Clinical EEG (electroencephalography)最新文献

This paper deals with a patient with the Frontal Arousal Rhythm (FAR), a rare rhythmic pattern usually seen in young children awakening from sleep, with a history of seizures. In this patient, subtle clinical changes were observed on the video during the pattern, consisting of a sequence of brief eye lid flutter, chewing, increased inspiration and upper lip quivering. This exact sequence was seen on three successive occasions lasting for 6,9, and 10 sec. The conclusion is the FAR is not just a sign of seizure disorder, but is actually an ictal pattern.

Benign neonatal sleep myoclonus (BNSM), characterized by myoclonic jerks of the extremities only in non-REM sleep, occurs in the first months of life with spontaneous disappearance within 3-4 months. We examined five siblings with typical BNSM, at the 3-10 years follow-up neurological examination. Psychomotor development, cognitive functions and EEG were completely normal. These cases confirm that BNSM is a self limited and nonepileptic disorder.

A simultaneous video-EEG on a waking 6-year-old male revealed rapid horizontal and then vertical eye movements and 10 sec later showed ictal rhythms maximal on the occipital areas, quickly spreading to all other areas. A second ictal event during wakefulness was very similar to the first. During sleep interictal discharges were seen from the right frontal-temporal area and one more ictal event was noted. This latter seizure in the NREM sleep record did not show any eye movements, but showed ictal activity on the right frontal-temporal area, which later became generalized. We propose that the interictal discharges on the right frontal-temporal area likely arose from the amygdala, which activated the pontine nuclei responsible for PGO (ponto-geniculo-occipital) spikes and the rapid eye movements seen in our patient. The PGO spikes activated the occipital areas, which then showed clear ictal rhythms to complete the sequence of events. This case demonstrates a sequence of rapid eye movements without ictal patterns, followed by seizure rhythms, but may still be an example of "epileptic nystagmus," assuming that the eye movements arose from an ictal activation of the deep subcortical portion of the PGO system.

The goal of this study was to assess the spikes systematically and to clarify an epileptc abnormality induced by electroconvulsive therapy (ECT). Our subjects were 20 psychotic patients with no spikes on prior EEGs. ECT was performed by applying electrical current to both sides of the patient's temple every 2 or 3 days for a period of between 1-4 weeks. The first EEG examination was performed either on the day that the ECT course was completed or on the following day. Subsequent EEG examinations were performed at intervals of 2 or 3 days. Thirteen of the 20 patients showed spikes. There were no significant differences in age, gender, diagnosis, or type of ECT. Patients with spikes had significantly more ECT sessions than those without spikes. The spikes were present in the frontal, temporal and central areas, predominantly frontal, anterior temporal and mid-temporal region, and almost disappeared in 1-3 weeks. The occurrence of spikes immediately after ECT was demonstrated. Although this abnormality was transient, it could indicate that in humans ECT causes the early stage of kindling phenomenon as a result of repeated application, and that the temporal lobe seems to play a major role in order to induce the phenomenon.

A 58-year-old patient who was somnolent, distractible and confused is presented. She was previously treated with lithium, and a plasma level was mildly elevated at 1.7 mmol/l (normal 0.5-1.5 mmol/l). The EEG was suggestive of electrographic status epilepticus. Following treatment with i.v. lorazepam, neither mental status nor EEG abnormalities improved. She had a full recovery of mental function and markedly improved EEG findings following discontinuation of lithium. The EEG is an effective tool for diagnosing lithium neurotoxicity in patients with normal or mildly elevated lithium plasma levels. However, caution is needed before making an assumption of status epilepticus.

This study investigated the relationship between slow waves and sharp waves (spikes) and also clinical seizures in 255 patients with 694 EEGs over a 25-yr period. Slow waves were quantified into five groups, sharp waves into three groups and clinical seizures also into three groups. In general, as clinical seizures increased, the number of patients with many discharges increased and the number with only rare discharges decreased. Also, as patients became seizure free, there was a decreasing incidence of many sharp waves and an increasing incidence of only rare sharp waves. No relationships could be found in patients with a typical number of discharges or a steady number of seizures. Thus, a relationship between sharp waves and seizures was found mainly when there were changes in these variables. For sharp and slow waves, rare discharges were most often associated with mild slowing, while many discharges were most often related to a marked degree of slow wave abnormality. The combination of slow and sharp waves together, compared with only one type of EEG abnormality, was associated with more clinical neurological symptoms, especially a mental status change. The EEG groups were divided into four types of findings of slow and sharp waves, appearing in at least a first and/or second record. The results from these four EEG groups allow for a prediction of the findings to be found in a second record, based on the results of the first EEG. In general, there was a relationship between more slow waves, more sharp waves and more seizures. Also minimal slowing and rare discharges on the first record tended to disappear in the next EEG.

Carbamazepine has been reported to exacerbate seizures in children with primary generalized epilepsy and epilepsy with mixed seizure types. Seizure exacerbation has been rarely observed in adults, mainly in the mentally retarded or in those with primary generalized epilepsy. We present an adult patient who had frequent absence seizures and simple partial seizures for 20 years. She was treated with carbamazepine for over 16 years. The patient's EEG showed generalized spike and wave complexes. Her seizures remitted and the EEG normalized after the discontinuation of carbamazepine therapy.

The pathophysiological relation between periodic lateralized epileptiform discharges (PLEDs) and epileptic seizures is not known and the exact causative mechanism of PLEDs still remains unclear. In this report, the authors present a case in which the EEG displayed PLEDs after a complex partial seizure. This patient, with a long history of complex partial seizures, had previously undergone right standard anterior temporal lobectomy with hippocampectomy, with a diagnosis of mesial temporal sclerosis. She had one complex partial seizure 72 days after operation and was admitted to hospital. Her brain MRI revealed changes due to temporal lobectomy and small residual posterior hippocampic anomalies. PLEDs over the right temporal lobe were seen in postictal EEGs and persisted for 4 days despite the patient's normal mental status and normal neurologic examination. Brain perfusion scintigraphy with Tc-99m-HMPAO during PLEDs was performed on the second day after the seizure, and right temporal hyperperfusion was detected. EEGs and scintigraphic imaging were repeated after cessation of PLEDs. The repeated brain scan displayed right temporal hypoperfusion. PLEDs during the postictal period may actually be an ictal pattern, and if hyperperfusion in the brain SPECT studies during PLEDs is seen, further aggressive antiepileptic drug therapy may be necessary in some cases.

The study of the early history of electroencephalography can yield fascinating insights and surprises. A revisit to the work of Mario Gozzano (1898-1986) has proved to be particularly stimulating. His EEG study of 1935 is a classic and should be resurrected from the graveyard of history. Gozzano was an eminent clinical neurologist-epileptologist and chairman of the neurological-psychiatric university departments in Cagliari, Pisa, Bologna and, from 1951 to his retirement, in Rome. He quickly recognized the significance of EEG and produced his major experimental EEG work in the wake of a stay at the Berlin-Buch Brain Institute. His prolonged corticograms of various regions in the rabbit demonstrated striking differences between various cortical areas. Topical cortical strychnine produced spikes (a barely known phenomenon at that time) and the evolution from interictal to ictal spiking. Spikes induced by visual stimuli may be regarded as precursors of evoked potentials. While Hans Berger was a holist ("the brain working as a whole"), Gozzano (influenced by Vogt and Kornmueller) provided EEG support for the localizationists.