Abnormal posturing

Last updated
Abnormal posturing
Specialty Neurology
Differential diagnosis Traumatic brain injury, Stroke, Intracranial hemorrhage, Brain tumors, and Encephalopathy.

Abnormal posturing is an involuntary flexion or extension of the arms and legs, indicating severe brain injury. It occurs when one set of muscles becomes incapacitated while the opposing set is not, and an external stimulus such as pain causes the working set of muscles to contract. [1] The posturing may also occur without a stimulus. [2] [ failed verification ] Since posturing is an important indicator of the amount of damage that has occurred to the brain, it is used by medical professionals to measure the severity of a coma with the Glasgow Coma Scale (for adults) and the Pediatric Glasgow Coma Scale (for infants).

Contents

The presence of abnormal posturing indicates a severe medical emergency requiring immediate medical attention. Decerebrate and decorticate posturing are strongly associated with poor outcome in a variety of conditions. For example, near-drowning patients that display decerebrate or decorticate posturing have worse outcomes than those that do not. [3] Changes in the condition of the patient may cause alternation between different types of posturing. [4]

Types

Three types of abnormal posturing are decorticate posturing, with the arms flexed over the chest; decerebrate posturing, with the arms extended at the sides; and opisthotonus, in which the head and back are arched backward.[ citation needed ]

Decorticate

Decorticate posturing, with elbows, wrists and fingers flexed, and legs extended and rotated inward Decorticate.PNG
Decorticate posturing, with elbows, wrists and fingers flexed, and legs extended and rotated inward

Decorticate posturing is also called decorticate response, decorticate rigidity, flexor posturing, or, colloquially, "mummy baby". [5] Patients with decorticate posturing present with the arms flexed, or bent inward on the chest, the hands are clenched into fists, and the legs extended and feet turned inward. A person displaying decorticate posturing in response to pain gets a score of three in the motor section of the Glasgow Coma Scale, caused by the flexion of muscles due to the neuro-muscular response to the trauma. [6]

There are two parts to decorticate posturing.

The effects on these two tracts (corticospinal and rubrospinal) by lesions above the red nucleus is what leads to the characteristic flexion posturing of the upper extremities and extensor posturing of the lower extremities.[ citation needed ]

Decorticate posturing indicates that there may be damage to areas including the cerebral hemispheres, the internal capsule, and the thalamus. [7] It may also indicate damage to the midbrain. While decorticate posturing is still an ominous sign of severe brain damage, decerebrate posturing is usually indicative of more severe damage at the rubrospinal tract, and hence, the red nucleus is also involved, indicating a lesion lower in the brainstem.[ citation needed ]

Decerebrate

Decerebrate rigidity or abnormal extensor posturing. Decerebrate.jpg
Decerebrate rigidity or abnormal extensor posturing.

Decerebrate posturing is also called decerebrate response, decerebrate rigidity, or extensor posturing. It describes the involuntary extension of the upper extremities in response to external stimuli. In decerebrate posturing, the head is arched back, the arms are extended by the sides, and the legs are extended. [8] A hallmark of decerebrate posturing is extended elbows. [7] The arms and legs are extended and rotated internally. [9] The patient is rigid, with the teeth clenched. [9] The signs can be present on only one side of the body or on both sides, and they may be present just in the arms, and they may be intermittent. [9]

A person displaying decerebrate posturing in response to pain receives a score of two in the motor section of the Glasgow Coma Scale (for adults) and the Pediatric Glasgow Coma Scale (for infants), due to the muscles extending because of the neuro-muscular response to the trauma. [6]

Decerebrate posturing indicates brain stem damage, specifically damage below the level of the red nucleus (e.g. mid-collicular lesion). It is exhibited by people with lesions or compression in the midbrain and lesions in the cerebellum. [7] Decerebrate posturing is commonly seen in pontine strokes. A patient with decorticate posturing may begin to show decerebrate posturing, or may go from one form of posturing to the other. [1] Progression from decorticate posturing to decerebrate posturing is often indicative of uncal (transtentorial) or tonsilar brain herniation. Activation of gamma motor neurons is thought to be important in decerebrate rigidity due to studies in animals showing that dorsal-root transection eliminates decerebrate rigidity symptoms. [10] Transection releases the centres below the site from higher inhibitory controls.

