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Biomedical subjects

J W Britton

Publications and source records attributed to J W Britton.

10 recordsLinked to original sources
PubMed2002

Comparative diagnostic utility of 1H MRS and DWI in evaluation of temporal lobe epilepsy.

OBJECTIVE: To compare the ability of diffusion-weighted MRI (DWI) and (1)H MRS to lateralize to the temporal lobe of seizure onset and to predict postoperative seizure control in patients with temporal lobe epilepsy (TLE). METHODS: Forty TLE patients who subsequently underwent epilepsy surgery and 20 normal subjects were studied with (1)H MRS and DWI. Medial parietal and temporal lobe N-acetylaspartate (NAA)/creatine (Cr) ratios and hippocampal and temporal stem apparent diffusion coefficients (ADC) were obtained. Lateralization to either temporal lobe with each MR measurement was based on the threshold values derived from +/-1-SD right/left ratios of normal subjects. RESULTS: Temporal lobe NAA/Cr lateralized to the operated temporal lobe in 18 of 40 (45%), hippocampal ADC in 32 of 40 (80%), and temporal stem ADC in 26 of 40 (65%) patients. Almost all of the cases that lateralized to the surgical side with NAA/Cr ratios (94%) had an excellent postoperative seizure control (p = 0.01). Lateralization to the side of surgery was not associated with surgical outcome with hippocampal and temporal stem ADC (p > 0.05). CONCLUSION: (1)H MRS and DWI complement each other in the clinical setting. DWI more frequently lateralized to the operated side, and (1)HMRS was a better predictor of postoperative seizure control.

Adolescent↗
PubMed2001

The relationship between quantitative T2 relaxometry and memory in nonlesional temporal lobe epilepsy.

PURPOSE: We investigated the relationship between preoperative quantitative magnetic resonance imaging (MRI) T2 relaxometry and volumetry of the hippocampi and pre- and postoperative verbal memory in temporal lobectomy patients who had nonlesional temporal lobe epilepsy. METHODS: Pre- and postoperative memory data based on the Logical Memory (LM) subtest of the Wechsler Memory Scale-Revised (WMS-R) and the 30-min delayed recall trial of the Rey Auditory Verbal Learning Test (AVLT) were obtained from 26 left and 15 right temporal lobectomy patients. Coronal MRI T2 maps were generated for these 41 temporal lobectomy patients as well as 61 control patients. Hippocampal T2 relaxation times and hippocampal volumes, converted to z scores using control group data, were correlated with neuropsychological performance in the patients. RESULTS: In left temporal lobe-onset patients, high T2 in the left hippocampal body predicted higher LM performance after surgery. Asymmetrically high T2 in the left hippocampal body (i.e., the right-minus-left difference), compared with the right hippocampal body, also predicted higher LM performance after surgery. In right temporal lobe-onset patients, high T2 in the left hippocampal body predicted relatively lower AVLT performance after surgery. Multiple regression analysis in left temporal-onset patients revealed that high T2 in the left hippocampal body together with higher preoperative LM performance predict higher postoperative LM performance. CONCLUSIONS: Our findings suggest that elevated (i.e., abnormal) hippocampal T2 signal is associated with memory ability (or hippocampal functional capacity) independent of MRI-determined hippocampal atrophy. Therefore, our findings support the use of quantitative T2 relaxometry as an independent predictor of verbal memory outcome in both left and right TLE patients who are candidates for temporal lobectomy.

Adult↗
PubMed1999

Nonaneurysmal thunderclap headache with diffuse, multifocal, segmental, and reversible vasospasm.

OBJECTIVE: To highlight the clinical profiles and angiographic findings of two patients with recurrent thunderclap headache (TCH) without subarachnoid hemorrhage (SAH) and to present modified diagnostic criteria for this unusual syndrome. BACKGROUND: TCH may be a benign recurrent headache disorder or it may represent a serious underlying process such as SAH or venous sinus thrombosis. The pathophysiology of this disorder in the absence of underlying pathology is not well understood and its potential angiographic features are not well appreciated. METHODS: Two case descriptions with illustrative angiography. RESULTS: Both cases demonstrated the potential for reversible intracranial vasospasm without intracranial aneurysm or SAH and a benign clinical outcome. CONCLUSIONS: Primary TCH has a distinctive clinical and angiographic profile and must be distinguished from central nervous system vasculitis and SAH.

Headache↗
PubMed1996

Selection of antiepileptic drugs: a practical approach.

