Differential association of [11C]PIB and [18F]FDDNP binding with cognitive impairment.

OBJECTIVE: To evaluate associations of [(11)C]Pittsburgh compound B (PIB) and [(18)F]FDDNP with impairment in specific cognitive domains over the broader spectrum comprising cognitively normal elderly subjects, patients with mild cognitive impairment (MCI), and patients with Alzheimer disease (AD). METHODS: Twelve patients with AD, 13 patients with MCI, and 15 cognitively normal elderly subjects were included. Paired [(11)C]PIB and [(18)F]FDDNP PET scans were performed in all subjects. Binding potential (BP(ND)) was calculated using parametric images of BP(ND) for global, frontal, parietal, and temporal cortex; medial temporal lobe; and posterior cingulate. Cognitive functions were assessed using a battery of neuropsychological tests. Linear regression analyses were used to assess associations of [(11)C]PIB and [(18)F]FDDNP binding with cognitive measures. RESULTS: Adjusted for age, sex, and [(18)F]FDDNP binding, higher global [(11)C]PIB binding was associated with lower scores on the Mini-Mental State Examination, immediate and delayed recall of the Rey Auditory Verbal Learning Task (RAVLT), Visual Association Task, and Trail Making Test part B. Conversely, higher [(18)F]FDDNP binding was independently associated with lower scores on immediate recall of the RAVLT. After additional adjustment for diagnosis, higher [(11)C]PIB binding remained independently associated with delayed recall (standardized beta = -0.39, p = 0.01), whereas higher [(18)F]FDDNP binding remained independently associated with immediate recall (standardized beta = -0.32, p = 0.03). When regional binding was assessed using stepwise models, both increased frontal [(11)C]PIB and temporal [(18)F]FDDNP binding were associated with memory, whereas increased parietal [(11)C]PIB binding was associated with nonmemory functions. CONCLUSION: Increased [(18)F]FDDNP binding is specifically associated with impairment of episodic memory, whereas increased [(11)C]Pittsburgh compound B binding is associated with impairment in a broader range of cognitive functions.

Synthesis of 2-(1,1-dicyanopropen-2-yl)-6-(2-[18F]-fluoroethyl)-methylamino-naphthalene ([18F]FDDNP).

2-(1,1-dicyanopropen-2-yl)-6-(2-[18F]-fluoroethyl)-methylamino-naphthalene ([18F]FDDNP) was synthesized in a single step labeling procedure. The precursor, 2-(1,1-dicyanopropen-2-yl)-6-(2-tosyloxyoethyl)-methylamino-naphthalene, was fluorinated with 18F in acetonitrile. After 15 min the reaction mixture was subjected to preparative HPLC purification. The product was isolated from the HPLC eluent with solid-phase extraction, and formulated in an ascorbic acid solution to prevent formation of side products during formulation. Quantitative sticking to tubing and filters was overcome by the addition of polysorbatum-80. This formulation yielded an isotonic, pyrogen-free and sterile solution of [18F]FDDNP. The overall decay-corrected radiochemical yield was 41+/-11% (n=22). Radiochemical purity was >98% and the specific activity was 102+/-56 GBq/micromol at the end of synthesis.

Osteogenesis imperfecta in childhood: effects of spondylodesis on functional ability, ambulation and perceived competence.

We studied the effects of spondylodesis on spinal curvature, functional outcome, level of ambulation and perceived competence in 11 children with osteogenesis imperfecta (OI). Mean age at surgical intervention was 13.1 years (SD 2.5 years) and follow-up amounted to 3.4 years (SD 2.3 years). Spinal curvature was measured according to Cobb. The level of ambulation was scored according to the modified criteria of Bleck. Functional abilities and the amount of parental assistance were scored using the Dutch version of the Pediatric Evaluation of Disability Inventory (PEDI). Perceived competence was measured using the Harter Self-Perception Profile for Children. The amount of fatigue, spinal pain and presence of subjective dyspnea were scored with a visual analog scale. The median progression per year before spondylodesis was 6.1 degrees (interquartile range 2.9 degrees -12.9 degrees ) and after the spondylodesis it was 5.0 degrees (interquartile range 1.6 degrees -11.0 degrees ). No significant progression or regression in the level of ambulation was found. Perceived competence improved slightly. In the total score of the perceived competence, a borderline significant increase was found ( P-value 0.068). We concluded that spinal fusion in children with OI does not materially influence functional ability and level of ambulation. Self-perceived competence seemed to improve after surgery. The amount of pain, fatigue and subjective dyspnea seemed to diminish after spinal surgery. Progression of scoliosis proceeded, as did development of spinal curvature at the junction of the spondylodesis. Therefore, oral or intravenous bisphosphonates before and after spinal surgery should be considered.