In competitive contact sports, posturing (typically of the forearms) can occur with an impact to the head and is termed the fencing response.

Causes

Posturing can be caused by conditions that lead to large increases in intracranial pressure. [11] Such conditions include traumatic brain injury, stroke, intracranial hemorrhage, brain tumors, brain abscesses and encephalopathy. [8] [ failed verification ] Posturing due to stroke usually only occurs on one side of the body and may also be referred to as spastic hemiplegia. [2] Diseases such as malaria are also known to cause the brain to swell and cause this posturing effect.[ citation needed ]

Decerebrate and decorticate posturing can indicate that brain herniation is occurring [12] or is about to occur. [11] Brain herniation is an extremely dangerous condition in which parts of the brain are pushed past hard structures within the skull. In herniation syndrome, which is indicative of brain herniation, decorticate posturing occurs, and, if the condition is left untreated, develops into decerebrate posturing. [12]

Posturing has also been displayed by patients with Creutzfeldt–Jakob disease, [13] diffuse cerebral hypoxia, [14] and brain abscesses. [2]

It has also been observed in cases of hanging. [15]

Children

In children younger than age two, posturing is not a reliable finding because their nervous systems are not yet developed. [2] However, Reye's syndrome and traumatic brain injury can both cause decorticate posturing in children. [2]

For reasons that are poorly understood, but which may be related to high intracranial pressure, children with malaria frequently exhibit decorticate, decerebrate, and opisthotonic posturing. [16]

Prognosis

Normally people displaying decerebrate or decorticate posturing are in a coma and have poor prognoses, with risks for cardiac arrhythmia or arrest and respiratory failure. [9]

History

Sir Charles Sherrington was first to describe decerebrate posturing after transecting the brain stems of cats and monkeys, causing them to exhibit the posturing. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Coma</span> State of unconsciousness

A coma is a deep state of prolonged unconsciousness in which a person cannot be awakened, fails to respond normally to painful stimuli, light, or sound, lacks a normal wake-sleep cycle and does not initiate voluntary actions. The person may experience respiratory and circulatory problems due to the body's inability to maintain normal bodily functions. People in a coma often require extensive medical care to maintain their health and prevent complications such as pneumonia or blood clots. Coma patients exhibit a complete absence of wakefulness and are unable to consciously feel, speak or move. Comas can be derived by natural causes, or can be medically induced.

Hemiparesis, or unilateral paresis, is weakness of one entire side of the body. Hemiplegia is, in its most severe form, complete paralysis of half of the body. Hemiparesis and hemiplegia can be caused by different medical conditions, including congenital causes, trauma, tumors, or stroke.

<span class="mw-page-title-main">Head injury</span> Serious trauma to the cranium

A head injury is any injury that results in trauma to the skull or brain. The terms traumatic brain injury and head injury are often used interchangeably in the medical literature. Because head injuries cover such a broad scope of injuries, there are many causes—including accidents, falls, physical assault, or traffic accidents—that can cause head injuries.

<span class="mw-page-title-main">Extrapyramidal system</span> Connection between brain and spinal cord

In anatomy, the extrapyramidal system is a part of the motor system network causing involuntary actions. The system is called extrapyramidal to distinguish it from the tracts of the motor cortex that reach their targets by traveling through the pyramids of the medulla. The pyramidal tracts may directly innervate motor neurons of the spinal cord or brainstem, whereas the extrapyramidal system centers on the modulation and regulation of anterior (ventral) horn cells.

<span class="mw-page-title-main">Intracranial pressure</span> Pressure exerted by fluids inside the skull and on the brain

Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury (mmHg) and at rest, is normally 7–15 mmHg for a supine adult. The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF.

