D-lactic acidosis and ataxia in a man with Crohn disease.

CMAJ • FEBRUARY 23, 2010 • 182(3) © 2010 Canadian Medical Association or its licensors 276 A49-year-old man presented to the emergency department with an eight-hour history of unsteady gait, impaired concentration, difficulty speaking and blurry vision, which had developed over the previous seven hours. During the preceding two days, he had been excessively thirsty and drank large amounts of water, cola and a “sports drink.” He had eaten a large portion of rice with dinner the evening before presentation. On the day he presented, he had awoken in the morning feeling dizzy. As he was leaving for work, he had experienced difficulty using his keys and turning doorknobs. The patient’s medical history included Crohn disease and two major small-bowel resections at 33 and 35 years of age that had left about one metre of small intestine. He had undergone an esophageal bougienage three weeks earlier for a stricture related to Crohn disease. After the bougienage, the patient had regained his ability to consume solids and dramatically increased his caloric intake to regain weight. His diet consisted mainly of fast food, candy bars and soft drinks. The patient reported that he did not smoke, consume substantial amounts of alcohol or have any drug allergies. On a daily basis, he took prednisone 20 mg, loperamide 2–4 mg, vitamin B12 and multivitamins. Except for the addition of prednisone for the Crohn-related stricture, his regimen of medications had not changed during the past year. He had experienced no changes in his usual Crohn symptoms. On clinical examination, the patient was alert, oriented and not in distress. His vital signs were normal and he had no significant postural changes. Other than mild vertical and horizontal nystagmus, the results of cranial nerve testing were normal. The patient had truncal ataxia and notable dysmetria on finger-nose testing. He had an unsteady, wide-based gait and could not tolerate walking more than five steps. Rapid alternating movements and heel-shin tests were normal. His strength and reflexes, and the results of sensory testing, were normal. The rest of the clinical examination was unremarkable except for midline abdominal surgical scars. Initial laboratory investigations are presented in Table 1 and include a serum carbon dioxide level of 10 mmol/L with an anion gap of 22 mEq/L. Complete blood count, creatinine, coagulation studies, liver enzymes and urinalysis were within normal limits. Arterial blood gas analysis showed a pH of 7.21, partial pressure of carbon dioxide (pCO2) of 23, partial pressure of oxygen (pO2) of 119 and HCO3 of 9. Serum lacCases