Biomedical subjects
Publications and source records attributed to A McDonnell.
This paper presents the pathophysiology, clinical symptoms, and a standard of care for the patient with MH. The information provided will assist the nurse in interpreting patient and technologic data to identify recurring episodes of MH, and prevent the negative outcomes associated with this syndrome.
CT-scan measurements of cortical and subcortical atrophy were carried out in 34 patients with Huntington's disease (HD). While a significant correlation was observed between parameters of subcortical atrophy (bicaudate ratio, bifrontal ratio and third ventricular ratio) and duration of the disease, there was no significant correlation between these parameters and age. On the other hand, measurements of cortical atrophy (frontal fissure ratio and cortical sulci ratio) correlated significantly with age but not with duration of the disease. When a group of 24 HD patients were compared on CT-scan measurements with a group of 24 age-matched normal controls, significant differences were obtained for all the variables examined, but the bicaudate ratio showed the highest sensitivity and specificity. Even mildly affected patients, with duration of motor symptoms less than 3 years had higher bicaudate ratios than age-matched controls.
Measurements of cortical and subcortical atrophy were made on CT scans of 34 patients with Huntington's disease. Significant correlations were found between the bicaudate ratio (BCR) and an eye movement scale (r = 0.44, p less than 0.01), and activities of daily living scale (r = 0.57, p less than 0.001) and the Mini-Mental State Exam (r = 0.49, p less than 0.01). No correlations were found between BCR values and severity of chorea or voluntary motor impairment. A detailed neuropsychological evaluation of 18 Huntington's disease patients showed significant correlations between the BCR and Symbol Digit Modalities test (r = 0.65, p less than 0.01), and parts A (r = 0.72, p less than 0.001) and B (r = 0.80, p less than 0.0001) of the Trail Making Test. These data support work in primates that demonstrates the role of the caudate nucleus in cognitive and oculomotor functions, but not in motor control (which is governed by putamino-subthalamic systems). The specific cognitive skills correlated with caudate atrophy in Huntington's disease are those reported in primate work to be served by the frontal-caudate loop system: eye movements, conceptual tracking, set shifting and psychomotor speed.
The incidence of fetal to maternal bleeding was studied in 773 consecutive patients having genetic amniocentesis by measuring maternal serum alpha-fetoprotein elevation following the procedure. The frequency of fetal to maternal bleeding was significantly lower in patients having amniocentesis immediately after real-time ultrasound (21 of 429 cases, 4.9%) when compared with patients having static B-mode ultrasound before the procedure (31 of 344 cases, 9.0%). A lower frequency of fetal to maternal bleeding was observed in the real-time group for anterior or partially anterior placentas (8.1%) and posterior or fundal posterior placentas (0%) when compared with the static B-mode group (12.9 and 5.2%, respectively). The rate of spontaneous abortion in patients with fetal to maternal bleeding (12.8%) was significantly higher than the rate in patients who did not demonstrate such bleeding (1.45%). The implications of these findings with regard to the safety of amniocentesis and the benefit of routine preliminary ultrasound evaluation are discussed.