Epilepsia partialis continua after an anterior circulation ischaemic stroke.

BACKGROUND AND PURPOSE: Although cerebrovascular disorders are the main cause of epilepsia partialis continua (EPC) in adulthood, the frequency of EPC after stroke is unknown. The aim was to prospectively ascertain its frequency 1 year after an ischaemic stroke. METHODS: This was a prospective study of consecutive acute anterior circulation ischaemic stroke patients, previously independent, with an admission National Institutes of Health Stroke Scale score ≥4, an acute ischaemic lesion on imaging and no previous epileptic seizures. During admission patients received standardized diagnostic and medical care and were submitted to a neurophysiological evaluation protocol. One year after stroke, patients were re-evaluated by an epilepsy expert neurologist and performed a video-electroencephalogram with electromyography co-registration whenever myoclonus was observed during neurological examination for jerk-locked back averaging analysis (JLBA). EPC was defined as continuously repeated fragments of epileptic seizures, with preserved consciousness, lasting at least 1 h, and representing locally restricted epileptic activity. RESULTS: In all, 151 acute anterior circulation stroke patients were consecutively included and prospectively evaluated, but 23 died in the first year. One year after stroke, from 127 patients alive, 117 (92.1%) underwent clinical and neurophysiological evaluation. In two (1.7%) patients, EPC diagnosis was made both by clinical and electroencephalographic criteria, namely JLBA. Both patients had a history of remote symptomatic seizures and one of them acute symptomatic seizures and non-convulsive status epilepticus criteria during the first 7 days after stroke. CONCLUSIONS: Despite its low frequency, the high stroke incidence makes post-stroke EPC relevant. This study draws attention to this recognizable condition with therapeutic and eventually prognostic implications.

Epileptic manifestations in stroke patients treated with intravenous alteplase.

BACKGROUND AND PURPOSE: Intravenous alteplase (rtPA) may be associated with seizures and epileptic activity in the electroencephalogram (EEG). The aim of this work was to compare the frequency of seizures and EEG abnormalities between stroke patients treated and not treated with rtPA. METHODS: This was a prospective study of consecutive acute anterior circulation ischaemic stroke patients, with 1-year follow-up. Patients were previously independent, had an admission National Institute of Health Stroke Scale score ≥4, an acute ischaemic lesion and no previous seizures. They received standardized diagnostic and medical care. A video-EEG was performed in 72 h (first EEG); during admission (daily until day 7 and after that if neurological worsening); at discharge and 1 year after stroke. RESULTS: In all, 151 patients (101 treated with rtPA) were included. The frequency of acute and remote symptomatic seizures was not significantly different between rtPA treated and non-treated patients (P = 0.726 and P = 0.748, respectively). Clinical paroxysmal phenomena during rtPA perfusion were observed in five (5%) patients. In the first EEG, rtPA treated patients more often had background diffuse slowing (43.6% vs. 26.0%, P = 0.036). This difference was no longer observed at discharge (24.0% vs. 19.1%, P = 0.517) nor 1 year after (11.8% vs. 10.0%, P = 0.765). No differences were found in the frequency of epileptiform (P = 0.867) or periodic discharges (P = 0.381). CONCLUSIONS: Intravenous alteplase is not associated with an increased risk of clinical or electroencephalographic epileptic phenomena.

Conformational behavior of dimethyl 5-methyl-1H,3H-pyrrolo[1,2-c][1,3]thiazole-6,7-dicarboxylate 2,2-dioxide isolated in low-temperature matrixes.

The structure of dimethyl 5-methyl-1H,3H-pyrrolo[1,2-c][1,3]thiazole-6,7-dicarboxylate 2,2-dioxide (PTD) was investigated in low-temperature noble gas matrixes (Ar, Kr, Xe), amorphous solid, and the crystalline state by infrared spectroscopy and computational methods. The geometry of PTD conformers is defined by the orientation of two methyl ester groups, which may adopt pseudo-trans or pseudo-cis positions in relation to the pyrrolo-thiazole system. For both methyl ester groups, the latter arrangement was predicted by the calculations to be energetically the most favorable in the isolated molecule. The envelope form of the thiazolidine ring is present in all conformers, with the sulfur atom placed in the apex position, while the pyrrole ring is almost planar. Three types of conformers differing in the orientation of the methyl ester groups relative to the pyrrolo-thiazole system (cis/cis, trans/cis, cis/trans) were identified in the matrixes. The cis/cis forms were found to be the most stable ones in both gaseous state and argon matrixes. On the other hand, the more polar trans/cis forms were found to be stabilized in the more polarizable krypton and xenon matrixes as well as in the neat amorphous and crystalline phases. On the basis of annealing experiments, performed in argon and xenon matrixes up to 35 and 68 K, respectively, conformational changes preceding the aggregation of the compound are suggested.

