Sweating impairment in patients with multiple sclerosis

OBJECTIVES

To measure sweating in patients with multiple sclerosis (MS).

MATERIALS AND METHODS

Sweating was measured by an evaporimeter after a heating stimulus in 29 MS patients and in 15 healthy control subjects.

RESULTS

The MS patients sweated markedly less than the controls. After 10 min of heating the sweating was significantly lower in the forehead (P = 0.034), feet (right, P = 0.033; left, P = 0.037) and legs (right, P = 0.043; left, P = 0.029) of the MS patients than in those of the controls. After 15 min of heating the difference was statistically significant only in the feet (right, P = 0.043; left, P = 0.029). The Expanded Disability Status Scale score correlated inversely with sweating at 15 min of heating in the left hand (r = 0.42, P < 0.05), and in the left (r = 0.36, P < 0.05) and right foot (r = 0.37, P < 0.05).

CONCLUSIONS

MS is associated with an impairment in thermoregulatory sweating which seems to be related to the disease severity.

Sympathetic skin responses in multiple sclerosis

OBJECTIVES

This study assessed the sympathetic skin responses (SSRs) and their correlation with brain lesion volumes in patients with multiple sclerosis (MS).

MATERIALS AND METHODS

The SSRs were measured in 27 patients with MS and 27 healthy controls. The volumes of the proton density-weighted MS lesions in the brain were measured using MRI.

RESULTS

The SSRs were abnormal in 52% of the patients with MS, but absent only in clinically severe MS. The total lesion volume in the whole brain correlated significantly with both the severity of MS expressed by the EDSS score (P < 0.001) and the decreased SSR amplitudes in the feet (P < 0.01). Focal lesion volumes in the temporal lobe (P < 0.01), in the pons (P < 0.01) and in the cerebellum (P < 0.01) were also separately associated with abnormal SSR reflexes.

CONCLUSIONS

Sudomotor regulation failure in MS is associated with certain focal MS lesions.

A handheld nerve conduction measuring device in carpal tunnel syndrome

OBJECTIVES

The diagnostic utility and reliability of an easy-to-operate novel handheld nerve conduction tester in carpal tunnel syndrome (CTS) were evaluated.

MATERIALS AND METHODS

Using the test device, the sensory nerve conductions (SNC) in the median and ulnar nerves were compared with each other in 194 patients with suspected CTS and 95 healthy controls. The test device results were compared with the results of nerve conduction studies (NCS) with traditional instrumentation.

RESULTS

The new device correctly classified 145 of the 149 hands (97.3%) without median nerve lesion and 171 of the 200 hands (85.5%) with median nerve lesions in traditional NCS. The specificity of the new tester compared with traditional instrumentation was 98%. The correlation coefficient for different technicians in different studies was 0.87.

CONCLUSIONS

The findings obtained with the new tester in CTS were reliable and reproducible. This tester may increase availability of NCS in CTS.

A 3-year clinical follow-up of adult patients with 3243A>G in mitochondrial DNA

OBJECTIVE

To follow the clinical course of patients with the mitochondrial DNA mutation 3243A>G for 3 years.

METHODS

Thirty-three adult patients with the 3243A>G mutation entered a 3-year follow-up study. They were clinically evaluated annually, audiometry was performed, and samples were drawn for the analysis of blood chemistry and mutation heteroplasmy in leukocytes. Holter recording was performed three times during the follow-up and echocardiography, neuropsychological assessment, and quantitative EEG and brain imaging conducted at entry and after 3 years.

RESULTS

The incidence of new neurologic events was low during the 3-year follow-up. Sensorineural hearing impairment (SNHI) progressed, left ventricular wall thickness increased, mean alpha frequency in the occipital and parietal regions decreased, and the severity of disease index (modified Rankin score) progressed significantly. The rate of SNHI progression correlated with mutation heteroplasmy in muscle. The increase in left ventricular wall thickness was seen almost exclusively in diabetic patients. Seven patients died during the follow-up, and they were generally more severely affected than those who survived.

CONCLUSIONS

Significant changes in the severity of disease, sensorineural hearing impairment, left ventricular hypertrophy, and quantitative EEG were seen in adult patients with 3243A>G during the 3-year follow-up.

Cardiovascular autonomic dysfunction correlates with brain MRI lesion load in MS

OBJECTIVE

The aim of the present study was to investigate the cardiovascular autonomic control in clinically definite multiple sclerosis (MS) patients with a standardised battery of cardiovascular tests and to correlate these findings with the brain magnetic resonance imaging (MRI) lesion load.

METHODS

Fifty-one patients with MS and 50 healthy controls were studied. Brain MRI was performed in all patients showing typical MS lesions. The cardiovascular tests were carried out using a standardised battery.

RESULTS

Heart rate (HR) responses to deep breathing (P < 0.05) and tilt table testing (P < 0.001) were significantly decreased in MS patients when compared to those of the controls. Blood pressure (BP) responses in the tilt table test were also impaired in MS patients (diastolic P < 0.001, systolic P < 0.05). Of the different brain areas investigated the total volume of the midbrain MRI lesions (P < 0.05) was the one most clearly associated with the impaired BP responses.

CONCLUSIONS

MS results in both reduced HR variation and decreased BP reactions indicating disturbed cardiovascular regulation. In particular, the midbrain lesions found in MS are associated with cardiovascular dysfunction.

Cardiovascular autonomic reactivity is decreased in adolescents with Type 1 diabetes

AIMS

To characterize autonomic nervous system function by means of the heart rate and blood pressure responses to various stimuli in relation to pubertal maturation in patients with Type 1 diabetes mellitus (DM).

METHODS

One hundred out of 138 eligible patients at the Out-patient Diabetes Clinic and 100 healthy control subjects were examined in terms of cardiovascular parameters at rest, during deep breathing and when standing. Heart rate variability was analysed with time domain,frequency domain and fractal dimension parameters. Tanner pubertal staging was performed before the examinations.

