr. Ommaya surgically embolized and removed an AVM which was located near the medulla. Dr. Ommaya was the honorary physician to the President of Pakistan and he received Pakistan’s highest civilian award the Star of Achievement. Dr. Ommaya was a man of diverse talents and also appeared with Peter Ustinov, Nick Nolte, and Susan Sarandon in the movie Lorenzo's Oil released in 1992.

Many Firsts

Dr. Ommaya's invention, the Ommaya reservoir, was the first subcutaneous reservoir that allowed for repeated intrathecal injections.13, 7 Before his invention patients had to suffer repeated lumbar punctures for intrathecal drug administration. Spinal angiography was pioneered by Ommaya, Di Chiro, and Doppman. This work allowed for the visualization of arteries and veins and allowed for understanding of spinal cord arteriography. The same team reported the treatment of spinal cord AVMs by percutaneous embolization of an intercostal artery using stainless steel pellets. This was one of the first reports of interventional neuroradiology.9

Dr. Ommaya's models and work in traumatic injury were foundational to the biomechanics of traumatic brain injury. 20, 21, 23, 24, 25, 26, 27 This work allowed for improved modeling of brain injury by engineers in their design of safety equipment in automobiles. Dr. Ommaya also published the first coma score for classification of traumatic brain injury. 17 The most widely used contemporary classification systems follow the Ommaya approach. 10 Dr. Ommaya's friendship with Congressman Lehman, then chair of the House Appropriations Subcommittee on Transportation, lead to the creation of the National Center for Injury Prevention and Control.32 Each of these efforts involved collaborators who were vital to their successful conclusion.

Dr. Ommaya worked with Sir Godfrey Hounsfield to determine the spatial resolution of the CT scanner which opened the door for its use in stereotactic surgery.15, 28 Ayub also invented the first spinal fluid driven artificial organ.17

Interventional Neuroradiology

The work of Di Chiro, Doppman, and Ommaya, and was critical to the development of spinal angiography. 4,5 The visualization of arteries and veins allowed for understanding of the pathophysiology of spinal AVMs in addition to classification of lesions. Di Chiro, Ommaya, and Doppman also reported one of the earliest interventional radiology approaches using stainless steel pellets to treat a spinal cord AVM. 6 This percutaneous embolization approach was noted as less traumatic than surgical treatment by the authors and represented another step forward in pecutaneous vascular embolization as an addition the surgical armamentarium for treating certain vascular disorders of the central nervous system.

CSF Rhinorrhea

Before Ommaya’s work, CSF rhinorrhea was classified as either traumatic or spontaneous. The second category was essentially a catchall category which did not assist in guiding treatment approaches.14,18 Ommaya classified non traumatic rhinorrhea as resulting from either high pressure leaks (tumors & hydrocephalus) or "normal" leaks (congenital abnormalities, focal atrophy, oysteomyelitis). Nontraumatic rhinorrhea is a challenge in diagnosis and choice of surgical approach. Of importance to successful surgical outcome is the demonstration of fistula. Within the non traumatic category, CSF rhinorrhea occurring with primary empty sella (PES) was first reported by Ommaya.31

Biomechanics of Traumatic Brain Injury

Ommaya’s cetripedal theory identified that the effects always begin at the surface of the brain in mild injury and extend inward to affect the diencephalic- mesencephalic core in more severe injury.20 His work showed that both translational and rotational acceleration produce focal lesions but that only rotational acceleration produced diffuse axonal injury. When damage is found in the rostral brainstem it is also associated with diffuse hemispheric damage. Prior to his work it was believed that the mechanism of consciousness was linked to primary brainstem injury. However, the brainstem and mesencephalon are the last structure to be affected in severe injury, and rotational rather than translational forces produce concussion. Contact phenomenon contribute to the development of focal lesions, e.g. frontal and temporal lesions due to contact with the sphenoid bone.18 Magnetic resonance imaging (MRI) studies have supported these theories. 11, 12 They have confirmed that the distribution of lesions follows a centripetal pattern that follows injury severity identified by the Glascow Coma Score.

Ommaya Reservoir

Dr. Ayub Ommaya first reported the Ommaya reservoir in 1963 (figure 2). The reservoir is subcutaneous implant for repeated intrathecal injections, to treat hydrocephalus and malignant tumors. 13, 16 The reservoir was the first medical port to use silicone which is biologically inert and self sealing. The Ommaya reservoir allows delivery of intermittent bolus injections for chemotherapy to the tumor bed. Agents are injected percutaneously into the reservoir and delivered to the tumor by compression of the reservoir. The Ommaya reservoir provided a great improvement for treatment which reduces the risk of infection.

Creation of the National Center for Injury Prevention and Control

While the Chief Medical Advisor for the Department of Transportation in the 1980s, Dr. Ommaya commissioned a report, Injury in America, from the Institute of Medicine (IOM) in 1985.3 This report and efforts by Congressman William Lehman and Dr. Ommaya lead to the creation of the Center for Disease Control's, National Center for Injury Prevention and Control which began to provide synthesis, direction, and funding for the field. Congressman William Lehman and Dr. Ommaya became friends when he cared for his daughter. They had many discussions focusing on the need for a center that emphasized injury prevention and research. Congressman Lehman, then chair of the House Appropriations Subcommittee on Transportation, was responsible for the initial $10 million awarded to the CDC to establish a new Center for Injury Control. 2 The FY 2008 budget for the center is $134 Million, and it funds basic and applied injury research. Ayub served on the National Advisory Committee for the Center for 15 years.

Spinal Fluid Driven Artificial Organ

Dr. Ommaya has two children who suffer from Type 1 diabetes. Motivated by his personal experience with the disease, Dr. Ommaya focused on the problem of transplantation of islet cells for the treatment of diabetes. A major challenge facing survival of islet cells is immune rejection. Dr. Ommaya thought that the CSF would provided an ideal setting for transplanted islets due to the immune protection provided by the blood brain barrier. He developed an artificial organ which would house transplanted islets, and the cells could be nourished by the CSF. Ayub, Illani Atwater, and colleagues identified that ventricular-peritoneal CSF shunts provided an immune protected site for the transplantation of mouse and rat islets in dogs and llamas.22, 30 Ayub and colleagues also identified that CSF glucose mirrors blood glucose. Islets cells were able to survive in this system and function in the llama model, but further work on the model is needed.1 Unfortunately Dr. Ommaya was not able to complete this research.

The role of emotions in consciousness

Dr. Ommaya focused much of his career on the study of consciousness, the brain, and mind. This interest derived from his reading of Pennfield’s work on surgical treatment of epilepsy. His work in traumatic brain injury was influenced by his interest in how consciousness is altered and how it recovers after traumatic injury. Key to his observations is the role of the limbic system and emotion as foundational for consciousness.29 In his view, emotion is the trigger to action and other aspects of rationality are tools to justify action. Dr. Ommaya saw consciousness as an emergent property of the evolution of neural structures. Consciousness is the result of evolutionary forces directed to improving the efficiency of mental function. The reintegration of thought and action after traumatic injury provided the experimental context for Dr. Ommaya's thoughts.

It is popularly assumed that emotion disrupts cognition. However, neurophysiology and Dr. Ommaya's TBI research emphasizes its fundamental inseparability. Dr. Ommaya defined four steps in the evolution of consciousness. 1) reflex and avoidance reactions; 2) sensory inputs merged with multisensory neurons in the mesencephalon; 3) interactions formed between sensory and limbic systems and memory; and 4) reinforcement of thalamic neural centers which relays information between sensory and motor centers. Dr. Ommaya discussed how the limbic system and emotion motivates action and focuses attention.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK