COMA-LOCKED IN SYNDROME

SUMMARY

1. The locked-in syndrome is rare and most often caused by a lesion of the ventral pons as a result of basilar artery occlusion.

2. The lesion interrupts the corticobulbar and corticospinal pathways, depriving the patient of speech and the capacity to respond except by vertical gaze and blinking.

3. The lesion typically spares the somatosensory pathways and the ascending RAS responsible for arousal and wakefulness, as well as midbrain structures.

4. Patients are awake and aware of the surrounding environment but may have only the ability to control eye movements.

5. Typically, they can communicate only by using eye blinks and vertical eye movements (efferent abducens nerve fibers controlling horizontal eye movements are commonly destroyed).

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].