A clinical neurological, neurophysiological, and neuropsychological study of sheep farmers and dippers exposed to organophosphate pesticides.
(49/492)
OBJECTIVES: To classify clinical diseases of the subjects with abnormal indices of peripheral neuropathy identified in field studies of sheep farmers and dippers exposed to organophosphate pesticides. To explore what neuropsychological profiles, if any, may be associated with neurophysiological damage in these subjects. METHODS: A case-control study (79 subjects) nested within the cross sectional study (685 subjects) of sheep farmers from the field study. Three groups with no, possible, and probable or definite neuropathy according to field studies were recruited. Investigations comprised symptoms of neuropathy, neurologial signs, motor and sensory nerve conduction, electromyography, quantitative sensory testing, and neuropsychological tests. RESULTS: The incidence of clinical neuropathy increased from 7% in the no neuropathy group to 52% in the probable or definite neuropathy group based on nerve conduction measurements or presence of neurological signs. Sensory abnormalities were found more often than motor deficits. Small diameter nerve fibres were also affected more than large fibres. CONCLUSIONS: The neuropathy is predominantly sensory and is characteristic of distal, chronic neuropathy with no acute features. Small fibre populations are affected more than large fibre populations. Increasing severity of neuropathy was associated with anxiety and depression as measured in the neuropsychological tests. (+info)
Clinical validation of methods of diagnosis of neuropathy in a field study of United Kingdom sheep dippers.
(50/492)
OBJECTIVES: To investigate the reproducibility of measured indices of chronic peripheral neuropathy from a field study of sheep dippers when compared with similar measurements carried out in a clinical setting. METHODS: A stratified random sample of field study subjects was invited to attend a clinic. Neuropathy was measured both in the field and at the clinic with a modified version of a standard symptoms questionnaire and quantitative sensory thresholds for hot, cold, and vibration. These were combined into a classification of the likelihood of neuropathy with a neuropathy scoring system. Indicators of sensory abnormality were based on comparison of sensory thresholds to age dependent reference values derived from an external reference group. RESULTS: Only 51% of subjects were assigned similar classifications in the field and clinic based on the neuropathy scoring system. Of the component indices, grouped symptom scores, with 65% of subjects showing exact agreement, proved to be more reproducible than quantitative sensory test indicators. There were biases in the comparison of field and clinic measurements of hot and vibration sensations, but no evidence of greater variation between individual people in sensory thresholds in the field relative to at the clinic. CONCLUSIONS: The neuropathy scoring system proved to be of limited reproducibility, due in a large part to the lack of reproducibility of the indicators of sensory test abnormality caused by inadequate temperature control. However, the symptoms score and measured sensory thresholds could be used separately as indices of neuropathy in exposure-response analyses. (+info)
Subclinical cerebellar anterior lobe, vestibulocerebellar and spinocerebellar afferent effects in young female lead workers in China: computerized posturography with sway frequency analysis and brainstem auditory evoked potentials.
(51/492)
By computerized static posturography with sway frequency analysis, subclinical effects of lead on postural balance was examined in 29 female workers (lead workers) employed at a glass factory for 3-17 (mean 7.9) years in Beijing, China, in relation to brainstem function assessed by brainstem auditory evoked potential (BAEP). Their blood lead concentrations ranged from 26 to 79 (mean 55.7) microg/dl; ages were 21-30 (mean 28) years. Control subjects, aged 22-29 (mean 27.0) years, were 14 healthy female workers at a textile factory located in the same district. With eyes closed, power of the sway of high (2-4 Hz) and low (1 Hz or less) frequencies in lead workers was significantly larger than that in controls; with eyes open, their power of the sway of low frequency was significantly larger (p<0.05). The multiple regression analysis showed that the power of high frequency sway with eyes closed and of low and high frequencies with eyes open were significantly related to blood lead concentrations in lead workers (p<0.05). On the other hand, no significant differences in BAEP latencies between lead workers and controls were observed. The low frequency sway with eyes open was significantly correlated with the high frequency sway with eyes closed in the lead workers. The pattern of changes in postural balance suggested that the anterior cerebellar lobe, vestibulo-cerebellar and spinocerebellar afferent systems were affected asymptomatically in female lead workers; the sway of vestibulo-cerebellar and anterior cerebellar lobe types were simultaneously affected by lead. It appears that a computerized static posturography with sway frequency analysis is useful technique for assessment of subclinical lead neurotoxicity. (+info)
Older people and ill fitting shoes.
