AN INTRODUCTION TO NEUROLOGY - TRUTH OR ENVY; DO NEUROLOGISTS ‘KNOW EVERYTHING AND DO NOTHING’?

If there was one medical speciality that can be called the speciality of extremes – it must be neurology. Perhaps no other subject is as loved, or as dreaded by medical students and doctors in equal measure. Either you love it or you hate it. Neurologists are either extremely admired, especially for their clinical acumen and sharpness. Or detested, especially because they appear to many outsiders to be doing nothing but waste NHS resources and not actually curing anybody. ‘Neurologists know everything and do nothing’ is almost a cliché heard daily in hospital doctors’ messes[1]. Or as put by Dr. John Larkin in his recent hit ‘Cynical Acumen’:

“Neurologists differ from the rest of us. Even their motto is different. Instead of Primum non Nocere (‘first do no harm’) they have Primum Nihil Facere (‘first do no..thing’). But at least they compensate by having extra mottoes…Secundum Nihil Facere..Tertium Nihil Facere” (1)

But nothing can be further from the truth, as anyone under the care of a neurologist will testify. The child whose progress in school is hampered by his petit mal epilepsy, who suddenly gets better on commencing anticonvulsant medication. The young lady with intractable migraines who is suddenly relieved of their nauseating attacks through the neurologist’s prescription. The young gentleman with Parkinson’s disease who is suddenly brought to life with anti-Parkinsonian medications. Those who say neurologists do nothing have probably not thought of these things.

Although we cannot deny that neurologists do not cure anybody, we can say the same of every other medical specialty. i have emphasised this point in a previous essay. Since when did endocrinologists cure diabetes? Or the rheumatologists remedy rheumatoid arthritis? Or gastroenterologists heal inflammatory bowel disease? Or respiratory physicians reverse COPD? Or cardiologists cure heart failure? Why should this ‘non-curing’ label be the first thing in the mind of most people only when they think of neurologists, when other specialists are as blameworthy? The only true healers in the medical world are the surgeons, as I have mentioned before.

And even if disorders are untreatable, it is no good to regard their encompassing specialty as futile. To quote a popular neurology textbook:

“Even when no therapy is possible, neurologic diagnosis is more than an intellectual pastime. The first step in the scientific study of a disease process is its identification in the living patient. Until that is achieved, it is impossible to apply adequately the “master method of controlled experiment”. The clinical method of neurology thus serves to the physician, in the practical diagnosis and treatment of a patient’s condition, and the clinical scientist, in the search for the mechanisms and cause of disease” (2)

Neurology is one of the youngest of clinical specialties, and part of its attraction is that, although a great deal has indeed been learnt about the nervous system, the only system by virtue of which we have become the supreme creatures of the earth, there is still so much to learn and discover about it and its disorders. A massive explosion in neuroscience research has been going on for the last three decades - supported by advances in molecular biology and genetics - and will probably continue for many decades, maybe even centuries. For the brain remains a most mysterious organ. Neurology can only advance forward with all these discoveries.

The other big attraction of neurology is that, in spite of possessing some of the most advanced diagnostic tests and procedures; it remains essentially a clinical field, where “clinical skills remain more important than in most specialties. For example, the prime diagnostic criteria remain clinical in disorders such as epilepsy and migraine” (3). Dr McDonald Critchley, a prominent neurologist was once asked while on a tour of the United States what impact CT scans will have on clinical neurology; will history and physical examination be thrown out of the window? His response was both poetic and prophetic: "CT scanning will take away the shadows of neurology, but the music will still remain." The history and physical examination combine to give, in the hands of the expert a ‘mind-bogglingly precise’ diagnosis. Two most valuable quotes are worth mention here – one from the aforementioned book by John Larkin, the other from the distilled wisdom of the great Henry George Miller (4).

“There is a doctrine – well regarded in cognoscenti circles – that examination of a patient tells you where the problem is, while taking the history tells you the pathogenesis behind the problem. When it comes to neurology, this view is spot on.” (Larkin)

“The peculiar charm of neurology lies in fact in the satisfaction implicit in its logical structure; and perhaps even more in the essentially clinical nature of the discipline..The physical signs of a neurological disorder are for the most part unequivocal: the pathognomonic significance of the extensor plantar response is inevitably more clear-cut that that of the basal rale or the suspicion of ankle oedema” (Miller)

Perhaps the importance of clinical diagnosis was best illustrated by the large study conducted by Chimowitz et al in the early 1990s, which showed that investigations failed to clarify the diagnosis in more than half of the selected patients (5). I hasten to add that there is another doctrine in neurology; that “a second examination is the most helpful diagnostic test in a difficult neurologic case” (6).

Finally, to one with even the most modest philosophical inclinations, the history of philosophy is full of reflections on the nature of mind, perception, and behaviour. (“Je pense, donc je suis (I think, therefore I am)”, remarked Rene Descartes in what is said to be the foundation stone of modern philosophy[2]). The only way that philosophers can find the answers to these questions is by studying neurology.

But, I hear you ask, isn’t that the province of neuroscience? Isn’t neuroscience defined as “the multidisciplinary bodies of science that analyse the nervous system to understand the biological basis of behaviour” (7)? Shouldn’t the interests of the philosopher therefore not be in neuroanatomy and neurophysiology, rather than neurology?

The answer to this question is that, neurology is special in being one of the few medical specialties that has contributed more to the basic sciences than it has taken from them, particularly to neuroanatomy. The first paragraph in a foreword to one textbook of neuroanatomy states the following, “(Medical students) must acquire a core of fundamental knowledge of neuroanatomy, without which it would be impossible for any doctor to be able to interpret the symptoms and signs of dysfunction of the nervous system in such a way as to construct a differential diagnosis which then leads in turn to a planned programme of investigation and treatment” (8) I actually believe the reverse to be true. Let me elaborate.

