CEREBRAL VENOUS THROMBOSIS AND TURNER SYNDROME: A RARE REPORTED ASSOCIATION.

Turner Syndrome is the only known viable chromosomal monosomy, characterised by the complete or partial absence of an X chromosome. It's the most common chromosomal abnormality in females. Apart from the well known dysmorphic features of the syndrome, it has been associated with a number of vascular pathologies; mainly involving the cardiovascular, renovascular, peripheral vascular and cerebrovascular system. It seems striking that thromboembolism is not considered as a feature of the syndrome. Most of the thromboembolism cases are related to the arterial vascular system; except for some rare reported portal venous thrombosis cases, peripheral venous thrombosis cases and to the best of our knowledge a single case of cerebral venous thrombosis with Dandy Walker malformation and polymicrogyria. We herein report a cerebral venous thrombosis case with Turner Syndrome. With no other found underlying etiology, we want to highlight that Turner Syndrome, itself, may have a relationship not only with the cerebral arterial vascular system pathologies but also with the cerebral venous thrombosis.

A comparative ID migraine screener study in ophthalmology, ENT and neurology out-patient clinics.

Migraine is more likely to be misdiagnosed in patients with comorbid diseases. Not only primary care physicians, but also specialists might misdiagnose it due to the lack of diagnostic criteria awareness. The ID migraine test is a reliable screening instrument that may facilitate and accelerate migraine recognition. This study aimed to compare the prevalence and characteristics of migraine in a large sample of patients admitted to clinics of ophthalmology (OC), ear, nose and throat diseases (ENTC) and neurology (NC), as well as to validate the use of the ID migraine test in OC and ENTC settings. This was a multicentre (11 cites) study of out-patients admitting either to NC, ENTC or OC of the study sites during five consecutive working days within 1 week. From each of the clinics, 100 patients were planned to be recruited. All recruited patients were interviewed and those having a headache complaint received an ID migraine test and were examined for headache diagnosis by a neurologist, blinded to the ID migraine test result. A total of 2625 subjects were recruited. Only 1.3% of OC patients and 5.4% of ENTC patients have been admitted with a primary complaint of headache, whereas the percentage of NC patients suffering from headache was 37.6%. Whereas 138 patients (19.3%) in OC, 154 (17.3%) in ENTC and 347 (34%) in NC were found to be ID migraine test positive, 149 patients (20.8%) in OC, 142 (16%) in ENTC and 338 (33.1%) in NC were diagnosed with migraine. The sensitivity, specificity, and positive and negative predictive ratios of the ID migraine test were found to be similar in all clinics. An important fraction of the patients admitted to NC, as well as to OC and ENTC, for headache and/or other complaints were found out to have migraine by means of a simple screening test. This study validated the ID migraine test as a sensitive and specific tool in OC and ENTC, encouraging its use as a screening instrument.

Calcium dobesilate reduces oxidative stress in cardiac surgery.

AIM: Calcium dobesilate (CD) is a synthetic benzene sulfonate derivative and an angioprotective agent used orally. It can be used in patients who have diabetic retinopathy or chronic venous insufficiency. The aim of this study was to investigate the effect of CD on the reduction of oxidative stress during coronary artery bypass graft operations on cardiopulmonary bypass. METHODS: A double-blind prospective randomized study was carried out on 30 patients who underwent coronary artery bypass operations. The control and study groups were composed of 15 patients each. Pretreatment with CD started two weeks before the operation. Serial blood samples for superoxide dismutase, glutathione peroxidase were collected for the serum concentration measurements of the major endogenous antioxidant enzyme systems and malondialdehyde for scavenging capacity. RESULTS: After the release of cross clamp levels of superoxide dismutase and glutathione peroxidase. they were significantly higher in the study group than in the control group (P<0.05). Malondialdehyde levels in the study group were significantly lower than those of the control group (P<0.05). The cardiac function after aortic declamping was affected by CD, indicating contribution of CD to myocardial injury from ischemia/reperfusion. CONCLUSIONS: The study suggests that pretreatment with CD alleviates malondialdehyde production and preserves endogenous antioxidant capacity during cardiopulmonary bypass and cardioplegic arrest.

Pleura preservation during coronary operation does not have any beneficial effect on respiratory functions.

