化学中毒对人记忆功能影响的研究

目的 探讨某些化学中毒对人记忆功能的影响.方法 采用韦氏记忆量表—中国修订版(WMS- RC)对35例某些化学中毒患者进行调查和研究.结果 35例患者中有28例发生记忆障碍(占80％),其中记忆轻度损害16例(占45.7％),中重度损害5例(占14.3％)；中毒患者各因子分均低于常模,除了1→100分和积累分外其余各因子分差异均有统计学意义(P＜0.05)；不同中毒类型分别与常模比较,大部分差异有统计学意义(P＜0.05)；不同病程组之间MQ差异无统计学意义(P＞0.05)；不同年龄组的MQ均较常模低,其中16～24岁、35～44岁与常模差异有统计学意义(P＜0.05).结论 某些化学中毒可致人脑记忆功能明显损害.     

Epileptic seizures in subcortical vascular encephalopathy

Cerebrovascular disease is one of the most common causes of epilepsy in the elderly. Most of the studies published relate to cortical infarction, subarachnoid, and intracranial hemorrhage, whereas the incidence of epilepsy from subcortical ischemia, i.e. deep lacunar infarctions and diffuse white matter lesions, is obscure. Therefore, we prospectively examined 18 patients with the precisely defined diagnosis of subcortical vascular encephalopathy (SVE), who were admitted to our hospital due to epileptic seizures (group A), and compared them to a similarly selected group matched for age, sex, risk factors, and neurological deficits with an equivalent severity of SVE but without seizures (group B). Subcortical lacunar infarctions were significantly more frequent in group A than group B (15/18 versus 4/18, p < 0.001), whereas neither the extension, degree, distribution of periventricular white matter changes, nor the presence of internal hydrocephalus, focal or diffuse cortical atrophy showed any statistical significance. However, a temporal constant theta or delta EEG focus was present in 10/18 patients in group A but only in 1/18 patients from group B (p 0.005). 10/18 patients developed epilepsy with further seizures during follow-up. The association of SVE, multiple subcortical lacunas, and temporal EEG abnormalities are suggestive for an increased risk for epileptic seizures, which is particularly important for the treatment of patients with SVE if uncertain paroxysmal episodes occur, e.g. transient ischemic attacks, seizures, or cardiac syncope.     

Imaging in acute toxic encephalopathy

Neuroimaging, particularly MR imaging, plays a major role for the diagnosis of many acute toxic encephalopathies. Toxic disorders are related to drugs (immunosuppressive agents, chemotherapeutic agents, anti-epileptic drugs, heroin...), to metals (lead, manganese, mercury...), and to industrial and environmental chemicals (solvent, carbon monoxide...). MR imaging with diffusion and perfusion imaging provides information regarding brain lesions induced by the toxic agents (vasogenic edema, cytotoxic edema, infarction, hemorrhage, demyelination...).     

Prognosis in chronic toxic encephalopathy

The prognosis of chronic toxic encephalopathy in former house painters was examined in a prospective study with a two-year observation period. Twenty-six patients, who at the initial examination had cerebral atrophy and/or intellectual impairment, were selected for the follow-up study. No competitive etiological factors (including alcohol) to the encephalopathy were suspected. During the two-year follow-up interval these patients were not professionally exposed to organic solvents. At the follow-up examination neurological, biochemical, neuropsychological, and neuroradiological parameters were reassessed and compared to the original findings. Generally the condition was unchanged. Slight improvements with regard to headache and dizziness were reported by some. However, the neurological status, the neuropsychological impairment, and the cerebral atrophy, did not change significantly. In three patients further deterioration was observed. It is argued that our patients suffered from a brain disorder different from presenile dementia of the Pick-Alzheimer type. Other alternative etiological entities were also excluded. Our findings indicate that long-term exposure to organic solvents may lead to a chronic brain syndrome. Once intellectual impairment and/or cerebral atrophy has developed, reversibility is not observed. Nor is further progression to be expected if exposure is stopped. Occupational exposure to organic solvents should be maximally restricted as it represents a risk of inducing invalidating brain syndromes.     

