SLC6A3 and Alzheimer disease: Studies have shown that co-existing AD-related pathologies, including amyloid β and tau abnormalities, are associated with poorer cognitive outcomes following shunt procedures.77, 78, 79 Furthermore, progressive ventricular enlargement has also been observed in patients with PD80 and a handful of neuroimaging studies using dopamine transporter (DAT) imaging have identified striatal dopaminergic deficits in more than 60% of patients with iNPH, which are partially reversed by shunt surgery.81