|A.||Unresponsiveness to stimuli|
Invariant pulse rate
Positive deep tendon reflexes
Ans. B. Constricted pupils
Brain death is defined as the state of irreversible cessation of all cerebral function with preservation of cardiac activity and maintenance of respiratory and somatic function by artificial means.
In brain death, the pupils are usually mid-sized but may be enlarged. However, they should not be small (constricted). Pupils are mid-position or dilated (4 to 9 mm)
The diagnosis of brain death should be confirmed with the following clinical findings:
The absent brain-originating motor response, including response to pain stimulus above the neck or other brain-originating movements (eg, seizures, decerebrate or decorticate posturing)
Unresponsiveness to any stimuli,
Brainstem damage as evidenced by dilated or mid-sized pupils without light reaction
Absent corneal, gag, and oculovestibular reflexes
Absent sucking or rooting reflexes
Absent cough with tracheal suctioning
Apnea, indicating medullary destruction.
The heart rate should be invariant and does not accelerate to atropine.
Movements originating from the spinal cord or peripheral nerve may occur in brain death including –
Finger flexor movements
Tonic neck reflexes – Passive neck displacements, especially flexion, may be accompanied by complex truncal and extremity movements, including adduction at the shoulders, flexion at the elbows, supination or pronation at the wrists, flexion of the trunk (sitting up to type movements), and neck-abdominal muscle contraction or head-turning to one side. These might be quite dramatic, often called a “Lazarus sign”
Other truncal movements include asymmetrical opisthotonic posturing of the trunk and preservation of superficial and deep abdominal reflexes.
Alternating flexion-extension of the toes with a passive displacement of the foot (undulating toe sign)
The presence or absence of the Babinski sign does not contribute to the diagnosis of brain death; however, the Babinski sign is generally absent and the toe response is often flexor.