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Biomedical subjects

J P Halonen

Publications and source records attributed to J P Halonen.

At least 19 recordsLinked to original sources
PubMed1999

Factors predicting lower extremity amputations in patients with type 1 or type 2 diabetes mellitus: a population-based 7-year follow-up study.

OBJECTIVES: The aim of the study was to find factors predicting lower extremity amputation in patients with type 1 or type 2 diabetes mellitus through a 7-year follow-up period. DESIGN: Follow-up study. SUBJECTS: Altogether 733 diabetic patients. aged 10-79 years, were drawn from the national drug reimbursement register. METHODS: At baseline, the patients underwent a podiatric, circulatory and neurophysiological examination. Seven years later a follow-up study was performed based on clinical and register data. Patient data for those who died during the follow-up were collected from hospital records and death certificates. All amputations were recorded. The patients with amputation were compared with the other patients and also, in a case-control manner, by taking three nonamputated patients matched by sex, type of diabetes, and age for each patient with amputation. RESULTS: The number of amputations was 25 in the sample. Compared with all patients without amputation, patients with amputation differed in altogether 24 variables concerning diabetes and its complications. Compared with the matched non-amputated patients, the amputated patients had longer duration of diabetes, lower ankle/brachial pressure index (ABI), more often history of retinopathy, nephropathy, and hypertension, more often visual handicap, elevated serum creatinine level, abnormal neurophysiological indices and electrophysiological findings. In the logistic regression analysis, vibration perception threshold, low ABI, history of retinopathy, visual handicap, and male sex were independently associated with lower extremity amputation. CONCLUSIONS: Lower extremity amputations were strongly associated with retinopathy, nephropathy, and neuropathy. The presence of any of these complications should lead to intensified actions in order to prevent amputations. As far as arterial circulation is concerned, claudication or absent peripheral pulses were not good predictors of amputation, whereas low ABI, despite its known weaknesses, was a reliable indicator of future amputation.

Adolescent↗
PubMed1999

Electroencephalography and magnetic resonance imaging after diving and decompression incidents: a controlled study.

Electroencephalography and magnetic resonance imaging after diving and decompression incidents: a controlled study. Undersea Hyper Med 1999.; 26(2):61-65.--Diving incidents with symptoms of decompression sickness (DCS) and/or arterial gas emboli (AGE) might increase the degree of pathologic change in the electroencephalogram (EEG) or magnetic resonance imaging (MRI) of the supraspinal central nervous system (CNS). Diving itself, even without known symptoms of DCS and/or AGE, has been proposed to increase the number of CNS lesions using either EEG or MRI. In the first part of a two-part study we examined the effects of recompression treatment on EEG in decompression incidents in a group of sport and professional divers compared with a control group of healthy naval divers. In the second part we recorded brain MRI from three groups of volunteers: 1) divers who were treated for DCS in pressure chamber, 2) divers who had never had symptoms of DCS (and/or AGE), and 3) healthy normal controls who were not divers. Our results indicate that DCS increases the incidence of pathologic EEG recordings, whereas recompression treatment decreases them. The results of MRI do not verify evidence of increased numbers of CNS lesions in normal divers as compared to non-diving, healthy control subjects, whereas some of the divers treated for DCS in a pressure chamber had hyperintense lesions in brain white matter. None of them had any abnormalities in EEG, neurologic performance, or psychologic behavior. Both EEG and MRI are sensitive and non-specific methods for judging suspected evidence of brain lesions from diving or diving accidents.

Adult↗
PubMed1998

Peripheral nerve conduction in healthy subjects during short-term hyperglycemia.

Aim of the present study was to evaluate the effect of acute hyperglycemia on peripheral nerve conduction measurements. Five healthy male volunteers aged 36-42 years underwent nerve conduction studies during hyperglycemia (blood glucose approximately 12 mmol/l) induced by intravenous infusion of glucose and maintained for 120 minutes. Peroneal motor and sural sensory nerve conduction velocities and amplitudes were measured from the right leg at 15 min intervals starting at 15 min before and continuing 30 min after glucose infusion. Data were analysed using paired t-test comparing measurements at each time point after the start of the infusion to the second control measurement immediately prior to the infusion. All nerve conduction velocities and amplitudes were similar before, during and after induced hyperglycemia. The results suggest that it is unnecessary to standardise blood glucose concentration during measurement of peripheral nerve functions.

Adult↗
PubMed1995

What does the multiple sleep latency test measure in a community sample?

