Quantitative analysis of NK1 receptor in the human brain using PET with 18F-FE-SPA-RQ

18F-fluoroethyl-SPA-RQ (18F-FE-SPA-RQ) was recently developed as a radioligand for the measurement of neurokinin 1 (NK1) receptor with PET. In this study, we used 18F-FE-SPA-RQ with PET to visualize and quantify NK1 receptor in the human brain. METHODS: PET scans were performed on 7 healthy men after intravenous injection of 18F-FE-SPA-RQ. Binding potential (BPND) was calculated by the indirect kinetic, simplified reference tissue model (SRTM), and ratio methods. The indirect kinetic method was used as the gold standard method and was compared with the SRTM method, with scan times of 180, 270, and 330 min, and with the ratio method, with time integration intervals of 120-180, 210-270, and 300-330 min. The cerebellum was used as the reference brain region. RESULTS: Regional radioactivity was highest in the caudate head and putamen; mid level in the parahippocampus, cerebral cortex, and thalamus; and lowest in the cerebellum. BPND values by the indirect kinetic method were 3.15 +/- 0.36, 3.11 +/- 0.66, 1.17 +/- 0.25, and 0.46 +/- 0.14 in the caudate, putamen, parahippocampal region, and thalamus, respectively. For cerebral cortical regions, BPND values by the indirect kinetic method were 0.94 +/- 0.23, 0.82 +/- 0.15, 0.76 +/- 0.15, and 0.69 +/- 0.16 in the occipital, temporal, frontal, and anterior cingulate cortices, respectively. BPND values by the SRTM and ratio methods were in good agreement with those by the indirect kinetic method (r = 0.94-0.98). CONCLUSION: The regional distribution of 18F-FE-SPA-RQ was in agreement with previous PET studies and postmortem studies of NK1 receptor in the human brain. The ratio method will be useful for clinical research of psychiatric disorders, for the estimation of NK1 receptor without arterial blood sampling and long dynamic PET.     

Dynamic change of proximal conduction in demyelinating neuropathies: a cervical magnetic stimulation combined with maximum voluntary contraction.

OBJECTIVE: To evaluate conduction abnormalities in the nerves innervating the proximal muscles in demyelinating neuropathies (DN) using cervical magnetic stimulation. METHODS: We applied cervical root magnetic stimulation in the biceps brachii muscles and examined its activity-dependent conduction changes produced by maximal voluntary contraction (MVC) in 12 DN patients (seven chronic inflammatory demyelinating polyradiculoneuropathy and five multifocal motor neuropathy), six motor neuron disease (MND) patients, and 12 healthy volunteers. RESULTS: Defining the upper normal limit of motor threshold (31%) and latency (6.7 ms) of the compound muscle action potential (CMAP) as mean+2SD, most DN patients revealed an abnormality in motor threshold (10/12) and latency (11/12) in contrast to MND patients (motor threshold (1/6) and latency (0/6)). These parameters contribute to the differentiation of DN from MND (P<0.01). Furthermore, the MVC maneuver transiently decreased the CMAP amplitude ratio (after MVC/before MVC x 100) in DN (83+/-18 %) compared with MND (P<0.01). Two of three DN patients who showed normal motor threshold or latency as in MND were successfully differentiated from MND by the MVC maneuver. CONCLUSIONS: In DN patients, conduction abnormality in the nerves innervating the proximal muscles was revealed by cervical magnetic stimulation combined with the MVC maneuver. SIGNIFICANCE: Our results suggested that conduction abnormalities in the proximal nerves innervating the proximal muscles could be evaluated by this method.     

Continuous urinary incontinence presenting as the initial symptoms demonstrating acontractile detrusor and intrinsic sphincter deficiency in multiple system atrophy

Severe stress incontinence due to intrinsic sphincter deficiency may be common in aged women. However stress urinary incontinence could be the initial symptom of severe neurogenic bladder even if no neurological signs have previously been recognized. Urodynamic study is necessary in such a case. Tension-free vaginal tape surgery and intermittent self-catheterization may be one option, but self catheterization might become difficult when the neurological disorders develop. In this case report, we highlight the need for caution in identifying the presence of an occult neurogenic bladder when intending to carry out surgery for patients with severe stress incontinence.     

Current state of fertility preservation for adolescent and young adult patients with gynecological cancer

International Journal of Clinical Oncology - Although the incidence of the various gynecological cancers has been increasing in recent years, long-term survival is now possible for many patients...