Biomedical subjects

D W Chadwick

Publications and source records attributed to D W Chadwick.

8 recordsLinked to original sources

PubMed1992

Development of prognostic index for primary supratentorial intracerebral tumours.

The clinical course of intrinsic supratentorial tumours is variable. Prediction of outcome would be useful in defining patients for specific treatment policies. A retrospective analysis of 560 patients with intrinsic supratentorial tumours was performed. Proportional hazards models for survival were derived by using a stepwise selection procedure with only clinical and CT features as possible explanatory variables. The variables of prognostic importance were age, a first symptom of epilepsy, focal signs at presentation, a cystic lesion on CT scan, and duration of symptoms before presentation. The model defined a group with a good prognosis (score less than or equal to 9, n = 211) and a group with a poor prognosis (score greater than 9, n = 344). The median survival was 27 months for those with a score less than or equal to 9 or less and three months for those with score greater than 9. An alternative model, not including duration of symptoms, is also capable of defining groups with long (score less than or equal to 16, n = 234) and short (score greater than 16, n = 325) survival. The model may provide a means of classifying patients for inclusion in prospective randomised studies.

Actuarial Analysis↗

PubMed1992

Do prophylactic anticonvulsant drugs alter the pattern of seizures after craniotomy?

A total of 276 patients with a high risk of developing postoperative seizures were randomised to treatment with carbamazepine or phenytoin for six or 24 months, or to no treatment. No significant differences were found (though the confidence limits were fairly wide) between the regimes in respect of the incidence of seizures or death. In a substantial proportion of the patients postoperative epilepsy remained a continuing disability. A high incidence of drug-related side effects was found in the treatment groups. Prophylactic anticonvulsants cannot therefore be recommended routinely following supratentorial craniotomy.

Actuarial Analysis↗

PubMed1991

Seizure frequency, patient-perceived seizure severity and the psychosocial consequences of intractable epilepsy.

It is generally recognised that the assessment of treatment effects in epilepsy using seizure frequency as the only outcome measure may lack sensitivity. A patient-based seizure severity scale has been developed and initial results confirm its reliability and validity. As part of the further development of this scale it is important to explore the relationship between seizure severity, seizure frequency and the psychosocial consequences of intractable epilepsy. One hundred patients with medically refractory partial seizures completed a quality of life questionnaire including measures of physical (seizure severity and frequency), social and psychological well-being (anxiety, depression, self-esteem, locus of control and happiness). Multivariate analysis demonstrated that individual psychological variables were best predicted by other psychological variables. However, when these were removed from analysis, seizure severity was the most significant predictor of self-esteem (P = 0.005), locus of control P = 0.039) and anxiety (P = 0.048). Seizure frequency did not contribute significantly to the variance of any of the psychological factors. These results highlight the importance of considering seizure severity when assessing treatment effects in epilepsy and provide further evidence for the construct validity of a novel patient-based seizure severity scale.

Activities of Daily Living↗

PubMed1991

The development of a seizure severity scale as an outcome measure in epilepsy.

In controlled trials of antiepileptic drugs (AEDs) seizure frequency is often the only variable considered. With little prospect of improving assessment of AEDs, using seizure counts as the only end-point, there is a need for the development of new outcome measures. Clinical experience indicates that seizure severity is equally important to the patient and, by preventing seizure spread, AEDs can influence seizure severity without necessarily reducing seizure frequency. A scale capable of measuring seizure severity and change of severity attributable to treatment could be a useful additional outcome measure. Such a scale should exhibit the basic properties of validity and reliability. An easily administrable 16-point scale, containing 2 subscales--perception of control and ictal/post-ictal effects--has been developed. This scale has been tested on a patient population (n = 159) representative of that seen in trials of novel AEDs. Using standardised statistical methods, the scale has been shown to be both reliable and valid.

Adolescent↗

PubMed1991

The prognosis of primary intracerebral tumours presenting with epilepsy: the outcome of medical and surgical management.

It is not known whether conservative or early aggressive (resective surgery with or without radiotherapy) management is better for tumours presenting with epilepsy. The prognosis of 560 patients with a clinical and CT diagnosis of intrinsic supratentorial tumour was examined retrospectively. Epilepsy was the first symptom in 164 patients. Histological confirmation of diagnosis was available in 391 (70%) of cases. Median survival was 37 months in the group presenting with epilepsy and six months in those presenting with other symptoms (p less than 0.0001). Patients presenting with epilepsy were more likely to have a normal clinical examination, a non-enhancing low density lesion on CT scan and a low grade tumour. From Cox's stepwise proportional hazards model, significant independent variables adversely affecting prognosis were increasing age, focal neurological signs and enhancing CT lesions at diagnosis, non-resective surgery and male sex. Of those presenting with epilepsy 80 patients had surgical treatment within two months of CT diagnosis. The Cox's model failed to identify any beneficial effects for either early resective surgery or radiotherapy. In primary intracerebral tumours with presentations other than epilepsy, resective surgery and radiotherapy were amongst the important factors associated with prolonged survival. Primary intracerebral tumours presenting with epilepsy are relatively benign and their outcome appears to be chiefly determined by clinical factors.

Adolescent↗

PubMed1991

Extracranial vertebral artery dissection following tonic clonic seizure.

A 34 year old woman developed cerebral infarction, following a tonic-clonic seizure. A vertebral artery dissection was demonstrated and may have been caused by arterial trauma during the seizure. This cause of morbidity following convulsive seizures may have been overlooked in the past and needs to be recognised in view of the potential benefits of anticoagulation.

Adult↗

PubMed1979

Acute intoxication with sodium valproate.

Two epileptic patients developed an acute toxic encephalopathy consisting of altered behavior, deteriorating seizure control, and confusion while taking sodium valproate alone. Serum valproate levels were greater than 100 microgram/ml in both. Toxic symptoms resolved when the dose of valproate was reduced, with a consequent fall in serum concentration of the drug.

Acute Disease↗

PubMed1975

Visual evoked responses in the diagnosis and management of patients suspected of multiple sclerosis.

Averaged visual evoked responses to pattern reversal stimuli have been recorded in 54 control subjects, 51 patients with multiple sclerosis, and 55 patients with other neurological diseases which might involve the visual apparatus. The latency to the peak of the major positive potential in normal subjects under the age of 60 was 104 msec or less (mean 90-5 msec+3 SD). The latency of the VER was prolonged above this value in one or both eyes in 67 per cent of the patients with multiple sclerosis (in 84 per cent of those with definite multiple sclerosis, in 83 per cent of those with probable multiple sclerosis, and in 21 per cent of those with possible multiple sclerosis). The latency of the VER was also prolonged in 25 percent of those with an acute spinal cord lesion of unknown cause; in 46 per cent of those with an isolated brain-stem lesion unknown cause; and in 49 per cent of patients presenting with a progressive spastic paraparesis. The extra delay in latency varied from a few msec to as much as a 100 msec. In patients with multiple sclerosis, a delayed VER was found in the affected eye in all with a previous history of optic neuritis, and in 47 per cent of those with no such history....

Adolescent↗