Secondary Fahr's syndrome mimicking meningoencephalitis.

Introduction and aim. Fahr's disease is a rare neurological disorder characterized by bilateral basal ganglia calcifications. The aim of this report is to highlight a case of Fahr's disease with atypical features such as neck rigidity and peripheral nerve involvement. Description of the case. Here, we present the case of a South Asian patient with secondary Fahr's disease whose clinical presentation mimicked that of meningoencephalitis. The patient had neurological and neuropsychiatric symptoms along with abnormal body movements. She also had restricted neck mobility. Computed tomography of the head revealed bilateral dense calcifications in the basal ganglia suggestive of Fahr's syndrome. Investigations revealed severe hypocalcemia, hyperphosphatemia, and low parathyroid hormone levels, which led to the identification of hypoparathyroidism as the underlying cause. The presence of pre-existing epilepsy and neck rigidity made the diagnosis difficult. The relatively rapid development of symptoms along with the presence of peripheral nerve involvement made this case even more unique. Calcium levels were corrected, and there was a marked symptomatic improvement. Conclusion. Neck rigidity and restricted neck mobility may be present in cases of Fahr's syndrome due to calcifications of the nuchal ligament or other spinal ligaments and thus must be differentiated from meningoencephalitis. Although the symptoms of Fahr's syndrome are generally limited to the central nervous system, there may be involvement of the peripheral nerves as well. [ABSTRACT FROM AUTHOR]