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Biomedical subjects

M Sadler

Publications and source records attributed to M Sadler.

At least 19 recordsLinked to original sources
PubMed2000

Scalp EEG in temporal lobe epilepsy surgery.

Electroencephalography (EEG) with standard scalp and additional noninvasive electrodes plays a major role in the selection of patients for temporal lobe epilepsy surgery. Recent studies have provided data supporting the value of interictal and postictal EEG in assessing the site of ictal onset. Scalp ictal rhythms are morphologically complex but at least one pattern (a five cycles/second rhythm maximum at the sphenoidal or anterior temporal electrode) occurs in >50% of patients and has a high predictive value and interobserver reliability for temporal lobe originating seizures. Thorough interictal and ictal scalp EEG evaluation, in conjunction with modern neuroimaging, is sufficient for proceeding to surgery without invasive recordings in some patients. Further studies are required to define the scalp ictal characteristics of mesial vs. lateral temporal lobe epilepsy.

Electroencephalography↗
PubMed1999

Lamotrigine associated with insomnia.

PURPOSE: To review the incidence of lamotrigine (LTG)-associated insomnia in an adult tertiary care epilepsy outpatient clinic. METHODS: The records of all patients who had received LTG were reviewed to identify patients who had experienced insomnia after introduction of this drug. Patients were included if they had experienced a sleep disturbance of sufficient severity to require a discontinuation of LTG or a dose reduction. RESULTS: Among 109 patients exposed to LTG, seven (6.4%) had a sleep disturbance of a severity to required a change in therapy. The descriptions of the sleep disturbance were similar among the patients, and the LTG-induced insomnia appeared to be dose dependent. Unlike the few previous descriptions of LTG-induced insomnia in the literature, no factors predisposing to this adverse effect were identified. CONCLUSIONS: The results of this retrospective review suggest an association between LTG and intolerable insomnia in a small proportion of patients. Physicians should inquire about sleep disturbances in patients treated with LTG.

Adult↗
PubMed1999

Criterion-based validity of an intracarotid amobarbital recognition-memory protocol.

PURPOSE: We tested whether the behavioral components of an Intracarotid Amobarbital Protocol (IAP) had criterion validity. It was hypothesized that a recognition-memory test designed for intracarotid injections and used to predict the risk of global amnesia before an elective temporal lobectomy should also identify persons who are severely amnesic due to other neurologic causes. Divergent validity predicts that speech tasks would be unaffected by amnesia. Test-retest reliability also was measured. METHODS: Fifteen persons with severe amnesia were administered four alternate forms of a yes/no recognition-memory protocol and a speech protocol. No drug injection occurred. Standardized neuropsychological tests were used to divide the amnesic group into those with Global Amnesia (i.e., retain no ongoing memories), Severe Amnesia (i.e., memory impaired), and Amnesia Plus (severe amnesia plus other neuropsychologic deficits). RESULTS: Two persons with Global Amnesia obtained scores at or below chance (i.e., failed) on the memory protocol. Unexpectedly, 12 of 13 severely amnesic persons obtained near-perfect memory scores. Amnesia had no impact on the speech protocol. Pass/Fail outcomes were highly correlated across all four sets. CONCLUSIONS: A four-item IAP memory protocol showed good reliability and criterion validity in identifying the rare condition of Global Amnesia, but it was insensitive to other disabling, severe amnesic disorders. This IAP memory protocol might have validity in predicting a postsurgical Global Amnesic disorder, but it did not identify and therefore could not predict other more common severe amnesic disorders.

Adolescent↗
PubMed1999

Conventional versus intensive diabetes therapy in children with type 1 diabetes: effects on memory and motor speed.