The selection of antiepileptic drugs (AEDs) is increasingly more complex as new agents become available. We discuss an individualized approach to selection of an AED that is tailored to each patient's needs by considering the following six factors: effectiveness of the drug in controlling seizures, adverse effects profile, pharmacokinetic properties, special or unique patient situations, drug interactions, and cost of treatment. When these factors are considered, treatment complications and failure can be minimized by anticipating incompatibilities among drugs or between the drugs and the patient's condition. We emphasize the concept that the best AED therapy is dependent on optimal seizure control and absence of unacceptable side effects. In the current environment of medical practice, the cost of treatment has also become a major concern. With rare exceptions, no single factor dictates the choice of an AED. In the long term, the most cost-effective treatment will be the one that provides the most therapeutic benefit with the fewest complications and maximal patient satisfaction.

Anticonvulsants↗
PubMed1995

Hereditary late-onset chorea without significant dementia: genetic evidence for substantial phenotypic variation in Huntington's disease.

We examined five individuals and obtained information concerning six other members from two unrelated families, nearly all of whom developed chorea after age 50 (one patient developed chorea at age 40). The severity of chorea progressed in all patients and became disabling in some individuals approximately 15 years after onset. Cognitive impairment was absent or minimal. All five examined patients were cognitively normal, even 10 to 30 years following the onset of chorea. Formal neuropsychometric testing demonstrated mild cognitive impairment in two individuals. Nevertheless, all patients were able to maintain employment or carry on with their usual household tasks until chorea was severe. One individual first became demented 30 years after the onset of chorea. Neuroimaging (with CT or MRI) in four patients failed to demonstrate significant caudate or putaminal atrophy 8 to 15 years following the onset of chorea. Three other family members (who were not available for examination) were said to have suffered chorea (without any mental decline) beginning after age 50, with subsequent survival of 20 years (in one) and 30 years (in two). Given this constellation of history and findings, three experienced neurologists and two medical geneticists concluded that these patients had a familial chorea syndrome distinct from Huntington's disease (HD). However, genetic analysis of the trinucleotide (CAG) repeat length associated with HD (in 4p16.3) determined repeat lengths of 44 and 46 in four patients tested (within the HD range). We conclude that these patients have HD and that such families represent further convincing examples of significant phenotypic variation for HD.

Age of Onset↗
PubMed1993

The constipated serviceman: prevalence among deployed U.S. troops.

The prevalence of constipation in deployed servicemen was determined in a sample of military personnel aboard the USS Iwo Jima LPH 2 during Operation Desert Shield. Results were obtained from a bowel function questionnaire issued to 500 deployed marines and sailors. When constipation is defined as no bowel movement for greater than 3 days, 3.9% of the Marine/sailor personnel are constipated when in their home environment as compared to 6.0% when they are aboard ship and 30.2% while in the field. Alternatively, when constipation is defined as the presence of certain anorectal complaints (hard stools, straining, painful defecation, and bleeding with defecation), the incidence is 7.2% when at home as compared to 10.4% aboard ship and 34.1% in the field. These results confirm that whether constipation is defined as infrequent bowel movements or presence of symptoms of constipation, significantly more servicemen will be constipated when in the field as compared to their home environment. Since approximately one-third of Navy/Marine Corps personnel deployed in a field environment will be constipated, preventive measures ought to be evaluated.

Adolescent↗
PubMedDate not supplied

Low-grade glial neoplasms and intractable partial epilepsy: efficacy of surgical treatment.

We performed a retrospective study of 51 consecutive patients who underwent operation for intractable partial epilepsy related to low-grade intracerebral neoplasms between 1984 and 1990. All patients had medically refractory partial seizures and a mass lesion identified on neuroimaging studies. Lesionectomy was performed on 17 patients, and 34 had lesion resection and corticectomy. Mean postoperative follow-up was 4.4 years (range 2-8 years). Sixty-six percent of patients were seizure-free, and 88% experienced a significant reduction in seizure frequency. In 16 patients (31%), antiepileptic drugs (AEDs) were successfully discontinued. Twenty-five of 31 (81%) eligible patients obtained a driver's license after successful operation. Patients with complete tumor resection and no interictal epileptiform activity on postoperative EEG studies had the best operative outcome. Epilepsy surgery can result in long-term improvement in seizure control and quality of life (QOL) in selected patients with intractable tumor-related epilepsy. Our results should be useful to clinicians considering treatment options for patients with intractable seizures related to low-grade intracerebral neoplasms.

Adolescent↗