Paralysis in the context of Developmental neuroscience

Friedrich Wilhelm Nietzsche (15 October 1844 – 25 August 1900) was a German philosopher. He began his career as a classical philologist, turning to philosophy early in his academic career. In 1869, aged 24, Nietzsche became the youngest professor to hold the Chair of Classical Philology at the University of Basel. Plagued by health problems for most of his life, he resigned from the university in 1879, and in the following decade he completed much of his core writing. In 1889, aged 44, he suffered a collapse and thereafter a complete loss of his mental faculties, with paralysis and vascular dementia, living his remaining 11 years under the care of his family until his death. His works and his philosophy have fostered not only extensive scholarship but also much popular interest.

Nietzsche's work encompasses philosophical polemics, poetry, cultural criticism and fiction, while displaying a fondness for aphorisms and irony. Prominent elements of his philosophy include his radical critique of truth in favour of perspectivism; a genealogical critique of religion and Christian morality and a related theory of master–slave morality; the aesthetic affirmation of life in response to both the "death of God" and the profound crisis of nihilism; the notion of Apollonian and Dionysian forces; and a characterisation of the human subject as the expression of competing wills, collectively understood as the will to power. He also developed influential concepts such as the Übermensch and his doctrine of eternal return. In his later work he became increasingly preoccupied with the creative powers of the individual to overcome cultural and moral mores in pursuit of new values and aesthetic health. His body of work touched a wide range of topics, including art, philology, history, music, religion, tragedy, culture and science, and drew inspiration from Hebrew literature, Indian literature and Greek tragedy, as well as figures such as Zoroaster, Arthur Schopenhauer, Ralph Waldo Emerson, Richard Wagner, Fyodor Dostoevsky and Johann Wolfgang von Goethe.

Diphtheria is an infection caused by the bacterium Corynebacterium diphtheriae. Most infections are asymptomatic or have a mild clinical course, but in some outbreaks, the mortality rate approaches 10%. Signs and symptoms may vary from mild to severe, and usually start two to five days after exposure. Symptoms often develop gradually, beginning with a sore throat and fever. In severe cases, a grey or white patch develops in the throat, which can block the airway, and create a barking cough similar to what is observed in croup. The neck may also swell, in part due to the enlargement of the facial lymph nodes. Diphtheria can also involve the skin, eyes, or genitals, and can cause complications, including myocarditis (which in itself can result in an abnormal heart rate), inflammation of nerves (which can result in paralysis), kidney problems, and bleeding problems due to low levels of platelets.

Diphtheria is usually spread between people by direct contact, through the air, or through contact with contaminated objects. Asymptomatic transmission and chronic infection are also possible. Different strains of C. diphtheriae are the main cause in the variability of lethality, as the lethality and symptoms themselves are caused by the exotoxin produced by the bacteria. Diagnosis can often be made based on the appearance of the throat with confirmation by microbiological culture. Previous infection may not protect against reinfection.

A cramp is a sudden, involuntary, painful contraction of one or more skeletal muscles, or an overshortening of such associated with electrical activity. While generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the affected muscle. A cramp usually goes away on its own over several seconds or (sometimes) minutes. Cramps are common and tend to occur at rest, usually at night (nocturnal leg cramps). They are also often associated with pregnancy, physical exercise or overexertion, and age (common in older adults); in such cases, cramps are called idiopathic because there is no underlying pathology. In addition to those benign conditions, cramps are also associated with many pathological conditions.

Cramp definition is narrower than the definition of muscle spasm: spasms include any involuntary abnormal muscle contractions, while cramps are sustained and painful. True cramps can be distinguished from other cramp-like conditions. Cramps are different from muscle contracture, which is also painful and involuntary, but which is electrically silent. The main distinguishing features of cramps from dystonia are suddenness with acute onset of pain, involvement of only one muscle, and spontaneous resolution of cramps or their resolution after stretching the affected muscle. Restless leg syndrome is not considered the same as muscle cramps and should not be confused with rest cramps. Cramps are sometimes also called a "Charley horse", which is the term used by the lay people.

Flaccid paralysis is a neurological condition characterized by weakness or paralysis and reduced muscle tone without other obvious cause (e.g., trauma). This abnormal condition may be caused by disease or by trauma affecting the nerves associated with the involved muscles. For example, if the somatic nerves to a skeletal muscle are severed, then the muscle will exhibit flaccid paralysis. When muscles enter this state, they become limp and cannot contract. This condition can become fatal if it affects the respiratory muscles, posing the threat of suffocation. It also occurs in the spinal shock stage in complete transection of the spinal cord occurring in injuries such as gunshot wounds.