RESULTS

The time domain parameters of heart rate variability at rest or during standing did not significantly differ between the patients and controls in total or at pubertal stages. In the spectral analysis of heart rate variability the very low frequency band was decreased in the patients during standing (P = 0.023).The increase in the very low frequency (P = 0.013)and low frequency (P = 0.031) spectral powers upon changing from a supine position to standing was attenuated in the patients in total, while no significant differences were observed within the Tanner pubertal stages between patients and controls. Heart rate variability during deep breathing was decreased in the patients with distal polyneuropathy (P = 0.006).

CONCLUSIONS

Although cardiovascular integrity is in the main well preserved in adolescent patients with Type 1 DM, these patients are prone to attenuated autonomic nervous system reactivity.

Ubiquinone and nicotinamide treatment of patients with the 3243A-->G mtDNA mutation

The efficacy and safety of ubiquinone (Q10) and nicotinamide were evaluated in a 6-month open-label trial in patients with the 3243A-->G mitochondrial DNA mutation. Blood lactate and pyruvate concentrations decreased, but there was little clinical improvement. Q10 and nicotinamide were well tolerated, but two patients died suddenly and unexpectedly during the trial. These deaths may have been unrelated to treatment. The unpredictable course of the disease makes evaluation of the clinical response difficult.

Comparison of heart rate variability analysis methods in patients with Parkinson's disease

The aim of the present study was to evaluate different analysis methods for revealing heart rate variability (HRV) differences between untreated patients with Parkinson's disease and healthy controls. HRV in standard cardiovascular reflex tests and during a 10 min rest period were measured by time- and frequency-domain and geometrical and non-linear analysis methods. Both frequency- and time-domain measures revealed abnormal HRV in the patients, whereas non-linear and geometrical measures did not. The absolute high-frequency spectral power of HRV was the strongest independent predictor to separate the patients from the controls (p = 0.001), when the main time-domain and absolute frequency-domain measures were compared with each other. When the corresponding normalised spectral units, instead of the absolute units, were used in the comparison, the two best single measures for separating the groups were the 30/15 ratio of the tilting test (p = 0.003) and the max/min ratio during deep breathing (p = 0.024). When the correlations between the different measures were estimated, the time-domain measures, fractal dimension and absolute spectral powers correlated with each other. The frequency- and time-domain analysis techniques of stationary short-term HRV recordings revealed significant differences in cardiovascular regulation between untreated patients with Parkinson's disease and the controls. This confirms cardiovascular regulation failure before treatment in the early stages of Parkinson's disease. The HRV spectral powers, in absolute units, were the most effective single parameters in segregating the two groups, emphasising the role of spectral analysis in the evaluation of HRV in Parkinson's disease.

Parasomnias decline during pregnancy

OBJECTIVES

A survey of the effects of pregnancy on parasomnias.

MATERIAL AND METHODS

In an area of a central hospital and the maternity care units in the nearby rural community, women were interviewed during and after their pregnancy with a series of five questionnaires to assess the frequency of their parasomnias. The first questionnaire covered the 3 months before becoming pregnant, the next three the trimesters of pregnancy and the last one the 3 months after delivery. Altogether 325 mothers filled all the five questionnaires and constitute the study group.

RESULTS

The total number of parasomnias declined (P < 0.001) during pregnancy and even more among the primiparas than among the multiparas (difference until third trimester, P=0.02). Among various parasomnias reported, sleep talking and sleepwalking decreased from the prepregnant period to the second trimester (22.8 vs 12.6%, change P=0.003), and the reported sleep starts also diminished from the prepregnant time to the first trimester (78.5 vs 63.1%, P < 0.001), but these phenomena did not change further during the follow-up. Altogether 55.7% of the women reported having nightmares 3 months before the pregnancy, and 47.7, 49.5, 41.2 and 40.3% (change from the prepregnant period, P < 0.001), respectively, at first, second and third trimester and after the delivery. Reported hypnagogic hallucinations decreased from the prepregnant time to the first trimester (9.8 vs 6.5%, P=0.027), but returned thereafter to the previous level. During the prepregnant period, 25.8% of the women reported bruxism and only 19.9% during the first trimester (P=0.009). Though the prevalence of sleep paralysis decreased during the first trimester of pregnancy, it was the only parasomnia that increased during later pregnancy (from 5.7 to 13.3% in the second trimester, P < 0.013).

CONCLUSIONS

The reported frequency of most parasomnias decreases during pregnancy and even more in primiparas than multiparas.

Effects of pregnancy on mothers' sleep

OBJECTIVES

To survey the effects of pregnancy on mothers' sleep.

METHODS

Mothers were interviewed during and after pregnancy with a series of five questionnaires to assess alterations in their sleep. The first questionnaire covered the 3 months before becoming pregnant, the next three the trimesters of pregnancy and the last the 3 months after delivery. The study was carried out in a central hospital and the maternity care units in the nearby rural community. Altogether, 325 pregnant women completed all five questionnaires.

RESULTS

The total amounts of reported sleep and of nocturnal sleep increased significantly during the first trimester of pregnancy, began to decrease thereafter and were shortest during the 3 months after pregnancy. During late pregnancy expectant mothers over 30 years of age reported less sleep than those under 30. During the whole pregnancy, but increasingly toward the end of pregnancy, sleep became more restless and fragmentary and its subjective quality worsened, due at least partly to increased restless legs and nightly awakenings increasing with advancing pregnancy.

CONCLUSIONS

The subjective quality of sleep is disturbed as early as the first trimester of pregnancy, although total sleeping time increases. The amount of reported sleep begins to decrease in the second trimester. The frequency of reported sleep disturbances, such as restless legs syndrome and nocturnal awakenings, is maximum in the third trimester but is about normal within 3 months after delivery.

Heart rate dynamics in refractory and well controlled temporal lobe epilepsy

OBJECTIVES

Disorders of cardiovascular and other autonomic nervous system functions are often found in patients with temporal lobe epilepsy (TLE). Cardiovascular dysregulation in TLE has previously been quantified assessing traditional time and frequency domain measures of heart rate (HR) variability from short term ECG recordings. However, new complexity and fractal measures of HR variability based on non-linear dynamics and fractals ("chaos theory") may disclose certain patterns of HR dynamics that cannot be detected using only conventional measures.