AIM: According to some reports the destruction the integrity of the pleura during acute myocardial infarction (AMI) harvesting during coronary surgery may also impair respiratory function in the postoperative period. The purpose of this study was to evaluate the influence of preserved integrity of pleura on respiratory function in patients undergoing coronary artery bypass grafting (CABG). METHODS: One hundred and forty-three patients who had on-pump-CABG operation with pedunculated LIMA graft were divided to 2 groups. The first group is the study group that pleura opened (group OP; N=69), and the other group is that their pleura protected (group C, N=74). All patients were evaluated with using respiratory function test parameters (functional vital capacity [FVC], force expiratory volume %-at the 1st second [FEV1%] in the preoperative period and on the 7th postoperative day). Respiratory problems, blood drainage amounts and used blood products in the postoperative period were measured. RESULTS: Preoperative FVC values were not different between the two groups (3.08+/-0.5 in group C and 3.37+/-0.7 L in OP group) (P>0.05). On the VII postoperative day this parameter did not show any significant difference between the groups (2.80+/-0.6 in group C and 2.75+/-0.5 liter in OP group) (P>0.05). Preoperative FEV1% values did not show any difference (77.6+/-4.6% and 76.0+/-2.7% in OP and C groups respectively. There was no significant difference between the postoperative FEV1% values (71.8+/-5.1% and 73.4+/-6.3% respectively) (P>0.05). Patients with protected pleura had significantly lower blood drainage and whole blood unit transfusion (P<0.05). CONCLUSIONS: Preservation of the pleural integrity during LIMA harvesting significantly reduces postoperative bleeding but not affects pulmonary functions.

Migrainous vertigo: clinical, oculographic and posturographic findings.

Migrainous vertigo (MV) is accepted as a common cause of episodic vertigo. The peripheral or central vestibular localization of the deficit as well as the pathophysiology is unclear. This prospective study was designed to assess the clinical features of MV and to search for the localization of the vestibular pathology. Thirty-five patients with MV, 20 patients with migraine and 20 healthy volunteers were studied. Comprehensive neurotological tests were performed between attacks. None of the normal controls or the patients with migraine had ocular motor deficits or caloric test abnormalities. Three patients in the MV group showed saccadic pursuit (8.6%), in one of whom saccadic hypometria was also present. Caloric test results revealed unilateral caloric hypofunction in seven patients (20%). Static posturography results revealed increased sway velocity when the eyes were closed or the platform was distorted in patients with MV. These findings during the symptom-free period revealed that peripheral vestibular dysfunction was more common than a central deficit.

Headache in primary Sjögren's syndrome: a prevalence study.

OBJECTIVES: To determine the prevalence of headache in patients with primary Sjögren's syndrome (pSS) and to examine the relationship between headache types and clinical, serologic features of the disease. METHODS: The study enclosed 133 patients with the diagnoses of pSS and 97 healthy controls. A questionnaire designed to assess the presence of headache and if present to classify it according to the criteria of the International Headache Society was used. RESULTS: In 133 of the pSS patients evaluated, 104 had headache. No association was present between types of headache and the clinical and laboratory manifestations of the disease. Both migraine and tension-type headache were more common in patients with pSS when compared with healthy controls (P < 0.001). CONCLUSIONS: The high prevalence of migraine in pSS patients might be explained by a vascular headache triggered by immuno-mediated disease activity without an obvious clinic or laboratory marker.

Generalized tonic-clonic status epilepticus: causes, treatment, complications and predictors of case fatality.

We retrospectively reviewed the clinical course of 66 patients treated for generalized tonic-clonic status epilepticus at the Ege University neurological intensive care unit from 1988 to 1997. Seventy-two per cent of the study group had a pre-existing seizure disorder, and antiepileptic drug withdrawal was the most prominent cause of status epilepticus. The other causes included drug toxicity, central nervous system infection, cerebrovascular disease, tumour and trauma. Seventy-three per cent of all patients responded to the first-line therapy (diazepam and/or phenytoin), and the remainder were considered to have refractory status epilepticus and required pentobarbital anaesthesia. Overall case fatality was 21%, but death could be attributed directly to status epilepticus and/or treatment complication in 10% of the study group. Major determinants of fatal outcomes were: increasing age, longer duration of status epilepticus before initiation of therapy and central nervous system infection as a causal factor.

Aprotinin reduces injury of the spinal cord in transient ischemia.

