David A. Shaw

Neurologic and neuropsychological morbidity following major surgery: comparison of coronary artery bypass and peripheral vascular surgery.

As part of a prospective study of the neurologic and neuropsychological complications of coronary artery bypass graft surgery, 312 patients were compared with a control group of 50 patients undergoing major surgery for peripheral vascular disease. The purpose of comparing the 2 groups was to determine to what extent neurologic complications after heart surgery can be attributed to cardiopulmonary bypass. The 2 groups were similar with respect to age, preoperative neurologic and intellectual status, anesthetic methods, duration of operation, perioperative complications, and time spent in the intensive therapy unit. Certain potential risk factors for cerebrovascular disease were more common in the control than the coronary bypass patients. The important difference between the 2 groups was that only the latter group underwent cardiopulmonary bypass. In this group 191 of 312 (61%) and 235 of 298 (79%), respectively, developed early neurologic and neuropsychological complications. By the time of hospital discharge 17% had neurologic disability and 38% had significant neuropsychological symptoms. In the control group 9 of 50 (18%) developed neurologic complications resulting largely from trauma to lower limb sensory nerves. Two patients developed primitive reflexes. Fifteen of 48 (31%) showed neuropsychological impairment on 1 or 2 subtest scores. Moderate or severe intellectual dysfunction was not seen in the control patients in contrast to the 24% thus affected in the coronary bypass group. The difference in frequency and severity of central nervous system complications between the 2 groups is likely to reflect cerebral injury resulting from cardiopulmonary bypass.

Early neurological complications of coronary artery bypass surgery.

A prospective study of 312 patients undergoing elective coronary artery bypass surgery was undertaken to determine the incidence, severity, and functional impact of postoperative neurological complications. Detailed evaluation of the patients showed that neurological complications after surgery were common, occurring in 191 of the 312 patients (61%). Although such a high proportion of the total developed detectable changes, serious neurological morbidity was rare. Neurological disorders resulted in death in only one patient (0.3%) and severe disability in only four (1.3%). Forty eight patients were mildly disabled during the early postoperative period, and the remaining 138 with neurological signs had no serious functional disability. The postoperative neurological disorders detected included one death from cerebral hypoxic damage. Prolonged depression of conscious level was observed in 10 patients (3%) and definite stroke in 15 (5%); 78 (25%) developed ophthalmological abnormalities and 123 (39%) primitive reflexes; postoperative psychosis was observed in four (1%); and 37 (12%) developed disorders of the peripheral nervous system. The incidence of serious neurological problems such as fatal cerebral damage, stroke, and brachial plexopathy is in accordance with experience elsewhere. Lesser abnormalities, whose detection required detailed neurological examination, were much commoner than expected from previous reports.

Prognosis in Nontraumatic Coma

We conducted serial neurologic examinations on 500 patients in nontraumatic coma to identify factors predicting recovery. Overall, 81 patients (16%) led an independent life at some point within the first year; the remainder either died without recovery from coma (61%), never improved beyond the vegetative state (12%), or regained consciousness but remained dependent on others for daily activities (11%). Functional recovery did not depend on age but was to some degree related to the cause of coma (subarachnoid hemorrhage and other cerebrovascular disease having the worst recovery; hypoxia-ischemia, intermediate; and hepatic and miscellaneous causes, best) and especially to early clinical signs of brain dysfunction. Even within hours of the onset of coma, only one of 120 patients lacking two of corneal, pupillary, and oculovestibular responses ever regained independent function. The study identifies clinical features of comatose patients that appear within the first week and that are important for predicting recovery and designing future therapeutic trials.

A double-blind controlled trial of long chain n-3 polyunsaturated fatty acids in the treatment of multiple sclerosis.

A trial of n-3 polyunsaturated fatty acids in the treatment of multiple sclerosis has been conducted over a 5 year period. Ambulant patients (312) with acute remitting disease were randomly allocated to treatment or placebo. Both groups were given dietary advice to increase the intake of n-6 polyunsaturated fatty acids and the treatment group in addition received capsules containing n-3 polyunsaturated fatty acids. Analysis of clinical outcome at the end of 2 years of treatment was made in terms of the duration, frequency and severity of relapses and the number of patients who had improved or remained unchanged. The results showed no significant difference at the usual 95% confidence limits but there was a trend in favour of the group treated with n-3 polyunsaturated fatty acids in all parameters examined.

