Prospective flutemetamol positron emission tomography and histopathology in normal pressure hydrocephalus.

UNLABELLED: BACKGOUND/OBJECTIVE: To determine the level of association between uptake of the amyloid positron emission tomography (PET) imaging agent [(18)F]flutemetamol and the level of amyloid-ß measured by immunohistochemical and histochemical staining in a frontal cortical region biopsy site. METHODS: Seventeen patients with probable normal pressure hydrocephalus (NPH) underwent prospective [(18)F]flutemetamol PET and subsequent frontal cortical brain biopsy during ventriculoperitoneal shunting. Tissue amyloid-ß was evaluated using the monoclonal antibody 4G8, thioflavin S and Bielschowsky silver stain. RESULTS: Four of the 17 patients (23.5%) had amyloid-ß pathology based on the overall pathology read and also showed increased [(18)F]flutemetamol uptake. [(18)F]Flutemetamol standardized uptake values from the biopsy site were significantly associated with biopsy specimen amyloid-ß levels (Pearson's r = 0.67; p = 0.006). There was also good correlation between the biopsy specimen amyloid-ß level and uptake of [(18)F]flutemetamol in the region contralateral to the biopsy site (r = 0.67; p = 0.006), as well as with composite cortical [(18)F]flutemetamol uptake (r = 0.65; p = 0.008). The blinded visual read showed a high level of agreement between all readers (κ = 0.88). Two of 3 readers were in full agreement on all images; 1 reader disagreed on 1 of the 17 NPH cases. Blinded visual assessments of PET images by 1 reader were associated with 100% sensitivity to the overall pathology read, and assessments by the 2 others were associated with 75% sensitivity (overall sensitivity by majority read was 75%); specificity of all readers was 100%. CONCLUSIONS: [(18)F]Flutemetamol detects brain amyloid-ß in vivo and shows promise as a valuable tool to study and possibly facilitate diagnosis of Alzheimer's disease both in patients with suspected NPH and among the wider population.

Effect of preoperative intravenous carbohydrate loading on preoperative discomfort in elective surgery patients.

BACKGROUND AND OBJECTIVE: We studied the effect of three different fasting protocols on preoperative discomfort and glucose and insulin levels. METHODS: Two hundred and ten ASA I-III patients undergoing general or gastrointestinal surgery were randomly assigned to three groups: overnight intravenous 5% glucose infusion (1000 ml), carbohydrate-rich drink (400 ml) at 6-7 a.m., or overnight fasting. The subjective feelings of thirst, hunger, mouth dryness, weakness, tiredness, anxiety, headache and pain of each patient were questioned preoperatively using a visual analogue scale. Serum glucose and insulin levels were measured at predetermined time points preoperatively. RESULTS: During the waiting period before surgery, the carbohydrate-rich drink group was less hungry than the fasting group (P = 0.011). No other differences were seen in visual analogue scale scores among the study groups. Trend analysis showed increasing thirst, mouth dryness and anxiety in the intravenous glucose group (P < 0.05). The carbohydrate-rich drink group experienced decreasing thirst but increasing hunger and mouth dryness (P < 0.05). In the fasting group, thirst, hunger, mouth dryness, weakness, tiredness and anxiety increased (P < 0.05). Both intravenous and oral carbohydrate caused a significant increase in glucose and insulin levels. CONCLUSION: Intravenous glucose infusion does not decrease the sense of thirst and hunger as effectively as a carbohydrate-rich drink but does alleviate the feelings of weakness and tiredness compared with fasting.

Presacral arteriovenous fistula: case report.

OBJECTIVE AND IMPORTANCE: We describe a case of arteriovenous fistula in front of the sacrum. Drainage induced epidural venous dilation in the sacral spinal canal. The fistula was embolized endoarterially with n-butyl-2-cyanoacrylate via its iliac arterial feeders. In follow-up digital subtraction angiography 1 month later, the fistula was found to be totally closed. The patient was followed up clinically for 2.5 years. She has remained symptom-free. CLINICAL PRESENTATION: A previously healthy 43-year-old woman presented with severe gluteal and perineal pain and a local sensation of hyperesthesia. The primary computed tomographic scan of the lumbosacral spine was normal, and emergency laparoscopy showed no signs of any pathological lesions. Magnetic resonance imaging discovered an unidentified mass in the sacral spinal canal, and the patient was hospitalized for neurosurgery. However, surgery on this mass had to be discontinued because of profuse bleeding, and the patient was referred for angiography. INTERVENTION: Diagnostic catheter angiography revealed a high-flow arteriovenous fistula anterior to the sacrum, and the mass detected earlier by magnetic resonance imaging seemed to be a dilated epidural vein draining the fistula. The feeders of the fistula originated in both internal iliac arteries, and the fistula was occluded via these arteries in two angiographic sessions. CONCLUSION: A paraspinal arteriovenous fistula may have venous drainage through the epidural venous plexus, and the ectatic veins may induce radicular symptomology. To the best of our knowledge, a paraspinal fistula at such a presacral location has not been documented previously. An unidentified mass in the sacral spinal canal should be suspected of being a dilated vascular structure. Prompt angiographic examinations with an option for embolization should be performed, and open surgical intervention should be avoided.