Sveto Gacinovic

L-dopa–responsive Parkinson's syndrome in association with phenylketonuria: In vivo dopamine transporter and D2 receptor findings

Reports of parkinsonism in phenylketonuria are exceedingly rare. We report on a patient who had received a delayed diagnosis of phenylketonuria as an infant and subsequently developed levodopa‐responsive parkinsonism at the age of 33. Single‐photon emission computed tomography (SPECT) using 123I‐FP‐CIT ([123)I]‐2 beta‐carbomethoxy‐3beta‐(‐4‐iodophenyl)‐N‐(3‐fluoropropyl)‐nortropane) used to measure dopamine transporter levels on two occasions, 7 and 9 years after the onset of neurological symptoms, were normal. Iodine‐123‐iodo‐lisuride SPECT (IBZM) imaging, however, showed reduced caudate over putamen binding. This combination of imaging findings indicates a possible upregulation of postsynaptic D2 receptors in the context of intact presynaptic dopamine nerve terminal density.

Parkinsonism due to Kernohan notch: Clinical, structural, and functional imaging correlates

A man aged 27 years fell backward down stairs, striking his head and losing consciousness. In the emergency department, he had a Glasgow Coma Score of 3, and his pupils were fixed and dilated. There was no significant hypoxia after the injury. CT showed left parieto-occipital fracture and underlying subdural hematoma with minimal midline shift. He underwent left hemicraniectomy and evacuation of subdural and epidural hematoma and required 2 weeks of postoperative respiratory support in an intensive care unit. As he regained voluntary movement, he had persistent slowing of left-sided movements and left hand tremor in the following months. Cerebral MRI 9 months after the injury confirmed left frontoparietal post-traumatic change and a lesion in the right cerebral peduncle involving the midbrain and region of the right substantia nigra (figure). One year after the injury, he had decreased left arm swing with walking, asymmetric facial hypomimia, marked rigidity of the left arm and leg, but no significant pyramidal signs. He could …