(52/492)
BACKGROUND: Foot health is an important issue in older people. Inappropriate shoes increase the risk of callous and ulcer formation, as well as increasing the risk of falls. There are no data defining the size of this problem. OBJECTIVE: The aim of the study was to investigate the proportion of elderly people on a general rehabilitation ward wearing incorrectly sized shoes and to look for the presence of complications. METHODS: Sixty five consecutive patients (mental state questionnaire score >6) admitted to a rehabilitation ward had their foot length and width measured, and the size of their current footwear recorded. Sensation was tested with a standard 10 g monofilament. The presence of ulceration was noted. Foot pain was recorded by the patient on a visual analogue scale. Any history of diabetes mellitus, peripheral vascular disease, or peripheral neuropathy was noted. RESULTS: The median age of the subjects was 82 (range 64-93). Six (9%) had a history of diabetes, seven (11%) had symptomatic peripheral vascular disease, and 17 (26%) had sensory impairment. Ten patients (15%) had foot ulceration present, and 47 patients (72%) had ill fitting shoes (a discrepancy in length of more than half a British shoe size fitting or more than one British width fitting, 7 mm). Incorrect shoe length was significantly associated with the presence of ulceration (odds ratio (OR) = 10.04, p = 0.016). Presence of ulceration was significantly associated with a history of peripheral vascular disease (OR = 11.56, p = 0.008). Pain was significantly associated with incorrect shoe length (p = 0.0238) and with sensory impairment (p = 0.0314). CONCLUSION: Most older people on a rehabilitation ward wore ill fitting shoes. An association was found between ill fitting shoes and self reported pain, and between ill fitting shoes and ulcer formation. A straightforward assessment of footwear in older people could improve comfort and avoid preventable foot disorders. (+info)
Links between anaesthetic modality and nerve damage during lower third molar surgery.
(53/492)
OBJECTIVE: To investigate the relationships between eruption status, gender, social class, grade of operator, anaesthetic modality and nerve damage during third molar surgery. DESIGN: Two centre prospective longitudinal study. SETTING: The department of oral and maxillofacial surgery, University Hospital Birmingham NHS Trust and oral surgery outpatient clinics at Birmingham Dental Hospital. SUBJECTS: A total of 391 patients had surgical removal of lower third molars. Sensory disturbance was recorded at one week post operatively. Patients with altered sensation were followed up at one month, three months and six months following surgery. RESULTS: 614 lower third molars in 391 patients were removed. Forty-six procedures (7.5%) were associated with altered sensation at one week with three procedures (0.49%) showing persistent symptoms at six months. Of these 46 nerve injuries, 26 (4.23%) involved the lingual nerve and 20 (3.25%) the inferior dental nerve (IDN). All three persistent sensations were IDN related. A logistic regression model found that the use ofa lingual retractor chi2 = 11.559, p = 0.003 was more significant than eruption status chi2 = 12.935, p = 0.007. There was no significant relationship between anaesthetic modality, age, social class, sex and seniority of operator. CONCLUSIONS: There was no link between the choices of local or general anaesthesia and nerve damage during lower third molar removal when difficulty of surgery was taken into account. (+info)
Evaluation of postural stability after low-dose droperidol in outpatients undergoing gynaecological dilatation and curettage procedure.
