Byline: Jamir. Rissardo, Ana. Fornari Caprara, Juliana. Freitas Silveira

Fahr's disease (FD) is a rare inherited or sporadic disorder characterized by symmetrical calcium deposits in the basal ganglia and dentate nuclei with the absence of biochemical abnormalities. Clinical manifestations can start at different ages with a variety of presentations. We report a case of a 68-year-old male who presented to our service with clinical signs and symptoms of pure and progressive dementia. Afterward, he developed mood changes, and finally, movement disorders, probably due to a sporadic form of FD. Noncontrast cranial computed tomography scan demonstrated scattered brain parenchyma, bilateral calcifications in the basal ganglia, and dentate nuclei. Standard blood tests were within the normal limits. In this way, FD can present with pure dementia at onset, reflecting a wide range of neurological manifestations. The diagnosis is challenging, and we proposed an acronym to facilitate the learning of the diagnostic criteria.

Introduction

Fahr's disease (FD), also known as bilateral striopallidodentate calcinosis, is a rare inherited or sporadic disorder, more commonly seen in men. It is characterized by the presence of symmetrical calcium deposits within the basal ganglia and the absence of biochemical abnormalities.[1],[2] Clinical manifestations are variable and may have different age of onset, even in familial FD cases.[3] Neurological dysfunction is usually progressive and includes symptoms of hypokinetic movement disorder and cognitive impairment.[4],[5]

The occurrence of cognitive impairment in bilateral striopallidodentate calcinosis has been rarely reported in the literature.[6] To the author's knowledge, there are four case reports of FD presenting with pure dementia at onset. In this way, we report a case of a 68-year-old male who presented to our service with clinical signs and symptoms of pure and progressive dementia. Afterward, he developed mood changes, and finally, movement disorders, probably due to a sporadic form of FD.

Case Report

A 51-year-old male was admitted to our hospital due to progressive short-term memory impairment with 6 months of onset. He was previously healthy and worked in agriculture. His family history was unremarkable and negative for neurological diseases. Neuropsychological assessment showed mild memory impairment with alterations in sequential complex tasks and calculation. A global cognitive assessment was obtained through the Mini-Mental State Examination, which showed mild cognitive impairment (23/30). His physical examination was normal. Laboratorial tests were within the normal limits, including complete blood count; fasting blood glucose and electrolytes (sodium, potassium, calcium, phosphorus, and magnesium); thyroid, liver, and renal function tests; Vitamin B12; and venereal disease research laboratory, hepatitis B surface antigen, anti-hepatitis C virus, and anti-human immunodeficiency virus types 1 and 2. Given the above clinical manifestations and laboratorial tests results, until this point, the main suspected diagnosis was a dementia with an irreversible cause, such as Alzheimer's disease.

More than 1 year after disease onset, the patient's cognitive function had further deteriorated. Learning and spontaneous recall had declined, and he...