Neurology

Neurology is a medical speciality dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue, such as muscle. Physicians who specialize in neurology are called neurologists, and are trained to investigate, or diagnose and treat, neurological disorders. Pediatric neurologists treat neurological disease in children. Neurologists may also be involved in clinical research, clinical trials, as well as basic research and translational research. In the United Kingdom, contributions to the field of Neurology stem from various professions; saliently, several biomedical research scientists are choosing to specialise in the technical/laboratory aspects of one of neurology's subdisciplines.

Field of work
Neurological disorders are disorders that affect the central nervous system (brain and spinal cord), the peripheral nervous system, or the autonomic nervous system.

Major conditions include:
 * behavioral/cognitive syndromes
 * headache disorders such as migraine, cluster headache and tension headache
 * seizure disorders
 * neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic lateral sclerosis (Lou Gehrig's disease).
 * cerebrovascular disease, such as transient ischemic attack and stroke.
 * sleep disorders
 * cerebral palsy
 * infections of the brain (encephalitis), brain meninges (meningitis), spinal cord (myelitis)
 * infections of the peripheral nervous system
 * neoplasms - tumors of the brain and its meninges (brain tumors), spinal cord tumors, tumors of the peripheral nerves (neuroma)
 * movement disorders such as Parkinson's disease, Huntington's disease, hemiballismus, tic disorder, and Gilles de la Tourette syndrome
 * demyelinating diseases of the central nervous system, such as multiple sclerosis, and of the peripheral nervous system, such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP)
 * spinal cord disorders - tumors, infections, trauma, malformations (e.g., myelocele, meningomyelocele, tethered cord)
 * disorders of peripheral nerves, muscle (myopathy) and neuromuscular junctions
 * traumatic injuries to the brain, spinal cord and peripheral nerves
 * altered mental status, encephalopathy, stupor and coma
 * speech and language disorders

Educational requirements
A neurologist's educational background and medical training varies with the country of training. In the United States and Canada, neurologists are physicians who have completed postgraduate training in neurology after the completion of medical school and attainment of the allopathic (MD, MBBS, MBChB, etc) or osteopathic (DO) degree.

Neurologists complete a minimum of 10 years of postsecondary education and clinical training. In the majority of cases this training includes obtaining an undergraduate degree (a few medical schools will admit students with as little as two years of undergraduate education), a medical degree (4 years), and then completing a four-year residency in neurology. The four-year residency consists of one year of internal medicine training followed by three years of training in neurology.

Many neurologists also have additional subspecialty training (fellowships) after completing their residency in one area of neurology such as stroke, epilepsy, neuromuscular, sleep medicine, pain management, neuroimmunology, clinical neurophysiology, or movement disorders.

Testing examinations
During a neurological examination, the neurologist reviews the patient's health history with special attention to the current condition. The patient then takes a neurological exam. Typically, the exam tests mental status, function of the cranial nerves (including vision), strength, coordination, reflexes and sensation. This information helps the neurologist determine if the problem exists in the nervous system and the clinical localization. Localization of the pathology is the key process by which neurologists develop their differential diagnosis. Further tests may be needed to confirm a diagnosis and ultimately guide therapy and appropriate management.

General caseload
Neurologists are responsible for the diagnosis, treatment, and management of all the above conditions. When surgical intervention is required, the neurologist may refer the patient to a neurosurgeon, an interventional neuroradiologist, or a neurointerventionalist. In some countries, additional legal responsibilities of a neurologist may include making a finding of brain death when it is suspected that a patient is deceased. Neurologists frequently care for people with hereditary (genetic) diseases when the major manifestations are neurological, as is frequently the case. Lumbar punctures are frequently performed by neurologists. Some neurologists may develop an interest in particular subfields, such as dementia, movement disorders, headaches, epilepsy, sleep disorders, chronic pain management, multiple sclerosis or neuromuscular diseases.

Overlapping areas
There is some overlap with other specialties, varying from country to country and even within a local geographic area. Acute head trauma is most often treated by neurosurgeons, whereas sequela of head trauma may be treated by neurologists or specialists in rehabilitation medicine. Although stroke cases have been traditionally managed by internal medicine or hospitalists, the emergence of vascular neurology and endovascular neurosurgery as disciplines has created a demand for stroke specialists. The establishment of JCAHO stroke centers has increased the role of neurologists in stroke care in many primary as well as tertiary hospitals. Some cases of nervous system infectious diseases are treated by infectious disease specialists. Most cases of headache are diagnosed and treated primarily by general practitioners, at least the less severe cases. Similarly, most cases of sciatica and other mechanical radiculopathies are treated by general practitioners, though they may be referred to neurologists or a surgeon (neurosurgeons or orthopedic surgeons). Sleep disorders are also treated by pulmonologists. Cerebral palsy is initially treated by pediatricians, but care may be transferred to an adult neurologist after the patient reaches a certain age.

Clinical neuropsychologists are often called upon to evaluate brain-behavior relationships for the purpose of assisting with differential diagnosis, planning rehabilitation strategies, documenting cognitive strengths and weaknesses, and measuring change over time (e.g., for identifying abnormal aging or tracking the progression of a dementia).

Relationship to clinical neurophysiology
In some countries, e.g. USA and Germany, neurologists may specialize in clinical neurophysiology, the field responsible for EEG, nerve conduction studies, EMG and evoked potentials. In other countries, this is an autonomous specialty (e.g. United Kingdom, Sweden).

Overlap with psychiatry
Although many mental illnesses are believed to be neurological disorders affecting the central nervous system, traditionally they are classified separately, and treated by psychiatrists. In a 2002 review article in the American Journal of Psychiatry, Professor Joseph B. Martin, Dean of Harvard Medical School and a neurologist by training, wrote that 'the separation of the two categories is arbitrary, often influenced by beliefs rather than proven scientific observations. And the fact that the brain and mind are one makes the separation artificial anyway.' (Martin JB. The integration of neurology, psychiatry and neuroscience in the 21st century. Am J Psychiatry 2002; 159:695-704)

There are strong indications that neuro-chemical mechanisms play an important role in the development of, for instance, bipolar disorder and schizophrenia. As well, 'neurological' diseases often have 'psychiatric' manifestations, such as post-stroke depression, depression and dementia associated with Parkinson's disease, mood and cognitive dysfunctions in Alzheimer's disease, to name a few. Hence, there is no sharp distinction between neurology and psychiatry on a biological basis - this distinction has mainly practical reasons and strong historical roots (such as the dominance of Freud's psychoanalytic theory in psychiatric thinking in the first three quarters of the 20th century - which has since then been largely replaced by the focus on neurosciences - aided by the tremendous advances in genetics and neuroimaging recently.)