Georg Leonhardt

Thrombolytic therapy in pregnancy.

Pregnancy due to its physiological changes is a procoagulant state. The rate of cardiac valve prosthesis thrombosis, deep venous thrombosis and pulmonary embolism are all increased. Thrombolytic therapy with tissue plasminogen activator (rt-PA) is an approved therapy for ischemic stroke, myocardial infarction, pulmonary embolism and thrombosis of cardiac valve prosthesis. However, there are no data from controlled randomized trials in pregnant patients. Thrombolytic therapy has been rarely used in pregnancy with only 28 cases of rt-PA thrombolysis reported in the literature so far. Indications for rt-PA thrombolysis were stroke (n = 10), thrombosis of cardiac valve prosthesis (n = 7), pulmonary embolism (n = 7), deep venous thrombosis (n = 3), and myocardial infarction (n = 1). Remarkably, all thrombosis of cardiac valve prostheses occurred after switching from warfarin to heparin in order to prevent teratogenicity and fetal loss. Two patients died (7%) and three suffered from complications that were managed conservatively (11%). In another three patients thrombolysis was not successful. Thrombolysis complication rates were similar compared to non-pregnant patients for the above mentioned indications. Six out of the 26 fetus from surviving mothers died (23%), three of them after induced abortion for maternal reasons (12%). A likely causal relation to the prior thrombolysis could only be established in two fetal fatalities (8%). None of the live born children suffered a permanent deficit.Considering that rt-PA does not cross the placenta and taking into account that the complication rates do not exceed those of large randomised controlled trials thrombolytic therapy should not be withheld in pregnant patients in case of life-threatening or potentially debilitating thrombembolic disease.

Evolution of functional reorganization in hemiplegic stroke: A serial positron emission tomographic activation study

We used serial positron emission tomography (PET) to study the evolution of functional brain activity within 12 weeks after a first subcortical stroke. Six hemiplegic stroke patients and three normal subjects were scanned twice (PET 1 and PET 2) by using passive elbow movements as an activation paradigm. Increases of regional cerebral blood flow comparing passive movements and rest and differences of regional cerebral blood flow between PET 1 and PET 2 in patients and normal subjects were assessed by using statistical parametric mapping. In controls, activation was found in the contralateral sensorimotor cortex, supplementary motor area, and bilaterally in the inferior parietal cortex with no differences between PET 1 and PET 2. In stroke patients, at PET 1, activation was observed in the bilateral inferior parietal cortex, contralateral sensorimotor cortex, and ipsilateral dorsolateral prefrontal cortex, supplementary motor area, and cingulate cortex. At PET 2, significant increases of regional cerebral blood flow were found in the contralateral sensorimotor cortex and bilateral inferior parietal cortex. A region that was activated at PET 2 only was found in the ipsilateral premotor area. Recovery from hemiplegia is accompanied by changes of brain activation in sensory and motor systems. These alterations of cerebral activity may be critical for the restoration of motor function.

Stroke following chiropractic manipulation of the cervical spine

Abstract We analyzed the clinical course and neuroradiological findings of ten patients aged 27–46 years, with ischemic stroke secondary to vertebral artery dissection (VAD; n = 8) or internal carotid artery dissection (CAD; n = 2), all following chiropractic manipulation of the cervical spine. The following observations were made: (a) All patients had uneventful medical histories, no or only mild vascular risk factors, and no predisposing vascular lesions. (b) VAD was unilateral in five patients and bilateral in three. VAD was located close to the atlantoaxial joint in all eight patients and showed additional involvement of lower sections in six, as well as temporary occlusion of one vertebral artery in three. (c) Nine of ten patients had brain infarction documented by magnetic resonance imaging or computed tomography. (d) Onset of symptoms was immediately after the manipulation (n = 5) or within 2 days (n = 5). (e) Progression of neurological deficits occurred within the following hours to a maximum of 3 weeks. (f) Maximum neurological deficits were severe in nine of ten patients. (g) Outcome after 4 weeks–3 years included no or mild neurological deficits in five patients, marked deficits in three, persistent locked-in syndrome in one, and persistent vegetative state in one. (h) Informed consent was obtained in only one of ten patients. Thus, patients at risk for stroke after chiropractic manipulation may not be identified a priori. Neurological deficits may be severely disabling and are potentially life threatening.

