Percutaneous removal of residual intrahepatic stones

In the Orient there is a high frequency of residual intrahepatic stones after biliary tract surgery. Percutaneous removal of residual intrahepatic stones was attempted in a group of 74 patients. Stones were exclusively intrahepatic in 57 patients, whereas 17 patients also had stones in the common bile duct. Biliary strictures were present in 60 cases (81%). A combination of techniques was used, including preshaped angulated catheters, irrigation-suction, balloon dilation of strictures, and crushing of large stones. In 36 cases all stones were removed and in 14 cases most stones were removed, for a success rate of 67.6%. Biliary stricture was the factor most often responsible for failure.     

Psychogenic seizures in children and adolescents: outcome after diagnosis by ictal video and electroencephalographic recording

Psychogenic seizures in 21 nonepileptic children and adolescents, aged 8 to 18 (mean 14.5) years, were recorded by means of video recording and electroencephalography. The episodes included thrashing movements, limb jerking, or staring, with unresponsiveness. Ictal and interictal electroencephalograms showed no abnormalities after antiepileptic medication was discontinued. Fifteen patients had psychogenic seizures spontaneously during recording, and six had seizures in response to suggestion and intravenous saline injection. After the video-electroencephalographic evaluation, patients and families were told that the episodes were emotional in origin. All patients but 1 agreed to remain without antiepileptic medication, and 16 patients (76%) agreed to begin psychiatric treatment. At 6 to 66 (mean 30) months' follow-up, 14 of 18 (78%) were free of episodes. These data indicate that the majority of young patients with psychogenic seizures have a good outcome. A firm diagnosis is critical so that the episodes can be classified and emphasized as medically not worrisome, permitting a shift away from antiepileptic medication and toward psychiatric treatment.     

Prefrontal cortex contributions to episodic retrieval monitoring and evaluation

Although the prefrontal cortex (PFC) plays roles in episodic memory judgments, the specific processes it supports are not understood fully. Event-related potential (ERP) studies of episodic retrieval have revealed an electrophysiological modulation – the right-frontal ERP old/new effect – which is thought to reflect activity in PFC. The functional significance of this old/new effect remains a matter of debate, and this study was designed to test two accounts: (i) that the effect indexes processes linked to the monitoring or evaluation of the products of retrieval in service of task demands, or (ii) that it indexes the number of internal decisions required for a task judgment. Participants studied words in one of two colours. In a subsequent retrieval task, old (studied) and new words were presented in a neutral colour. Participants made initial old/new judgments, along with study colour judgments to words thought to be old. They also indicated their confidence (high/low) in the colour decision. Right-frontal ERP old/new effects were larger for high than for low confidence correct colour judgments, and the magnitude of the right-frontal effect was correlated with the proportions of low confidence judgments that were made. Because the numbers of decisions associated with these response categories are equivalent, these findings do not support a decision-based account of the right-frontal ERP old/new effect. Rather, the correlation between confidence and the magnitude of the effect links it with retrieval monitoring and evaluation processes.     

Breast and axillary tissue MR imaging: correlation of signal intensities and relaxation times with pathologic findings

We tested a variety of inversion-recovery (IR) and spin-echo (SE) sequences by imaging the breast masses of 22 patients before surgery and 23 tissue specimens with magnetic resonance (MR) imaging at 0.6 T to determine the most effective pulse sequences to evaluate breast disease. An SE pulse sequence using a long repetition time (TR) of 1,600 msec and a long echo time (TE) of 90 msec was found to be the most sensitive in depicting carcinoma in the excised tissue specimens, with all of the carcinomas (n = 15) demonstrating irregular areas of higher signal intensity (SI) than that of the adjacent fat. However, only five of 11 breast carcinomas present in the preoperative patients produced a higher SI than that produced by fat on the same T2-weighted sequence. Five of the remaining six carcinomas in the preoperative patients appeared as localized distortions of fibroductular architecture on both T2-weighted SE and IR sequences. In axillary tissue specimens, both metastatic carcinoma and hyperplastic lymph nodes produced a high SI on T2-weighted SE sequences. However, metastatic carcinoma had a significantly longer T2 relaxation time than did hyperplastic lymph nodes.