Post-polio syndrome (PPS, poliomyelitis sequelae) is a group of latent symptoms of poliomyelitis (polio), occurring in more than 80% of polio infections. The symptoms are caused by the damaging effects of the viral infection on the nervous system and typically occur 15 to 30 years after an initial acute paralytic attack. Symptoms include decreasing muscular function or acute weakness with pain and fatigue. The same may also occur years after a nonparalytic polio infection.

The precise mechanism that causes PPS is unknown. It shares many features with myalgic encephalomyelitis/chronic fatigue syndrome, but unlike that disorder it tends to be progressive and can cause loss of muscle strength. Treatment is primarily limited to adequate rest, conservation of available energy, and supportive measures, such as leg braces and energy-saving devices such as powered wheelchairs, analgesia (pain relief), and sleep aids.

A neurological disorder is any disorder of the nervous system. Structural, biochemical or electrical abnormalities in the brain, spinal cord, or other nerves can result in a range of symptoms. Examples of symptoms include paralysis, muscle weakness, poor coordination, loss of sensation, seizures, confusion, pain, tauopathies, and altered levels of consciousness. There are many recognized neurological disorders; some are relatively common, but many are rare.

Interventions for neurological disorders include preventive measures, lifestyle changes, physiotherapy or other therapy, neurorehabilitation, pain management, medication, operations performed by neurosurgeons, or a specific diet. The World Health Organization estimated in 2006 that neurological disorders and their sequelae (direct consequences) affect as many as one billion people worldwide and identified health inequalities and social stigma/discrimination as major factors contributing to the associated disability and their impact.

Conversion disorder (CD) was a formerly diagnosed psychiatric disorder characterized by abnormal sensory experiences and movement problems during periods of high psychological stress. Individuals diagnosed with CD presented with highly distressing neurological symptoms such as numbness, blindness, paralysis, or convulsions, none of which were consistent with a well-established organic cause and could be traced back to a psychological trigger. CD is no longer a diagnosis in the WHO's ICD-11 or APA's DSM-5 and was superseded by functional neurologic disorder (FND), a similar diagnosis that notably removed the requirement for a psychological stressor to be present.

It was thought that these symptoms arise in response to stressful situations affecting a patient's mental health. Individuals diagnosed with conversion disorder have a greater chance of experiencing certain psychiatric disorders including anxiety disorders, mood disorders, and personality disorders compared to those diagnosed with neurological disorders.

Anesthesia (American English) or anaesthesia (British English) is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), amnesia (loss of memory), and unconsciousness. An individual under the effects of anesthetic drugs is referred to as being anesthetized.

Anesthesia enables the painless performance of procedures that would otherwise require physical restraint in a non-anesthetized individual, or would otherwise be technically unfeasible. Three broad categories of anesthesia exist:

Palsy is a medical term which refers to various types of paralysis or paresis, often accompanied by weakness and the loss of feeling and uncontrolled body movements such as shaking. The word originates from the Anglo-Norman paralisie, parleisie et al., from the accusative form of Latin paralysis, from Ancient Greek παράλυσις (parálusis), from παραλύειν (paralúein, "to disable on one side"), from παρά (pará, "beside") + λύειν (lúein, "loosen"). The word is longstanding in the English language, having appeared in the play Grim the Collier of Croydon, reported to have been written as early as 1599:

In some editions, the Bible passage of Luke 5:18 is translated to refer to "a man which was taken with a palsy". More modern editions simply refer to a man who is paralysed. Although the term has historically been associated with paralysis generally, it "is now almost always used in connection to the word cerebral—meaning the brain".

Faith healing is the practice of prayer and gestures (such as laying on of hands) that are believed by some to elicit divine intervention in spiritual and physical healing, especially the Christian practice. Believers assert that the healing of disease and disability can be brought about by religious faith through prayer or other rituals that, according to adherents, can stimulate a divine presence and power. Religious belief in divine intervention does not depend on empirical evidence of an evidence-based outcome achieved via faith healing. Virtually all scientists and philosophers dismiss faith healing as pseudoscience.