Brain diffusion after single seizures.

Summary:  Purpose: Diffusion‐weighted magnetic resonance imaging (DWI) after focal status epilepticus has demonstrated focal alterations of the apparent diffusion coefficient (ADC) in the epileptogenic zone. We hypothesized that localized dynamic alterations of brain diffusion during the immediate postictal state will be detectable by serial DWI and correlate with the epileptogenic zone.

Clinical outcome and neuropsychological deficits after right decompressive hemicraniectomy in MCA infarction

Abstract.Background and Purpose: The purpose of this study was to analyse in detail the functional outcome and the neuropsychological deficits in patients with space-occupying infarction of the non-dominant hemisphere one year after surgery. Methods: Postoperative complications and retrospective consent to surgery were assessed in a semi-structured interview in 26 patients. Functional outcome was measured with the Barthel-Index (BI) and Rankin-Scale. Neuropsychological tests in 14 patients focused on visuo-spatial and visuo-constructive abilities, attention, spatial span and self-rated mood. Results: The one-year survival rate was 69 % (18 of 26). The functional outcome was good (BI ≥ 90) in 3 patients, fairly good (BI 75–85) in 6, moderate (BI 30–70) in 6, and poor (BI 0–25) in 3 patients. Age was an independent predictor of outcome, patients above 52 years had a BI of 50 or below. Neuropsychological tests (14 of 18) showed profound attention deficits in all patients, and visuo-spatial and visuo-constructive deficits in patients with lower formal education. Retrospectively, 4 of 18 patients would not give consent to surgery again, mostly because of the bad quality of life postoperatively. Conclusion: Older patients do not seem to benefit from decompressive hemicraniectomy; more than half of the surviving younger patients have a good outcome and live independently. Attention deficits are prominent in all patients; visuo-spatial and constructive deficits are less pronounced in patients with higher formal education. Retrospective agreement to decompressive hemicraniectomy is high in patients with good functional outcome.

Brain Perfusion Following Single Seizures

Summary:  Purpose: The aim of this study was to assess the regional relative interictal and postictal perfusion changes in temporal and parietal lobe epilepsy.

Presurgical Evaluation of Epilepsy by Brain Diffusion : MR-detected Effects of Flumazenil on the Epileptogenic Focus

Summary:  Purpose: After focal status epilepticus, focal alterations of the apparent diffusion coefficient (ADC) have been demonstrated in the epileptogenic zone by using diffusion‐weighted magnetic resonance (MR)imaging (DWI). Effects of flumazenil on an epileptogenic focus have been demonstrated by EEG recordings, but not by functional MRI. We hypothesized that dynamic spatiotemporal alterations of brain diffusion of the epileptogenic focus after application of flumazenil will be detectable by DWI and correlate with the epileptogenic zone.

Cortical activation in patients with functional hemispherectomy.

Abstract Functional hemispherectomy, a safe and effective therapeutical procedure in medically intractable epilepsy, offers the chance to investigate a strictly unilateral cortical activation in ipsilateral limb movement. We assessed the pattern of cortical activation in a group of patients following functional hemispherectomy. We measured regional cerebral blood flow (rCBF) in 6 patients postoperatively and 6 normal subjects with positron emission tomography using 15[O]H2O as a tracer. Brain activation was achieved by passive elbow movements of the affected arm. Analysis of group results and between-group comparisons were performed with statistical parametric mapping, (SPM96). In normal subjects brain activation was found contralaterally in the cranial sensorimotor cortex and the supplementary motor area and ipsilaterally in the inferior parietal cortex. In patients significant rCBF increases were found in the inferior parietal cortex, caudal sensorimotor cortex and the supplementary motor area ipsilaterally. The activation was weaker than in normal subjects. Compared with normal subjects patients showed additional activation in the premotor cortex, caudal sensorimotor cortex and the inferior parietal cortex of the remaining hemisphere. Less activation compared with normal subjects was found in the cranial sensorimotor cortex and the supplementary motor area. A functional network connecting the inferior parietal cortex, premotor cortex and the supplementary motor area as well as the existence of ipsilateral projections originating from these regions may explain why these areas are predominantly involved in reorganization confined to a single hemisphere.

Cortical reorganization following multiple subpial transection in human brain - a study with positron emission tomography.