OBJECTIVE: The protective effect of aprotinin, which is a protease inhibitor, was assessed in a rabbit spinal cord ischemia model. DESIGN: Randomized, controlled, prospective study. SETTING: University research laboratory. SUBJECTS: New Zealand white rabbits (36) of both sexes. METHODS: In 24 animals, ischemia was induced with midline laparotomy and clamping the aorta just distal to left renal artery and proximal to aortic bifurcation for 20 min. Aprotinin was given 30000 KIU as a short intravenous injection after anesthesia, and was followed by 10000 KIU/h by continuous infusion in group 1 (n = 12). Similar volume of saline solution was used in control group of animals (group 2, n = 12). Group 3 of animals (sham group, n = 12) were anesthetized and subjected to laparotomy without aortic occlusion. Physiological parameters and somatosensory evoked-potentials (SEP) were monitored in animals before ischemia, during ischemia and in the first 60 min of reperfusion. Their neurological outcome was clinically evaluated up to 48 h postischemia. Their motor function was scored, and the intergroup differences were compared. The animals were sacrificed after two days of postischemia. Their spinal cord, abdominal aorta, and its branches were processed for histopathological examination. RESULTS: In group 3, SEP amplitudes did not change during the procedures, and all animals recovered without neurologic deficits. At the end of ischemic period, the average amplitude was reduced to 53+/-7% of the baseline in all ischemic animals. This was followed by a gradual return to 89+/-8 and 81+/-13% of the initial amplitude after 60 min of reperfusion in group 1 and group 2 correspondingly (P > 0.05). The average motor function score was significantly higher in group 1 than group 2 at 24 and 48 h after the ischemic insult (P < 0.05). Histological observations were clearly correlated with the neurological findings. CONCLUSION: The results suggest that aprotinin reduces spinal cord injury and preserves neurologic function in transient spinal cord ischemia in rabbits.

Neuroprotective effects of preischemia subcutaneous magnesium sulfate in transient cerebral ischemia.

OBJECTIVE: Neurological injury due to transient cerebral ischemia is a potential complication of cardiovascular surgery. The neuroprotective effect of magnesium, when given subcutaneously before the ischemia, was assessed in a rat model of transient global cerebral ischemia. METHODS: Thirty-six male Wistar albino rats were included to this randomized, controlled, prospective study. In 24 animals, ischemia was induced with four-vessel occlusion technique with the duration of 15 min. MgSO4 was given 600 mg/kg subcutaneously 48 h before the procedure in group 1 (n = 12). Similar volume of saline solution was used in animals of control group (group 2, n = 12). The animals in group 3 (sham group, n = 12) were anesthetized and subjected to operative dissections without vascular occlusion. Physiological parameters and somatosensory evoked-potentials (SEP) were monitored in animals before ischemia, during ischemia and in the first 30 min of reperfusion. Their neurological outcome had been clinically evaluated and scored up to 4 days postischemia. The intergroup differences were compared. Then the animals were sacrificed and their brains were processed for histopathological examination. RESULTS: In group 3, SEP amplitudes did not change during the procedures, and all animals recovered without neurologic deficits. At the end of ischemic period, the average amplitude was reduced to 5 +/- 3% of the baseline in all ischemic animals. This was followed by a gradual return to 87 +/- 10% and 83 +/- 8% of the initial amplitude after 30 min of reperfusion in group 1 and group 2, respectively (P > 0.05). The average neurological score was significantly higher in group 1 than in group 2 at 48, 72 and 96 h after the ischemic insult (P < 0.05). Histological observations were clearly correlated with the neurological findings. CONCLUSION: The results suggest that subcutaneous MgSO4 reduces cerebral injury and preserves neurologic function when given two days before the transient global ischemia in rats.

Comparison of magnetic coil stimulation and needle electrical stimulation in the diagnosis of lumbosacral radiculopathy.

Electrical stimulation (ES) of lumbosacral nerve roots using a needle electrode inserted to the laminar level at the midline of Th12-L1 or L1-2 intervertebral interspace, was compared with magnetic stimulation using a 9-cm diameter coil (MCS) at the L3-4 or L4-5 spine levels, Compound muscle action potentials (CMAP) were superficially recorded from homologous muscles in both sides in 15 normal control subjects and in 20 patients with lumbosacral radiculopathy. Soleus muscles were used for S1, tibialis anterior (TA) for L5, and rectus femoris (RF) muscles for L4 roots. According to the clinical or radiological diagnosis (CAT, MRI and/or myelography) conventional needle EMG was capable to localise the root lesion in 16 of 20 patients (80%) and ES localised the root involvement in 18 of 20 patients (90%); the diagnostic value of MCS was lower, about 65% (13 of 20 patients). Although ES is uncomfortable and invasive, it is superior to needle EMG in localising unilateral or multiple lumbosacral root involvement. At present, MCS is not suitable for the diagnosis of lumbar radiculopathy.

