Uolevi Tolonen

Interictal Cardiovascular Autonomic Responses in Patients with Temporal Lobe Epilepsy

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

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, which may be involved in cardiovascular and other known manifestations of autonomic failure associated with stroke. (Stroke. 1994;25:787‐792.)

Interictal cardiovascular autonomic responses in patients with epilepsy.

Summary: 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.

Dental arch morphology in children with sleep-disordered breathing

The aim of the present study was to examine the effects of nocturnal breathing disorders such as obstructive sleep apnoea (OSA) and snoring on developing dental arches. The study group comprised 41 children (22 males, 19 females, mean age 7.2 years, standard deviation 1.93) with diagnosed OSA. Age- and gender-matched groups of 41 snoring and 41 non-obstructed control children were selected. Orthodontic examination was carried out and dental impressions were taken. Malocclusions were diagnosed clinically and 13 linear variables were measured from the dental casts. The differences between the dental arch measurements of the OSA, snoring, and control groups were studied using analysis of variance followed by Duncans multiple comparison method. Children with diagnosed OSA had a significantly increased overjet, a reduced overbite, and narrower upper and shorter lower dental arches when compared with the controls. Snoring children had similar but not as significant differences as OSA children when compared with the controls. There were more children with an anterior open bite (AOB) in the OSA group (P=0.016) and with a Class II or asymmetric molar relationship in the groups of OSA (P=0.013) and snoring (P=0.004) subjects compared with the non-obstructed controls. There were more subjects with mandibular crowding (P=0.002) and with an AOB (P=0.019) with an increasing obstructive apnoea-hypopnoea index (AHI). These findings are in agreement with previous studies of the effects of increased upper airway resistance on dental arch morphology and can be explained by long-term changes in the position of the head, mandible, and tongue in order to maintain airway adequacy during sleep.

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 patients history only. In order to evaluate snoring childrens 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.

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.

Cardiovascular Reflexes in Parkinson’s Disease

The autonomic nervous system (ANS) function of patients with Parkinsons disease (PD) was investigated in 30 patients with PD, and in 21 healthy subjects of similar age by utilizing cardiovascular reflex measurements as indicators. In deep breathing, in the Valsalva manoeuvre, and in the tilting test the heart rate variability (R-R variation) differed significantly between the patients and the controls: the beat-to-beat variation was clearly decreased in patients with PD. Responses in diastolic pressure to isometric work were also clearly diminished. However, no significant differences in any measured ANS indices were found between the patients who were treated with levodopa and those who were not. Similarly, anticholinergics did not seem to affect the results.

Atypical perceptual narrowing in prematurely born infants is associated with compromised language acquisition at 2 years of age

BackgroundEarly auditory experiences are a prerequisite for speech and language acquisition. In healthy children, phoneme discrimination abilities improve for native and degrade for unfamiliar, socially irrelevant phoneme contrasts between 6 and 12 months of age as the brain tunes itself to, and specializes in the native spoken language. This process is known as perceptual narrowing, and has been found to predict normal native language acquisition. Prematurely born infants are known to be at an elevated risk for later language problems, but it remains unclear whether these problems relate to early perceptual narrowing. To address this question, we investigated early neurophysiological phoneme discrimination abilities and later language skills in prematurely born infants and in healthy, full-term infants.ResultsOur follow-up study shows for the first time that perceptual narrowing for non-native phoneme contrasts found in the healthy controls at 12 months was not observed in very prematurely born infants. An electric mismatch response of the brain indicated that whereas full-term infants gradually lost their ability to discriminate non-native phonemes from 6 to 12 months of age, prematurely born infants kept on this ability. Language performance tested at the age of 2 years showed a significant delay in the prematurely born group. Moreover, those infants who did not become specialized in native phonemes at the age of one year, performed worse in the communicative language test (MacArthur Communicative Development Inventories) at the age of two years. Thus, decline in sensitivity to non-native phonemes served as a predictor for further language development.ConclusionOur data suggest that detrimental effects of prematurity on language skills are based on the low degree of specialization to native language early in development. Moreover, delayed or atypical perceptual narrowing was associated with slower language acquisition. The results hence suggest that language problems related to prematurity may partially originate already from this early tuning stage of language acquisition.

Cephalometric evaluation of children with nocturnal sleep-disordered breathing

The present study aimed to assess the cephalometric features in children with sleep-disordered breathing (SDB). The subjects were 70 children (34 boys and 36 girls, mean age 7.3, SD 1.72, range 4.2-11.9 years) with habitual snoring and symptoms of obstructive sleep disorder for more than 6 months. On the basis of overnight polygraphic findings, the subjects were further divided into subgroups of 26 children with diagnosed obstructive sleep apnoea (OSA), 17 with signs of upper airway resistance syndrome (UARS), and 27 with snoring. A control group of 70 non-obstructed children matched for age and gender was selected. Lateral skull radiographs were taken and cephalograms were traced and measured. The differences between the matched groups were studied using t-test for paired samples. Differences between the subgroups were studied using analysis of variance followed by Duncans multiple comparison method. Children with SDB were characterized by an increased antero-posterior jaw relationship (P = 0.001), increased mandibular inclination in relation to the palatal line (P = 0.01), increased total (P = 0.019) and lower (P = 0.005) anterior face heights, a longer (P = 0.018) and thicker (P = 0.002) soft palate, smaller airway diameters at multiple levels of the naso- and oropharynx, larger oropharyngeal airway diameter at the level of the base of the tongue (P = 0.011), lower hyoid bone position (P = 0.000), and larger craniocervical angles (NSL-CVT, P = 0.014; NSL-OPT, P = 0.023) when compared with the non-obstructed controls. When divided into subgroups according to the severity of the disorder, OSA children deviated significantly from the control children especially in the oropharyngeal variables. Children with UARS and snoring also deviated from the controls, but the obstructed subgroups were not confidently distinguishable from each other by cephalometric measurements. Logistic regression analysis indicated that UARS and OSA were associated with decreased pharyngeal diameters at the levels of the adenoids (PNS-ad1) and tip of the uvula (u1-u2), an increased diameter at the level of the base of the tongue (rl1-rl2), a thicker soft palate, and anteriorly positioned maxilla in relation to the cranial base. Lateral cephalogram may thus reveal important predictors for SDB in children. Attention should be paid to pharyngeal measurements. Systematic orthodontic evaluation of SDB children is needed because of the effects of obstructed sleep on the developing craniofacial skeleton.

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).