Secondary parkinsonism induced by hydrocephalus after subarachnoid and intraventricular hemorrhage

Secondary parkinsonism induced by hydrocephalus after subarachnoid and intraventricular hemorrhage Hydrocephalus can induce secondary parkinsonism (Shahar et al., 1988; Aggarwal et al., 1997; Racette et al., 2004). Physical factors such as increased ventricular pressure near the upper midbrain and basal ganglia are thought to cause mechanical disruption of dopaminergic systems (i.e., the nigrostriatal pathways from the medial substantia nigra to the caudate nuclei and putamen and its frontal projection fibers from the basal ganglia) (Asamoto et al., 1998; Yomo et al., 2006). Symptoms of parkin-sonism are bradykinesia with rigidity, resting tremor, or postural instability, which can deteriorate a patient's physical function and functional recovery (Racette et al., 2004). Parkinsonian symptoms can be controlled by dopaminergic medication, meaning that the accurate diagnosis of secondary parkinsonism is important for proper management of stroke patients (Shahar et al., 1988; Aggarwal et al., 1997; Racette et al., 2004). Previous studies have investigated dopaminergic system dysfunction induced by hydrocephalus using single photon emission computed tomogra-phy (SPECT) and position emission tomography (PET) scanning However, these methods are limited in their ability to clearly present the dopaminergic system. Recently, 18