Biomedical subjects

M A Hamilton-Bruce

Publications and source records attributed to M A Hamilton-Bruce.

3 recordsLinked to original sources

PubMed1991

Interoperator variability in quantitative electroencephalography.

The purpose of the study was to determine whether quantitative or discriminant analysis of the electroencephalograph (EEG) would vary significantly when the same EEG was analysed by 3 different operators. EEGs on 10 healthy volunteers were recorded on the Cadwell Spectrum AT 386, using the Electrocap (10-20 system). The EEGs were analysed independently, with each operator selecting the first 48 artifact-free epochs. The results were analysed using the non-parametric Friedman two-way analysis of variance (ANOVA) for the discrimination analysis and a one-way ANOVA for the monopolar and bipolar Absolute Power raw measures. Statistical analysis of the discriminant data showed no significant differences between operators, with 7 of 10 studies yielding the same results. The remaining 3 studies were classified either as borderline or normal when analysed by different operators. Although a series of "t" tests comparing 2 operators showed most variability occurring in Absolute Power as compared with Relative Power, Power Asymmetry and Coherence, ANOVA of the raw mono- and bipolar Absolute Power measures showed no significant differences between the operators at the P = 0.05 level. Thus the differences between the operators were non-significant when comparing quantitative EEG analyses with respect to both the raw measures and the discriminant analyses.

Analysis of Variance↗

PubMed1991

Familial spastic paraplegia: an electrophysiological study of central sensory conduction pathways.

An electrophysiological assessment has been performed studying somatosensory, visual and auditory pathways in clinically affected and unaffected members from 4 pedigrees with the autosomal form of 'pure' familial spastic paraplegia (n = 32). In some members from 2 families, testing of all 3 sensory pathways showed abnormal results, even in those clinically unaffected. In another family, some had abnormal somatosensory and visual pathways, with no involvement of the auditory pathway. In a further family, the somatosensory and brainstem auditory pathways were abnormal, with sparing of the visual pathway. These findings indicate that the neuronal degeneration in familial spastic paraplegia extends beyond the spinal cord and involves the visual and auditory pathways. The differences between families, and the asymptomatic abnormalities in clinically unaffected members, suggest diversity in the expression of the genetic defect.

Evoked Potentials, Auditory, Brain Stem↗

PubMed1989

Evaluation of evoked potentials and cerebrospinal fluid analysis in the differential diagnosis of multiple sclerosis.

During the 6 years to December 1988, 191 patients underwent evoked potential (EP) studies and cerebrospinal fluid (CSF) analysis for oligoclonal bands at the Queen Elizabeth Hospital, for the differential diagnosis of multiple sclerosis (MS). Clinical data at the time of study separated patients into 3 groups, as follows: (i) multiple sclerosis (n = 90) - McDonald and Halliday Classification, 1977, (ii) other neurological disease (n = 82) and (iii) no neurological disease (n = 19). In cases of clinically definite MS, visual evoked potentials (VEPs) were abnormal and oligoclonal bands were detected in 64% and 59% of cases, respectively. However, only 15% of patients with suspected MS had abnormal VEPs, and only 23% had oligoclonal bands. Other studies have shown figures differing from these, though not necessarily significantly. We found a substantial number of EP (20%) but few CSF (4%) abnormalities in disorders other than MS, and no abnormalities in cases without neurological disease. The various figures for abnormal results in cases assessed for the differential diagnosis of MS are influenced not only by laboratory methods, but by the degree of clinical suspicion in relation to the cases selected, as well as by differences in populations from which cases are derived. Long-term prospective studies of diagnostically indeterminate cases are still required to determine the diagnostic weighting that can be applied on the basis of abnormal investigational results. Magnetic resonance imaging will not resolve these questions since it has limitations of its own, particularly with regard to specificity.

Adult↗