INTRODUCTION: The relation between subjective sleep quality and the stages of polysomnography is unclear. Computerized sleep analysis provides a reliable tool for the study of sleep dynamics. OBJECTIVE: To study the relation between subjective sleep quality and spectral EEG parameters during nocturnal sleep. MATERIAL AND METHODS: Nocturnal sleep were recorded ambulatory in 26 subjects aged from 8 to 63. The following variables were extracted from EEG signal (Fz-Pz) quantified through the Fast Fourier Transformation (FFT): delta maximum, spectral peak, delta sleep time, efficiency and desynchronized sleep. A sleep diary was administered in the morning to assess the subjective sleep quality. Multiple regression and Anova were used for statistical analysis. RESULTS: Efficiency and delta maximum became significant predictors accounting for 54% of subjective sleep variance. The item 'how was your sleep?' was answered in a different way according to the delta maximum. CONCLUSIONS: Sleep depth, measured by spectral analysis, is an important predictor of the subjective sleep quality. The sleep classification in discrete stages ignores this feature.

Adolescent↗

PubMedDate not supplied

[Severe polyneuropathy after using nitrous oxide as an anesthetic. A preventable disease?].

INTRODUCTION: Nitrous oxide is a commonly used anaesthetic agent. One complication of this is due to its capacity to inactivate cobalamin. Therefore, in patients with poor reserves of vitamin B12, neurological and hematological alterations may be induced after a short period of exposure to nitrous oxide. CLINICAL CASE: A 69 year old man was anesthetized for three hours with 50% nitrous oxide during a surgical operation. Two weeks later he complained of severe mixed, mainly sensory polyneuropathy and was unable to walk. On diagnostic studies, vitamin B12 levels were found to be 18 pg/ml. The Shilling test confirmed that there was lack of intrinsic factor. In the preoperative studies a striking increase in motor conduction velocity was observed. Neurophysiological studies showed that there was mixed polyneuropathy, predominantly axonal. After starting treatment with hydroxycobalamin there was marked improvement and the patient became able to walk unaided. CONCLUSION: Since nitrous oxide may cause serious neurological alterations in patients with subclinical deficits of cobalamin, which may not always be accompanied by hematological changes, we consider the need for determination of plasma levels of vitamin B12 and if possible, of methylmalonic acid and homocysteine in elderly patients who are to have general anesthetics involving nitrous oxide.

Aged↗

PubMedDate not supplied

[P300 and auditory information processing during natural sleep].

INTRODUCTION: The P300 is elicited, in the waking state and during an 'attention condition', in response to deviant stimuli of an oddball paradigm. This component of event related potentials (ERP) may be a useful research tool in the assessing of cortical sensory processing during normal sleep since a subject does not need to be awake or totally conscious in order to generate a measurable response. OBJECTIVE: This study used an classical oddball paradigm as a means to assess the auditory information processing during sleep. PATIENTS AND METHODS: The auditory ERP were registered in twelve healthy volunteers during the waking state and sleep stages II, III-IV and REM. The amplitude, latency and scalp distribution parameters of the positivity observed were contrasted with the results obtained in the waking state. RESULTS: A 'P300-like' with a significantly smaller peak amplitude and an increment of latency was elicited during stage II and the REM stage of sleep. As in the waking state, the positivity during this sleep stages was maximal at central-parietal regions. CONCLUSIONS: The response obtained seems to correspond both for the morphology of the potential as for the centro-parietal predominance with a waking P3b component. These results suggest that certain processes of attention and memory-related operations involved in the auditory processing of simple signals remain operative during these sleep stages.

Adult↗

PubMedDate not supplied

IFNalpha 2b induces apoptosis and proteasome-mediated degradation of p27Kip1 in a human lung cancer cell line.

IFNs are a family of cytokines involved in antiviral defense, cell growth regulation and immune activation. IFNs either inhibit cell proliferation or control apoptosis depending on factors such as cell type and state of cell differentiation. It is important to determine how IFN-induced gene products interact with other cellular proteins to produce these responses. We have investigated the effect of IFNalpha 2b on a human small cell lung carcinoma (SCLC) cell line H82. We have found that IFNalpha efficiently induces apoptosis in H82 cells. The induction of apoptosis by IFNalpha 2b is accompanied by decreased levels of c-myc and Cdk2. We have also observed that in H82 cells IFNalpha induces downregulation of p27 and this is in contrast to the upregulation of p27 observed in other cell types where IFNs induce cell cycle arrest. IFNalpha-induced downregulation of p27 is due to protein destabilization and can be prevented by the proteasome inhibitor LLnL. The data suggest that in H82 cells, IFNalpha 2b induces degradation of p27Kip1 independently of CDK2 kinase activity and through a ubiquitin or ubiquitin-related pathway and that the degradation of p27Kip1 could be a molecular event of importance for IFN-induced apoptosis in cancer cells.

