Impaired dynamic balance control in adolescents with idiopathic scoliosis and abnormal somatosensory evoked potentials.

BACKGROUND: Both balance control dysfunction and dysfunction of the central nervous system have been proposed as being causative factors in adolescent idiopathic scoliosis (AIS), yet the relationship between these factors has not been investigated in detail. An intergroup comparative study was conducted to investigate the effect of abnormal somatosensory function on the dynamic balance parameters of girls with AIS. METHODS: The relationship between dynamic balance control and abnormal somatosensory function seen in AIS patients was examined by studying the dynamic balance parameters in normal controls, in AIS patients with normal posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEPs), and in AIS patients with abnormal PTN-SCEPs. Gait parameters were recorded in 18 AIS girls (8 showing abnormal PTN-SCEPs and 10 showing normal PTN-SCEPs). Eight healthy age-matched volunteers served as a control group. RESULTS: No significant left-right asymmetry of gait parameters was found for the controls or the AIS patients with normal PTN-SCEPs, whereas significantly higher gait parameters were found on the side of the curvature in the AIS patients with abnormal PTN-SCEPs. CONCLUSIONS: Somatosensory dysfunction in AIS patients shows to have an impact on dynamic balance control. Further studies to examine the association between somatosensory dysfunction and balance control and how they may be related to the etiology of AIS are recommended. LEVEL OF EVIDENCE: Diagnostic study, level IV (case-control study).

The effect of backpack weight on the standing posture and balance of schoolgirls with adolescent idiopathic scoliosis and normal controls.

Concerns have been raised regarding the effect of carrying a backpack on adolescent posture and balance, but the effect of backpack loading combined with other factors affecting balance, such as adolescent idiopathic scoliosis (AIS), has not been determined. This study examines the effects of backpack load on the posture and balance of schoolgirls with AIS and normal controls. The standing posture of 26 schoolgirls with mild AIS (mean age 13, Cobb angle 10-25 degrees ) and 20 age-matched normal schoolgirls were recorded without a backpack and while carrying a standard dual-strap backpack loaded at 7.5%, 10%, 12.5% and 15% of the subject's bodyweight (BW). Kinematics of the pelvis, trunk and head were recorded using a motion analysis system and centre of pressure (COP) data were recorded using a force platform. Reliable COP data could only be derived for 13 of the subjects with AIS. Increasing backpack load causes a significantly increased flexion of the trunk in relation to the pelvis and extension of the head in relation to the trunk, as well as increased antero-posterior range of COP motion. While backpack load appears to affect balance predominantly in the antero-posterior direction, differences between groups were more evident in the medio-lateral direction, with AIS subjects showing poor balance in this direction. Overall, carrying a backpack causes similar sagittal plane changes in posture and balance in both normal and AIS groups. Load size or subject group did not influence balance, but the additive effect of backpack carrying and AIS on postural control alters the risk of fall in this population. Therefore, load limit recommendations based on normal subjects should not be applicable to subjects with AIS.

The effect of the pulsatile electromagnetic field in children suffering from bronchial asthma.

From the bibliography it is well known that pulsatile electromagnetic field has an anti-inflammatory and analgesic effect. It causes vasodilatation, myorelaxation, hyper-production of connective tissue and activation of the cell membrane. Therefore our aim was to study the possible therapeutic effect of pulsatile electromagnetic field in asthmatic children. Forty-two children participating in this study were divided in two groups. The 1st group consisting of 21 children (11 females, 10 males, aged 11.8 +/- 0.4 yr) was treated by pulsatile electromagnetic field and pharmacologically. The 2nd group served as control, consisting also of 21 children (11 females, 10 males, aged 11.7 +/- 0.3 yr) and was treated only pharmacologically. Therapeutic effect of the pulsatile electromagnetic field was assessed on the basis of pulmonary tests performed by means of a Spirometer 100 Handi (Germany). The indexes FVC, IVC, ERV, IRV, FEV1, FEV1/FVC%, MEF75,50,25, PEF, PIF and the changes of the flow-volume loop were also registered. The pulsatile electromagnetic field was applied by means of the device MTU 500H, Therapy System (Brno, Czech Republic) for 5 days, two times daily for 30 minutes (magnetic induction: 3 mT, frequency: 4 Hz as recommended by the manufacturer). The results in children of the 1st group showed an improvement of FVC of about 70 ml, IVC of about 110 ml, FEV1 of about 80 ml, MEF75 of about 30 ml, PEF of about 480 ml, PIF of about 550 ml. The increases of ERV, IRV and FEV1/FVC and decreases of MEF25,50 were statistically insignificant. The results in the 2nd group were less clear. The flow-volume loop showed a mild improvement in 14 children. This improvement in the 2nd group was less significant. The clinical status of children and their mood became better. We believe that the pulsatile electro-magnetotherapy in children suffering from asthma is effective. On the basis of our results we can recommend it as a complementary therapy.

