Journal of neurology, neurosurgery, and psychiatry
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J. Neurol. Neurosurg. Psychiatr. · Jul 1992
Cerebral blood flow, arteriovenous oxygen difference, and outcome in head injured patients.
Cerebral blood flow (CBF) and other physiological variables were measured repeatedly for up to 10 days after severe head injury in 102 patients, and CBF levels were related to outcome. Twenty five of the patients had a reduced CBF [mean (SD) 0.29 (0.05) ml/g/min]; 47 had a normal CBF, (0.41 (0.10) ml/g/min); and 30 had a raised CBF (0.62 (0.14) ml/g/min). Cerebral arteriovenous oxygen differences were inversely related to CBF and averaged 2.1 (0.7) mumol/ml in the group with reduced CBF, 1.9 (0.5) mumol/ml in the group with normal CBF, and 1.6 (0.4) mumol/ml in the group with raised CBF. ⋯ Systemic factors did not significantly contribute to the differences in CBF among the three groups. A logistic regression model of the effect of CBF on neurological outcome was developed. When adjusted for variables which were found to be significant confounders, including age, initial Glasgow Coma Score, haemoglobin concentration, cerebral perfusion pressure and cerebral metabolic rate of oxygen, a reduced CBF remained significantly associated with an unfavourable neurological outcome.
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J. Neurol. Neurosurg. Psychiatr. · Jun 1992
Motor and somatosensory evoked potentials in coma: analysis and relation to clinical status and outcome.
Central sensory and motor conduction were studied in 23 comatose and three brain-dead patients. Motor evoked potentials (MEPs) to transcranial magnetic (magMEP) and electrical (elMEP) stimulation were recorded from the hypothenar muscle, and somatosensory evoked potentials (SEPs) were recorded after median nerve stimulation. Comparison of clinical with evoked potential (EP) findings revealed: 1) a painful stimulus applied to the skin of the arm lowered excitation threshold to cortical stimulation and was a prerequisite to obtain MEPs in 14 instances; 2) only in braindead patients were all EPs abolished simultaneously and bilaterally; 3) MEPs (p less than or equal to 0.05, chi 2-Test), but not necessarily SEPs (p greater than 0.1) were preserved in the arms that showed normal motor reaction during clinical examination; 4) no correlation was found between EP findings and the Glasgow Coma Scale (GCS). The results of clinical and EP testing were examined in the light of the patient's outcome 10 months later: 1) fatal outcome was predicted by a GCS of three (38% of cases, p less than or equal to 0.05, Fisher's exact test), abolished brainstem- or papillary reflexes (38%, p less than or equal to 0.05), the combination of these clinical signs (54%, p less than or equal to 0.01), bilateral abolition of elMEPs (38%, p less than or equal to 0.05), magMEPs (38%, p less than or equal to 0.05), or SEPs (23%, p greater than 0.1), or a combination of clinical and EP data (85%, p less than or equal to 0.0005); 2) good outcome was predicted by a GCS of greater than or equal to 8 only in post-traumatic coma, and EPs did not help to predict fatal outcome of coma; 1) if this appears impossible on the basis of clinical data alone; 2) if a second indicator is needed to confirm a clinical impression; 3) SEPs may be first evaluated during the acute stage of coma treatment, because they can be recorded in the presence of anaesthetic or relaxant agents; 4) MEP may be studied if outcome prediction remains ambiguous, and if the clinical situation allows for discontinuation of these agents.
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J. Neurol. Neurosurg. Psychiatr. · May 1992
Case ReportsAcute polyneuropathy due to lightning injury.
The case of a 19 year old man struck by lightning is described. He sustained quadriplegia for several months and fully recovered. ⋯ In addition, he displayed many well recognised medical complications of lightning injury including acute renal failure, rhabdomyolysis, respiratory distress syndrome, autonomic dysfunction, perforated ear drum, uveitis and cataract. The literature relating to the neurology of lightning strike is briefly reviewed.
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Mechanisms of pain relief induced by vibration and movement were investigated. A CO2 laser beam, which is useful for pure nociceptive stimulation, was used for recording pain-related somatosensory evoked potentials (pain SEPs) and for measuring pain threshold and reaction time (RT). ⋯ In contrast, continuous cooling enhanced pain SEPs and decreased pain threshold, probably due to the spatial summation of two kinds of nociceptive impulses mediated by the same pathways. The results of this investigation throw light on the mechanisms of the alleviation of pain by vibration and movement.