Cerebral hemorrhage and apoE.

The epsilon4 allele of apolipoprotein E (apoE) is found more commonly among patients with Alzheimer's disease (AD) than in the normal population. ApoE is associated with brain amyloid, a component of cerebral amyloid angiopathy (CAA), which is both a pathological feature of AD and a frequent cause of lobar intracerebral hemorrhage (ICH). We hypothesized that the frequency of epsilon4 allele is higher in patients with CAA-related ICH than in hypertensive ICH and in the normal population. To test this hypothesis we compared the frequency of apoE alleles in four populations: 24 patients with lobar ICH, 24 matched patients with hypertensive ICH, 24 matched normal controls, and 173 population controls. Although there was a tendency to a higher frequency of apoE epsilon4 in lobar ICH patients, we found no significant differences in the frequency of this allele between the four studied populations. In addition we did not confirm the finding of some authors of a higher frequency of apoE epsilon2 in patients with lobar ICH than in the normal population. Previous studies on the subject are discussed. The relationship between apoE polymorphism and lobar CAA-related ICH remains to be clearly defined.

Vascular risk factors for perimesencephalic nonaneurysmal subarachnoid hemorrhage.

No data have been published on the role of vascular risk factors for perimesencephalic nonaneurysmal subarachnoid hemorrhage (PMSAH). In a case-control study we compared the prevalence of vascular risk factors in 40 consecutive patients who suffered a perimesencephalic subarachnoid hemorrhage with that in two controls groups: (a) 120 subjects registered with a general practitioner (GP: matched at a 3:1 ratio for age and sex) and (b) 81 proxies of patients of a hospital outpatient clinic. A conditional multivariate logistic regression model was performed taking into account the matched design. Hypertension was more frequent among PMSAH patients than among the two control group subjects for men and women. Among women, smoking was more common in PMSAH than in the GP control group. The conditional multivariate logistic regression model confirmed that hypertension was an independent risk factor for PMSAH (P = 0.036) Hypertension is a preventable risk factor of PMSAH.

Paralytic shellfish poisoning: clinical and electrophysiological observations.

In paralytic shellfish poisoning a mollusc contaminated with a toxin (saxitoxin) causes a potentially lethal disease, clinically characterised by gastrointestinal and neurological symptoms, of which possible respiratory depression is the most serious. The toxin acts by blocking the sodium channels. We report 9 Portuguese patients with this disease. The mollusc was identified as Mytilus edulis, contaminated with the dinoflagellate Gymnodinium catenatum, and the toxin saxitoxin. Our patients had a benign clinical course with cerebellar ataxia as the most severe neurological impairment. Eight out of 9 patients had neurophysiological investigations, the largest number so far reported. Motor and sensory conduction velocities and amplitudes were normal. The proximal conduction times, as assessed by F waves, showed delayed conduction and decreased frequency, which returned to normal in few weeks. The somatosensory evoked potentials confirmed normal peripheral and central sensory conduction. The rich vascular supply at root level of the sodium channels of the proximal motor nerves may explain the greater vulnerability to toxin damage. The typically transient and quickly reversible nerve dysfunction caused by ion channel blockade is reported.

[Perimesencephalic hemorrhage]. / Hemorragia perimesencefálica.

Among 293 subarachnoid hemorrhages admitted to the Neurology and Neurosurgery departments of Sta Maria Hospital, 108 patients had a normal cerebral angiography. Twenty-three meet the radiological criteria for perimesencephalic hemorrhage (center of the hemorrhage located in front of the mesencephalon, without blood in the interhemispheric and lateral sylvian fissures, nor significant intraventricular hemorrhage). The clinical picture was one of sudden, severe headache with meningeal signs, without focal signs or decreased alertness. Evolution was benign: there was no intrahospital mortality, morbidity or rebleeds on follow-up (3.5 years). In this subgroup of subarachnoid hemorrhage there is no need for a repeated angiogram if the first angiography is considered normal.