Editing Coma (section)

===Body movements===
Assessment of the brainstem and cortical function through special reflex tests such as the [[oculocephalic reflex]] test (doll's eyes test), [[Vestibulo-ocular reflex|oculovestibular reflex]] test (cold caloric test), [[corneal reflex]], and the [[gag reflex]].<ref>{{Cite web|url=https://www.lhsc.on.ca/media/2014/download|title=Neurological Assessment Tips|date=2014|website=London Health Sciences Centre}}</ref> Reflexes are a good indicator of what [[cranial nerves]] are still intact and functioning and is an important part of the physical exam. Due to the unconscious status of the patient, only a limited number of the nerves can be assessed. These include the cranial nerves number 2 (CN II), number 3 (CN III), number 5 (CN V), number 7 (CN VII), and cranial nerves 9 and 10 (CN IX, CN X).

{| class="wikitable"
!Type of reflex
!Description
|-
|[[Oculocephalic reflex]]
|Oculocephalic reflex, also known as the doll's eye, is performed to assess the integrity of the brainstem.
* Patient's eyelids are gently elevated and the cornea is visualized.
* The patient's head is then moved to the patient's left, to observe whether the eyes stay or deviate toward the patient's right; same maneuver is attempted on the opposite side.
* If the patient's eyes move in a direction opposite to the direction of the rotation of the head, then the patient is said to have an intact brainstem.
* However, failure of both eyes to move to one side can indicate damage or destruction of the affected side. In special cases, where only one eye deviates and the other does not, this often indicates a lesion (or damage) of the [[medial longitudinal fasciculus]] (MLF), which is a brainstem nerve tract.
|-
|[[Pupillary light reflex]]
|Pupil reaction to light is important because it shows an intact retina, and cranial nerve number 2 (CN II)
* If pupils are reactive to light, then that also indicates that the cranial nerve number 3 (CN III) (or at least its [[parasympathetic]] fibers) are intact.
|-
|[[Caloric reflex test|Oculovestibular reflex<br>(Cold Caloric Test)]]
|Caloric reflex test also evaluates both cortical and brainstem function
* Cold water is injected into one ear and the patient is observed for eye movement
* If the patient's eyes slowly deviate toward the ear where the water was injected, then the brainstem is intact, however failure to deviate toward the injected ear indicates damage of the brainstem on that side.
* The cortex is responsible for a rapid [[nystagmus]] away from this deviated position and is often seen in patients who are conscious or merely lethargic.
|-
|[[Corneal reflex]]
|The corneal reflex assesses the proper function of the [[trigeminal nerve]] (CN 5) and [[facial nerve]] (CN 7), and is present at infancy.
* Lightly touching the [[cornea]] with a tissue or cotton swab induces a rapid blink reflex of both eyes.
* Touching the sclera or eyelashes, presenting a light flash, or stimulating the [[supraorbital nerve]] will induce a less rapid but still reliable response.
* Those in a comatose state will have altered corneal reflex depending on the severity of their unconscious and the location of their lesion.<ref>{{cite book |doi=10.1016/B978-1-4160-3618-0.X1000-4 |title=Textbook of Clinical Neurology |date=2007 |isbn=978-1-4160-3618-0 }}{{pn|date=December 2024}}</ref>
|-
|[[Gag reflex]]
|The gag, or pharyngeal, reflex is centered in the medulla and consists of the reflexive motor response of pharyngeal elevation and constriction with tongue retraction in response to sensory stimulation of the pharyngeal wall, posterior tongue, [[tonsil]]s, or faucial pillars.
* This reflex is examined by touching the posterior [[pharynx]] with the soft tip of a cotton applicator and visually inspecting for elevation of the pharynx.
* Those in comatose states will often demonstrate poor gag reflexes if there has been damage to their glossopharyngeal (CN 9) or vagus nerve (CN 10).<ref>{{cite book |doi=10.1016/b978-141603618-0.10013-x |chapter=Cranial Nerves IX (Glossopharyngeal) and X (Vagus) |title=Textbook of Clinical Neurology |date=2007 |last1=Hermanowicz |first1=Neal |pages=217–229 |isbn=978-1-4160-3618-0 }}</ref>
|}

[[File:Decorticate.PNG|thumb|alt=Illustration of characteristic pose laying face-up, arms bent with knuckles held together at sternum, legs together and straight|[[Decorticate posturing]], indicating a [[lesion]] at the [[red nucleus]] or above. This positioning is stereotypical for upper [[brain stem]], or [[Cortex (anatomy)|cortical]] damage. The other variant is [[decerebrate posturing]], not seen in this picture.]]

Assessment of posture and physique is the next step. It involves general observation about the patient's positioning. There are often two stereotypical postures seen in comatose patients. [[Decorticate posturing]] is a stereotypical posturing in which the patient has arms [[Flexion|flexed]] at the elbow, and arms adducted toward the body, with both legs [[Extension (kinesiology)|extended]]. [[Decerebrate posturing]] is a stereotypical posturing in which the legs are similarly extended (stretched), but the arms are also stretched (extended at the elbow). The posturing is critical since it indicates where the damage is in the central nervous system. A decorticate posturing indicates a lesion (a point of damage) at or above the [[red nucleus]], whereas a decerebrate posturing indicates a lesion at or below the red nucleus. In other words, a decorticate lesion is closer to the [[Cortex (anatomy)|cortex]], as opposed to a decerebrate posturing which indicates that the lesion is closer to the [[brainstem]].