慢性海洛因中毒性脑病

目的 :报道 3例 (男 2例 ,女 1例 )慢性海洛因中毒性脑病的临床和 MRI特征 ,并结合文献进行分析。 3例均有明确吸毒史 (吸毒时间 3～ 5年 ) ,表现为进行性智能障碍、言语障碍、肌张力障碍及共济失调等慢性脑损害的特点 ,1例 (女性 )发展为意识障碍。头颅 MRI显示双侧镜像般对称性大脑白质、内囊后肢、内侧丘系、胼胝体、中脑及小脑半球内白质广泛性长 T1 、长 T2 信号 ,无强化 ,似脱髓鞘改变。经皮质激素治疗后 ,2例 (男性 )好转 ,1例无改善。因此 ,认识慢性海洛因中毒性脑病的临床及影像学特征是十分重要的 ,及时诊治可望使病情得到缓解     

Epileptic encephalopathy in children possibly related to immune-mediated pathogenesis

Severe epilepsy in the paediatric population negatively influences neurological and cognitive development. Different etiological factors could be responsible of these severe epilepsies, and an early diagnosis could change, in some cases, the neurological and cognitive development. Immune mechanisms have been reported in epilepsy. Epilepsy has been associated with systemic lupus erythematosus, with the presence of anti-phospholipid antibodies (aPL), anti-cardiolipin antibodies, anti-nuclear antibodies, Β2-glycoprotein antibodies, and anti-glutamic acid decarboxylase (anti-GAD) antibodies. CNS inflammation and markers of adaptive immunity have been, also, associated with some epileptic syndromes, such as West syndrome, temporal lobe epilepsy, febrile seizures, tonic–clonic seizures, and tuberous sclerosis. Inflammation and blood–brain barrier (BBB) disruption could be one of the mechanisms responsible for seizure recurrence. Recently clinical entities, characterized by severe epilepsy with a febrile, acute or sub-acute onset, sometimes associated with status epilepticus, followed by drug-resistant, partial epilepsy have been described. Some of these publications also suggested acronyms for the condition described: Acute Encephalitis with Refractory, Repetitive Partial Seizures (AERRPS) reported by Japanese authors, Devastating Epileptic Encephalopathy in School-aged Children (DESC) reported by French authors. Among children with acquired symptomatic severe epilepsy, we identified a group of previously normal children who had developed severe partial epilepsy after an acute/sub-acute illness resembling encephalitis. The etiological factors for those patients seems to remain unknown, and a possible immune-mediating or inflammatory process as pathogenesis of the disease could be hypothesized. More studies need to be addressed to finally define this peculiar epileptic entity.     

Epileptic and imaging findings in perinatal hypoxic-ischemic encephalopathy with ulegyria

Hypoxic-ischemic encephalopathy due to fetal or neonatal asphyxia is a major cause of acute mortality and chronic disability involving cerebral palsy, seizures, and mental retardation. The gestational age of the infant is one of the main variables determining the neuropathological picture of hypoxic-ischemic brain injury, and ulegyria (one of its neuropathological correlates) typically affects full-term infants. The damage usually involves the deeper sulcal portion of the convolutions while sparing the crowns, and includes subcortical white matter atrophy and gliosis. The aim of this study was to characterize the electroclinical features of hypoxic-ischemic encephalopathy when ulegyria is one of its main neuropathological features. To this end, nine patients with MRI-proven ulegyria and epilepsy underwent a complete neurological work-up. The ulegyric lesions were mainly distributed in the parasagittal watershed areas and frequently associated with other hypoxic-ischemic lesions. The neurological picture was characterized in most patients by mental retardation, motor deficits, and drug-refractory partial epilepsy. The ulegyria in our patients was associated with a complex clinical picture: epilepsy was a prominent component, and its severity directly correlated with the extent of the ulegyria and the associated hypoxic-ischemic lesions. Drug refractoriness was an almost constant correlate of this form of symptomatic epilepsy.     