METHODS

In addition to the traditional spectral and non-spectral components of HR variability, fractal correlation properties, approximate entropy (ApEn) of RR interval dynamics, and the slope of the power law relation were measured from 24 hour ambulatory ECG recordings to evaluate interictal autonomic cardiovascular regulatory function in 19 patients with refractory TLE, 25 patients with well controlled TLE, and in 34 healthy age and sex matched control subjects.

RESULTS

The traditional time and frequency domain measures were lower in patients with TLE than in controls (p<0.05). In addition, the power law slope (p<0.005) and ApEn (p<0.05) were also reduced in TLE patients. Furthermore, ApEn was smaller in patients with refractory TLE than in patients with well-controlled TLE ( p<0.01), whereas the long term fractal correlation value alpha2 was lower in patients with well controlled TLE (p<0.05). An altered HR variation was not associated with any particular AED regimen.

CONCLUSIONS

In addition to reduced overall HR variability, the long term fractal organisation and complexity of HR dynamics seem to be altered in TLE. These abnormalities in HR behaviour may partly contribute to the occurrence of adverse cardiovascular events, such as life threatening arrhythmias in patients with TLE.

Peripheral nerve function is increasingly impaired during puberty in adolescents with type 1 diabetes

OBJECTIVE

To evaluate the impact of puberty on peripheral nerve function in adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Of 138 eligible patients with type 1 diabetes, 100 patients (age >9 years and diabetes duration >2 years) attending an outpatient diabetes clinic and 100 age- and sex-matched healthy control subjects took part in this cross-sectional study. Peripheral motor and sensory nerve conduction tests, cardiovascular reflex tests on the autonomic nervous system, and measurements of vibration-perception threshold (VPT) were performed.

RESULTS

Nerve conduction velocity (NCV) in the distal motor and sensory nerves, the motor nerve distal latency, and the sensory nerve action potential (SNAP) amplitude were impaired in the adolescent patients with type 1 diabetes. The deterioration in motor NCV, H-reflex latency, and SNAP amplitude became more conspicuous in late puberty and postpuberty and was related to poor metabolic control. A total of 10 patients had distal diabetic polyneuropathy (DP) neurophysiologically, and these patients had significantly lower heart-rate variation in the deep breathing test than the other patients. Three of the patients with DP had peripheral neurological signs or symptoms. A slight difference in the VPT between the patients and control subjects was observed after puberty.

CONCLUSIONS

Increasing subclinical motor nerve impairment can be detected during late puberty and after puberty, and sensory NCV and SNAP amplitude are reduced in adolescents with type 1 diabetes. Poor metabolic control during puberty appears to induce deteriorating peripheral neural function in young patients with type 1 diabetes.

Motor nervous pathway function is impaired after treatment of childhood acute lymphoblastic leukemia: a study with motor evoked potentials

BACKGROUND

The objective was to evaluate whether motor nervous pathways are affected when patients are treated for childhood acute lymphoblastic leukemia (ALL).

PROCEDURE

Thirty-two children with ALL were studied at the end of treatment by means of motor evoked potentials (MEPs) elicited by magnetic stimulation (MS) transcranially and peripherally and underwent a detailed neurological examination. Thirty-two healthy children matched with them for age, sex, and height served as a control group.

RESULTS

The latencies of the MEPs were significantly prolonged along the entire motor nervous pathway in the patients with ALL compared with the healthy controls, indicating demyelination in the thick motor fibres. The MEP amplitudes of the distal extremities elicited by stimulation at the brachial plexus and LV spinal level were significantly lowered in the patients treated for ALL, also indicating anatomical or functional loss of descending motor fibres and/or muscle fibres. The MEP amplitudes elicited by cortical MS showed wider variation and no clear abnormalities were found. Neurological signs and symptoms were common after treatment: 41% of the patients had depressed deep tendon reflexes, 31% had fine motor difficulties and 63% gross motor difficulties, and 34% had dysdiadochokinesia. The conduction delay within the peripheral nerve was related to the post-therapeutic interval after administration of vincristine and the lesions within the CNS to the number of injections of intrathecal methotrexate.

CONCLUSIONS

The present results show adverse effects of the ALL treatment on the entire motor nervous pathways. In our experience, the measurement of MEPs by MS provides an objective, painless, and practical tool for assessing the treatment-related neurotoxicity in both the CNS and the peripheral nerves. These disturbances in the motor nervous pathways at the end of treatment raise the question of the long-term effects of ALL treatment on the motor nerve tracts, and have led us to employ MEPs to study these effects in long-term survivors of ALL.

Suppressed sympathetic skin response in Parkinson disease

The sympathetic skin response (SSR) was used to evaluate sympathetic sudomotor activity in Parkinson disease (PD) and the effects of antiparkinsonian medication on the disease. We recorded SSRs to electric and auditory stimulation in 58 untreated patients with PD and in 20 healthy controls. In addition to amplitude and latency measurements, we examined the number of SSRs evoked by a single stimulus and the response adaptation after repetitive stimuli. The patients with PD subsequently were randomized for administration of levodopa/ carbidopa (n = 19), bromocriptine (n = 20), or selegiline (n = 19) as their initial treatment. The measurements were repeated after 6 months of medication and after a washout period. SSR amplitudes were significantly lower in patients with PD than in the control subjects at baseline. The amplitude reduction was more pronounced in patients with high Unified Parkinson's Disease Rating Scale scores, in those with high tremor scores, and in those with PD symptoms that had lasted more than 1 year. The levodopa/carbidopa and bromocriptine treatments did not influence SSRs, although selegiline slightly decreased the amplitude. The synchronous responses after a single stimulus were more often repetitive in the patients with PD than in the controls, although the response adaptation tendencies were similar. In conclusion, the degenerative process in PD involves the sudomotor system as reflected by the progressive suppression of SSR amplitudes with a correlation to PD symptom duration and clinical disability, whereas PD medications seems to have only minor effects. The changes in amplitude and the repetitiveness of SSRs with normal adaptation may be caused by deficits at several levels of the SSR reflex arch.

