Section XI: Neurologic Disorders
A 78-year-old man with a history of prostate cancer presents to the emergency department with weakness affecting his right arm and leg and left face. The weakness began abruptly earlier during the day and is associated with numbness and paresthesias. On physical examination, strength is 4/5 in the right leg and arm. The upper and lower facial muscles fail to move on the left. Babinski sign is positive. Sensation is decreased in the right extremities and on the left face. Based on this information, what is the most likely site of the lesion causing the patient’s symptoms?
D. Multiple spinal cord levels
E. Neuromuscular junction
The answer is A. (Chap. 437) This patient is presenting with symptoms of metastatic neurologic disease, and a careful neurologic examination can localize the site of disease in most patients. The patient has “crossed” weakness and sensory abnormalities, which localizes the lesion to the brainstem. In this setting, the limbs exhibit weakness and sensory symptoms opposite from the facial symptoms. Moreover, the facial weakness localizes to lower motor neuron as it involves both the upper and lower facial muscles. If the upper facial muscles had preserved movement, this might suggest multiple areas of metastatic disease in both the cerebrum and spinal cord.
During a neurologic examination, you ask a patient to stand with both arms fully extended and parallel to the ground with his eyes closed for 10 seconds. What is the name of this test?
The answer is D. (Chap. 437) The ability to perform a thorough neurologic examination is an important skill for all internists to master. A careful neurologic examination can localize the site of the lesion and is important in directing further workup. The components of the neurologic examination include mental status, cranial nerves, motor function, sensory function, gait, and coordination. The motor examination is further characterized by appearance, tone, strength, and reflexes. Pronator drift is a useful tool for determining if upper extremity weakness is present. In this test, an individual is asked to stand with both arms fully extended and parallel to the floor while closing his or her eyes. If the arms flex at the elbows or fingers or there is pronation of the forearm, this is considered a positive test. Other tests of ...