Claims that "a myriad of techniques" such as prayer, divine intervention, or the ministrations of an individual healer can cure illness have been popular throughout history. There have been claims that faith can cure blindness, deafness, cancer, HIV/AIDS, developmental disorders, anemia, arthritis, corns, defective speech, multiple sclerosis, skin rashes, total body paralysis, and various injuries. Recoveries have been attributed to many techniques commonly classified as faith healing. It can involve prayer, a visit to a religious shrine, or simply a strong belief in a supreme being.

Guillain–Barré syndrome (GBS) is a rapid-onset muscle weakness caused by the immune system damaging the peripheral nervous system. Typically, both sides of the body are involved, and the initial symptoms are changes in sensation or pain often in the back along with muscle weakness, beginning in the feet and hands, often spreading to the arms and upper body. The symptoms may develop over hours to a few weeks. During the acute phase, the disorder can be life-threatening, with about 15% of people developing respiratory muscle weakness requiring mechanical ventilation. Some are affected by changes in the function of the autonomic nervous system, which can lead to dangerous abnormalities in heart rate and blood pressure.

Although the cause is unknown, the underlying mechanism involves an autoimmune disorder in which the body's immune system mistakenly attacks the peripheral nerves and damages their myelin insulation. Sometimes this immune dysfunction is triggered by an infection or, less commonly, by surgery, and by vaccination. The diagnosis is usually based on the signs and symptoms through the exclusion of alternative causes and supported by tests such as nerve conduction studies and examination of the cerebrospinal fluid. There are several subtypes based on the areas of weakness, results of nerve conduction studies, and the presence of certain antibodies. It is classified as an acute polyneuropathy.

In evolutionary ecology, a parasitoid is an organism that lives in close association with its host at the host's expense, eventually resulting in the death of the host. Parasitoidism is one of six major evolutionary strategies within parasitism, distinguished by the fatal prognosis for the host, which makes the strategy close to predation.

Among parasitoids, strategies range from living inside the host (endoparasitism), allowing it to continue growing before emerging as an adult, to paralysing the host and living outside it (ectoparasitism). Hosts can include other parasitoids, resulting in hyperparasitism; in the case of oak galls, up to five levels of parasitism are possible. Some parasitoids influence their host's behaviour in ways that favour the propagation of the parasitoid.

Akinetic mutism is a medical condition where patients tend neither to move (akinesia) nor speak (mutism). It is the most extreme disorder of diminished motivation. Akinetic mutism was first described in 1941 as a mental state where patients lack the ability to move or speak. However, their eyes may follow their observer or be diverted by sound. Patients lack most motor functions such as speech, facial expressions, and gestures, but demonstrate apparent alertness. They exhibit reduced activity and slowness, and can speak in whispered monosyllables. Patients often show visual fixation on their examiner, move their eyes in response to an auditory stimulus, or move after often repeated commands. Patients with akinetic mutism are not paralyzed, but lack the will to move. Many patients describe that as soon as they "will" or attempt a movement, a "counter-will" or "resistance" rises up to meet them.

The development of the nervous system, or neural development (neurodevelopment), refers to the processes that generate, shape, and reshape the nervous system of animals, from the earliest stages of embryonic development to adulthood. The field of neural development draws on both neuroscience and developmental biology to describe and provide insight into the cellular and molecular mechanisms by which complex nervous systems develop, from nematodes and fruit flies to mammals.

Defects in neural development can lead to malformations such as holoprosencephaly, and a wide variety of neurological disorders including limb paresis and paralysis, balance and vision disorders, and seizures, and in humans other disorders such as Rett syndrome, Down syndrome and intellectual disability.

Central facial palsy (colloquially referred to as central seven) is a symptom or finding characterized by paralysis or paresis of the lower half of one side of the face. It usually results from damage to upper motor neurons of the facial nerve.

The facial motor nucleus has dorsal and ventral divisions that contain lower motor neurons supplying the muscles of the upper and lower face, respectively. The dorsal division receives bilateral upper motor neuron input (i.e. from both sides of the brain) while the ventral division receives only contralateral input (i.e. from the opposite side of the brain).

Hemiparesis, also called unilateral paresis, is the weakness of one entire side of the body (hemi- meaning 'half'). Hemiplegia, in its most severe form, is the complete paralysis of one entire side of the body. Either hemiparesis or hemiplegia can result from a variety of medical causes, including congenital conditions, blunt trauma, tumors, traumatic brain injury, and stroke.