Abstract
Parkinsonism can be caused by a variety of factors, such as drugs, vascular disease, toxicity, infection, and autoimmune, neoplastic, metabolic and functional diseases. Parkinsonism is associated with both motor and nonmotor clinical symptoms. Notably, the accurate diagnosis of Parkinson's disease and parkinsonism remains challenging. Meningioma is the most common type of extraparenchymal brain tumor, which typically presents with headaches, focal symptoms and cranial nerve symptoms. Parkinsonism is a rare initial symptom of meningioma. The present report describes an unusual case of a 70-year-old man who presented with tremors, pill-rolling tremors and left-sided rigidity. In addition, the patient exhibited asymmetrical bradykinesia (left > right) and mild postural instability. Magnetic resonance imaging (MRI) revealed a homogeneously enhanced cerebral falx meningioma and dilated tortuous veins. Dopamine transporter single-photon emission computed tomography revealed decreased (123)I-ioflupane uptake in the right striatum. The patient underwent two surgical interventions due to tumor growth and symptom deterioration. Pathological examination revealed transitional meningioma. Postoperatively, the symptoms of the patient improved, and MRI revealed a residual tumor without basal ganglia mechanical compression or venous congestion. It was hypothesized that involuntary movements, including parkinsonism in the present case, were associated with the disruption of the cortico-cerebellar-cortical and the dentato-rubro-olivary pathways (the Guillain-Mollaret triangle) due to tumor mechanical compression and venous congestion. Meningioma, which is a type of extraparenchymal tumor, is more likely to cause mechanical compression and venous congestion than the infiltration of the basal ganglia circuit, leading to symptom improvement after surgical removal. This case highlights the importance of considering meningioma as a rare cause of lateral parkinsonism and its potential for symptom improvement after surgical intervention.