Diagnosis: The Man With the Wobbly Walk
The middle-aged man was watching late-night reruns on television when his legs suddenly began to shake and jerk. He watched helplessly as his limbs disobeyed his mental command to stop moving. He felt nauseated, sweaty, out of breath. His heart raced. He called to his wife. She hurried out to see him, then called 911.
THE HOSPITAL, AGAIN
By the time the man arrived at Huntsville Hospital, in Huntsville, Ala., the twitching in his legs had subsided and his heart and breathing were back to normal.
The man told the emergency-room doctor that he hadnâ€™t felt great for about a year. He had been dizzy, tired, depressed. He figured that at 56 he was just getting old.
Then one day about two weeks earlier, while at work, he stood up, and all of a sudden everything felt off-kilter, as if the ground were tilted. That scared him, and he called his doctor. The doctor sent the patient to that same emergency room at Huntsville Hospital. He was there for several days, being poked, prodded, imaged and stuck. But they couldnâ€™t figure out what was wrong with him.
The only abnormality found during that first hospital stay was that his blood pressure dropped when he stood up. Why this happened wasnâ€™t clear, but doctors gave him a set of compression stockings and a pill to keep his blood pressure up, then sent him home.
But at home, he was still dizzy and having trouble walking. He tried to go back to work, but he couldnâ€™t drive. Behind the wheel, he felt as if he were veering off the road, even though he could see he wasnâ€™t. A few days later, his legs started jumping around. Thatâ€™s when he went back to the hospital.
The emergency-room doctors didnâ€™t know what to make of this patient the second time around. The patient felt too dizzy to stand up. The rest of his exam, though, was normal. So were the blood tests, electrocardiogram (EKG) and head CT scan â€” just as they were the first time. The doctor suspected that his symptoms were related to anxiety, but he wasnâ€™t sure.
When Dr. Robert Centor, the attending physician, came to see the patient, he asked why the patient had come to the hospital.
â€œEvery time I get up, I get dizzy,â€ the man replied. He could hardly walk, he told the doctor. Can you show us how you walk? the doctor asked.
â€œDonâ€™t let me fall,â€ the patient responded. An intern and a resident stood on either side as the man eased himself up. He stood with his feet strangely far apart. When he took a few steps, he wobbled dangerously. His heel and toes hit the ground at the same time, making a strange slapping sound.
That walk was the key, Centor told me. He wasnâ€™t sure of the diagnosis, but the walk suggested where to look. It had to be somewhere in the patientâ€™s nervous system. The team decided to get an M.R.I. to see if the problem was in his brain; a nerve-conduction study would determine if it was in his legs. They would also send off blood tests to look for the most common causes of this kind of imbalance.
Cerebellar disease: A problem with the area of the brain responsible for coordinating muscle activity.
Tabes dorsalis: An advanced form of syphilis that attacks the spinal cord and causes a loss of balance.
Peripheral neuropathy: A loss of sensation in the nerve endings, which can be caused by diabetes, infections or toxics, including heavy metals.
Vitamin-B12 deficiency: Can cause problems in the brain, the spinal cord and the nerve endings, resulting in this kind of wobble.
GOOD QUESTIONS, GOOD ANSWERS
Once you know the right questions to ask, itâ€™s much easier to get useful answers. The M.R.I. of the brain was normal â€” so it wasnâ€™t the cerebellum. The nerve conduction tests, however, were not. The nerves to the muscles were fine, but those responsible for sensation showed that the patientâ€™s feet could not sense the floor. Why? Blood tests showed it wasnâ€™t diabetes; it wasnâ€™t syphilis; it wasnâ€™t an infection. Late that afternoon the answer finally arrived: The neuropathy was caused by a lack of vitamin B12.
THE RIGHT STUFF
Vitamin B12 is used by every cell in the body, but a deficiency usually shows up first in nerve cells, where it can cause a wide variety of symptoms including neuropathy, and in red blood cells, where it causes anemia. Although B12 is found in eggs, milk and meat, it is one of the most common nutritional deficiencies in this country, because the process of absorbing the vitamin is complex and easily disrupted. Surgery, medications and illness can all affect B12 absorption. Helicobacter pylori, a bacterium linked to ulcer formation, can cause a deficiency. As can diseases of the small intestines like celiac or Crohnâ€™s. In still others, the immune system mistakenly goes after the parts of the absorption process leading to vitamin-B12 deficiency â€” a condition known as pernicious anemia.
But no matter what the cause, flooding a patientâ€™s body with B12 will reverse the deficiency â€” and usually the problems caused by it.
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