Apoptosis↗

PubMedDate not supplied

[Demyelinating pseudotumoral lesion prior to a primary cerebral lymphoma].

INTRODUCTION: Some case of demyelinating pseudotumoral lesions preceding the appearance of primary cerebral lymphoma have been reported. The relation between the two conditions is not known. We report the case of a woman in whom a demyelinating pseudotumoral lesion had been diagnosed on biopsy and who developed a primary cerebral lymphoma 13 months later. CLINICAL CASE: In October 1997 a 38 year old woman presented with a secondarily generalized focal motor seizure. Neuroimaging showed a left frontal tumour with marked oedema and uptake of contrast medium. Based on the clinicoradiological suspicion of a primary cerebral tumour or metastasis, treatment was started with dexamethasone. Approximately two weeks later a stereotaxic biopsy was done, in which there was demyelination with conservation of the axons and perivascular inflammatory infiltration with polyclonal T and B lymphocytes. The diagnosis was 'a pseudotumoral form of a demyelinating disease'. Thirteen months later the patient had episodes of falling to the floor, followed by subsequent slight confusion and difficulty in speaking. On neuroimaging studies (cerebral CAT and MR) there was a tumour of the left basal ganglia, considerable oedema and homogeneous marking following the injection of contrast. Anatomopathological study of the lesion showed a B cell lymphoma. CONCLUSION: In cases of pseudotumoral demyelinating lesions the possibility of a primary cerebral lymphoma of the central nervous system must be remembered.

Adult↗

PubMedDate not supplied

[Hypoxic encephalopathy and cortical laminar necrosis].

INTRODUCTION: Cortical laminar necrosis is characterized by destruction of the cerebral cortex, mainly of the third layer, in situations of reduced energy supply to the brain. The cerebral lesions caused are known through studies made at autopsies, but there are few descriptions in the literature of the neuroimaging changes. We report the case of a patient who suffered hypoxic encephalopathy secondary to prolonged status epilepticus, and in whom cerebral MR showed changes compatible with cortical laminar necrosis. CLINICAL CASE: A 16 year old girl who had been epileptic since infancy presented with a state of generalized tonic-clonic convulsions followed by coma. Three weeks later she was mute, had a blink reflect to threats and followed visual stimuli with eye movements but no voluntary motor or verbal response. She also showed generalized hypertonia and fine tremor of her arms, which she moved spontaneously with no asymmetry. After two months her clinical condition became stable. Cerebral MR at this time showed diffuse hypersignal of the cortex and basal ganglia in T2 and FLAIR sequences and hyposignal of the subcortical white matter associated with a marked hypersignal delimiting the grooves of convexity in T1 sequences. CONCLUSIONS: Situations of prolonged hypoxia, such as in status epilepticus, lead to necrosis of layers of the cerebral cortex. Clinically this is seen as the appearance of hypoxic encephalopathy and radiologically as characteristic alterations of neuroimaging known as cortical laminar necrosis.

Basal Ganglia↗

PubMedDate not supplied

[Multiple intracranial tuberculomas in infancy].

INTRODUCTION: Tuberculous involvement of the CNS is most frequent in children aged between 6 months and 6 years, although it may occur at any age. It may present as meningoencephalitis, basal arachnoiditis or intracranial tuberculomas. Whilst meningitis is typical of infancy, tuberculomas and arachnoiditis are commoner in adults. It has been estimated that tuberculomas make up 3% of the cases of neurotuberculosis. The increasing use of CAT and MR has been a great help for diagnosis of this serious complication of tuberculosis. CLINICAL CASE: A 5 month old patient presented with tuberculous meningitis which had been treated with streptomycin, isoniazid, pyrazinamide and rifampicin at the usual dosage. One month later, after good initial progress, triventricular hydrocephaly was diagnosed and a ventriculoperitoneal shunt inserted. Three months after this, there was an episode of intracranial hypertension. Cranial CAT showed considerable zones of hypodense parenchyma without ventricle dilatation. On MR there were multiple, disseminated, rounded areas which were hyperintense on T2 and compatible with intracranial tuberculomas. After fresh insertion of a ventricular shunt, the patient progressed but still had a residual right hemiparesia and retarded development. CONCLUSIONS: Although intracranial tuberculomas usually occur in adults, they may be seen in children following meningoencephalitis. Occasionally, following a good initial response to tuberculostatic drugs, tuberculomas appear, although not present before, as happened in our patient. This usually occurs within the first three months, and although the mechanism is unknown, it is believed to be due to the accumulation of lymphocytes and macrophages at preexisting microscopic foci when treatment is started.

Female↗

PubMedDate not supplied