Changes in brain activation caused by caloric stimulation in the case of cochleovestibular denervation--PET study.

There are a number of well-known stimulation methods for the investigation of the central projection of the vestibular system. In addition to optokinetic, galvanic and neck vibration tests, the most widespread method is caloric stimulation. These listed methods cause not only vestibular, but also other effects on the central nervous system (CNS) (acoustic, tactile and nociceptive). In this paper, positron emission tomography (PET) was used to investigate whether caloric stimulation contains a non-vestibular (extravestibular) component, which would cause a distortion in the cortical activity and therefore in the vestibular effect on the CNS. Caloric stimulation was carried out in six patients who had been operated on due to cerebello-pontine angle tumour. These patients suffered post-operatively from a complete lesion of the vestibular system and anacusis on the operated side. Ipsilaterally activated areas were the inferior pole of the post-central gyrus and temporoparietal junction, caudal part of the post-central gyrus (SI, SII), inferior parietal lobule and medial frontal gyrus. Contralaterally activated areas were the anterior cingulate gyrus, medial frontal gyrus, posterior part of the insula, post-central gyrus and temporoparietal junction (SII). Ipsilaterally deactivated areas were the caudal and cranial part of the medial occipital gyrus (V2, V3, V4, V5). Contralaterally deactivated areas were the lingual gyrus, inferior occipital gyrus (V2, V3) and fusiform gyrus. On the basis of these data, it was postulated that, during caloric stimulation, extravestibular reaction also occurs, which corresponds to the subjective feeling of heat and pain. The deactivation of the occipital cortex due to an extravestibular effect was demonstrated. This is the first observation to suggest the possibility of nociceptivevisual interaction.

Somatosensory and motor evoked potentials in patients with tumours in the spinal canal.

Motor and sensory evoked potentials were recorded in 27 patients with expanding spinal tumour. The patients were divided into 2 groups: I. tumours at the level of the spinal cord and II. at the level of the cauda equina. On the basis of the localization of the tumour, midline and lateral subgroups were distinguished. The latencies of motor evoked potentials were prolonged in most of the patients, even those without paresis, in both groups. The motor evoked potentials detected subclinical motor lesions in 7 patients. All patients but one manifested sensory deficits, which could not be shown with the somatosensory evoked potentials. Significantly more prolonged cortical motor latencies were found in most of the patients with a laterally located tumour on the tumour side than contralaterally, whereas in somatosensory evoked potentials this difference was not apparent. On the basis of these observations, we concluded that motor evoked potentials, 1. could more reliably detect the neural deficit than somatosensory evoked potentials; 2. could show the side where the tumour was located; 3. proved useful in the detection of subclinical motor lesions. The general conclusion may be drawn that this electrophysiological method can provide useful information for the surgeon.

Transtracheal electrical stimulation of the spinal cord for intraoperative monitoring of the motor pathway.