Levodopa, bromocriptine and selegiline modify cardiovascular responses in Parkinson's disease

Autonomic nervous system (ANS) involvement is frequently found in Parkinson's disease (PD), but its causal relationship to the disease itself and its medication is unclear. We evaluated the effects of PD medications on cardiovascular ANS functions. Heart rate (HR) responses to normal and deep breathing, the Valsalva manoeuvre and tilting, and blood pressure (BP) responses to tilting and isometric work were measured prospectively in 60 untreated PD patients randomised to receive either levodopa (n = 20), bromocriptine (n = 20) or selegiline (n = 20) as their initial treatment. The results were compared with those of 28 healthy controls. The responses were recorded at baseline, after 6 months on medication and following a 6-week washout period. At baseline HR responses to normal breathing, deep breathing and tilting were already lower and the fall in the systolic BP immediately and at 5 min after tilting was more pronounced in the PD patients than in the controls. Six months' levodopa treatment diminished the systolic BP fall after tilting when compared to baseline, whereas bromocriptine and selegiline increased the fall in systolic BP after tilting and selegiline diminished the BP responses to isometric work. The BP responses returned to the baseline values during the washout period. The drugs induced no change in the HR responses. Thus PD itself causes autonomic dysfunction leading to abnormalities in HR and BP regulation and the PD medications seem to modify ANS responses further. Bromocriptine and selegiline, in contrast to levodopa, increase the orthostatic BP fall and suppress the BP response to isometric exercise reflecting mainly impairment of the sympathetic regulation.

Heart rate variability in patients with untreated Parkinson's disease

The aim of this study was to evaluate cardiovascular responses as a marker of autonomic nervous system (ANS) disturbances in patients with untreated Parkinson's disease (PD) and to assess the relationship between them and the clinical characteristics of PD. The ANS functions were investigated in 50 patients with PD and 55 healthy subjects by measuring standard cardiovascular autonomic reflexes and heart rate variability (HRV) at rest using spectral analysis (the autoregressive model and the fast Fourier transformation), the percentage of the counts of beat-to-beat variation greater than 50 ms and the fractal dimension. Significantly attenuated HRV and deficient blood pressure reaction to tilting were found in the PD patient group. The patients with hypokinesia/rigidity as the initial symptom of PD had a more pronounced HRV deficit than those with tremor onset. Untreated PD patients suffer significant failure in cardiovascular nervous system regulation, and in patients with hypokinesia/rigidity as their initial disease manifestation the risk of this ANS dysfunction is high. However, in the early stages of PD these changes did not reach significance at individual level.

Central and peripheral nervous system dysfunction in the clinical variation of Salla disease

OBJECTIVE

To evaluate the degree of possible peripheral nervous system (PNS) involvement in addition to CNS manifestations in Salla disease, a free sialic acid storage disorder leading to severe mental retardation with a wide clinical variation.

BACKGROUND

Salla disease is a lysosomal storage disorder that affects the white matter of the CNS. MRI findings and recent 1H MRS study results provide evidence for delayed central myelination, but there is no previous evidence for PNS involvement in this disease. The gene coding for a presumptive sialic acid transport protein has recently been identified, and the first disease-causing mutations have been characterized.

METHODS

Nerve conduction studies; evoked potentials to visual (VEP), brainstem auditory (BAEP), and somatosensory stimuli (SEP); and EEG were carried out on 22 patients (age range 2 months to 57 years) with biochemically and genetically confirmed Salla disease. Brain MRI were available on 14 patients.

RESULTS

Nerve conduction studies revealed abnormalities in nearly half of the patients (10/21). The four severely disabled patients and the oldest patient had greatly reduced nerve conduction velocities and prolonged distal latencies compatible with demyelinating polyneuropathy. In addition, SEP was abnormal in the majority of the patients, but VEP and BAEP in only a few cases. PNS involvement was clearly associated with both the phenotypic severity and MRI findings.

CONCLUSIONS

The results indicate that dysmyelination in Salla disease occurs not only in the CNS but also in the peripheral nervous system, contributing to the phenotypic variation, which can now be correlated with the molecular basis of the disease.

Snoring and obstructive sleep apnea in children: a 6-month follow-up study

BACKGROUND

Snoring children may present symptoms suggestive of obstructive sleep apnea syndrome (OSAS). Different and controversial methods to establish the diagnosis and to choose the treatment modalities have been proposed.

OBJECTIVES

To study children with symptoms raising the suspicion of OSAS with overnight polysomnography (PSG). To evaluate the efficacy of adenotonsillectomy as treatment of pediatric OSAS and to elucidate the natural history of OSAS and primary snoring.

DESIGN

A controlled, prospective, nonrandomized clinical trial.

SETTING

Academic medical center.

SUBJECTS

Fifty-eight snoring but otherwise healthy children aged 3 to 10 years with symptoms suggestive of OSAS underwent PSG twice, 6 months apart. Thirty healthy children served as controls.

RESULTS

Twenty-seven children had OSAS with an obstructive apnea/hypopnea index greater than 1, while 31 had primary snoring. There were statistical differences in the symptoms and signs among the 3 study groups. Adenotonsillectomy was curative in the 21 children with OSAS who were operated on. Obstructive apneas and hypopneas in the healthy, nonsnoring children were almost nonexistent in this study.

CONCLUSIONS

Half of the children or fewer with symptoms suggestive of OSAS actually had the condition. Clinical symptoms may raise the suspicion, but it is not possible to establish the diagnosis without PSG. Because snoring and obstructive symptoms may resolve over time, a normal PSG finding may help the clinician decide on an observation period. Adenotonsillectomy is curative in most cases of pediatric OSAS. Obstructive symptoms may continue after adenoidectomy alone.

