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Biomedical subjects

A McKenzie

Publications and source records attributed to A McKenzie.

80 records · Page 5Linked to original sources
PubMedDate not supplied

Repeat sudden unexpected and unexplained infant deaths: natural or unnatural?

BACKGROUND: There have been suggestions that when two or three unexpected unexplained infant deaths occur within a family they are more likely to be unnatural than natural. We aimed to estimate the probability that a second infant death is natural versus unnatural. METHODS: The Care of Next Infant programme (CONI) supports parents who have previously had an unexpected and apparently unexplained infant death and is currently available in over 90% of health districts in England, Wales, and Northern Ireland. We studied all deaths in 6373 infants who had completed the CONI programme by December, 1999. After a CONI death, we made detailed enquiries into the previous death and the CONI death, including a family interview, a review of autopsies, and case discussion. FINDINGS: 57 (8.9 per 1000) CONI infants died. Nine deaths were inevitable, and 48 were unexpected. 44 families lost one child, and two families lost two children. Of the 46 first CONI deaths, 40 were natural; the other six were probable homicides, five committed by one or both parents (two criminally convicted). The ratio of 40 natural to six unnatural deaths is 6.7 (95% CI 2.8-19.4). Enquiries identified 18 families with two SIDS(sudden infant death syndrome) deaths and two families with probable covert double homicides (ratio 9.0 [2.2 to 80.0]). There were no convictions in 13 incomplete cases. Families with three deaths are reported. INTERPRETATION: Repeat unexpected infant deaths are most probably natural.

Humans↗
PubMedDate not supplied

Treatment effectiveness for patients with a history of repetitive hand use and focal hand dystonia: a planned, prospective follow-up study.

Recent studies show that rapid, nearly simultaneous, stereotypical repetitive fine motor movements can degrade the sensory representation of the hand and lead to a loss of normal motor control with a target task, referred to as occupational hand cramps or focal hand dystonia. The purpose of this prospective follow-up study was to determine whether symptomatic patients in jobs demanding high levels of repetition could be relieved of awkward, involuntary hand movements following sensory discriminative retraining complemented by a home program of sensory exercises, plus traditional posture, relaxation, mobilization, and fitness exercises. Twelve patients participated in the study. They all had occupational hand cramps, as diagnosed by a neurologist. Each patient was evaluated by a trained, independent research assistant before treatment and three to six months after treatment, by use of a battery of sensory, motor, physical, and functional performance tests. Care was provided by a physical therapist or a supervised physical therapist student in an outpatient clinic. Patients were asked to stop performing the target task and to come once a week for supervised treatment that included 1) heavy schedules of sensory training with and without biofeedback to restore the sensory representation of the hand, and 2) instructions in stress-free hand use, mirror imagery, mental rehearsal, and mental practice techniques designed to stop the abnormal movements and facilitate normal hand control. Patients were instructed in therapeutic exercises to be performed in the home to improve postural alignment, reduce neural tension, facilitate relaxation, and promote cardiopulmonary fitness. Following the defined treatment period, all patients were independent in activities of daily living, and all but one patient returned to work. Significant gains were documented in motor control, motor accuracy; sensory discrimination, and physical performance (range of motion, strength, posture, and balance). This descriptive study that includes patients with occupation-related focal hand dystonia provides evidence that aggressive sensory discriminative training complemented by traditional fitness exercises to facilitate musculoskeletal health can improve sensory processing and motor control of the hand.

Adult↗
PubMedDate not supplied

Differences in somatosensory hand organization in a healthy flutist and a flutist with focal hand dystonia: a case report.

Focal hand dystonia is a disabling, involuntary disorder of movement that can disrupt a successful musician's career. This problem is difficult to treat, to some extent because we do not fully understand its origin. Somatosensory degradation has been proposed as one etiology. The purpose of this case study was to compare the differences in the somatosensory hand representation of two female flutists, one with focal dystonia of the left hand (digits 4 and 5) and one a healthy subject (the control). Noninvasive magnetic source imaging was performed on both subjects. The somatosensory evoked potentials of controlled taps to the fingers were measured with a 37-channel biomagnetometer and reported in terms of the neuronal organization, latency, amplitude, density, location, and spread of the digits on each axis (x, y, and z). The somatosensory representation of the involved hand of the flutist with dystonia differed from that of the healthy flutist. The magnetic fields evoked from the primary somatosensory cortex had a disorganized pattern of firing, with a short latency and excessive amplitude in the involved digits of the affected hand, as well as inconsistency (decreased density). In addition, the patterns of firing were different in terms of the location of the digits on the x, y, and z axes and sequential organization of the digits. This study confirms that somatosensory evoked magnetic fields can be used to describe the representation of the hand on the somatosensory cortex in area 3b. Degradation in the hand representation of the flutist with focal hand dystonia was evident, compared with the hand representation of the healthy flutist. It is not clear whether the sensory degradation was the cause or the consequence of the dystonia. The questions are whether re-differentiation of the representation could be achieved with aggressive sensory retraining and whether improvement in structure would be correlated with improvement in function.

Adult↗