Focused Neurological Evaluation

An 18-year-old boy is struck on the side of the head by a ball during a cricket match. He appears dazed for about 30 s, but is lucid for several minutes before he abruptly becomes stuporous. His limbs on the side opposite the site of the blow are more flaccid than those on the same side as the injury. On arrival in the emergency room 25 min after the accident, he is unresponsive to painful stimuli. His pulse is 40 beats per minute, with an electrocardiography (ECG) revealing no arrhythmias. His blood pressure in both arms is 170/110 mmHg. You are called upon to assess the neurological status. How to proceed?