Idiopathic basal ganglia calcification as a differential diagnosis of parkinsonism: a case report in an older adult.

We present the case of a 76-year-old man who was admitted to the emergency room of Dario Fernandez General Hospital, ISSSTE (Mexico City, Mexico) with slurred speech of a few hours of onset. His relevant background included hypertension since he was 68 years-of-age without current treatment, and a posterior cervical laminectomy because of medullar injury when he was 72 years-of-age. During the physical examination, motor aphasia was found. His gait was slow, with short steps and reduced arm swing; his trunk bent forward and there was slight flexion of the neck. Increased muscle tone in the pelvic limbs and muscle stretch reflexes were also found. There were no signs of cerebellar involvement, and the plantar extensor reflex was present. In order to assess parkinsonism, a Unified Parkinson’s Disease Rating Scale (UPDRS) was carried out, resulting in a score of 17 points. No behavioral or psychiatric symptoms were found. Because of these findings, a cranial tomographic scan was carried out (Fig. 1). Symmetrical and bilateral nodular calcifications in the basal ganglia, and the cerebellar dentate nuclei were reported, without evidence of ischemic or hemorrhagic stroke. In order to discard secondary sources of calcinosis; laboratory investigations were carried out: prostatespecific antigen 1.27 ng/mL, parathyroid hormone 71 pg/mL, calcium 8.8 mg/dL, phosphorus 3.30 mg/ dL, magnesium 2.03 mg/dL, alkaline phosphatase 74 IU/L and uric acid 4.3 mg/dL. Consensus among the faculty staff concluded that the final diagnosis was transient ischemic attack and idiopathic basal ganglia calcification (IBGC). The patient was prescribed treatment and appointed for follow-up in 3 months. This entity has a frequency, in the general population, of less than 0.5%, and some authors considered it a rare disease. In 1930, Karl Theodor Fahr described an 81-year-old patient with a long history of dementia, decubitus ulcer and “immobility without paralyses”. Post-mortem examination of the brain showed brain calcifications localized in the semiovale centrum and the striatum. There are a number of names given for this disease including Fahr’s disease bilateral striopallidodentate calcinosis or IBGC (which is codified in the International Classification of Diseases as G23.8), among others; however, the most common name today is IBGC. The main characteristic is bilateral symmetrical calcification of the basal ganglia, thalamus, cerebellum, dentate nucleus and brain hemispheres, in the absence of other metabolic causes of calcinosis – such as hypoparathyroidism. Although still considered idiopathic, there is some evidence of an association with genetic abnormalities; in particular with an autosomic dominant transmission. The clinical characteristics of this condition are circumscribed to movement (mainly parkinsonism), but