Clinical Geriatrics

I first met Mr. M, a 79-year-old man, after he fell and fractured his femur. He reported to me that for the past two years he has noted reduced sensation from his knees down and has not felt steady ambulating. This has progressed to the point where he currently spends most of his day in a wheelchair. He uses a walker or cane when transferring from his bed, chair, or car. He has continued to drive, though admitted he recognizes that it is not safe since he cannot feel the bottom of his feet, and at times is not sure whether he is applying the brakes correctly. Mr. M stated that he tries to drive on roads that are less crowded, but said that this is not always possible.

When the patient presented to the hospital with his fractured femur, the radiologist noted that he also had radiological evidence of Paget’s disease with involvement in the bone that fractured. The orthopedic surgeon chose to repair his leg in two stages, with the first being a bone biopsy to assess the integrity of his bone and to rule out Paget’s disease transformation to osteogenic sarcoma, a rare but often deadly occurrence.

He was taking thyroid medication for hypothyroidism that had been diagnosed several years ago and some medications for high blood pressure. Mr. M was anemic with borderline high mean corpuscular volume levels. He had no position or vibratory sense in his feet and was unable to feel either sharp or dull stimuli below his knees when tested. His attention span was good, though he could remember only one of three objects in five minutes, and his family reported a decline in his cognition over the past few years. Clinically, I was convinced that he had a B₁₂ deficiency and suggested that a level be obtained. His B₁₂ level returned low at 152, and a diagnosis of B₁₂ deficiency was confirmed.

While this patient is not uncommon and clearly has several serious problems, I could only wonder whether he would have been in this same situation if he had been diagnosed with a B₁₂ deficiency earlier. He reported going to a physician for his ongoing medical care and seemed to have been resigned to his disability, though he admitted that no explanation was given to him as to why he had lost his independence.

I have seen several other similar cases in the past few months, and therefore thought it would be a good idea to review B₁₂ deficiency and to raise the level of suspicion of this treatable but potentially devastating problem. While many persons who are vitamin B₁₂-deficient have a megaloblastic anemia, this is not an essential part of the problem, and other serious sequelae may be present prior to anemia being manifest, including impaired sense of smell, loss of deep-tendon reflexes, personality or memory changes, tachycardia, tingling, and numbness of the hands and feet, unsteady gait, difficulty in proprioception, neuropathic pain, and glossitis, among many others. Anemia has its own set of symptoms, including fatigue.

Dr. Thomas Addison was the first to describe what is now called pernicious anemia, though it was originally referred to as Addison’s anemia. In 1907, Dr. Richard Cabot reported a series of 1200 patients with this disorder. They had an average survival of 1-3 years, and thus the name “pernicious anemia.” In a study worthy of medical history, Dr. William Bosworth Castle was said to have performed a study whereby he ate raw hamburger meat and regurgitated it after 1 hour; he fed his stomach’s content to a group of 10 patients and compared effects to a control group that was fed untreated raw hamburger meat. The study group reportedly responded to this treatment with improvement in their anemia, leading to the conclusion that there was some “intrinsic factor” present in gastric juice that was essential.

Until 1920, pernicious anemia was considered to be a fatal disease. Dr.