Osteomalacia - A commonly misdiagnosed cause of gait difficulty

ABSTRACT

Osteomalacia is a metabolic bone disorder caused by deficiency of Vitamin D and its active metabolites. We report 46 cases of Osteomalacia diagnosed on the basis of clinical features of bone pain, gait difficulty and muscle weakness, plus biochemical findings of a low or normal serum calcium, low phosphorus and raised serum alkaline phosphatase level. Urinary calcium, phosphorus and serum paratharmone levels were also estimated in a few cases. Radiologic features included a typical fuzziness of bone architecture and Looser's zones. Out of 46 cases, 4 were males and 42 females. Age ranged from 13 to 45 years. In 3 males disease was attributed to drugs [Phenytoin, and Carbamazepine] and one to renal osteodystrophy. Out of the 42 female patients 4 were diagnosed as Renal Tubular Acidosis, 3 had Neurofibromatosis associated with Osteomalacia, 1 had malabsorption with Crohn's disease, 2 had hypophosphataemic Osteomalacia, and 2 were diagnosed to be associated with drugs [Rifampicin, Phenytoin and Phenobarbitone]. Eight female patients had onset of symptoms during or after pregnancy [mostly multiparous]. 10 female patients had history of deprivation of sunshine and low Vitamin D diet [deprivational Osteomalacia]. In 12 female patients cause could not be ascertained despite search. All showed good responses to Vitamin D or its analogues. The time between the onset of symptoms and presentation to the department of Neurology where they were diagnosed varied from 1 to 4 years. It is essential that the awareness level of the medical community be raised so that unnecessary morbidity from Osteomalacia may be prevented