Wikia

Psychology Wiki

Choreoathetosis

Talk0
34,142pages on
this wiki
Revision as of 07:14, June 2, 2010 by Dr Joe Kiff (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Assessment | Biopsychology | Comparative | Cognitive | Developmental | Language | Individual differences | Personality | Philosophy | Social |
Methods | Statistics | Clinical | Educational | Industrial | Professional items | World psychology |

Biological: Behavioural genetics · Evolutionary psychology · Neuroanatomy · Neurochemistry · Neuroendocrinology · Neuroscience · Psychoneuroimmunology · Physiological Psychology · Psychopharmacology (Index, Outline)


CBell1809.jpg|
Choreoathetosis
ICD-10
ICD-9 781.0
OMIM [1]
DiseasesDB 31293
MedlinePlus [2]
eMedicine /
MeSH {{{MeshNumber}}}

Opisthotonus or opisthotonos, from Greek roots, opistho meaning "behind" and tonos meaning "tension", is a state of a severe hyperextension and spasticity in which an individual's head, neck and spinal column enter into a complete "bridging" or "arching" position.[1] This abnormal posturing is an extrapyramidal effect and is caused by spasm of the axial muscles along the spinal column.

Causes

It is seen in some cases of severe cerebral palsy and traumatic brain injury or as a result of the severe muscular spasms associated with tetanus.

Opisthotonus can be produced experimentally in animals by transection of the midbrain (between superior and inferior colliculus) which results in severing all the corticoreticular fibers. Hyperextension occurs due to facilitation of the anterior reticulospinal tract caused by the inactivation of inhibitory corticoreticular fibers which normally act upon the pons reticular formation. It has been shown to occur naturally only in birds and placental mammals.

Opisthotonus is more pronounced in infants. Opisthotonus in the neonate may be a symptom of meningitis, tetanus, or severe kernicterus. This marked extensor tone can cause infants to "rear backwards" and stiffen out as the mother or nurse attempts to hold or feed them. Opisthotonus can be induced by any attempt at movement such as smiling, feeding, vocalization, or by seizure activity. A similar tonic posturing may be seen in Sandifer syndrome. Individuals with opisthotonus are quite challenging to position, especially in wheelchairs and car seats.

Opisthotonus can sometimes be seen in lithium intoxication. It is a rare extrapyramidal side effect of phenothiazines, haloperidol, and metoclopramide.

Opisthotonus with the presence of the risus sardonicus is also a symptom of strychnine poisoning.

References

External links


Template:Bone and cartilage navsTemplate:Joint navs

|}

This page uses Creative Commons Licensed content from Wikipedia (view authors).

Around Wikia's network

Random Wiki