Sequelae of moderate finger frostbite as assessed by subjective sensations, clinical signs, and thermophysiological responses

The aim of the study was to investigate prevalence and qualities of sequelae following moderate finger frostbite. The study material comprised 30 subjects, who had suffered second-degree frostbite (73% contact frostbite) 4-11 years before this study. In clinical tests 66% of the subjects had an elevated tendency for vasospasm, yet only 20% suffered from white fingers. However, no marked traces of frostbite-related alterations were observed in systemic cardiovascular reflex tests or in X-ray examinations of the frostbite area. Subjective assessments revealed a high prevalence of sequelae (63%), although the primary frostbite was moderate and local. The sequelae in the frostbite area included hypersensitivity to cold (53%), numbness of fingers (40%), and declined sensitivity of touch (33%). Also working ability was lowered due to frostbite sequelae (13%). In cold air provocation tests, the skin temperature of the frostbitten areas decreased more quickly and reached lower values than in healthy control subjects. In conclusion the suffered frostbite was associated with an increased tendency for vasospasm. Subjective sensations of the frostbitten area were associated with thermophysiological changes. The sequelae were reported to worsen in the cold environment thus emphasizing the probable occupational limitations of even moderate cold injury.

Motor evoked potentials of subjects over 70 years of age with and without recurrent falls

Motor evoked potentials (MEPs) of 83 elderly (79+/-4 years) subjects, 43 with recurrent falls and 40 without, and of 31 healthy young (42+/-9 years) subjects were measured from thenar (and hypothenar) and tibialis anterior muscles. Forty-four of the aged subjects without overt neurological diseases were used as controls. Absolute latencies from the cortex to the target muscles as well as the latency differences from the cortex to the level of the fifth lumbar vertebra (LV) were longer in the aged than in the young, but the latency difference from the cortex to the brachial plexus was shorter. The cortical, brachial plexus and lumbar (LV) latencies were all dependent on height as well as age. The latency differences from the cortex to the plexus or LV were not height-dependent but were age-dependent. The thenar MAXMEP/CMAP ratio was significantly higher in hands with thenar atrophy (in 30% of the aged subjects) than without; thenar atrophy thus excludes the use of this parameter in about one-third of the aged subjects. There were no significant differences in the MEP latencies or amplitudes of the recurrent fallers and the non-fallers. Subjects having more frequent falls, however, tended to have lower amplitudes of MEPs in the lower extremities.

Auditory P300 event related potential in minor ischemic stroke

OBJECTIVE

Various degenerative cerebral diseases and even depression may cause abnormalities of the cognitive event related potentials (ERPs). We conducted the present study to elucidate the effects of ischemic stroke on the P300 ERP component.

MATERIAL AND METHODS

We recorded the P300 wave using an auditory oddball paradigm in 38 consecutive brain infarct patients with mild neurological deficits at 3 and 12 months post-stroke, and in 29 healthy control subjects.

RESULTS

Brain infarction slightly prolonged the P300 latency, and the observed delay was related to the presence and degree of post-stroke depression evaluated with the Zung Depression Scale and the DSM-III criteria. Infarction did not affect the P300 amplitude or its distribution on the scalp. The results of the patients with hemispheric brain infarction and those of the patients with brainstem infarction were similar, and also the values of the patients with the left- and right-sided lesions. The normal physiological correlation between subject age and the P300 latency was absent at 3 months post-stroke, but was present at 12 months post-stroke.

CONCLUSION

Brain infarction delays the P300 ERP and temporarily distorts its age-related physiology. The increase of the P300 latency seems to be associated with the post-stroke depression.

Stretch- and H-reflexes of the lower leg during whole body cooling and local warming

BACKGROUND

This study was undertaken to evaluate if possible changes in stretch- and H-reflexes could be related to the changes in the EMG activity of the cooled lower leg muscles observed during a stretch-shortening cycle exercise.

METHODS

Eight subjects wearing shorts and jogging shoes were exposed once to 27 degrees C and twice to 10 degrees C for 60 min each. During the second exposure to 10 degrees C, the subject's lower legs were kept warm (10 degrees Clw) with electrical pillows. After the exposures Achilles tendon reflex (stretch reflex) was induced and the EMG activity of the triceps surae was measured. Immediately after reflex measurements the EMG activity of the triceps surae and tibialis anterior during a drop-jump (stretch-shortening cycle) was measured. After similar thermal exposures electrically induced H-reflex from the calf was measured.

RESULTS

During the preactivity and stretch phases the EMG activity of the triceps surae increased after the exposure to 10 degrees C, whereas during the shortening phase it decreased. During the shortening phase cooling, on the contrary, increased the activity of tibialis surae anterior. These changes disappeared at 10 degrees Clw. At 10 degrees C the maximum EMG-amplitude of triceps surae during stretch reflex decreased (p<0.05), reflecting suppressed muscle spindle activity. Suppressed spindle activity causes the agonist to be unfacilitated and the antagonist muscle contraction to be uninhibited, which was seen in the present study as decreased agonist and increased antagonist EMG activity during the shortening phase at 10 degrees C. The Hmax/Mmax-ratio, H-reflex latency and amplitude increased at 10 degrees C (p<0.05), reflecting increased motoneuron pool excitability. This in part may explain the increased EMG activity during the preactivity and stretch phases.

CONCLUSION

Cooling-induced increase in the excitability of the motoneuron pool and suppression of muscle spindle activity seem to be responsible of the EMG activity changes during the stretch-shortening cycle, consequently decreasing muscular performance.

Nasalance scores in snoring children with obstructive symptoms

OBJECTIVE

Snoring and the sleep apnea syndrome (OSAS) in children are usually caused by adenotonsillar hypertrophy, which may affect air escape into the nose and nasal resonance. A microcomputer-based system makes it possible to objectively determine whether the oral passage is adequately separated from the nasal passage during phonation. The score thus obtained is called nasalance. This study was conducted to verify whether there exists differences in nasalance between primary snorers and OSAS-children.

DESIGN

Fifty-three habitually snoring children (31 boys), mean age 6.1 years (range 3.2-10.5 years), were subjected to overnight sleep polygraphy (PG) and nasalance measurements with the Nasometer 6200. The study was successfully repeated 6 months later on 36 children.

RESULTS

Nineteen children had obstructive apnea-h ypopneaindex (OAHI)> 1 on overnight polygraphy (OSAS-children), while 32 were considered primary snorers (PS), (OAHI<1). No statistically significant difference in nasalance scores was found between the OSAS- and PS children. Both groups of children had somewhat higher mean nasalance values both for oral and nasal passage sentences than the normative values for Finnish speech. In general, the most habitual snorers had lower nasalance scores than the less frequently snoring children (P=0.05). Earlier adenoidectomy or palatine tonsillar size did not have a significant influence on the nasalance. Adenotonsillectomy did not affect the nasalance scores of the nine children operated on during the follow-up period.