Pentoxifylline reduces injury of the brain in transient ischaemia.

OBJECTIVE: The beneficial effect of pentoxifylline (PTX) on ischaemic-reperfusion injury was assessed in a rat model of transient global cerebral ischaemia. DESIGN: Randomized, controlled, prospective study. SETTING: University research laboratory. SUBJECTS: Thirty-six male Wistar albino rats. INTERVENTIONS: Ischaemia was induced with a four-vessel occlusion technique in 24 animals with the duration of 15 minutes. Group 1 animals (n = 12) received PTX treatment started 20 minutes before the occlusion of carotid arteries (60 mg/kg bolus followed by infusion at 0.1 mg/kg/min). A similar volume of saline solution was used in animals of the control group (group 2, n = 12). The animals in group 3 (sham group, n = 12) were anaesthetized and subjected to operative dissections without vascular occlusion. MEASUREMENTS: Physiological parameters and somatosensory evoked potentials (SEP) were monitored in animals before ischaemia, during ischaemia and in the first 30 minutes of reperfusion. Their neurological outcome had been clinically evaluated and scored up to 4 days post ischaemia. The intergroup differences were compared. Then the animals were sacrificed and their brains were processed for histopathological examination. MAIN RESULTS: In group 3, SEP amplitudes did not change during the procedures, and all animals recovered without neurologic deficits. At the end of the ischaemic period, the average amplitude was reduced to 4 +/- 3% of the baseline in all ischaemic animals. This was followed by a gradual return to 92 +/- 9% and 82 +/- 8% of the initial amplitude after 30 minutes of reperfusion in group 1 and group 2, respectively (p < 0.05). The average neurological score was significantly higher in group 1 than in group 2 in the post-ischaemia period (p < 0.05). Histological observations were clearly correlated with the neurological findings. CONCLUSION: The results suggest that PTX reduces cerebral injury and preserves neurologic function in transient global ischaemia in rats.

[Callosal infarction after bilateral occlusion of the internal carotid arteries with hemineglect syndrome and astasia-abasia]. / Infarctus calleux après occlusion bilatérale des artères carotides internes avec syndrome d'héminégligence et astasie-abasie.

We report a patient who had a callosal infarct, showed by Computer Tomography and Magnetic Resonance Imaging, without injury to the adjacent hemispheres. Angiography revealed an occlusion of both internal carotid arteries. Besides interhemispheric disconnection with unilateral left agraphia, left tactile anomia, left ideomotor apraxia and left ear auditivoverbal extinction, the patient showed signs of left hemineglect and astasia-abasia, both persistent.

Subfascial endoscopic perforator surgery ameliorates the symptoms of chronic venous ulcer (C6) patients.

AIM: Chronic venous insufficiency and the development of venous ulceration, as a result of this condition affects quality of life. In order to avoid skin changes and allow for quick remedy, subfacial endoscopic perforator surgery (SEPS) has been suggested and gained some popularity. The purpose of this study was to assess the healing rate of venous ulcers in patients undergoing SEPS. METHODS: The SEPS procedure by using two ports was applied in 20 patients with active venous ulceration (CEAP-C6). The results were evaluated by Doppler findings, Venous Disability Score (VDS) and Venous Clinical Severity Score (VCSS) before and after the operation. Patients with prior deep vein thrombosis were excluded from this study. RESULTS: The ulcers healed in all patients. Significant clinical improvement according to VDS and VCSS values was obtained in all patients after the procedures. There was no mortality or any other major complication during the follow up period. CONCLUSION: The advantages of using two-port, video-controlled SEPS procedure may provide freedom from the skin complications that can be seen after Linton operation with quick and sustainable ulcer healing.

Treatment of idiopathic intracranial hypertension: topiramate vs acetazolamide, an open-label study.

OBJECTIVES - To assess the efficacy of topiramate in the treatment of idiopathic intracranial hypertension (IIH) and to compare it with acetazolamide. METHODS - Fourty patients diagnosed as IIH and randomly assigned to treatment with either acetazolamide or topiramate were assessed prospectively. Improvement in the visual fields at the end of third, sixth and twelfth months were taken into consideration. RESULTS - The demographic, clinical features and the cerebrospinal fluid (CSF) pressure of the two treatment groups were similar at the beginning of the study. When the follow-up visual field grades were compared with the visual field grades at the beginning of the study in each group a statistically significant improvement was detected with both drugs. When the results of the two treatment groups were compared with each other no statistically significant difference was present. Prominent weight loss was recorded in the topiramate group. CONCLUSIONS - Topiramate seems to be effective in the treatment of IIH. Weight reduction as well as the reduction of the CSF formation is the possible mechanism of action.