Multiple sleep latency test (MSLT)-defined daytime sleepiness and its relationships with nocturnal and daytime psychophysiological activation were investigated in a random community sample of 77 subjects aged 35-55 years. The correlation structure between all study variables was explained by a simple model of daytime sleepiness. The model suggested that indicators of psychophysiological arousal (psychological distress, nocturnal motor activity and serum thyrotropin level) and daytime reported tiredness, body mass index (BMI) and age were related significantly and independently to MSLT-defined daytime sleepiness. The arousal theory of insomnia and poor sleep in relation to MSLT behavior is discussed and the need of a multivariate approach is emphasized in MSLT studies.

Adult↗
PubMed1994

Infrared pupillometry in the assessment of autonomic function.

In order to study normal dynamic pupillary function and to determine reference limits for various pupillary variables, 81 healthy subjects aged between 32 and 60 years were examined using a portable infrared pupillometer. Additionally, 36 patients with type I diabetes mellitus were studied. In healthy subjects, sex had no, or only marginal, effect on the responses. Body mass index or smoking habits had no effect on pupillary dynamics. The relative reflex amplitude (RRA) was independent of age. The time to minimum diameter tmin was dependent on maximum constriction velocity (MCV) (P < 0.001) but not on age, initial diameter or reflex amplitude (RA). The MCV, maximum redilatation velocity (MRV) and time to 75% redilatation (t75%) were strongly dependent on RRA (P < 0.001 for each), but age had no or only a marginal effect. No correlation existed between the results of pupillometry and those of Valsalva or deep breathing tests. The lowest normal value for RRA was 29%. The reference limits for MCV, MRV and t75% were calculated in relation to RRA. The smaller the RRA was, the slower the velocities and the shorter the t75% were. Using these reference limits, 25% of the diabetic patients without cardiac autonomic neuropathy and 50% with definite cardiac autonomic neuropathy had abnormalities in at least one out of four pupillary variables. It is concluded that infrared pupillometry may be a useful additional method for the assessment of autonomic function.

Adult↗
PubMed1992

Effect of disease duration on cardiac autonomic reflexes in young patients with insulin-dependent diabetes mellitus.

The association of disease duration with deterioration of cardiovascular autonomic reflexes was studied in two groups of young patients with insulin-dependent diabetes mellitus (IDDM). The mean age of the patients in both groups was 31 years and the mean duration of the disease was 3 (n = 18) and 16 (n = 22) years. No significant difference in group means was seen in the test parameters of autonomic nerve function. However, five patients with long-term disease, but none with short-term disease, had test scores indicating cardiac autonomic neuropathy. It was concluded that (1) the duration of the disease has no overall effect on autonomic nerve function in young patients with IDDM, but (2) a few individuals with IDDM may have some precipitating factors leading to autonomic neuropathy in the course of the disease.

Adult↗
PubMed1990

Multi-level epidural recordings of spinal SEPs during scoliosis surgery.

Spinal somatosensory evoked potentials were recorded in 35 neurologically normal patients undergoing surgery for scoliosis. The recording electrodes were placed in the dorsal epidural space. Stimulation was of the tibial nerve in the popliteal fossa and the posterior tibial and sural nerves at the ankle. At thoracic levels the response consisted of at least 3 components with different peripheral excitation thresholds and spinal conduction velocities (range 35-85 m/sec). All components were conducted mainly in tracts ipsilateral to the stimulus, component 1 being most laterally located. At low stimulus intensity only the fastest activity was recorded but higher intensities elicited additional, slower conducting components. Component 1 was much less prominent when the posterior tibial nerve was stimulated at the ankle and absent from the (cutaneous) sural nerve response. Component 1 is likely to be due to the stimulation of group 1 muscle afferents which terminate in the dorsal horn and activate second-order neurones, many of whose axons go to form the ipsilateral dorsal spinocerebellar tract. Components 2 and 3 are believed to be largely cutaneous in origin and to be conducted mainly in the dorsal columns.

Electric Stimulation↗
PubMed1990

SCSB method compared to EEG-based polygraphy in sleep state scoring of newborn infants.

Knowledge of the sleep state is important in physiological studies since many physiological variables show different properties in different sleep states. The recently developed static charge sensitive bed (SCSB) method allows long-term recordings of body movements, respiration and ballistocardiogram without electrodes attached to the subject. The recordings are easy to carry out and they do not disturb the subject in any way. The recorded variables are basic characteristics of different sleep states. SCSB-recordings and electroencephalography (EEG) based polygraphy as well as blind sleep state scoring were carried out in 8 newborn infants. The positive correlation between SCSB-scoring and EEG-based polygraphy scored by two clinical neurophysiologists was 68.1 and 64.1%. Only in 2% of all epochs was active sleep scored as quiet sleep or vice versa. The results indicate the usefulness of the SCSB method in sleep state scoring of newborn infants.

Ballistocardiography↗
PubMed1986

Early surgical exploration and epineural repair in birth brachial palsy.