CONCLUSIONS

According to the present study, nasalance measurements cannot be used to predict the incidence of OSAS among snoring children.

Interictal cardiovascular autonomic responses in patients with temporal lobe epilepsy

PURPOSE

To measure interictal cardiovascular autonomic functions in patients with either refractory or well-controlled temporal lobe epilepsy (TLE).

METHODS

For autonomic assessment, heart rate variation during normal and deep breathing, Valsalva maneuver, and tilting were measured in 19 patients with chronic refractory TLE, 19 patients with well-controlled TLE, and 38 age- and sex-matched healthy control subjects. Blood pressure responses to tilting and isometric work also were evaluated.

RESULTS

Heart-rate (HR) variation during normal breathing (p = 0.006) and tilting (p = 0.043) was lower in patients with refractory TLE than in control subjects. Heart-rate response to tilting (p = 0.036) was also lower in patients with well-controlled TLE than in control subjects. Blood-pressure responses showed no differences between the patients and the control subjects. Patients taking carbamazepine (CBZ) medication had decreased HR responses to deep breathing (p = 0.046) and to tilting (p = 0.014) compared with the control subjects.

CONCLUSIONS

Refractory TLE seems to be associated with dysfunction of the cardiovascular autonomic regulation, manifesting as impaired HR responses to certain stimuli. Interictal autonomic dysfunction is seen in patients with well-controlled TLE as well, but it may be more evident in patients with refractory epilepsy. CBZ medication may also be associated with altered autonomic cardiac control.

Cervical headgear therapy as a factor in obstructive sleep apnea syndrome

PURPOSE

Obstructive sleep apnea syndrome (OSAS) has been a subject of increasing interest from the orthodontic point of view, but less attention has been paid to the possible influence of orthodontic treatment on its occurrence. The aim here was to study possible associations between the use of cervical headgear and nocturnal cessations of airflow and the severity of the latter.

METHODS

The subjects were 30 children (12 boys, 18 girls, mean age 8.2, sd 1.61 years), divided into three groups: a group of 10 children undergoing headgear therapy, selected for this examination because of symptoms of OSAS while using headgear, an age-matched control group of 10 healthy children and a group of 10 with OSAS. Standard cephalograms of the headgear group prior to the orthodontic therapy and the corresponding cephalograms of healthy controls were analysed. A polygraphic (PG) sleep evaluation was used to assess the tendency for OSAS. Apnea and hypopnea periods were summated as apnea index (AI) and number of desaturations as desaturation index (ODI). All the subjects spent one night sleeping under laboratory conditions, those with orthodontic treatment spending the first half of the night with the headgear and the latter half without.

RESULTS

The position of the mandible was found to be slightly more posterior in the headgear group than in the control group. The children in the headgear group were found to have significantly more apnea/hypopnea periods during the hours when the appliance was used, and the ODI-index showed increased values in this group.

CONCLUSIONS

We suggest that headgear therapy may contribute to the occurrence of sleep apnea, when a strong predisposition, such as mandibular retrognathia to the development of upper airway occlusion already exists.

Interictal cardiovascular autonomic responses in patients with epilepsy

PURPOSE

To evaluate the interictal autonomic nervous system function in 84 patients with epilepsy: 37 with newly diagnosed, previously untreated epilepsy, and 47 patients receiving long-term carbamazepine (CBZ), phenytoin (PHT), or valproate (VPA) monotherapy, or CBZ plus PHT, or CBZ plus VPA for their seizure disorder.

METHODS

We assessed autonomic control of the cardiovascular regulatory system by standardized cardiovascular reflex tests measuring changes in heart rate (HR) and blood pressure (BP) at rest and after certain stimuli.

RESULTS

The HR and BP responses were similar to those of control subjects in patients with newly diagnosed epilepsy. However, HR variation during normal breathing and maximum systolic BP increase in isometric work were diminished in patients, who had been treated with antiepileptic drugs (AEDs) for epilepsy for a long time. Diminished HR responses to the Valsalva maneuver were noted in patients receiving CBZ as monotherapy and during deep breathing in patients receiving CBZ combined with PHT or VPA. Furthermore, patients receiving CBZ had diminished BP responses in isometric work. When analyzed in relation to epilepsy type, suppressed HR responses in normal breathing were associated with primary generalized epilepsy (PGE), whereas diminished BP responses in isometric work were associated with partial epilepsy. Two patients with recently diagnosed partial epilepsy and 1 patient receiving long-term CBZ monotherapy for partial epilepsy had two abnormal cardiovascular response test results.

CONCLUSIONS

Our results show that cardiovascular responses mediated by both the parasympathetic and sympathetic nervous system are diminished in patients with epilepsy. However, the changes appear to be clinically significant in only a few of them and appear to be associated with CBZ medication. Further studies are needed to detect the underlying complex interactions and clinical significance of autonomic nervous system dysfunction in patients with epilepsy.

Selegiline diminishes cardiovascular autonomic responses in Parkinson's disease

Selegiline (L-deprenyl), a selective inhibitor of monoamine oxidase type B, is an established adjuvant to levodopa therapy in Parkinson's disease (PD). To evaluate whether selegiline also effects the severity and progression of autonomic nervous system dysfunction in PD, we studied autonomic functions by measuring cardiovascular responses to normal breathing, deep breathing, the Valsalva maneuver, the tilting test, and the isometric contraction test prospectively in 52 PD patients receiving either selegiline (n = 27) or placebo (n = 25) in randomized order in a double-blind parallel trial. The study also continued double-blind after the introduction of levodopa. Recordings of cardiovascular responses were carried out annually, with the median follow-up period being 6 years. Cardiovascular autonomic reflexes were diminished in the patient groups compared with those of healthy control subjects (n = 45). There was no progression (except age-related) in dysautonomia in patients on placebo, but there was a decrease in cardiovascular responses in the selegiline group. The heart rate variability in normal breathing, in the Valsalva maneuver, and in the tilting test was clearly diminished during the selegiline treatment. In addition, in the tilting test, the fall in diastolic blood pressure immediately after tilting and in systolic blood pressure 2 minutes after standing up was more pronounced in the selegiline group than in the placebo group. Levodopa treatment had no effect on the measured autonomic responses. In the isometric contraction test, the two treatment groups showed no difference. We conclude that selegiline treatment diminishes autonomic responses, especially those of the sympathetic division. This sympatholytic effect may signal an increased risk of orthostatic hypotension.