International survey of seat belt use exemptions.

BACKGROUND: Substantial evidence of seatbelt efficacy has been shown by several studies, and it is widely recommended that motor vehicle occupants use properly fitted seat belts. However, some (but a heretofore unknown number of) countries with national seat belt laws permit various exemptions which may lower use rates. The aim of this study was to survey the variety of exemptions to national seat belt laws. METHODS: This investigation relied on identifying respondents from national traffic safety agencies, other governmental and non-governmental organizations, Internet searches, personal contacts, and other sources. Questionnaires were deployed through a web based survey supplemented by email and postal versions. RESULTS: Responses were received from 30 countries of which 28 (93.7%) had a national seat belt law. About two thirds (63.7%) of the 28 national laws applied to both front and back seat passengers. The leading exemption types included vehicles made before a certain year (n = 13), antique vehicles (n = 12), military vehicles (n = 11), buses (n = 9), and emergency vehicles (n = 8). Most responding countries reported one or more specific categories of individuals as exempt including those with medical exemptions (n = 20), taxi drivers (n = 11), police (n = 9), emergency medical personnel (n = 8), physically disabled people (n = 6), and pregnant women (n = 6). Out of 26 responses to the question regarding current level of enforcement, 42.3% felt enforcement was "very good or good" and 57.7% characterized it as "fair or poor". CONCLUSIONS: This study represents one of the largest international traffic law surveys reported. Most national seatbelt laws offer perilous exemptions to a broad array of vehicle types and road user groups. These findings, coupled with concern over the level of enforcement in the majority of countries surveyed, suggest that international road safety efforts have a long way to go to improve coverage and enforcement of national seat belt laws.

Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates.

BACKGROUND: Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT. METHODS: Forty-six patients with venous stroke proved on MRI included in our Registry, corresponding to 0.1% of 4650 patients with stroke, were studied. Magnetic resonance angiography (MRA) was performed in all patients, and 18 of them had follow-up MRA. Outcome was evaluated by using the Glasgow Outcome Scale at the time of discharge and during follow-up. RESULTS: Thirty-two patients presented cortical venous stroke; 21 of them had involvement of the dorsomedial venous system, six had a defect in the posteroinferior venous group, and five had a defect in the anteroinferior venous group. Thirteen patients presented simultaneous involvement of the superficial and deep venous system; seven with a defect in the parietal and internal cerebral veins (three with involvement of vein of Gallen), four with a defect in the temporooccipital (vein of Labbé) and basal vein of Rosenthal, two with a deficit in the anterior frontotemporal and uncal-pterygoid venous system. One patient had deep venous thrombosis primarily localized to the thalami bilaterally and the basal ganglia on the right because of occlusion of the thalamostriate veins. The main presenting symptoms of CDVT were headache, focal neurologic signs, partial complex or secondary generalized seizures, and consciousness disturbances in those with deep venous thrombosis, presented alone or in combination at onset. CDVT was more than twofold more frequent in women than in men. Pregnancy, puerperium, oral contraceptive use, and infections were the most common predisposing factors. CONCLUSION: Computerized tomography, conventional MRI and diffusion-weighted imaging showing ischemic and/or hemorrhagic lesion that does not follow the boundary of classical arterial boundaries without signs of sinus thrombosis, and partial or generalized seizures followed by focal neurologic signs may predict CDVT. The outcome of patients with cortical venous stroke was good, but not in those with cortical plus deep venous infarction.

X-linked bulbospinal muscular atrophy (Kennedy's syndrome): a report of three cases.

Two cases of X-linked bulbo-spinal muscular atrophy and one sporadic case with the same clinical features are presented. All three cases were extensively studied by electrophysiological methods. One of the patients showed some transient weakness, which was partly improved by pyridostigmin. In this patient the Decrement test and jitter revealed a mild degree of motor-end plate dysfunction. Clinical and electrophysiological findings obtained from all three patients suggest that in Kennedy syndrome cell bodies of group IA muscle afferents are also affected selectively, with other peripheral afferents.

Wallenberg's lateral medullary syndrome: diffusion-weighted imaging findings.

