Do not Squeeze the Toenails or Administer a Painful Stimulus to the foot to Test Response to Pain in Comatose Patients as this may Trigger a Spinal Reflex that may be seen even in Brain-Dead Patients



Do not Squeeze the Toenails or Administer a Painful Stimulus to the foot to Test Response to Pain in Comatose Patients as this may Trigger a Spinal Reflex that may be seen even in Brain-Dead Patients


Jose I. Suarez MD



The evaluation of the comatose patient using the Glasgow Coma Scale (GCS) requires testing the respective modalities of eye opening, verbal response, and motor response. In testing motor response, it is important to precisely characterize the degree of motor responsiveness. This helps to characterize the degree of coma and it may also have prognostic value when assessing a patient after hypoxic or ischemic injury.


Watch Out For

One specific element in the motor exam that often creates confusion for the examiner (and the family) is the interpretation of the patient’s response to a painful stimulus in the lower extremity. The confusion relates to the issue of differentiating between a purposeful withdrawal response to pain versus a simple spinal reflex withdrawal to pain. The importance of this differentiation is that a purposeful withdrawal response to pain may be a good prognostic sign in patients with hypoxic-ischemic injury, whereas a spinal reflex withdrawal may be seen in brain-dead patients. It is important to realize that brain-dead patients may exhibit a variety of movements that are spinally mediated and do not imply intact brain-stem or cortical function. Among the possible movements are extensor plantar responses, jerks of the fingers, toe flexion, and a Lazarus sign, which involves flexion of the arms at the elbow, adduction of the shoulders, lifting of the arms, dystonic posturing of the hands, and crossing of the hands. Furthermore, a triple-flexion response with dorsiflexion at the ankle, knee, and hip may be seen with distal lower-extremity pain stimulation, which may appear at first glance to be a purposeful withdrawal response but is actually a spinal cord reflex.

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Jul 1, 2016 | Posted by in ANESTHESIA | Comments Off on Do not Squeeze the Toenails or Administer a Painful Stimulus to the foot to Test Response to Pain in Comatose Patients as this may Trigger a Spinal Reflex that may be seen even in Brain-Dead Patients

Full access? Get Clinical Tree

Get Clinical Tree app for offline access