OBJECTIVE: Severe hypoglycemia may impair medial temporal-mediated cognitive skills, such as the ability to recall past events explicitly (delayed declarative memory). The objective of this study was to determine whether delayed declarative memory deficits are present in a group of diabetic children with an increased risk of severe hypoglycemia. RESEARCH DESIGN AND METHODS: Nondiabetic children (n = 16) and children with type 1 diabetes who had been randomly assigned to either intensive (IT) (n = 13) or conventional (CT) (n = 12) diabetes therapy at the time of diagnosis participated in the study. All episodes of severe hypoglycemia were prospectively ascertained. All children were tested on memory tasks that have been closely linked to medial temporal functioning and on reaction time measures. RESULTS: Our results demonstrated that the IT group had a threefold higher rate of severe hypoglycemia, performed less accurately on a spatial declarative memory task, and performed more slowly, but not less accurately, on a pattern recognition task than did the CT group or control subjects. In addition, both groups of type 1 diabetic children were significantly impaired on a motor speed task compared with their nondiabetic peers. CONCLUSIONS: These results indicate a selective relative memory impairment associated with IT that is consistent with the effects of severe hypoglycemia and medial temporal damage or dysfunction. If larger prospective studies determine that severe hypoglycemia is the mediating factor for this memory impairment, extreme caution in imposing overly strict standards for glucose control in young patients with type 1 diabetes would be indicated because of the increased risk of hypoglycemia associated with IT regimens.

Adolescent↗
PubMed1998

Management of intracerebral lesions in patients with HIV: a retrospective study with discussion of diagnostic problems.

A total of 95 patients who presented in 1994 and 1995 with focal brain lesions at a London HIV centre were studied retrospectively. Patients were allocated to "definite" or "presumed" diagnostic categories of toxoplasma encephalitis (TE), primary CNS lymphoma (PCNSL) or progressive multifocal leukoencephalopathy (PML), based on strict criteria. The number in each category was: TE, 20; PCNSL, 9; PML, 7; presumed TE, 12; presumed PCNSL, 8 and presumed PML, 17. There were 20 patients in whom a diagnosis could not be made, and there were three non-HIV diagnoses. Demographic data, features at presentation and routine CSF analysis were not discriminatory in making a diagnosis. Toxoplasma titres were a median of 1:256 in those with TE compared to 1:16 in all other groups (p < 0.001) and those with TE were less likely to be on toxoplasma prophylaxis compared to those with PCNSL (p < 0.002). Survival with TE (median of 446 days) was significantly longer than survival in all other groups. Survival with either confirmed or presumed PML was similar. The problems of diagnosis of focal brain lesions in HIV patients are discussed and a management flow chart for mass lesions is proposed.

AIDS-Related Opportunistic Infections↗
PubMed1998

Peripheral neuropathy with nucleoside antiretrovirals: risk factors, incidence and management.

Distal symmetrical peripheral neuropathy is a common adverse experience in persons with HIV infection. This condition, which presents as a pain, numbness. burning and/or dysaethesia initially in the feet, is often multi-factorial in its origin. Nucleoside analogue reverse transcriptase inhibitors represent an important contributor to peripheral neuropathy. Specifically, around 10% of patients receiving stavudine or zalcitabine and 1 to 2% of didanosine recipients may have to discontinue therapy with these agents due to neuropathy. Prompt withdrawal of these therapies enables gradual resolution of signs and symptoms in most patients, although a period of symptom intensification may occur shortly after withdrawal. Risk factors for developing peripheral neuropathy during nucleoside analogue therapy include low CD4+ cell count (<100 cells/mm3), a prior history of an AIDS defining illness or neoplasm, a history of peripheral neuropathy, use of other neurotoxic agents including high alcohol (ethanol) consumption and nutritional deficiencies such as low serum hydroxocobalamin levels. Thus, patients at increased risk of peripheral neuropathy should potentially avoid the use of the neurotoxic nucleoside analogues or be more carefully monitored during therapy. Management of this problem includes patient education. prompt withdrawal of the likely causative agent (giving consideration not to leave the patient on a sub-optimal therapy regimen) and simple analgesia. with augmentation with tricyclic antidepressants or anticonvulsant agents when pain is severe. New agents that may assist in managing this condition include levacecarnine (acetyl-L-carnitine) and nerve growth factors such as recombinant human nerve growth factor.

Clinical Trials, Phase I as Topic↗
PubMed1997

Cross sensitivity of skin rashes with antiepileptic drugs.