Snoring children: factors predicting sleep apnea

Many snoring children present obstructive symptoms according to their parents. The seriousness of the symptoms and the possibility of the obstructive sleep apnea syndrome (OSAS) in these children may be difficult to judge on the basis of the clinical findings and the patient's history only. In order to evaluate snoring children's relative risk (RR) to have OSAS, their symptoms and signs, as reported by the parents, and clinical findings were compared with the results of overnight polysomnography (PSG). An obstructive apnea index (AI) > or = 1 in PSG was regarded as the criterion for OSAS. The mean AI was 1.55 (range 0-15), and 29 children had a pathological AI, while 49 had a normal PSG recording. Apneic episodes every night detected by the parents was the most important single risk factor for OSAS (RR 3.6, 95% confidence interval (CI) 1.7-7.7). The RR ratio decreased when apneas appeared less frequently, but any detected apnea was still a single risk factor (RR 1.4, CI 1.2-1.8). The other risk factors of night-time symptoms were constant snoring (RR 1.5, CI 1.0-2.1) and restless sleep (RR 2.1, CI 1.1-4.0). Of the daytime symptoms, absence of excessive sleepiness was a protective factor against OSAS (RR 0.3, CI 0.1-1.0). Previous adenoidectomy was found to be a risk factor (RR 1.7, CI 1.1-2.7), as was tonsillar enlargement (RR 1.4, CI 1.1-1.8). These two findings suggest that the epipharyngeal space does not play a central role in the development of OSAS in children. OSAS cannot be reliably diagnosed without PSG, which is the most important examination for snoring children with obstructive symptoms. For clinical decisions, the consideration of risk factors is essential.

Chemotherapy for acute lymphoblastic leukemia may cause subtle changes of the spinal cord detectable by somatosensory evoked potentials

Intrathecal chemotherapy has been determined to cause transient or permanent paraparesis due to myelopathy in patients with leukemia or other malignancies. To systematically evaluate the effect of methotrexate on spinal cord function, somatosensory evoked potentials (SEP) were measured in children with acute lymphoblastic leukemia (ALL). A prospective evaluation was performed in 38 consecutive children aged 1.4-15.3 years with newly diagnosed ALL during treatment. Intrathecal methotrexate therapy was included in the therapy schedule of all patients as central nervous system (CNS) therapy in addition to intravenous chemotherapy in 19 standard risk patients and intravenous chemotherapy with cranial irradiation in 19 intermediate or high-risk patients. The measured conduction times were compared with those of 38 control children matched for age, height, and sex. A significant increase in the conduction time of the tibial nerve SEP was found between the Th12 level and the cortex in children with ALL after receiving intrathecal methotrexate therapy during the induction and CNS therapy phases when compared with their controls. The difference of the mean latencies was 1.45 ms (95% CI 0.39-2.51; P < 0.01). There was no significant delay in the median nerve SEP from the brain stem to the cortex, indicating that the conduction delay was in the area of the spinal cord exposed to intrathecal methotrexate. Moreover, the cortical amplitudes of the median nerve SEPs were significantly reduced when measured immediately after intravenous and intrathecal methotrexate and compared to the amplitudes measured after induction therapy in standard risk patients (P = 0.001). Intrathecal methotrexate with systemic chemotherapy causes a deterioration in the somatosensory pathways within the CNS, suggesting also spinal cord dysfunction in children with ALL in addition to the cerebral dysfunction described earlier.

Vincristine therapy for children with acute lymphoblastic leukemia impairs conduction in the entire peripheral nerve

Somatosensory evoked potentials were measured prospectively in 38 children with acute lymphoblastic leukemia to evaluate the side effects of vincristine therapy on conduction of the peripheral nerves. Nineteen patients at standard risk received vincristine 12 mg/m2 during induction therapy and 19 patients at intermediate or high risk received 6 mg/m2 during induction therapy and an additional 6 mg/m2 during delayed intensification therapy. These latencies were compared with those of 38 age-, height-, and sex-matched controls. A prolongation in the peripheral conduction time of the posterior tibial nerve was found in the standard risk patients after induction compared with that of the controls, and a delay was found not only from the ankle to the popliteal fossa, but also from the popliteal fossa to the spinal cord (P < .01). The conduction times of the median nerve from the wrist to the plexus (P < .01) and from the wrist to the spinal cord (P < .01) were prolonged after delayed intensification therapy. There was a significant delay in the median and tibial nerve conduction between the intermediate and high risk patients and their controls after a total vincristine dose of 12 mg/m2. These delays were found along the entire length of the nerves, especially in the proximal part of the tibial nerve (P < .001).

Demyelinating polyneuropathy in a patient with the tRNA(Leu)(UUR) mutation at base pair 3243 of the mitochondrial DNA

A novel feature of demyelinating polyneuropathy was observed in a patient with the tRNA(Leu(UUR)) mutation at base pair 3243 of the mitochondrial DNA. Based on electrodiagnostic examination, the polyneuropathy was defined as being of the demyelinating, mixed (motor more than sensory) type. In a 1-year follow-up we observed approximately 7% reduction in both the motor and sensory conduction velocities. The other clinical features of the proband included a mild to moderate cognitive impairment and a combined hearing loss with a moderate sensorineural component. The proportion of the mutant genome found in the muscle of the proband was 29%, but the mutation was not found in his blood. A wide variability of the clinical phenotype was observed in the family of the proband. Heteroplasmic mutation was detected in the blood of most family members. The proportion of abnormal mitochondrial DNA was highest in the proband's brother, who had clinically definite mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome, while the mutant genome was less frequent or absent in the subjects with less severe phenotypes and in healthy individuals. The findings on this pedigree emphasize the need for studies of complete families in the search for new clinical phenotypes of mutations in mitochondrial DNA.

