Electrodiagnostic evaluation of the foot.

Focal entrapment neuropathies in the foot, as compared to those of the hand, represent a daunting diagnostic challenge to many electromyographers. This article emphasizes an understanding of the anatomy of the foot as a fundamental key to its electrodiagnostic evaluation. The anatomic course of specific nerves will be described in terms of entrapment sites, and the clinical and electrophysiologic manifestations of each nerve entrapment will be discussed.

Electrophysiologic mapping and cadaveric dissection of the lateral foot: implications for tibial motor nerve conduction studies.

Objective: To clarify, through electrophysiologic mapping and cadaveric dissection of the lateral foot, the previously published "proximal" and "distal" recording sites for tibial motor nerve conduction studies.

Design: Observational.

Setting: Electromyography laboratory; anatomy laboratory.

In vitro activities of co-amoxiclav at concentrations achieved in human serum against the resistant subpopulation of heteroresistant Staphylococcus aureus: a controlled study with vancomycin.

The effects of concentrations that simulated those in human serum after a single intravenous dose of amoxicillin (2 g), amoxicillin-clavulanic acid (2,000 and 200 mg, respectively), or vancomycin (500 mg), on the viability and beta-lactamase activity of two isogenic (beta-lactamase and non-beta-lactamase producer) heteroresistant Staphylococcus aureus strains were studied in an in vitro pharmacodynamic model. A reduction of > or = 97% of the initial inoculum was obtained with vancomycin and amoxicillin-clavulanic acid against both strains, with respect to the total bacterial population and the oxacillin-resistant subpopulation. The same pattern was observed with amoxicillin and the beta-lactamase-negative strain.

Abductor hallucis false motor points: electrophysiologic mapping and cadaveric dissection.

False motor points (FMPs) can occur in intrinsic foot or hand muscles, causing spuriously prolonged distal motor latencies by misrepresenting the compound muscle action potential (CMAP) onset. We investigated the motor point (MP) and possible FMPs in abductor hallucis (AH) by three methods: (1) electrophysiologic mapping of the CMAP with a grid of approximately 29 G1 sites over AH (n = 20), including commonly used MPs just anterior to (Ant-MP) and posterior to (Post-MP) the navicular tuberosity; (2) electrophysiologic mapping with direct percutaneous threshold stimulation of AH (same grid as above); and (3) cadaveric dissection (n = 4). We found AH FMPs in 19 of 20 feet (2.

Generator sources for the early and late ulnar hypothenar premotor potentials: short segment electrophysiologic studies and cadaveric dissection.

Objective: Determine the generator sources for the ulnar hypothenar premotor potentials (PMPs).

Design: Observational.

Setting: EMG laboratory.

Generators of the early and late median thenar premotor potentials.

The generator sources of the median thenar premotor potentials (PMPs) have remained elusive despite debate in the literature. By studying the median nerve in the hand with a variety of bipolar and referential recording montages, we systematically examined the possible near-field and far-field sources that may determine these potentials. The results suggest that the early PMP is a near-field potential recorded by G1 and generated by the median nerve traversing the distal carpal tunnel.

The medial calcaneal nerve: anatomy and nerve conduction technique.

We report a new technique for studying conduction in the medial calcaneal nerve (MCN). Dissection of 14 cadaver feet revealed the optimal G1 site to be one third of the way from the apex of the heel to a point midway between the navicular tuberosity and the prominence of the medial malleolus. Seventy-two feet (36 healthy volunteers) were studied using surface stimulation of the tibial nerve 10 cm proximal to the G1 surface electrode.

Development of a model of the premotor potential.

This study explored the sensory nature of the small negative premotor potential (PMP) that is often seen preceding the compound muscle action potential. We developed a model of the PMP, using the ulnar and superficial radial sensory (SRS) nerves. Standard conduction studies of the deep ulnar motor nerve recording over the first dorsal interosseous manus (FDIM) and of the SRS nerve recording over the same site were done separately, then simultaneously, on 20 normal hands.

Esophageal motility patterns in a Puerto Rican population.

One hundred consecutive patients underwent esophageal motility testing at the Gastroenterology Section of the University Hospital for symptoms of esophageal dysfunction. These were dysphagia (55), non cardiac chest pain (11), gastroesophageal reflux (32), and other (2). Fifty five studies were abnormal.

Pseudomyxoma peritonei: case report and review of the literature.

Pseudomyxoma peritonei is a rare entity manifested by implants of a mucinous gelatinous material arising from either the appendix or ovary and involves the peritoneal cavity, peritoneum and omentum. Preoperative diagnosis is feasible by means of radiographic studies. The main step in the treatment is debulking surgery with appendectomy, bilateral oophorectomy and omentectomy.

Gastric campylobacter-like organisms and active antral gastritis in Puerto Rico.

We attempted to verify if the reported association of gastric campylobacter like organisms (GCLO) with active antral gastritis holds true in our population. All patients undergoing elective upper endoscopy were eligible for the study unless they had a history of gastric cancer or previous antrectomy. Biopsy specimens from 100 consecutive patients were examined blindly for the presence of inflammatory activity and/or intestinal metaplasia.

Corneal sensory pathway in the rat: a horseradish peroxidase tracing study.

The methods of transganglionic transport of horseradish peroxidase (HRP) and horseradish peroxidase--wheat germ agglutinin (HRP-WGA) were used to determine the location within the trigeminal ganglion of the primary afferent neurons that innervate the rat central cornea, and the brainstem and spinal cord termination sites of these cells. In each of 18 animals, solutions of HRP or HRP-WGA were applied to the scarified corneal surface and allowed to infiltrate into the corneal epithelium and stroma for 15 minutes. Postmortem examination of the corneal whole mounts from the experimental animals, and of corneas and neural tissues from several control animals, showed that the HRP/HRP-WGA remained confined to the central cornea with no spread into adjacent intra- or extraorbital tissues.

[Munchausen syndrome induced as recurrent imipramine poisoning].

A nine-year-old girl with Munchausen syndrome by proxy is reported. She had been admitted to different hospitals for 17 times in the last seven years. Clinical complaint were complex neurological symptoms and the first diagnosis was acute intermittent porphyria.