Because of the suppressant effects of anesthetic drugs and muscle relaxants on motor responses elicited by either magnetic or electrical transcranial stimulation, intraoperative monitoring of the motor system, and especially monitoring of lower limb function, presents many difficulties. The upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed above the upper cervical spinous processes. Action potentials evoked by single and serial stimuli were recorded from the exposed right femoral nerve and quadriceps muscle Averaging was necessary for serial stimulations. Reproducible early and late responses to both single and serial stimulations were recorded during regular anesthesia. The origin of the different responses is discussed. Transtracheal stimulation of the spinal cord is easy to perform and the responses recorded from the peripheral nerve or limb muscle are well reproducible in regular anesthesia. The method seems to be appropriate for intraoperative monitoring of the thoracolumbar spine.

Intraoperative monitoring of the motor pathway using transtracheal stimulation of the cervical spine in dogs.

Although SEP monitoring of the spinal cord has been a well established method recently, not an ultimate, perfectly developed technique for monitoring of the motor system is known so far, particularly, because of the disturbing effect of narcotic drugs and relaxants on the motor evoked potentials. In this study the upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed to the cervical spinous processes. Single and serial stimuli were applied. Recordings were obtained from the exposed right femoral nerve and quadriceps muscle. Averaging was necessary when using serial stimulations. Responses were consequent and reproducible during regular anesthesia. The origin of the different responses in the spinal cord is discussed. The method seems to be appropriate for intraoperative monitoring of the thoracolumbar spine.

Correlation between central somatosensory conduction time, blood flow velocity, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

In this retrospective study of 67 aneurysmal patients, the predictive role of central conduction time (CCT) on vasospasm occurrence evaluated by means of transcranial Doppler sonography (TCD) and the correlation of CCT to blood flow velocity measured simultaneously in postoperative course were studied. Data about the clinical state of patients at the time of admission (Hunt Hess scale), severity of subarachnoidal hemorrhage on initial CT scan (Fisher grade), timing of surgery (acute or delayed), outcome (Glasgow Outcome Scale), severity of vasospasm graded by highest mean blood flow velocity (BFV) during the entire clinical course and CCT values measured at admission (preoperatively), then postoperatively (one day after surgery) and simultaneously with later TCD investigations were collected from the files. Interhemispheric difference of CCT was also calculated. The results showed that CCT at admission was not predictive for vasospasm. CCT measured either at admission or on the first postoperative day did not differ significantly in the different grades of vasospasm. Similar results were obtained in the acute and in the late operated group of patients. The results also suggest that increased CCT and interhemispheric difference at the time of admission indicate a worse prognosis, but this can be related to higher surgical risk rather than to a higher incidence of late ischemic deterioration. Simultaneous CCT and TCD examinations demonstrated that coincident and statistically significant (p < 0.01) increase of actual CCT (6.7 msec) was found only in the severe grade of vasospasm (BFV 200 cm/s). The authors discuss the role of CCT and TCD monitoring in the management of aneurysmal subarachnoid hemorrhage.

Are intra- and suprasellar masses detected by CT and MR really tumours?

The difficulties of differential diagnosis between intra- and suprasellar tumours resp. inflammatory processes are discussed, based on three personal cases. In all three computed tomography (CT) and magnetic resonance imaging (MR) had demonstrated a tumour, but the clinical signs with discrepancies between radiological and clinical findings were pointing to an inflammatory process. The correct diagnosis of an inflammation was achieved by co-operation between neurologist, neurosurgeon, otologist and ophthalmologist. An unnecessary neurosurgical operation was avoided and the patients were cured by otological intervention and antibiotic therapy.

[Intracranial pressure increase and changes in cerebrovascular circulation, associated with brain death, studied by transcranial Doppler sonography]. / Koponyaüri nyomásfokozódást és agyhalált kísérö agyi véráramlás változások vizsgálata transcranialis Doppler szonográfiával.

Blood flow velocity of 24 patients in state of the brain death were examined by transcranial Doppler sonography. Authors expound the characteristic velocity-pulse graphs recorded in progressively increasing intracranial pressure and their chronology as well. The different forms of the oscillating flow and their successive development are described. The oscillating flow, the systolic spikes and the so called "zero Flow" are the transcranial Doppler signs of the ceased cerebral blood flow, and these signs can be used as one of the evidence of the brain death.