<span class="mw-page-title-main">Plantar reflex</span> Reflex elicited when the sole of the foot is stimulated with a blunt instrument

The plantar reflex is a reflex elicited when the sole of the foot is stimulated with a blunt instrument. The reflex can take one of two forms. In healthy adults, the plantar reflex causes a downward response of the hallux (flexion). An upward response (extension) of the hallux is known as the Babinski response or Babinski sign, named after the neurologist Joseph Babinski. The presence of the Babinski sign can identify disease of the spinal cord and brain in adults, and also exists as a primitive reflex in infants.

<span class="mw-page-title-main">Epidural hematoma</span> Build-up of blood between the dura mater and skull

Epidural hematoma is when bleeding occurs between the tough outer membrane covering the brain and the skull. Often there is loss of consciousness following a head injury, a brief regaining of consciousness, and then loss of consciousness again. Other symptoms may include headache, confusion, vomiting, and an inability to move parts of the body. Complications may include seizures.

<span class="mw-page-title-main">Reticular formation</span> Spinal trigeminal nucleus

The reticular formation is a set of interconnected nuclei that are located throughout the brainstem. It is not anatomically well defined, because it includes neurons located in different parts of the brain. The neurons of the reticular formation make up a complex set of networks in the core of the brainstem that extend from the upper part of the midbrain to the lower part of the medulla oblongata. The reticular formation includes ascending pathways to the cortex in the ascending reticular activating system (ARAS) and descending pathways to the spinal cord via the reticulospinal tracts.

<span class="mw-page-title-main">Rubrospinal tract</span> Part of the nervous system

The rubrospinal tract is a part of the nervous system. It is a part of the lateral indirect extra-pyramidal tract.

Decerebration is the elimination of cerebral brain function in an animal by removing the cerebrum, cutting across the brain stem, or severing certain arteries in the brain stem.

Monoplegia is paralysis of a single limb, usually an arm. Common symptoms associated with monoplegic patients are weakness, numbness, and pain in the affected limb. Monoplegia is a type of paralysis that falls under hemiplegia. While hemiplegia is paralysis of half of the body, monoplegia is localized to a single limb or to a specific region of the body. Monoplegia of the upper limb is sometimes referred to as brachial monoplegia, and that of the lower limb is called crural monoplegia. Monoplegia in the lower extremities is not as common of an occurrence as in the upper extremities. Monoparesis is a similar, but less severe, condition because one limb is very weak, not paralyzed. For more information, see paresis.

<span class="mw-page-title-main">Brain herniation</span> Potentially deadly side effect of very high pressure within the skull

Brain herniation is a potentially deadly side effect of very high pressure within the skull that occurs when a part of the brain is squeezed across structures within the skull. The brain can shift across such structures as the falx cerebri, the tentorium cerebelli, and even through the foramen magnum. Herniation can be caused by a number of factors that cause a mass effect and increase intracranial pressure (ICP): these include traumatic brain injury, intracranial hemorrhage, or brain tumor.

<span class="mw-page-title-main">Vestibulospinal tract</span> Neural tract in the central nervous system

The vestibulospinal tract is a neural tract in the central nervous system. Specifically, it is a component of the extrapyramidal system and is classified as a component of the medial pathway. Like other descending motor pathways, the vestibulospinal fibers of the tract relay information from nuclei to motor neurons. The vestibular nuclei receive information through the vestibulocochlear nerve about changes in the orientation of the head. The nuclei relay motor commands through the vestibulospinal tract. The function of these motor commands is to alter muscle tone, extend, and change the position of the limbs and head with the goal of supporting posture and maintaining balance of the body and head.

<span class="mw-page-title-main">Brown-Séquard syndrome</span> Human spinal cord disorder

Brown-Séquard syndrome is caused by damage to one half of the spinal cord, i.e. hemisection of the spinal cord resulting in paralysis and loss of proprioception on the same side as the injury or lesion, and loss of pain and temperature sensation on the opposite side as the lesion. It is named after physiologist Charles-Édouard Brown-Séquard, who first described the condition in 1850.

