Biological psychology: Neurology

Neurology (from Greek νεῦρον, neuron, "nerve"; and -λογία, -logia) is a medical specialty 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 specialize in the technical/laboratory aspects of one of neurology's subdisciplines.

Field of work
Neurological disorders are disorders that can 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
 * epilepsy
 * traumatic brain injury
 * 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
 * exciting injuries to the brain, spinal cord and peripheral nerves
 * altered mental higher status, encephalopathy, stupor and coma
 * speech and language disorders
 * functional symptoms, having no apparent physiological cause

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 graduation from medical school.

Neurologists complete, on average, 12 years of postsecondary education and clinical training. This training includes obtaining a four-year undergraduate degree, a medical degree, which is an additional four 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, interventional neurology, epilepsy, neuromuscular, sleep medicine, pain management, neuroimmunology, clinical neurophysiology, or movement disorders.

In the United Kingdom and Ireland, neurology is a subspecialty of general (internal) medicine. After five or six years of medical school and a year as a pre-registration house officer (or two years on the new Foundation Programme) a would-be neurologist has to get enough training in internal medicine to pass the examination for Membership of the Royal College of Physicians (or the Irish equivalent) before entering specialist training in neurology. A generation ago some neurologists would also spend a couple of years working in psychiatric units and obtain a Diploma in Psychological Medicine, but that became uncommon and now that a basic psychiatric qualification takes three years to obtain it is no longer practical. A period of research is essential, and obtaining a higher degree aids career progression: many found it was eased after an attachment to the Institute of Neurology at Queen Square in London. Some neurologists enter the field of rehabilitation medicine (known as physiatry in the US) to specialise in neurological rehabilitation, which may include stroke medicine as well as brain injuries.

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. 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 sequelae 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 interventional neurologists has created a demand for stroke specialists. The establishment of JCAHO certified 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. In the United Kingdom and other countries, many of the conditions encountered by older patients such as movement disorders including Parkinson's Disease, stroke, dementia or gait disorders are managed predominantly by specialists in geriatric medicine.

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.''

There are strong indications that neurochemical mechanisms play an important role in the development of, for instance, bipolar disorder and schizophrenia. Also, "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 reasoning and strong historical roots (such as the dominance of Freud's psychoanalytic theory 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.)

In Germany, a compulsory year of psychiatry must be done to complete a residency of neurology.