Cardiovascular autonomic reflexes in brain infarction

BACKGROUND AND PURPOSE

Increased sympathetic activity is associated with cardiovascular complications in stroke, but the role of the parasympathetic nervous system has not been carefully outlined. In the present study our purpose was to assess quantitatively autonomic cardiovascular disturbances in brain infarction by measuring cardiovascular autonomic reflexes.

METHODS

We studied the autonomic regulation of cardiovascular functions prospectively in 40 patients with brain infarction (acute phase, 1 month, and 6 months) and in 55 healthy control subjects by recording heart rate and blood pressure responses to normal and deep breathing, the Valsalva maneuver, tilting, and isometric work.

RESULTS

In the acute phase, heart rate responses to normal breathing, deep breathing, the Valsalva maneuver, and tilting were significantly (P < .05) impaired in both hemispheric and brain stem infarctions, thus indicating hypofunction of the parasympathetic nervous system. At 1 month heart rate responses to normal breathing (brain stem, P < .05), the Valsalva maneuver (brain stem, P < .01), and tilting (hemispheric, P < .05) were still significantly lower than those of the control subjects, but at 6 months significant suppression of the response was found only in tilting (hemispheric, P < .05).

CONCLUSIONS

These findings suggest that in addition to the previously well-established sympathetic hyperfunction, brain infarction also seems to cause parasympathetic hypofunction, brain which may be involved in cardiovascular and other known manifestations of autonomic failure associated with stroke.

Suppressed sympathetic skin response in brain infarction

BACKGROUND AND PURPOSE

Autonomic failure is known to manifest commonly in stroke, but very little attention has been given to various features of sympathetic dysfunction such as sudomotor dysregulation in cerebrovascular diseases. In the present study, our purpose was to assess quantitatively sympathetic reflex activity in brain infarction by measuring the sympathetic skin response.

METHODS

We recorded the sympathetic skin response to electric and auditory stimulations simultaneously on both hands in 58 patients with brain infarction and in 36 healthy control subjects.

RESULTS

The response amplitudes were significantly decreased and the latencies prolonged in both hemispheral (n = 49) and brain stem (n = 9) infarctions compared with the control subjects. The amplitudes were diminished in both the acute and late phases of infarction, but the latencies were prolonged only in the acute phase.

CONCLUSIONS

Sympathetic dysfunction in brain infarction seems to be much more extensive than has previously been thought. In the present study, we have demonstrated impaired sympathetic skin responses, reflecting definite suppression of the reflex activity of the sympathetic nervous system.

A prospective one-year follow-up study with somatosensory potentials evoked by stimulation of the median nerve in patients with cerebral infarct

Somatosensory potentials evoked by stimulation of the median nerve (median nerve SEPs) were studied in a prospective and sequential series of 40 patients with first supratentorial and nonhaemorrhagic cerebral infarct. In 35 patients the SEPs were recorded three times during the first year after the stroke. The location of the infarcted zone was reflected in the number of detected abnormalities: most patients with infarct changes extending to the gray matter of the Rolandic cortex showed abnormalities in the median nerve SEPs, and all patients with involvement of both precentral and postcentral cortical gray matter had abnormal median nerve SEPs. In the entire patient group when both latency and amplitude abnormalities were included about half (48%) of the patients had abnormal median nerve SEPs a week after the stroke, 39% 2-3 months after the stroke and 29% about one year after the stroke. These changes were not significant. When separately surveying the changes in the numbers of latency and amplitude abnormalities the difference between the first and the third examinations was nearly significant only in the number of latency abnormalities. Furthermore, in the absolute latency and amplitude values, no significant changes could be seen within the first two-three months after the infarct; within the whole one-year follow-up period a nearly significant change was noted between the second and the third examination in only one parameter (P22 peak latency). Thus, the abnormalities in the median nerve SEPs, especially the amplitude abnormalities, were relatively permanent during the one-year period after cerebral infarct.

Cerebral trauma and alcohol abuse

We report results of clinical examinations, computed tomography, quantitative electroencephalography (QEEG), and cerebral blood flow measurements performed on a series of 56 consecutive brain injury patients including 15 alcohol abusers and 41 non-alcoholic subjects. Greater volumes of intracranial haemorrhage were noted in the alcoholics for a similar severity of injury and local brain atrophy became more pronounced in them during a follow-up of 1 year. After this time, the third ventricle width, distance between frontal horns, the sum of lateral ventricle dimensions and cortical sulci were all markedly larger in the alcoholics. The QEEG results also indicated a weaker improvement in the alcoholics. The cerebral blood flow at the site of the injury was initially slow in the alcoholics when compared to the contralateral region of the other hemisphere, although these differences disappeared during the follow-up. Permanent occupational disability was also found to be associated with pretraumatic alcohol abuse. The findings indicate that ethanol abuse is not only commonly associated with cerebral trauma but is also a risk factor for a more severe brain damage following the injury.

Effect of reinnervation on collagen synthesis in rat skeletal muscle

The effect of reinnervation on the activities of prolyl 4-hydroxylase (PH) and galactosylhydroxylysyl glucosyltransferase (GGT), both enzymes of collagen biosynthesis, and on the concentration of hydroxyproline (Hyp) was studied in gastrocnemius, soleus, and tibialis anterior muscles of rat 19, 26, 40, and 61 days after crush denervation of the sciatic nerve. The GGT activity was elevated in denervated gastrocnemius and soleus muscles and the PH activity in gastrocnemius. Muscular Hyp concentration was increased in denervated tibialis anterior muscle. Both the PH and GGT activities and the Hyp concentration returned to the control level during the reinnervation period (19-61 days from the start of denervation). It seems that denervation atrophy of skeletal muscle is associated with an increased rate of muscular collagen biosynthesis and that during reinnervation collagen synthesis rate decreases despite accelerated muscular growth. The results thus suggest that innervation is a powerful suppressive regulator of muscular collagen biosynthesis.