PURPOSE: To investigate the efficacy of diffusion-weighted imaging in patients with Wallenberg's lateral medullary syndrome. MATERIAL AND METHODS: Thirteen patients with Wallenberg's lateral medullary syndrome were examined with conventional and echoplanar diffusion-weighted magnetic resonance (MR) imaging in a 1.5 T magnetic resonance unit. MR examinations were obtained in the acute or subacute stage of clinical syndrome, and diffusion-weighted imaging (DWI) was considered to be positive for infarction when an increase in signal was seen on b = 1000 s/mm2 images in the posterolateral medullary localization. RESULTS: DWIs were positive in 12 patients in the acute or subacute stages of this clinical syndrome. A false-negative result was obtained in only one patient examined within the first day, 10 h after onset of the symptoms. In the visual evaluation of the DWI, the contrast between normal and infarcted brainstem area was better in the high b-value images than in the apparent diffusion coefficient map images. CONCLUSION: DWI is a valuable technique for examining patients presenting with the signs and symptoms of Wallenberg's syndrome and high b-value images can provide complementary data to T2-weighted images. However, because most of our case group were in either the acute or subacute stage, true sensitivity of the method in the hyperacute stage of the syndrome remains unclear.

The Ege Stroke Registry: a hospital-based study in the Aegean region, Izmir, Turkey. Analysis of 2,000 stroke patients.

We present the profile of risk factors, etiologic and clinical data of 2,000 consecutive patients with first-ever-in-a-lifetime stroke (cerebral infarction, cerebral hemorrhage and subarachnoid hemorrhage), admitted to the Ege University Hospital between January 1, 1991, and September 31, 1995. This hospital-based registry is the first systematic epidemiologic report on the stroke profile of Turkish people The Ege University Stroke Unit is the only tertiary medical care facility which is organized for patients with different stroke subtypes in Izmir, Turkey. A prospective hospital-based registry using systematic computer coding of data of all stroke patients has been used since January 1991. All patients were evaluated by clinical examination, CT and/or MRI, color duplex and specific cardiac investigations. They were followed up for at least 6 months. The mean age was 62.3 +/- 12 years, and 44.4% were females. Ischemic stroke was found in 77%, primary intracerebral hemorrhage in 19% and subarachnoid hemorrhage in 4%. The major risk factor of ischemic stroke was hypertension (63%), followed by hypercholesterolemia (37%), diabetes mellitus (35%), ischemic heart disease (23%), atrial fibrillation (20%) and smoking (17%). The main cause of primary intracerebral hemorrhage was hypertension (88%), and the principal localization was the thalamus (38%), followed by putamen (28%), lobar(16%), pons(6%), cerebellar(4%), primary intraventricular hemorrhage (4%) and multiple hemorrhages (2%). The over- all 30-day case-fatality rate was 19.7% and the higher mortality rate was found in patients with primary intracerebral hemorrhage (29%) than in those with ischemic stroke (17%). The Ege Stroke Registry allows to estimate the stroke-related problems in patients admitted to a stroke unit and to evaluate the risk factors, etiology and clinical manifestations of stroke in Turkey.

A stable late soleus EMG response elicited by cortical stimulation during voluntary ankle dorsiflexion.

Transcranial electrical or magnetic stimulation was performed in 47 experiments on 42 normal adult subjects. Surface compound muscle action potentials were recorded from the antagonistic tibialis anterior (TA) and soleus (SOL) muscles. A stable late response recorded from SOL during voluntary ankle dorsiflexion is described and called soleus MEP-80. Its origin has been studied with different experimental procedures. (1) It is only obtained during active voluntary dorsiflexion of the ankle within 70-100 msec (mean 86.9 +/- 6.4 msec) whereas passive dorsiflexion does not promote such a response. The size of SOL MEP-80 was always bigger than the primary SOL response. (2) A similar constant response has not been obtained during voluntary plantar flexion from SOL and TA muscles. (3) SOL MEP-80 is not changed significantly by the Jendrassik manoeuvre. (4) It is not obtained or is suppressed when the subject is sitting with the feet free in space. On the other hand, it is obtained when the subject is standing, especially when standing is made difficult. (5) SOL MEP-80 has not been obtained by brain-stem, spinal cord or root stimulation. (6) A later response of longer than 100 msec latency was sometimes obtained at rest but such an S100 soleus response was abolished or transformed to the SOL MEP-80 immediately during ankle dorsiflexion. (7) It is concluded that SOL MEP-80 is a polysynaptic extensor response related to postural mechanisms and originating through convergence of descending motor commands and peripheral sensory feedback.