Magnetic resonance spectroscopy in toxic encephalopathy and neurodegeneration

Magnetic resonance spectroscopy allows neurochemistry to be probed noninvasively in vivo. Recent advances in our understanding of the biochemical significance of the various neurochemicals that are observable allow a variety of pathologic states of relevance to encephalopathies and neurodegenerative disorders to be observed. Measurements of brain glutamate and glutamine allow observation of neuronal/glial substrate cycling and ammonia detoxification. Myo-inositol allows changes in cerebral osmolarity and gliosis to be observed. N-acetylaspartate is a marker of neuronal health and number. Lactate allows nonoxidative glycolysis to be observed. These molecules are now being used to ask etiologic questions that are of relevance to encephalopathies and neurodegeneration, as well to probe longitudinally both natural history and therapeutic interventions in these conditions. Combined with recent advances in anatomic magnetic resonance imaging as well as perfusion magnetic resonance imaging, magnetic resonance spectroscopy has the potential to aid greatly in our understanding of neuronal dysfunction in a wide variety of neurologic pathologies, even in single patients.     

E.E.G. changes in 15 patients with bismuth encephalopathy (author's transl)

The authors describe the E.E.G. changes found in 15 cases of iatrogenic encephalopathy caused by bismuth salts. All the patients had been taking bismuth, for periods varying from 6 weeks to 30 years, in doses from 5 to 20 g per day. The clinical picture included mental confusion to varying degrees, disturbances of standing and walking, myoclonus, dysarthria, and convulsions in 5 cases. Myoclonic jerks were not occompanied by E.E.G. paroxysmal features in any of the cases observed. Eleven of the patients presented similar E.E.G. findings at one time or another during the course of the condition: monomorphic, stable 4-6 c/s activity, present bilaterally in the temporo-fronto-rolandic regions, unaffected by eye opening and by photic stimulation. In the other four patients, the above E.E.G. features were not found (recording performed too early or too late? co-existing electrical or metabolic disturbances? post-critical recording?).     

Myoclonic encephalopathy due to bismuth following colectomy. Apropos of a case]

Bismuth encephalopathy mainly affects chronic constipation sufferers. The case described, which is practically identical, should be considered (in the absence of constipation) within the context of resection for cancer. The responsibility of bismuth, suggested in five similar cases by Burns and colleagues, is here confirmed by the blood, C.S.F. and urine levels. The mechanism of encephalopathy and the possibility of a failure to eliminate bismuth affecting these levels are discussed.     

Asterixis and toxic encephalopathy induced by gabapentin

PURPOSE: To date, only one case of asterixis associated with the use of gabapentin (GBT) has been reported. No data, instead, are available on the occurrence of asterixis related to a dementing encephalopathy during GBT therapy in the elderly. METHODS: Case reports of two elderly patients, one with asterixis, the other with asterixis and encephalopathy, associated with the use of GBT, as adjunctive therapy, at dosages of 900 to 3600 mg/day are given. In one patient, GBT was added to oxcarbazepine (OXCBZ). FINDINGS: Both patients experienced resolution of the clinically apparent asterixis, and of the toxic encephalopathy, on discontinuation or reduction of GBT dosages. One patient developed asterixis after drug rechallenge. In the patient on OXCBZ, the analysis of the electromyogram (EMG) activity showed the occurrence of a subclinical asterixis. CONCLUSIONS: Our study indicates that high doses of GBT may induce asterixis related to a reversible encephalopathy. Low doses of GBT, instead, may induce a disabling asterixis when given in combination with OXCBZ because of a synergistic interaction between these drugs.     

Epileptic aphasia: a consequence of regional hypometabolic encephalopathy?

