Perception of motor strength and stimulus magnitude are correlated in stroke patients.

The authors examined whether perception of contralateral limb strength is altered and whether perception of strength correlates with perception of stimulus intensity (magnitude) in a prospective sample of patients with unilateral right (RHL: n = 13) and left (LHL: n = 6) hemisphere lesions due to stroke. Patients with RHL tended to overestimate strength and patients with LHL tended to underestimate strength; both patterns were highly correlated with altered perception of stimulus magnitude.

Atypical atrial flutter originating in the right atrial free wall.

BACKGROUND: Data from experimental models of atrial flutter indicate that macro-reentrant circuits may be confined by anatomic and functional barriers remote from the tricuspid annulus-eustachian ridge atrial isthmus. Data characterizing the various forms of atypical atrial flutter in humans are limited. METHODS AND RESULTS: In 6 of 160 consecutive patients referred for ablation of counterclockwise and/or clockwise typical atrial flutter, an additional atypical atrial flutter was mapped to the right atrial free wall. Five patients had no prior cardiac surgery. Incisional atrial tachycardia was excluded in the remaining patient. High-density electroanatomic maps of the reentrant circuit were obtained in 3 patients. Radiofrequency energy application from a discrete midlateral right atrial central line of conduction block to the inferior vena cava terminated and prevented the reinduction of atypical atrial flutter in each patient. Atrial flutter has not recurred in any patient (follow-up, 18+/-17 months; range, 3 to 40 months). CONCLUSIONS: Atrial flutter can arise in the right atrial free wall. This form of atypical atrial flutter could account for spontaneous or inducible atrial flutter observed in patients referred for ablation and is eliminated with linear ablation directed at the inferolateral right atrium.

Radiofrequency catheter ablation of atrioventricular nodal reentry tachycardia utilizing nonfluoroscopic electroanatomical mapping.

The advent of catheter ablation stimulated extensive research into anatomical localization of the pathways involved in atrioventricular nodal reentrant tachycardia (AVNRT). Conventional electrophysiological methods that attempt to correlate intracardiac electrograms with two-dimensional fluoroscopic anatomy are limited by the relative inaccuracy and poor reproducibility of this technique, and the requirement for high levels of radiation exposure. A new method of nonfluoroscopic electroanatomical mapping utilizes magnetic field sensing with a specialized catheter to construct three-dimensional electroanatomical endocardial maps of selected heart chambers with spatial resolution of < 1 mm. This system can be used in patients undergoing catheter ablation for AVNRT to create accurate maps of Koch's triangle and to guide application of radiofrequency energy. Initial experience in 14 patients suggests efficacy and safety comparable to conventional mapping and ablation techniques. Further evaluation may confirm the potential benefits of this system with respect to success rates, complications, procedure time, and radiation exposure.

Electroanatomic imaging using magnetic catheter tracking in the diagnosis and treatment of atrial arrhythmias.

Recent data emphasize the importance of structural factors in the pathophysiology of atrial arrhythmias. As a consequence, catheter ablation increasingly has become an anatomically oriented procedure. A recently developed magnetic catheter tracking system provides spatially precise and realistic three-dimensional reconstructions of endocardial geometry. A variety of electrophysiologic data can be superimposed on these reconstructions, including activation sequence, electrogram amplitude and morphologic features, response to pacing maneuvers, and sites of planned or delivered radiofrequency energy ablation. These features enhance the ability to analyze and visualize arrhythmia mechanisms, plan and execute appropriate ablation strategies, and provide new opportunities for physiologic research.

Bimanual hand writing in right-handed and left-handed stutterers and nonstutterers.

Right-handed stutterers performed more poorly with their nondominant hand when writing digits and letters bimanually, and also made more nondominant hand mirror reversals than did nonstutterers. Left-handed stutterers and nonstutterers differed only in the incidence of mirror reversals with the nondominant hand. The results support the hypothesis that disorganization in the integration of left- and right-hemisphere inhibitory and excitatory processes may be an integral component of stuttering.

Assessment of sensitivity to interpersonal stress in stutterers and nonstutterers.

The Revised Willoughby Personality Schedule (WPS-R) was used to determine its applicability for assessing social sensitivity in stutterers. Forty-one adult stutterers and 41 nonstutterers completed the WPS-R. Confirmatory factor analysis revealed three dimensions differentiating stutterers from nonstutterers. The dimensions--labeled social isolation, social confidence, and social sensitivity--were similar to dimensions of the WPS-R labeled as sensitivity to interpersonal stress by other investigators. The results suggest that the WPS-R may be useful for evaluating general anxiety and for monitoring changes in emotional reactivity as clinical intervention progresses.

Fibromuscular dysplasia of the extracranial carotid arteries. Case reports.

Seven cases of fibromuscular dysplasia of the carotid artery are presented. Six of these patients presented with transient or fixed neurological deficit and 1 with intracranial haemorrhage. The uncertainty about the natural history of this condition is highlighted, and guidelines to the management of symptomatic patients as well as the more controversial incidentally diagnosed asymptomatic patient are outlined. A novel form of intra-operative use of a Grunzig balloon dilatation catheter in the management of fibromuscular dysplasia is presented.

Some airflow, volume, and duration characteristics of oral reading.

Inspiratory and expiratory airflow (oral + nasal), volume, and duration characteristics during oral reading were investigated for eight young adults. Flow signals, sensed through a facemask-pneumotachometer-pressure transducer system, were quantified and analyzed by a computer program. Results showed that the modification of volume and flow during oral reading was primarily related to the timing of inspiratory and expiratory phases and secondarily to the magnitude of oronasal air volume. Effects of linguistic constraints were observed in inspiratory behavior, within and between sentences. Connected utterances showed lower and more variable peak flows than those reported for isolated syllables or words.

Perceptual and acoustic analysis of repetitions in stuttered speech.

This study presents perceptual and acoustic data on a carefully selected set of part-word repetitions from the speech of adult stutters. Results indicated that the schwa vowel was perceived in only 25% of the repetitions, far less than previously indicated. Spectrographic analysis showed that although abnormal consonant duration and C-V formant transitions characterized the initial segment of the stuttered word, the remainder of the word is identical to its identical to its fluently produced counterpart. The results were interpreted to mean that for the type of dysfluency selected, the articulatory breakdown is confined to the initial consonant, and it is likely that abnormal formant transitions from initial consonant to vowel, when present, are due to deviant formation of the consonant rather than to faulty transition dynamics.

Surgical treatment of renovascular hypertension in children.

In fourteen children with renovascular hypertension the most prevalent lesion was fibromuscular dysplasia (nine patients). Nephrectomy was performed in four patients prior to the adoption of reconstructive vascular techniques. Revascularization of a variety of lesions was employed with autogenous arterial grafts, which gave excellent results over a long follow-up period in ten patients. Ex vivo microvascular repair was used in one patient rather than nephrectomy for management of branch artery lesions. These results indicate that careful and precise arterial repairs will yield a high cure rate in children with renovascular hypertension without the sacrifice of renal parenchyma.