Susan was 75 and could barely walk. She had become uncoordinated and lived in constant fear of falling. Each tiny step required enormous effort. Maintaining even a simple daily routine was becoming impossible. Her primary care doctor had referred her to me, and as she succinctly put it during her first visit to my office, her life was a mess. She said that I was her last resort.
Her symptoms had appeared abruptly, which is uncommon in most chronic neurological diseases. That was an important clue. Three months ago she had developed numbness in her fingers and toes. Within several weeks it had spread to her wrists, then her ankles and feet. This numbness did not come and go, she told me. It was constant. As a result, she was dropping things around the house. This clumsiness affected her legs as well, and she felt very unsteady. Although she wasn’t experiencing vertigo or dizziness, she said that she felt off balance, as if she were drunk. When she walked, the numbness was so profound that she couldn’t feel her feet touching the floor.
Susan said that her speech, vision, swallowing, hearing, and strength were normal. So were her bowel and bladder functions. She did not travel and was not in contact with anyone who was ill. Except for mild high blood pressure and high cholesterol, Susan’s medical history was unremarkable.
A brief general exam revealed no abnormalities. She was vibrant and healthy, and the results from her initial neurological testing were normal. She was alert, oriented, and could follow my hands easily with her eyes. Susan’s strength was typical for women her age, but I found severe deficits in her sensation. She could barely feel a light stroke with my fingers, and she couldn’t feel pinpricks well in her hands and feet. When I used a tuning fork to test how well the nerves in her legs were working, Susan couldn’t feel the fork’s vibration until I reached her knees. When I moved her toes up and down, she couldn’t tell me which direction they were moving in (this ability is called proprioception, or sense of joint position).
I checked her muscle stretch reflexes by tapping her elbows, knees, and ankles with a small hammer. The reflexes were absent at the ankles and knees. Her gait was ataxic: Her feet were planted wider apart than normal, and her walk was unsteady, almost wobbly. When she walked, she had to reach out to the wall to keep from falling.
Something else caught my attention. I asked Susan to close her eyes and stand with her feet together and arms outstretched, as if she were carrying a pizza. When she did, she nearly fell over. Neurologists call this response Romberg’s sign, and it signals sensory dysfunction. When patients have this kind of problem, they can’t feel the relationship between their body and their feet, so they must rely on visual cues to keep themselves upright. Without these cues, they lose their spatial orientation and fall.
I finished my examination. Before I could speak, Susan looked at me and said, “Dr. Pettinato, please help me walk again.” I assured her I would.
But I knew it was not going to be easy. The essence of neurology is localization: When I evaluate a patient I ask myself, is this a disease of the brain, spinal cord, nerve, or muscle? In Susan’s case, her decision-making skills as well as her speech, language, vision, hearing, coordination, and swallowing were normal, so I knew her illness did not involve the brain. Spinal cord? Symptoms of spinal-cord disease include numbness of the trunk, weakness, and bowel/bladder dysfunction. She showed none of these problems. Her strength was normal, so I felt confident that Susan did not have a myopathy, or muscle disease. Nerve problems were all that was left. Based on her symptoms and sensory deficits, I knew Susan had a neuropathy.