A series of 25 children, 13 females and 12 males, who had an acquired communication disorder together with epilepsy, but did not fulfil the strict criteria of the Landau-Kleffner syndrome, was studied. All children had a clinical neurological evaluation, speech and language assessment, an awake and sleep EEG, cranial MRI, SPET scan, and audiometry. Clinical seizures were most often polymorphic in type (17 of 25). Atypical absences were the commonest individual seizure type occurring in 15 cases. All patients had an unequivocal epileptiform EEG. Normal sleep phenomena were only observed in 10 cases, enhancement of epileptiform activity in sleep was seen in 16. Cranial MRI was abnormal in six and normal in 19 cases. The SPET scans were abnormal in 22 of 25 children. The language deficits were classified neurologically as receptive aphasia, 24 of 25; expressive aphasia, 20 of 25; nominal aphasia, eight of 25; articulator dyspraxia, 10 of 25; and auditory agnosia, nine of 25. It is hypothesized that the loss of communication skills is due to an encephalopathy secondary to the persistent epileptic discharge and manifests as a hypometabolic area on the SPET scan.     

Characterization of a murine model for human bismuth encephalopathy

An epidemic of bismuth (Bi)-related neurotoxicity in France remains poorly understood, partly because no satisfactory animal model exists. We have now characterized such a model. Single or multiple intraperitoneal injections of Bi subnitrate into female mice produced neurologic signs (myoclonus, ataxia, tremors, convulsions) and blood (1.2 micrograms/g) and brain (8.4 micrograms/g) Bi levels like those in human cases. Hydrocephalus and axonal swellings in spinal cord were the major neuropathologic lesions.     

Epileptic discharges and phasic sleep phenomena in patients with juvenile myoclonic epilepsy

Purpose:   Epileptiform discharges (EDs) may be part of the internal arousing stimuli that affect the quality of sleep in patients with epilepsies. We studied the association between EDs and sleep phasic phenomena, and its relevance to seizure control in 19 patients with juvenile myoclonic epilepsy (JME).
Methods:   We analyzed the first cycle of non-REM (rapid eye movement) sleep in 22 sleep-deprived electroencephalography (EEG) studies and classified EDs within the cyclical alternating pattern (CAP) frame, grouping separately the EDs that occurred at the transition between phases (B to A and A to B).
Results:   Within CAP periods, 36.7% of EDs occurred in A phase, 26.7% in B phase, 31.5% at "B to A" transition, and 3% at "A to B" transition. Poor seizure control was strongly associated with increased EDs in phase B (p = 0.0016) and at the "B to A" transition (p = 0.002), but marginally with increased EDs in phase A (p = 0.03). Focal spikes were increased in phase B.
Discussion:   EDs are facilitated by increased vigilance (A phase), but they may also enhance CAP cycling by generating A phases when those that occur at the "B to A" transition are interpreted as successfully breaking through the state of reduced arousal (phase B) because of increased epileptic pressure. This promotes sleep instability and further fosters epileptic activity, and conceivably seizures. This hypothesis is also supported by the strong correlation between EDs during phase B (including "B" and "B to A") and poor seizure control. The enhanced nonlocalizing focal spikes in phase B may reflect successful inhibition of generalized EDs.     

Extradural application of bismuth iodoform paraffin paste causing relapsing bismuth encephalopathy: a case report with CT and MRI studies.

Bismuth iodoform paraffin paste (BIPP) is used in dressings in ear, nose, and throat, dental, and neurosurgical practice. Neurotoxicity due to absorption of bismuth from the BIPP pack is rare. It is preventable and reversible but likely to be fatal if unrecognised. A case of relapsing but reversible toxic encephalopathy due to a large extradural BIPP pack is reported in a 57 year old Caucasian woman, operated on for a huge basal cell carcinoma of the vertex invading the skull and extradural space. Clinical, neuroradiological (CT and MRI), and biochemical studies are presented and discussed in the light of the available literature.     

Star fruit (Averrhoa carambola) toxic encephalopathy

Ingestion of star fruit (Averrhoa carambola) can induce severe intoxication in subjects with chronic renal failure. Oxalate plays a key role in the neurotoxicity of star fruit. We report the cases of two patients with unknown chronic renal insufficiency who developed severe encephalopathy after ingestion of star fruit. The two patients developed intractable hiccups, vomiting, impaired consciousness and status epilepticus. Diffusion-weighted MR imaging showed cortical and thalamic hyperintense lesions related to epileptic status. They improved after being submitted to continuous hemofiltration which constitutes the most effective treatment during the acute phase.