Carotid endarterectomy in patients with transient cerebral ischaemia

A randomised controlled trial of endarterectomy in patients with carotid artery disease showed that operation significantly reduced the frequency of transient ischaemic attacks (TIA) in the relevant vascular territory. Because of the high post-operative morbidity in the surgical group, the trial was abandoned before conclusions could be drawn as to the influence of endarterectomy on long-term survival or on the incidence of subsequent strokes.

The prognostic value of stress hyperglycaemia and previously unrecognized diabetes in acute stroke

In a prospective study of 86 patients with acute stroke, blood glucose and HbA1 were estimated within 72 h of onset. The prevalence of previously diagnosed diabetes mellitus was 8% whereas 28% could be assumed to have had unrecognized hyperglycaemia preceeding the acute event as identified by a stable HbA1 raised more that two SD above the mean reference value. Complete functional recovery of the limbs within 4 weeks of the stroke was confined to those patients with a normal admission blood glucose. None of the patients with a raised admission blood glucose regained full functional recovery within 4 weeks. Cumulative mortality at 4 weeks was significantly raised in patients with an elevated blood glucose value irrespective of their HbA1 values (p <0.05). The prevalence of unrecognized hyperglycaemia as a risk factor for acute stroke is greater than previously reported in the UK and admission blood glucose concentration is of greatest importance in predicting early mortality and morbidity.

Cerebrovascular Disease: Trial of Long-term Anticoagulant Therapy

were reducing either the mortality or the recurrence rate of cerebrovascular accidents; indeed, the data suggested an adverse effect, particularly in hypertensive patients. The trial was therefore modified by withdrawing those who were hypertensive, and we report here the further progress of the trial in its modified form to its conclusion in October, 1961. The design of the trial, the selection of patients, and the methods of treatment and control were described in detail in the original report (Hill, Marshall, and Shaw, 1960). All the patients included were under 70 years of age and had suffered one or more disturbances of neural function lasting more than 24 hours and attributed to non-haemorrhagic cerebral, carotid, or vertebral arterial disease. Admission to the trial was permissible any time after 14 days had elapsed since the last acute episode. The usual contraindications to anticoagulant therapy were observed and patients were included in the trial only if it seemed likely that their personal, occupational, and geographical situations would permit regular attendance and adequate co-operation. Patients admitted to the trial were differentiated by sex and allotted by pairs to high-dosage (treatment)

Hyperbaric oxygen and multiple sclerosis: final results of a placebo-controlled, double-blind trial.

The long term results are reported of a trial involving 120 patients with chronic multiple sclerosis who were randomised to receive either 100% oxygen at 2 atmospheres absolute (ATA) for 90 minutes daily for 20 sessions or placebo therapy with air using a simulated compression procedure. The previous finding of subjective improvement in bowel/bladder function at the end of treatment was not confirmed by objective urodynamic assessment. The treatment did not alter disease progression as measured by the Kurtzke disability status scale nor did it alter the rate of acute relapse. There was less deterioration in cerebellar function at one year in the treated patients as measured by the Kurtzke functional systems scale. No other differences were found between the two groups. Psychometric tests and measurements of lymphocyte sub-populations showed no treatment related effects. Evoked potential studies showed no improvements but there was a significant reduction in amplitude of the visual evoked potential in the treated patients at the end of therapy. This might indicate a reversible degree of retinal damage induced by oxygen toxicity.

Hypothyroidism with true myotonia.

A patient with subclinical hypothyroidism who presented with true myotonia is described. There was no evidence that either he or members of his family had dystrophia myotonica or myotonia congenita. Treatment with thyroxine resolved his symptoms completely.

A Comparison of Two Programs for Training Primary-Care Physician's Assistants.

Excerpt The physicians assistant concept appears likely to effect changes in health care delivery. Many questions vital to implementation of this concept remain, however. Two of these questions—th...