BACKGROUND: Skin rashes are a well known complication of antiepileptic drug (AED) treatment. It has also been recognized that some patients will develop rashes from multiple AEDs (cross sensitivity). There are very few studies that have attempted to determine the frequency of cross sensitivity among AEDs. METHODS: Charts of all patients attending an epilepsy outpatient clinic were reviewed to determine AED exposure and the occurrence of a rash from AEDs. RESULTS: 633 patients had 1,875 exposures to 14 AEDs. Rashes occurred from carbamazepine (N = 27), phenytoin (N = 21), phenobarbital (N = 5) and lamotrigine (N = 1). A rash from 2 or more AEDs occurred in 14 patients and involved predominantly carbamazepine and phenytoin. Among the patients exposed to both phenytoin and carbamazepine 10/17 (58%) of patients with a rash from phenytoin also had a rash from carbamazepine; conversely 10/25 (40%) patients with a carbamazepine rash also had a rash from phenytoin. 4/5 patients with a phenobarbital rash were sensitive to carbamazepine and/or phenytoin. Amongst the other most commonly used AEDs no rashes occurred from valproic acid or clobazam. CONCLUSIONS: The cross sensitivity rate for rashes involving carbamazepine and phenytoin is 40-58%. If a rash develops from either of these AEDs, valproate or clobazam are safe alternatives.

Adult↗
PubMed1997

Serum total cholesterol and risk of hospitalization, and death from respiratory disease.

BACKGROUND: In earlier studies, serum total cholesterol was inversely associated with death due to respiratory diseases. METHODS: Relationships of cholesterol with risk of respiratory diseases were examined between 1978 and 1993 in a health maintenance organization in Northern California (48,188 men, 55,276 women, about 60% white, age range 25-89). Incident and fatal endpoints were ascertained using hospital discharge diagnostic codes and underlying cause of death, respectively. RESULTS: An inverse association of cholesterol level with pneumonia/influenza hospitalization was found among men and women except that, contrary to hypothesis, a positive association was seen in women under 55 years of age. Inconsistent inverse associations were found in men, but not women, between cholesterol level and hospitalization for chronic obstructive pulmonary disease (COPD). Hospitalization for asthma was unrelated to cholesterol level. An inverse association existed between cholesterol level and hospitalization for miscellaneous respiratory diseases among men, but not women. Exclusion of early hospitalizations tended to attenuate risk for cholesterol level below 4.14 mmol/l, but not the risk gradient across higher cholesterol levels. For deaths, cholesterol level was statistically significantly inversely associated only with COPD. CONCLUSIONS: Cholesterol had graded inverse associations with some respiratory diseases, but not others, tending to be stronger in men than in women, and in older than in younger participants. Associations varied for hospitalizations compared to deaths. More epidemiological and basic research is needed to elucidate the potential mechanisms underlying the observed associations.

Adult↗
PubMed1997

Serum screening for Down's syndrome: how much do health professionals know?

OBJECTIVE: To assess knowledge about serum screening for Down's syndrome in health professionals involved in antenatal care. DESIGN: Postal questionnaire survey of knowledge of performance and interpretation of serum screening. SETTING: Portsmouth and South East Hampshire health district. POPULATION: All health professionals likely to be involved in antenatal care. METHODS: Questionnaires were sent to all general practitioners (n = 288), hospital midwives (n = 129), community midwives (n = 71), and obstetricians (n = 29) working in the district. MAIN OUTCOME MEASURES: Total number of correct responses given to eight factual questions and percentage of correct responses to each individual question. RESULTS: Responses were received from 434 health professionals (84%). Fifty-nine percent of health professionals correctly answered only a half or less of the factual questions on serum screening. Questions relating to the sensitivity, specificity, and positive predictive value were particularly poorly answered. Obstetricians scored most highly. General practitioners scored significantly less than the other groups. CONCLUSIONS: Women need accurate information to give informed consent to serum screening. Most health professionals likely to be involved in antenatal care in this district do not fully understand the test and are thus unlikely to provide such information. Changes in the provision of maternity services following Changing Childbirth may increase the input of midwives and general practitioners. Training of professionals about serum screening should be reviewed.

Down Syndrome↗