(54/492)
BACKGROUND: Low-dose droperidol is suggested to be cost-effective in preventing nausea and vomiting after ambulatory surgery. This clinical study evaluated patient postural stability using a computerized force platform after an i.v. dose of droperidol 0.625 mg in outpatients undergoing gynaecological dilatation and curettage procedures. METHODS: After institutional approval and informed consent, 120 females were randomly assigned to receive either 0.9% saline (placebo) or droperidol 0.625 mg i.v. before surgery. Anaesthesia was induced with propofol 2-2.5 mg kg-1 and fentanyl 50-100 micrograms, and was maintained with intermittent boluses of propofol 25-50 mg and fentanyl 25-50 micrograms i.v. After operation, the Post-Anaesthesia Discharge Score (PADS), patient self-assessment scores for pain, nausea, drowsiness and dizziness, and extrapyramidal symptoms were recorded. Body sway velocity was measured while the patient was standing on a firm surface with eyes open then closed vs standing on a foam surface with eyes open then closed, at the time of arrival in the operation holding area (baseline), on achieving a PADS of 9 after surgery and on discharge home. RESULTS: At the time of achieving a PADS of 9, body sway was significantly greater in the droperidol group than in the placebo group (overall 61% vs 33% above baseline). There were no differences between groups with respect to scores for pain, nausea, drowsiness and dizziness. Three patients (5%) in the droperidol group reported nervousness and restlessness postoperatively (not significant). CONCLUSION: Low-dose droperidol 0.625 mg i.v. for anti-emetic prophylaxis can cause balance disturbances in females after gynaecological dilatation and curettage procedures. (+info)
Vestibular-evoked postural responses in the absence of somatosensory information.
(55/492)
In order to investigate the ways in which sensory channels interact to control balance, we measured the postural response evoked by galvanic vestibular stimulation (GVS) in a rare subject (I. W.) with a large-fibre sensory neuronopathy. I. W. has no sensations of cutaneous light touch and movement/position sense below the neck, and without vision he has no knowledge of where his limbs and body are in space. He was tested with and without vision while seated. With eyes closed, I. W.'s responses to pure vestibular stimuli were an order of magnitude larger than those of healthy controls. In other respects his responses were normal. Part of this phenomenon may have been due to lack of response modification by somatosensory feedback. However, the initial development of his ground reaction force, which is the earliest mechanical indicator of the response, differed from that of a control subject from its beginning. Similarly, opening his eyes resulted in a reduction (>50%) of the response from its beginning. We propose that these early changes reflect changes in initial response selection, possibly by alterations in the gain of vestibulopostural channels. We suggest that similar gain changes operate in healthy subjects and occur through a fast dynamic process. A model is put forward in which the weight of each sensory channel is adjusted continuously in a competitive manner according to the balance-relevant information content of the other sensory channels. As a secondary issue, the nature of I. W.'s head and trunk tilt response provides insight into the question of which vestibular afferents are recruited by GVS. I. W.'s responses consisted of an initial, relatively fast tilt followed by a slower, continuous tilt. When the stimulus was turned off, his body partially tilted back at an intermediate velocity. We modelled this behaviour as the algebraic sum of a position response and a constant velocity response. We suggest that these two components arise from stimulation of otolith and semicircular canal afferents, respectively. (+info)
Balance confidence among people with lower-limb amputations.
(56/492)
BACKGROUND AND PURPOSE: Confidence in a person's balance has been shown to be an important predictor of social activity among people with lower-limb amputations. The purposes of this study were to describe confidence in balance among people with transtibial or transfemoral lower-limb amputations and to compare people whose amputations were due to vascular and nonvascular causes. SUBJECTS AND METHODS: A survey of a sample of 435 community-dwelling individuals from 2 regional clinics was conducted. The sample consisted of people with unilateral transfemoral (26.7%) and transtibial (73.3%) amputations who lost their limb for vascular (53%) and nonvascular (47%) reasons. The mean age of the primarily male (71%) sample was 62.0 years (SD=15.7). RESULTS: Mean scores, using the Activities-specific Balance Confidence (ABC) Scale, were 63.8 for the total sample, 54.1 for the subjects with amputations due to vascular reasons, and 74.7 for the subjects with amputations due to nonvascular reasons. Given a maximum possible ABC Scale score of 100, the results suggest that confidence was low. A difference between the subjects with amputations due to vascular reasons and those with amputations due to nonvascular reasons was observed over each item of the ABC Scale. Variables that were statistically related to balance confidence included age, sex, etiology, mobility device use, the need to concentrate while walking, limitations in activities of daily living, depression, and fear of falling. DISCUSSION AND CONCLUSION: Balance confidence scores among the study sample were low when compared with values previously reported by other researchers. Confidence was particularly low among individuals who had their amputation for vascular reasons. Balance confidence might be an important area of clinical concern. (+info)