In medicine, pronator drift refers to a pathologic sign seen during a neurological examination. Jean Alexandre Barré is credited with having first described it; thus it is sometimes known as the Barré test or sign. A positive result indicates palsy. This sign can appear due to an upper motor neuron lesion or various other conditions which include palsy as a symptom.

<span class="mw-page-title-main">Blocq's disease</span> Loss of memory of specialized movements causing the inability to maintain an upright posture

Blocq's disease was first considered by Paul Blocq (1860–1896), who described this phenomenon as the loss of memory of specialized movements causing the inability to maintain an upright posture, despite normal function of the legs in the bed. The patient is able to stand up, but as soon as the feet are on the ground, the patient cannot hold himself upright nor walk; however when lying down, the subject conserved the integrity of muscular force and the precision of movements of the lower limbs. The motivation of this study came when a fellow student Georges Marinesco (1864) and Paul published a case of parkinsonian tremor (1893) due to a tumor located in the substantia nigra.

<span class="mw-page-title-main">Altered level of consciousness</span> Measure of arousal other than normal

An altered level of consciousness is any measure of arousal other than normal. Level of consciousness (LOC) is a measurement of a person's arousability and responsiveness to stimuli from the environment. A mildly depressed level of consciousness or alertness may be classed as lethargy; someone in this state can be aroused with little difficulty. People who are obtunded have a more depressed level of consciousness and cannot be fully aroused. Those who are not able to be aroused from a sleep-like state are said to be stuporous. Coma is the inability to make any purposeful response. Scales such as the Glasgow coma scale have been designed to measure the level of consciousness.

<span class="mw-page-title-main">Athetoid cerebral palsy</span> Type of cerebral palsy associated with basal ganglia damage

Athetoid cerebral palsy, or dyskinetic cerebral palsy, is a type of cerebral palsy primarily associated with damage, like other forms of CP, to the basal ganglia in the form of lesions that occur during brain development due to bilirubin encephalopathy and hypoxic–ischemic brain injury. Unlike spastic or ataxic cerebral palsies, ADCP is characterized by both hypertonia and hypotonia, due to the affected individual's inability to control muscle tone. Clinical diagnosis of ADCP typically occurs within 18 months of birth and is primarily based upon motor function and neuroimaging techniques. While there are no cures for ADCP, some drug therapies as well as speech, occupational therapy, and physical therapy have shown capacity for treating the symptoms.

Alternating hemiplegia is a form of hemiplegia that has an ipsilateral cranial nerve palsies and contralateral hemiplegia or hemiparesis of extremities of the body. The disorder is characterized by recurrent episodes of paralysis on one side of the body. There are multiple forms of alternating hemiplegia, Weber's syndrome, middle alternating hemiplegia, and inferior alternating hemiplegia. This type of syndrome can result from a unilateral lesion in the brainstem affecting both upper motor neurons and lower motor neurons. The muscles that would receive signals from these damaged upper motor neurons result in spastic paralysis. With a lesion in the brainstem, this affects the majority of limb and trunk muscles on the contralateral side due to the upper motor neurons decussation after the brainstem. The cranial nerves and cranial nerve nuclei are also located in the brainstem making them susceptible to damage from a brainstem lesion. Cranial nerves III (Oculomotor), VI (Abducens), and XII (Hypoglossal) are most often associated with this syndrome given their close proximity with the pyramidal tract, the location which upper motor neurons are in on their way to the spinal cord. Damages to these structures produce the ipsilateral presentation of paralysis or palsy due to the lack of cranial nerve decussation before innervating their target muscles. The paralysis may be brief or it may last for several days, many times the episodes will resolve after sleep. Some common symptoms of alternating hemiplegia are mental impairment, gait and balance difficulties, excessive sweating and changes in body temperature.

<span class="mw-page-title-main">Mesencephalic locomotor region</span>

The mesencephalic locomotor region (MLR) is a functionally defined area of the midbrain that is associated with the initiation and control of locomotor movements in vertebrate species.

