True Negative Group Research Articles

An electromyographic marker for neuroleptic-induced akathisia: preliminary measures of sensitivity and specificity.

Previous polysomnographic (PSG) investigations have reported a rhythmic electromyographic (EMG) pattern (0.5-3.0 cps) of leg movement activity in a subset of patients with neuroleptic-induced akathisia (NIA). It has been suggested that this EMG pattern may represent a pathophysiological correlate of NIA and thus have clinical utility as an objective marker for this condition. We present preliminary measures of sensitivity and specificity for this EMG pattern as a diagnostic marker for NIA for 26 neuroleptic-treated patients. The EMG marker yielded a diagnostic sensitivity of 68.9% and a specificity of 70.0%, falling just short of statistical significance (Fisher's exact test p = 0.06). Quantitative analysis of the EMG pattern revealed a significant positive correlation between the percentage of time the NIA marker occurred during wakefulness and corresponding chlorpromazine equivalent levels. Clinical demographic findings for true-positive, false-positive, true-negative, and false-negative groups are discussed. Overall findings suggest that this particular pattern of EMG marker activity observed in neuroleptic-treated patients during PSG and EMG studies is valuable in facilitating the diagnosis and monitoring treatment.

Prognostic significance of clinically false positive cervical lymph nodes in patients with laryngeal carcinoma.

A significant proportion of clinically positive palpable cervical lymph nodes in patients with head and neck cancer are histologically benign. The biologic and prognostic significance of this reactive lymph node enlargement has not been fully clarified. In this study, the incidence of clinically positive microscopically negative cervical lymph nodes in a series of 902 patients who had neck procedures as a part of their primary treatment for N0-2 laryngeal cancer was analyzed and survival rates of 342 patients with true negative lymph nodes (N0- necks) were compared with those of 106 patients with clinically false positive lymph nodes (N1-2b- necks). In 86 patients with false positive lymph nodes, a histopathologic analysis was performed to determine the histomorphologic pattern of the enlarged lymph nodes and to evaluate which parameters, if any, correlated with 5-year patient survival. Overall actuarial survival did not differ significantly in the two groups. However, the actuarial survival curves in the false positive group were clearly better compared with those of the true negative group with more advanced laryngeal cancers, particularly T4 lesions (P < 0.05). Interestingly, the analysis of pattern of recurrence showed a higher incidence of distant metastases in false positive patients with advanced stage laryngeal cancer than in true negative subjects. In addition, the histologic examination of 375 enlarged hyperplastic cervical lymph nodes from 86 neck specimens showed the prevalence of sinus histiocytosis in the false positive group and its favorable prognostic significance. No statistically significant differences with regard to the number and size of enlarged lymph nodes were found. On the contrary, lymph node location seems to have a prognostic impact on survival and the reactive benign enlargement of a digastric lymph node is a possible poor prognostic factor. Survival of patients with clinically false positive, histologically benign hyperplastic cervical lymph nodes who have more advanced laryngeal carcinoma is higher than clinically negative patients, suggesting that the presence of palpable benign nodes may be a sign of the host's immune activation, with favorable prognostic significance.

937-1Color Doppler M-Mode Assessment of Flow Velocity Propagation During Early Filling; A Useful Adjunct to Wall Motion Analysis During Dobutamine Stress Echocardiography

Flow velocity propagation (FVP) during early left ventricular (LV) filling correlates with LV relaxation and has been shown to be a sensitive index of ischemia during angioplasty. To test the ability of color Doppler M-mode to detect ischemia during dobutamine (Db) stress echo we prospectively evaluated 26 pts (13 females. age 61 ± 13 y). FVP was evaluated in digitally acquired recordings of color Doppler M-mode as the slope of the color/non-color (black to red) transition of transmitral flow during early filling, at rest and with each increment of Db. An abnormal FVP response was defined by reduction of the slope with increase of Db dose. Digitized echo images were compared at rest and during stress to identify the presence of new or worsening wall motion abnormalities (WMA). Nine pts (group A) were designated as having coronary disease on the basis of WMA. typical angina and ST depression. and abnormal coronary anatomy. Seventeen pts (group B) without WMA in the presence of normal coronary anatomy or low ( &lt; 10%) pretest probability of disease were designated as having no curonary disease. All pts in group A developed an abnormal FVP response to Db stress (sensitivity 100%). In group B, 7 of 17 pts without coronary disease presented an abnormal response as evaluated by FVP (specificity 59%). Of the false positive group. 86% had echocardiographic evidence of left ventricular hypertrophy, with a strain pattern by EKG. compared with only 30% in the true negative group (p &lt; 0001). i) Color Doppler M-mode is very sensitive to ischemia during dobutamine stress echo, ii) Other conditions as left ventricular hypertrophy with strain pattern can produce the same response, iii) Color Doppler M-mode evaluation of diastolic function may be a useful tool during dobutamine stress echo.

Patient Attitudes Toward Testing for Maternal Serum Alpha-Fetoprotein Values When Results Are False-Positive or True-Negative

We investigated the attitudes toward the maternal serum alpha-fetoprotein (MSAFP) test of patients whose results from MSAFP testing were either false-positive or true-negative. Forty-six women who had previous false-positive results from MSAFP testing and 46 who had previous true-negative values participated. Patients were matched for age and socioeconomic status, and all were delivered of normal neonates. A significantly larger number of patients in the group with false-positive results believed they had not understood the MSAFP test than in the group with true-negative results (19.6% vs 0%). Significantly more women in the "false-positive" group felt that the test caused anxiety than in the "true-negative" group (65.2% vs 17.4%). Fewer women in the false-positive group than in the true-negative group said they would have MSAFP testing in a subsequent pregnancy (58.7% vs 91.3%). Further, the women in the false-positive group were less likely than those in the true-negative group to recommend MSAFP testing to a friend (52.1% vs 80.4%). In patients whose results were false-positive, there was a significant relationship between the patient's perception of understanding the MSAFP test and her attitude toward MSAFP testing.