In most other specialities, knowledge of anatomy of an organ can lead to reasonable predictions as to its underlying function. For example, the heart is part muscle, hence its pumping function, part pericardium – for lubrication and protection; it has valves to control the inflow and outflow of blood. Knowledge that the stomach has glandular columnar epithelium helps us predict it has a secretory function; it has an underlying muscularis to propel the food into the small intestine, and two sphincters to control the flow of food from the oesophagus, and into the small intestine. The lung has empty alveoli, made of simple squamous epithelium, that store oxygen and pass it on by simple diffusion to nearby capillaries. This is called the “principle of complementarity of structure and function”. It is present and true of most organs, but not the brain.

The gross anatomy of the brain reveals very surprisingly, a pretty homogenous, un-aesthetic, dull organ, “about two good fistfuls of pinkish gray tissues, wrinkled like a walnut, and somewhat the consistency of cold oatmeal” (9). We cannot make many predictions from knowledge of its anatomy. (“Who could have foretold, from the structure of the brain, that wine could derange its functions”, remarked Hippocrates). Historically, it is knowledge of the symptoms and signs of neurological disease that gave birth to functional anatomy of the brain – the only true anatomy; for what is anatomy but a boring, lifeless set of descriptions if we did not know the function of what it was describing? Although neurological disorders can kill, they can be said to bring neuroanatomy to life (tongue in cheek).

The study of disease is often the biggest contributor to understanding normal function. Indeed, some philosophers and theologians believe that disease exists so that we can appreciate the blessings of normal function. I cannot help but quote two of the biggest giants of medicine in this context: firstly, the great Charles Horace Mayo, founder of the Mayo Clinic, from a statement he made to the American College of Surgeons at the turn of the century; and secondly, the greatest medical writer of our time, Arthur Clifton Guyton, from the introduction to one of his fine physiology books.

“Disease at times creates experiments that physiology completely fails to duplicate, and the wise physiologist can obtain clues to the resolution of many problems by studying the sick” (10) (Mayo)

“A small but important part of this text presents not only knowledge that has come from basic experiments in animals, but also knowledge that has come from human experiments, especially unplanned experiments caused by disease. Literally thousands of human experiments proceed each day in the fields of high blood pressure, congestive heart failure, gastrointestinal disturbances, respiratory disease, and so forth. The physiology of these abnormalities is discussed briefly, partly because study of the diseases themselves can be enlightening, but even more because they give important insights into basic physiological concepts” (11) (Guyton)

This cannot be said to be true for any field as much as it is for neuroanatomy and neurophysiology – in short, the neurosciences. It is mainly through learning about the diseases of the nervous system that we have come to understand what the role of the different areas of the brain is. There is thus an inherent source of intellectual satisfaction within neurology. The deeply personal quest to understanding what makes us, US, begins, and ends, with neurology. “It is not our guts or our liver that has created sapiens..it is the human brain..At long last not only neurologists but the rest of us are realising it is the most extraordinary development of all. Liver, spleen, heart and guts are all intriguing, but cannot hold a candle to the brain. It is the most important thing on Earth, for good or ill” concludes one popular book on the brain (12).

So far from doing nothing, the neurologist, besides what we have discussed above about his clinical role, is also the biggest contributor amongst medical professionals to understanding ourselves. And in that, he (and increasingly she) may be regarded as a most valuable contributor to intellectual medicine, if not practical medicine. With progress in neuroscience and neuropathology, the adventurous tendencies of the neurologists of today, manifest to anyone who has worked with them in their request for the most exotic, expensive and extreme investigations, will decline, to the benefit of the neurologist, the patient patient, and the nation's economy.

REFERENCES
1. Larkin J. Cynical Acumen – The Anarchic Guide To Clinical Medicine. Radcliffe Publishing, Oxford, 2005
2. Adams R & Victor M. Principles of neurology. 6th edition. McGraw Hill, New York, 1997
3. Ward C, Eccles S, eds. So you want to be a brain surgeon? Oxford: Oxford University Press, 1997
4. Miller H G. The charm of neurology. British Clinical Journal. Oct 1974, pp.435-7.
5. Chimowitz MI, Logigian EL, Caplan LR..The accuracy of bedside neurological diagnoses. Ann Neurol. 1990 Jul;28(1):78-85
6. Adams R & Victor M. Principles of neurology. 6th edition. McGraw Hill, New York, 1997
7. Squire L R.et al (2003) Fundamental Neuroscience. 2nd edition. San Diego, Calif.
8. Wilkinson JL. Neuroanatomy for Medical Students.3rd ed. Oxford. Butterworth Heinemann. 1998
9. Marieb, E. N. (1989). Human anatomy and physiology. Redwood City, Calif.: Benjamin Cummings Pub. Co.
10. Mayo C H. Speech given to the Clinical Congress of the American College of Surgeons, Boston, October 9, 1928.
11. Guyton, Arthur C. Basic Human Physiology: Normal Function and Mechanisms of Disease, W.B. Saunders Co, 1998
12. Smith A. The Mind. Pelican Publishers, Middlesex, 1985.
[1] The first recorded instance of this statement being said is in the Archives of the great French neurosurgeon Clovis Vincent; having won the gold medal at Salpetriere, he was asked whether he would like to work for the great George Widal . He replied, “Oh, no, they say you are too much of a rabbit doctor. I want to get a job where I can learn something of general medicine, the neurologists just talk and do nothing.”
[2] The reverse is not true however; “I do not think therefore I do not exist”. In this context, I once came across a joke that goes: Descartes is sitting in a bar, having a drink. The bartender asks him if he would like another. "I think not," he says, and vanishes(!)