The management of birth brachial palsy (Erb-Duchenne, Klumpke) has been traditionally conservative, and that is why the condition leaves some patients with impaired upper limb function for life. Development of anaesthesiology and microsurgical techniques have made safe early surgical repair of selected palsies possible. A 12 years' experience of early exploration of 11 patients aged from 2 weeks to 7 months is evaluated. The technique of direct epineural repair of ruptured roots has been successful in the early treatment of birth palsy. In the follow-up of 1 to 13 years after operation 7/11 patients regained good to excellent hand function.

Birth Injuries↗
PubMed1986

Quantitative vibratory perception thresholds of healthy and epileptic children.

Quantitative vibratory perception threshold (VPT) measurements were performed on 102 healthy children and 79 children receiving anti-epileptic medication. Their ages ranged from three to 16. The VPTs correlated significantly with age and height. The rise in VPT with age may be associated with decreased receptor density. The level of mental alertness seemed to have no significant effect on vibratory perception. Only three of the children on anti-epileptics showed elevated VPTs. On the basis of this study, epileptic children seem to be free of the adverse effects of medication which occur later in adulthood. Children as young as three or four are quite capable of co-operating in this examination. The method can be recommended for use in follow-up studies of children and as a diagnostic aid when a disturbance of the sensory tract is suspected.

Adolescent↗
PubMed1986

Vibratory perception thresholds in shipyard workers exposed to solvents.

Vibratory perception thresholds were determined for 90 subjects working at a shipyard with industrial solvents. The duration of exposure varied from 1 to 44 years (mean 19.6 years). Four of the men but none of women had bilaterally significantly increased thresholds in the lower limbs. In addition, seven subjects had increased thresholds in the upper extremities only. Fifteen subjects were further examined at a neurophysiological laboratory to determine the degree of possible peripheral polyneuropathy. The following measurements were made at the laboratory: motor and sensory conduction velocities, electromyography and heart rate variation during normal and forced breathing. The laboratory investigations revealed abnormalities in most of the subjects with increased vibratory perception thresholds in the lower limbs. On the other hand the laboratory measurements were normal for all subjects with increased thresholds in the upper limbs only. It is concluded that when peripheral polyneuropathy is suspected, quantitative vibratory perception threshold measurement is an easily applicable screening method for selecting subjects for further laboratory investigations.

Adult↗
PubMed1986

Vibratory perception threshold in patients with mild multiple sclerosis.

The vibratory perception threshold (VPT) was measured bilaterally on both the upper and lower extremity in 69 patients with mild multiple sclerosis. In the case of the lower extremities the VPT measurements were closely correlated with qualitative vibratory perception measurements performed with a tuning fork; in the upper extremities the association was weak. The VPT was abnormal at least in one extremity in 38% of the patients. Quantitative VPT measurement seem to be a suitable technique for the detection of sensory symptoms of central origin.

Adolescent↗
PubMed1984

EEG findings in tick-borne encephalitis.

EEG findings of epidemiologically and serologically confirmed tick-borne encephalitis patients were compared with findings of patients having acute encephalitis of viral or undetermined origins. Tick-borne encephalitis patients had more bilaterally synchronous bursts of slow waves and more focal abnormalities than did controls. Moreover, their EEGs remained mildly pathological, with increased slow and beta activity and intermittent focal abnormalities in some patients, whereas, EEGs in the controls became normal or borderline, usually within two months. EEG can thus reveal differences between individuals' responses to encephalitis and between different types of encephalitis, even though the clinical pictures are rather similar. Finally, the study shows that tick-borne encephalitis causes changes in the EEG that persist long after the clinical disease appears to have resolved.

Adolescent↗
PubMed1981

Sensory neuropathy in rheumatoid arthritis: an electroneurographic study.

In a selected series of twenty-three RA patients, aged from 23 to 56 years, mean 41, the neurophysiological functions of six sensory nerves were measured and the results were correlated with clinical and laboratory data. Significant changes in the functions of one or more nerves were found in 10 patients, 2 of whom had no symptoms of clinical neuropathy. There was a highly significant correlation between neurophysiological symptoms and clinical neuropathy symptoms, although the combination of the clinical and electrophysiological findings was variable. On the other hand, there was no significant correlation between neurophysiological/neurological findings and clinical/laboratory data (age, sex, duration of disease, stage of disease, rheumatoid factor and erythrocyte sedimentation rate). Manifest or sub-clinical mono-neuropathies in n. medianus were found in 5 patients. In the light of these results it would seem in order to recommend the inclusion of an electro-neurophysiological examination of the medianus nerves of RA patients in routine diagnostic procedures.

Adult↗