References

  1. 1 2 AllRefer.com. 2003 "Decorticate Posture" [ failed verification ] Archived October 3, 2005, at the Wayback Machine . Retrieved January 15, 2007.
  2. 1 2 3 4 5 WrongDiagnosis.com, Decorticate posture: Decorticate rigidity, abnormal flexor response (Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series). Retrieved on September 15, 2007.
  3. ↑ Nagel, FO; Kibel SM; Beatty DW (1990). "Childhood near-drowning—factors associated with poor outcome". South African Medical Journal. 78 (7): 422–425. PMID   2218768.
  4. ↑ ADAM. Medical Encyclopedia: Abnormal posturing. Archived September 11, 2007, at the Wayback Machine Retrieved on September 3, 2007.
  5. ↑ Shah, Tilak (November 2008). NMS Medicine Casebook. Lippincott Williams & Wilkins. ISBN   9780781784689.
  6. 1 2 Davis, RA; Davis, RL (May 1982). "Decerebrate rigidity in humans". Neurosurgery. 10 (5): 635–42. doi:10.1097/00006123-198205000-00017. PMID   7099417.
  7. 1 2 3 4 Elovic E, Edgardo B, Cuccurullo S (2004). "Traumatic brain injury". In Cuccurullo SJ (ed.). Physical Medicine and Rehabilitation Board Review. Demos Medical Publishing. pp. 54–55. ISBN   1-888799-45-5.
  8. 1 2 ADAM. 2005. "Decorticate Posture" Archived 2008-10-14 at the Wayback Machine . Retrieved January 15, 2007.
  9. 1 2 3 4 Silverberg, Mark; Greenberg, Michael R.; Hendrickson, Robert A. (2005). Greenberg's Text-Atlas of Emergency Medicine. Hagerstwon, MD: Lippincott Williams & Wilkins. p. 53. ISBN   0-7817-4586-1.
  10. ↑ Berne and Levy principles of physiology/[editors] Matthew N. Levy, Bruce M. Koeppen, Bruce A. Stanton.-4th ed. Philadelphia, PA: Elsevier Mosby, 2006.
  11. 1 2 Yamamoto, Loren G. (1996). "Intracranial Hypertension and Brain Herniation Syndromes". Radiology Cases in Pediatric Emergency Medicine. Kapiolani Medical Center for Women and Children; University of Hawaii; John A. Burns School of Medicine. 5 (6). Retrieved January 24, 2007.
  12. 1 2 Ayling, J (2002). "Managing head injuries". Emergency Medical Services. Vol. 31, no. 8. p. 42. PMID   12224233.
  13. ↑ Obi, T; Takatsu M; Kitamoto T; Mizoguchi K; Nishimura Y (1996). "A case of Creutzfeldt–Jakob disease (CJD) started with monoparesis of the left arm". Rinsho Shinkeigaku . 36 (11): 1245–1248. PMID   9046857.
  14. ↑ De Rosa G, Delogu AB, Piastra M, Chiaretti A, Bloise R, Priori SG (2004). "Catecholaminergic polymorphic ventricular tachycardia: successful emergency treatment with intravenous propranolol". Pediatric Emergency Care . 20 (3): 175–7. doi:10.1097/01.pec.0000117927.65522.7a. PMID   15094576.
  15. ↑ Sauvageau, Anny; Racette, Stéphanie (2007). "Agonal Sequences in a Filmed Suicidal Hanging: Analysis of Respiratory and Movement Responses to Asphyxia by Hanging". Journal of Forensic Sciences. 52 (4): 957–959. doi:10.1111/j.1556-4029.2007.00459.x. PMID   17524058. S2CID   32188375.
  16. ↑ Idro, R; Otieno G; White S; Kahindi A; Fegan G; Ogutu B; Mithwani S; Maitland K; Neville BG; Newton CR (2005). "Decorticate, decerebrate and opisthotonic posturing and seizures in Kenyan children with cerebral malaria". Malaria Journal. 4 (57): 57. doi: 10.1186/1475-2875-4-57 . PMC   1326205 . PMID   16336645.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.