Endoscopic submucosal dissection of a squamous cell carcinoma in situ in the anal canal diagnosed by magnifying endoscopy with narrow-band imaging

A 60-year-old female underwent screening colonoscopy. Narrow-band imaging (NBI) without magnification showed a 20-mm, well-demarcated brownish area located close to the dentate line of the anal canal. Conventional white-light imaging revealed an ill-defined, flat lesion with scattered reddish spots at the same site. Magnifying endoscopy with NBI (M-NBI) revealed abnormal microvessels with dilatation, tortuosity, caliber change and various shapes that were similar to the intrapapillary capillary loop patterns seen in esophageal squamous cell carcinoma in situ. Endoscopic submucosal dissection (ESD) was performed, and on histological examination, the resected specimen showed squamous cell carcinoma (SCC) in situ and clear surgical margins. Thus, NBI is an efficient method for detecting superficial SCC in the anal canal and M-NBI may be useful for determining the extent of the lesion. During screening colonoscopy, the anal region should be carefully observed using NBI, as early detection offers a greater opportunity for ESD which is a less invasive procedure.     

Contralateral glissonian pedicle occlusion in a case of portal vein tumor thrombosis

To dissect portal vein branches directly and encircle them separately is a common procedure that is performed to control back flow bleeding during operations for hepatocellular carcinoma with portal vein tumor thrombosis. However, this technique has an increased risk of injuring contralateral portal branches and disseminating thrombosis fragments to the remnant liver. We present an alternative technique using right-sided glissonian pedicle occlusion for hepatocellular carcinoma with left portal vein tumor thrombosis due to complex anatomical vasculatures of the hepatic pedicle. This technique would be very useful for liver resection of hepatocellular carcinoma with the major type of portal vein tumor thrombosis.     

Prominent fatigue in spinal muscular atrophy and spinal and bulbar muscular atrophy: Evidence of activity-dependent conduction block

ObjectivesTo clarify whether patients with spinal muscular atrophy (SMA) or spinal and bulbar muscular atrophy (SBMA) suffer disabling muscle fatigue, and whether activity-dependent conduction block (ADCB) contributes to their fatigue. ADCB is usually caused by reduced safety factor for impulse transmission in demyelinating diseases, whereas markedly increased axonal branching associated with collateral sprouting may reduce the safety factor in chronic lower motor neuron disorders.MethodsWe assessed the fatigue severity scale (FSS) in 22 patients with SMA/SBMA, and in 100 disease controls (multiple sclerosis, myasthenia gravis, chronic inflammatory demyelinating polyneuropathy (CIDP), and axonal neuropathy). We then performed stimulated-single fibre electromyography (s-SFEMG) in the extensor digitorum communis (EDC) muscle of 21 SMA/SBMA patients, 6 CIDP patients, and 10 normal subjects.ResultsThe FSS score was the highest in SMA/SBMA patients [4.9 ± 1.1 (mean ± SD)], with 81% of them complaining of disabling fatigue, compared with normal controls (3.5 ± 1.0), whereas patients with multiple sclerosis (4.3 ± 1.6), myasthenia gravis (4.0 ± 1.6) or CIDP (4.3 ± 1.4) also showed higher FSS score. When 2000 stimuli were delivered at 20 Hz in s-SFEMG, conduction block of single motor axons developed in 46% of patients with SMA/SBMA, and 40% of CIDP patients, but in none of the normal controls.ConclusionSMA/SBMA patients frequently suffer from disabling fatigue presumably caused by ADCB induced by voluntary activity.SignificanceADCB could be the mechanism for muscle fatigue in chronic lower motor neuron diseases.     

Patterns of sensory nerve conduction abnormalities in Fisher syndrome: More predominant involvement of group Ia afferents than skin afferents

ObjectiveTo elucidate the features of sensory nerve involvement in Fisher syndrome (FS), this study extensively investigated sensory electrophysiology.MethodsIn 47 consecutive FS patients, results of sensory nerve conduction studies in the median, ulnar and sural nerves, soleus H-reflexes, and median or tibial somatosensory-evoked potentials (SEP) were reviewed. Because of the large effects of age on amplitude of sensory nerve action potentials (SNAP), we strictly defined reduction of SNAP amplitudes by using a nomogram which age and amplitude obtained from 87normal subjects.ResultsIn routine nerve conduction studies, SNAP amplitude was reduced only in 32% of the patients, and conduction velocity was decreased in 2%. In contrast, soleus H-reflexes were frequently absent or reduced (67%). SEPs were abnormal only in 17%.ConclusionsIn FS, absent soleus H-reflexes are the most frequent electrophysiologic abnormalities, whereas SNAPs amplitudes are rarely affected. The pattern is characterized by predominant involvement of group Ia afferents with relatively preserved cutaneous afferents without evidence suggestive of demyelination.SignificanceThe major targets of immune attack by anti-GQ1b antibodies in FS appear to be group Ia neurons in the dorsal root ganglia, and this is presumably responsible for ataxia and areflexia in FS.     

Successful radiofrequency catheter ablation of common atrial flutter at the bottom of a coronary sinus diverticulum

We describe a patient who underwent radiofrequency (RF) catheter ablation of cavo-tricuspid isthmus-dependent atrial flutter (AFL). Extensive ablation at the isthmus failed to terminate the AFL. A coronary sinus (CS) diverticulum arising from the proximal portion of the middle cardiac vein was found near the isthmus. An RF energy application at the bottom of the CS diverticulum resulted in completion of a bidirectional block line at the isthmus, as well as AFL termination.     

Social isolation perturbs experience‐driven synaptic glutamate receptor subunit 4 delivery in the developing rat barrel cortex

In neonates, the stress of social isolation can alter developing neural circuits and cause mental illness. However, the molecular and cellular bases for these effects are poorly understood. Experience‐driven synaptic AMPA receptor delivery is crucial for circuit organisation during development. In the rat, whisker experience drives the delivery of glutamate receptor subunit 4 (GluA4) but not glutamate receptor subunit 1 (GluA1) to layer 4–2/3 pyramidal synapses in the barrel cortex during postnatal day (P)8–10, whereas GluA1 but not GluA4 is delivered to these synapses during P12–14. We recently reported that early social isolation disrupts experience‐driven GluA1 delivery to layer 4–2/3 pyramidal synapses during P12–14. Here, we report that neonatal isolation affects even earlier stages of development by preventing experience‐dependent synaptic GluA4 delivery. Thus, social isolation severely affects synaptic maturation throughout early postnatal development.