We investigated the cortical activation pattern in a 30-year-old woman 4 years after multiple subpial transection (MST) of the right fronto-parietal cortex and six healthy controls using positron emission tomography. Sequential finger-to-thumb opposition at the frequency of 1.5 Hertz contralateral to the operated hemisphere was used as the activation paradigm. We found preserved cortical activation in the transected fronto-parietal cortex and additional activation of the prefrontal cortex bilaterally and the inferior parietal cortex contralaterally when compared with the control group. This activation pattern indicates that MST induces a rather selective lesion leaving the cortical structures functionally intact. However, it necessitates the recruitment of additional motor areas.

Hypokalemic thyrotoxic periodic paralysis (HTPP). Rare differential diagnosis in case of acute tetraparesis in Europe

ZusammenfassungHintergrund:Die Differentialdiagnose der akut aufgetretenen Tetraparese umfasst neben traumatisch, vaskulär, tumorös und entzündlich verursachten Querschnittssyndromen u.a. die Polyradikulitis (Guillain-Barré-Syndrom), dyskaliämische Lähmungen, eine myasthene Krise und psychogene Lähmungen.Fallbeschreibung:Berichtet wird der Erkrankungsverlauf eines 45-jährigen Mannes, der nach schwerer körperlicher Arbeit eine Schwäche beider Beine und Parästhesien beider Hände entwickelte. Am Abend war ihm das Treppensteigen nur noch mit Mühe möglich, in der Nacht traten zusätzlich eine Schwäche beider Arme und Hände sowie Atemnot auf. Es bestand eine ausgeprägte Tetraparese mit abgeschwächten Muskeleigenreflexen. Der Hirnnervenbefund war unauffällig. Pathologisch waren eine Hypokaliämie (Kalium 1,9 mmol/l) und eine manifeste Hyperthyreose. Erhöhte Anti-TRAK- und TPO-Antikörper sowie sonographische und szintigraphische Befunde belegten eine Autoimmunhyperthyreose Morbus Basedow. Nach intravenöser Substitution von Kalium bildete sich die Tetraparese vollständig zurück.Schlussfolgerung:Sehr ungewöhnlich ist im vorliegenden Fall das Auftreten einer hypokaliämischen thyreotoxischen periodischen Paralyse (HTPP) als spezielle Form der dyskaliämischen Lähmung bei einem Kaukasier. Diese Erkrankung wird überwiegend bei jungen Männern in Asien beschrieben. Zugrunde liegt der Attacke kein absoluter Kaliummangel, sondern eine extraintrazelluläre Kaliumverschiebung. Im Gegensatz zur hereditären autosomaldominanten hypokaliämischen Lähmung ist ein zugrundeliegender Gendefekt bei der HTPP bislang nicht bekannt. Meist wird die Diagnose der HTPP dadurch erschwert, dass die klinischen Symptome der Hyperthyreose nur mild ausgeprägt sind.AbstractBackground:Differential diagnosis of acute tetraparesis includes paraplegia caused by trauma, ischemia, inflammation or tumor, Guillain-Barré syndrome, periodic paralysis, myasthenia gravis, and dissociative paralysis.Case Report:The case of a 45-year-old man is reported who noticed weakness of both legs after heavy labor. In the evening he was unable to climb stairs, at night he noticed additional weakness in both arms and dyspnea. After transfer to the authors’ department profound tetraparesis, tachycardia and slight dyspnea were found on examination. Cranial nerve examination was unremarkable. Deep tendon reflexes, however, were only slightly diminished. Laboratory work-up revealed hypokalemia (potassium 1.9 mmol/l) and hyperthyreosis. Elevated TRAK and TPO antibodies as well as sonography and scintigraphy of the thyroid gland gave evidence of Graves’ disease. After intravenous administration of potassium tetraparesis resolved completely.Conclusion:Hypokalemic thyrotoxic periodic paralysis (HTPP), a subtype of hypokalemic paralysis, is unusual in Caucasians. In Asian men the disease is more common. The underlying mechanism is an extra-intracellular shift of potassium in the voluntary muscle cells. In contrast to hereditary autosomal dominant paralyses, a genetic defect is not known. Usually, symptoms of hyperthyreosis in HTPP are mild which can hamper the correct diagnosis.