The diagnostic accuracy of CSF analyses in stroke

Diagnostic and therapeutic approach to adult central nervous system vasculitis

The clinical manifestations of central nervous system (CNS) vasculitis are highly variable. In the absence of a positive CNS biopsy, CNS vasculitis is particularly suspected when markers of both vascular disease and inflammation are present. To facilitate the clinical and therapeutic approach to this rare condition, CNS vasculitis can be classified according to the size of the involved vessels. Vascular imaging is used to identify medium vessel disease. Small vessel disease can only be diagnosed with a CNS biopsy. Medium vessel vasculitis usually presents with focal neurological signs, while small vessel vasculitis more often leads to cognitive deficits, altered level of consciousness and seizures. Markers of CNS inflammation include cerebrospinal fluid pleocytosis or elevated protein levels, and vessel wall, parenchymal or leptomeningeal enhancement. The broad range of differential diagnoses of CNS vasculitis can be narrowed based on the disease subtype. Common mimickers of medium vessel vasculitis include intracranial atherosclerosis and reversible cerebral vasoconstriction syndrome. The diagnostic workup aims to answer two questions: is the neurological presentation secondary to a vasculitic process, and if so, is the vasculitis primary (i.e., primary angiitis of the CNS) or secondary (e.g., to a systemic vasculitis, connective tissue disorder, infection, malignancy or drug use)? In primary angiitis of the CNS, glucocorticoids and cyclophosphamide are most often used for induction therapy, but rituximab may be an alternative. Based on the available evidence, all patients should receive maintenance immunosuppression. A multidisciplinary approach is necessary to ensure an accurate and timely diagnosis and to improve outcomes for patients with this potentially devastating condition.

Cerebrospinal Fluid Pleocytosis in Critical Care Patients With Seizures

OBJECTIVES

To assess the etiology of cerebrospinal fluid (CSF) pleocytosis in critical care patients with seizure(s) or status epilepticus (SE). Many previous studies, some performed decades ago, concluded that CSF pleocytosis may be entirely attributable to seizure activity.

METHODS

We undertook a retrospective chart review of adult patients with an admitting or acquired diagnosis of seizure(s) or SE in critical care units at the Winnipeg Health Sciences Centre between 2009 and 2012. Patients were identified through a critical care information database at a tertiary care center. We limited our study to patients who had lumbar punctures at our center within 5 days of seizure(s) or SE.

RESULTS

Of 426 patients with seizures in critical care units, 51 met the inclusion criteria. Seizure subtypes included focal seizures (5 or 10%), generalized seizures (14 or 27%), and SE (32 or 63%). Twelve (seven with SE) of the 51 (24%) were found to have CSF pleocytosis. A probable etiological cause for the CSF pleocytosis was identified in all 12 cases.

CONCLUSIONS

We conclude that seizures do not directly induce a CSF pleocytosis. Instead, the CSF pleocytosis more likely reflects the underlying acute or chronic brain process responsible for the seizure(s). This was not readily apparent in early studies without magnetic resonance imaging (MRI) of the brain and currently available laboratory investigations. An etiological cause of CSF pleocytosis must always be sought when patients present with seizures and it should never be assumed that seizures are the cause.

Differential diagnostic yield of lumbar puncture in investigation of suspected subarachnoid haemorrhage: a retrospective study

The diagnostic algorithm of computerized tomography (CT) and lumbar puncture (LP) for suspected subarachnoid haemorrhage (SAH) has lately been challenged by the advancement of radiological techniques, such as higher resolution offered by newer generation CT-scanners and increased availability of CT-angiography. A purely radiological workup of suspected SAH offers great advantages for both patients and the health care system, but the risks of abandoning LP in this setting are not well investigated. We have characterized the differential diagnostic yield of LP in the investigation of suspected SAH by a retrospective study. From the hospital laboratory database, we analyzed the medical records of all patients who had undergone CSF-analysis in search of subarachnoid bleeding during 2009-2011. A total of 453 patients were included. In 14 patients (3%) the LP resulted in an alternative diagnosis, the most common being aseptic meningitis. Two patients (0.5%) received treatment for herpes meningitis. Five patients (1%) with subarachnoid haemorrhages were identified. Among these, the four patients presenting with thunderclap headache had non-aneurysmal bleedings and did not require surgical intervention. We conclude that the differential diagnostic yield of LP in investigation of suspected SAH is low, which indicates that alternative diagnoses is not a reason to keep LP in the workup when a purely radiological strategy has been validated. However, algorithms should be developed to increase the recognition of aseptic meningitis. One hundred and fifty-three patients (34%) were admitted to undergo LP, which estimates the number of hospital beds that might be made available by a radiological diagnostic algorithm.

Diagnosing Suspected Stroke: A Cost-Effectiveness Analysis

Acute cerebrovascular disease (CBVD) has an annual incidence of 100–300 per 100,000 inhabitants in the industrialized countries (1,2). CBVD occurs mainly in the elderly. Acute mortality is around 15%. Disablement and decreased quality of life are common consequences. Institutionalized care will be needed after the acute phase for around one-third of the patients (3). Considering the volume of patients and the growing proportion of elderly persons in most countries, stroke poses a major problem for health care. An effective diagnostic work-up as the base for therapy to improve the situation is, therefore, a matter of great public concern, for humanitarian as well as economic reasons.

Evaluation of long-term outcome and safety after hemodilution therapy in acute ischemic stroke

BACKGROUND AND PURPOSE

In a previous single-center, randomized controlled trial including 102 patients treated in a stroke unit, we showed that rapid, modest hemodilution improved short-term clinical outcome in ischemic stroke patients. I now evaluate the long-term outcome and potential risks of this combined venesection/dextran 40 therapy in the same 52 treated and 50 control patients.

