Potential of integrated [18F] fluorodeoxyglucose positron-emission tomography/CT in identifying vulnerable carotid plaques.

BACKGROUND AND PURPOSE: There is a need for improved risk stratification of patients with TIA/stroke and carotid atherosclerosis. The purpose of this study was to prospectively investigate the potential of integrated (18)F-FDG PET/MDCT in identifying vulnerable carotid plaques. MATERIALS AND METHODS: Fifty patients with TIA/stroke with an ipsilateral carotid plaque causing <70% stenosis and a plaque on the contralateral asymptomatic side underwent integrated (18)F-FDG PET/MDCT within 36.1 ± 20.0 days (range, 9-95 days) of the last symptoms. Carotid plaque (18)F-FDG uptake was measured as both the mean and maximum blood-normalized SUV, known as the TBR. Using MDCT, we assessed volumes of vessel wall and individual plaque components. RESULTS: Mean TBR was only significantly larger in the ipsilateral plaques of patients who were imaged within 38 days (1.24 ± 0.04 [SE] versus 1.17 ± 0.05, P = .014). This also accounted for maximum TBR (1.53 ± 0.06 versus 1.42 ± 0.06, P = .015). MDCT-assessed vessel wall and LRNC volumes were larger in ipsilateral plaques of all patients (982.3 ± 121.3 versus 811.3 ± 106.6 mm(3), P = .016; 164.7 ± 26.1 versus 134.3 ± 35.2 mm(3), P = .026, respectively). CONCLUSIONS: In the present study, (18)F-FDG PET only detected significant differences between ipsilateral and contralateral asymptomatic plaques in patients with TIA/stroke who were imaged within 38 days, whereas MDCT detected larger vessel wall and LRNC volumes, regardless of time after symptoms. In view of the substantial overlap in measurements of both sides, it remains to be determined whether the differences we found will be clinically meaningful.

Glossopharyngeal neuralgia triggered by non-noxious stimuli at multiple cephalic and extracephalic sites.

Glossopharyngeal neuralgia (GN) triggered by non-noxious stimuli at multiple cephalic and extracephalic sites with positron emission tomography (PET) evidence for involvement of the upper brainstem has never been reported. We present such a patient, a 73-year-old man who since the age of 50 had suffered from GN with a high recurrence rate and very severe unilateral, non-familial GN episodes with very easy trigger zones widely extending beyond the n IX territory. Extensive neuroimaging and neurophysiological tests detected no precise underlying cause. PET scan revealed activation in the upper brainstem on extracephalic triggers. Single-fibre electromyography data will be discussed. We hypothesize that deficient inhibition as seen in trigeminal nociceptive reflexes on the level of brainstem interneurons, a functional lesion in the primary somatosensory cortex-sensory thalamic nuclei circuit and the dorsal column-thalamic pathway both activated by light touch may in part be involved in the extracephalic triggering.

Hydroxocobalamin, a nitric oxide scavenger, in the prophylaxis of migraine: an open, pilot study.

Drugs which directly counteract nitric oxide (NO), such as endothelial receptor blockers, NO-synthase inhibitors, and NO-scavengers, may be effective in the acute treatment of migraine, but are also likely to be effective in migraine prophylaxis. In the underlying pilot study the prophylactic effect of the NO scavenger hydroxocobalamin after intranasal administration in migraine was evaluated. Twenty patients, with a history of migraine of > 1 year and with two to eight migraine attacks per month, were included in an open trial. A baseline period was followed by an active treatment period of 3 months with 1 mg intranasal hydroxocobalamin daily. Patients were instructed to complete a diary in which details of each attack were described. A reduction in migraine attack frequency of >/ or = 50% was seen in 10 of 19 patients, which corresponds to 53% of the patients (responders). A reduction of > or = 30% was noted in 63% of the patients. The mean attack frequency in the total study population showed a reduction from 4.7 +/- 1.7 attacks per month to 2.7 +/- 1.6 (P < 0.001). For the responders the migraine attack frequency was reduced from 5.2 +/- 1.9 (baseline) to 1.9 +/- 1.3 attacks per month (P < 0.005), while for those who did not respond a non-significant reduction was found: 4.1 +/- 1.4 to 3.7 +/- 1.5 (P > 0.1). A reduction was also observed for the total duration of the migraine attacks per month, the total number of migraine days per month and the number of medication doses for acute treatment used per month. This is the first prospective, open study indicating that intranasal hydroxocobalamin may have a prophylactic effect in migraine. As a percentage of responders in prophylactic trials of > 35-40% is unlikely to be a placebo effect, a double-blind study is warranted.

[Two patients with isolated vasculitis of the central nervous system]. / Twee patiënten met geïsoleerde vasculitis van het centrale zenuwstelsel.

Over the course of time, a 43-year-old woman and a 39-year-old man developed visual, sensory, motor, cerebellar and cognitive disturbances. Initially these occurred episodically, but later became continuous. Isolated vasculitis of the central nervous system was only diagnosed after brain biopsies were taken, upon which treatment with prednisone and cyclophosphamide was instituted. In both patients the symptoms persisted for 23 and 19 months, respectively, after treatment was initiated, but no new symptoms developed. The woman did, however, develop pancytopenia as a result of the cyclophosphamide treatment. Non-infectious vasculitis of the small veins and arterioles of the brain is lethal if left untreated. Leptomeningeal and cortical biopsy is essential in establishing the diagnosis in order to rule out other causative diseases. Combination therapy consisting of prednisone and cyclophosphamide for at least one year is recommended. The efficacy of this treatment is unknown due to the rarity of this disease.