Cortical thickness, gray matter volume, and cognitive performance: a crosssectional study of the moderating effects of age on their interrelationships.

In a sample comprising younger, middle-aged, and older cognitively healthy adults (N = 375), we examined associations between mean cortical thickness, gray matter volume (GMV), and performance in 4 cognitive domains-memory, speed, fluency, and crystallized intelligence. In almost all cases, the associations were moderated significantly by age, with the strongest associations in the older age group. An exception to this pattern was identified in a younger adult subgroup aged <23 years when a negative association between cognitive performance and cortical thickness was identified.

US-guided core biopsy of the breast with a coaxial system.

From July 1993 through June 1994, the authors performed 42 ultrasound (US)-guided core biopsies with use of a coaxial technique in which a 14- or 15-gauge core biopsy needle was passed through a 12-gauge introducer needle. This technique proved to be effective in all 42 biopsies. Use of the coaxial technique decreased the procedure time necessary for US-guided core biopsy and may be less traumatic than the standard core biopsy technique.

A method to prevent unintentional removal of a Hickman catheter.

Many patients benefit from the use of tunneled Dacron-cuffed central venous catheters. Operative insertion with the aid of fluoroscopy is required for the proper placement of these devices. Perioperative unintentional removal of the catheter is a reported complication.

Transtracheal/transesophageal stimulation of the recurrent laryngeal nerve.

A new technique is described which allows stimulation of the recurrent laryngeal nerve (RLN) through intact tracheal and esophageal mucosa. In ten anesthetized dogs, the posterior-lateral tracheal wall and the anterior-lateral esophageal wall were stimulated by a 1 to 2 mA current with a probe placed just distal to the edge of the cricoid cartilage. The tracheal mucosa was approached through a tracheostomy stoma and the esophageal mucosa through the mouth.

Transcutaneous electrical stimulation of the recurrent laryngeal nerve in monkeys.

The recurrent laryngeal nerve (RLN) of four anesthetized adult Macaca fascicularis monkeys was stimulated by applying current with blunt electrodes placed unilaterally and bilaterally on the intact neck skin along the tracheoesophageal groove. The stimulus consisted of 2.5- to 4.