METHODS

Mortality, need for institutional care, and recurrent strokes were registered during 1 year following inclusion in the trial, and a final evaluation of functional outcome was performed at 12 months after the stroke. Cerebrospinal fluid was analyzed for protein content and hemorrhagic admixture at two occasions during the acute phase.

RESULTS

Thirty-six hemodiluted and 30 control patients survived the first year following the stroke (difference not significant). One year after the stroke, persistent neurological deficits were less frequent among the hemodiluted patients and a larger proportion of hemodiluted survivors was independent in walking (92% versus 73%, p less than 0.05). Two hemodiluted patients (6%) and nine control patients (30%) were totally dependent in the activities of daily living (p less than 0.05). Three hemodiluted patients (8%) and eight control patients (27%) remained hospitalized 1 year after the stroke (p less than 0.05). With the possible exception of patients with a medical history of congestive heart failure, subset analyses revealed a tendency toward improved outcome for hemodiluted patients in all clinically important subgroups compared with the controls. When analyzing cerebrospinal fluid, signs of blood-brain barrier breakdown and hemorrhagic admixture to the cerebrospinal fluid during the acute phase were less frequent in the hemodiluted subjects.

CONCLUSIONS

These results suggest that, when applied in a stroke unit, the combination of venesection and dextran 40 administration is a clinically safe, therapeutic regimen in the treatment of acute cerebral infarction that improves long-term clinical outcome.

Investigation of acute stroke: what is the most effective strategy?

Techniques of investigation of acute stroke syndromes have progressed rapidly in recent years, outpacing developments in effective stroke treatment. The clinician is thus faced with a variety of tests, each with different cost implications and each altering management to a greater or lesser extent. This review will concentrate on the basic tests which should be performed for all strokes (full blood count, ESR, biochemical screen, blood glucose, cholesterol, syphilis serology, chest X-ray and electrocardiogram). Additional tests may be required in selected cases: CT scan to diagnose 'non-stroke' lesions, to exclude cerebral haemorrhage if anti-haemostatic therapy is planned, and to detect strokes which may require emergency intervention (such as cerebellar stroke with hydrocephalus); echocardiography to detect cardiac sources of emboli; and in a few cases lumbar puncture and specialized haematological tests. Other tests, which are currently research tools, may be suitable for widespread use in the future including NMR, SPECT and PET scanning.

[Cerebrospinal fluid in cerebrovascular disorders. Study of 1500 cases]

In order to evaluate information on acute stroke through the study of cerebrospinal fluid (CSF) data em 1500 patients were analysed in the first 48 hours following stroke. Cases were distributed in three groups according to CSF basic findings: type 1, CSF without erythrocytes and without xanthochromia; type 2, CSF without erythrocytes and with xanthochromia; type 3, CSF with erythrocytes and with xanthochromia. Data on each type are discussed as well as correlation findings. Systemic metabolic disturbances, blood-brain barrier impairment and central nervous system lesions are discussed as to the role they have in CSF changes observed in stroke. Indication of CSF exam in stroke is reviewed taking into account progress in neuroimaging techniques.

Clinical diagnosis of intracranial haemorrhage using Guy's Hospital score

We tested the Guy's Hospital stroke diagnostic score using the clinical data from two independent samples of patients with acute stroke. These were 228 patients from the Oxfordshire community stroke project and 130 referred to the National Hospital for Nervous Diseases in London. The diagnosis was confirmed by computed tomography or necropsy in each case. The optimum cut off point on the clinical score for the differentiation of intracranial haemorrhage from infarction was found to be the same for both the patients in our study and those from whose data the score was derived originally. Set at this level, the score achieved a sensitivity for the diagnosis of haemorrhage of 81% and 88% in the patients from Oxford and London, respectively. In those from Oxford infarction was diagnosed with a sensitivity of 78% with an overall predictive accuracy of 78% with an overall London the sensitivity for infarction was also 78% with an overall predictive accuracy of 82%. When it is essential to exclude intracerebral blood before starting treatment in the small proportion of patients with stroke who require anticoagulation the Guy's Hospital score is not sufficiently accurate to replace computed tomography. The score is, however, the most accurate clinical means of differentiating haemorrhage from infarction as the cause of stroke. It is suggested that it should be used as a screening test in epidemiological studies and in large scale trials of low risk treatment for the secondary prevention of stroke when computed tomography in all cases is impracticable.

Non-rheumatic atrial fibrillation as a risk factor for stroke

The association between non-rheumatic atrial fibrillation (AF) and stroke has been studied in 402 patients consecutively admitted to a stroke unit. Brain infarction patients with sinus rhythm (n = 196) and non-rheumatic AF (n = 92) were further compared. Some findings supported an embolic origin of the stroke: half of the deceased AF patients (n = 24) at autopsy either had left atrial thrombosis or arterial embolism compared to none of the ten with sinus rhythm. Patients with AF also had a higher mortality and more severe brain lesions, findings compatible with a sudden occlusion of blood flow. However, these differences might also be explained by an atherothrombotic occlusion with impaired autoregulation in the ischaemic region in conjunction with heart failure, which was more common in the AF patients. Other findings supporting an atherothrombotic mechanism were: the prevalence of AF was higher (19-29%) in all kinds of stroke, including haemorrhage, than in age-matched controls (3-9%). Also patients with previous AF and no present embolic source resembled the whole AF group and differed from patients with sinus rhythm. Thus embolism is a plausible cause of stroke in many AF patients, whereas an atherothrombotic origin is more likely in others. Characteristics identifying the mechanism in an individual case were not found.