Raised ICP in a child with cryptococcal meningitis: CT evidence of a distal CSF block

Raised intracranial pressure (ICP) often complicates the course of cryptococcal meningitis. The pathogenesis of the severely raised cerebrospinal fluid (CSF) pressure commonly associated with this condition is largely unexplained, because the majority of patients have normal cranial computed tomographic (CT) findings when diagnosed. We report a case of cryptococcal meningitis in a child who had severely raised CSF pressure on admission, and in whom repeated CT scanning showed progressive enlargement of the subarachnoid space and ventricular system during the course of treatment. The normalization of these spaces after ventriculoperitoneal (VP) shunting suggests a distal CSF block as the cause of the raised ICP in this patient. The CSF pressure was monitored and treatment with oral acetazolamide and furosemide resulted in a definite, but slow and incomplete lowering of ICP. Intrathecal therapy with hyaluronidase had no beneficial effect on either ICP or the degree of visual loss.     

Clinical correlation of CT changes in 64 Chinese patients with tuberculous meningitis

Summary CT changes in 64 Chinese patients with proven tuberculous meningitis were compared with the clinical features at diagnosis. In patients presenting with advanced disease, hydrocephalus and cerebral infarction were common, and the hydrocephalus in these patients was more likely to require surgery at a later date for control of raised intracranial pressure. New infarctions were only seen in follow-up scans of patients who had presented with disturbed consciousness. Meningeal enhancement, the commonest finding, and intracranial tuberculomata were not related to the severity of disease at presentation. A normal scan in a drowsy patient virtually excludes the diagnosis of tuberculous meningitis. Present address: MRI Centre. Churchill Clinic, London SE1 7PW. UK     

Clinical features, complications, and outcome in adults with pneumococcal meningitis: a prospective case series

BACKGROUND: Bacterial meningitis is a grave disease of high incidence, especially in less developed countries. Here, we describe its clinical presentation, spectrum of complications, prognostic factors, and outcome in adults with pneumococcal meningitis. METHODS: From October, 1998, to April, 2002, we assessed 352 episodes of community-acquired pneumococcal meningitis, confirmed by culture of cerebrospinal fluid (CSF), which occurred in patients older than 16 years. Predictors for an unfavourable outcome (Glasgow outcome scale score 1-4) were identified by logistic regression with multiple imputation techniques. FINDINGS: 245 (70%) episodes of pneumococcal meningitis were associated with an underlying disorder. Cranial CT was done for 85% of episodes and revealed underlying disorders in 17% (50/299) and meningitis-associated intracranial complications in 39% (117/299). Independent predictors for an unfavourable outcome were a low score on the Glasgow coma scale, cranial nerve palsies, a raised erythrocyte sedimentation rate, a CSF leucocyte count less than 1000 cells per mm(3), and a high CSF protein concentration on admission. Overall in-hospital mortality was 30%. Prevalence of neurological and systemic complications did not differ between patients aged younger than 60 years and those aged 60 years and older; however, systemic complications were the cause of death in 59% (32/54) of fatal episodes in patients aged 60 years and older, whereas neurological complications were the cause of death in 65% (20/31) of fatal episodes in younger patients. INTERPRETATION: Pneumococcal meningitis is associated with high mortality and morbidity rates in adults. Whereas neurological complications are the leading cause of death in younger patients, elderly patients die predominantly from systemic complications.     

Anti ICAM-1 (CD 54) monoclonal antibody reduces inflammatory changes in experimental bacterial meningitis

We investigated whether monoclonal antibodies directed against intracellular adhesion molecule 1 (ICAM-1 mAb) inhibit brain edema, increase of intracranial pressure (ICP), regional cerebral blood flow (rCBF) and recruitment of white blood cells (WBC) into the cerebrospinal fluid (CSF) in the rat model of the early phase of bacterial meningitis. Brain edema was assessed by brain water content determinations. rCBF measured by laser Doppler flowmetry and ICP were recorded continuously for 6 h after intracisternal challenge. Meningitis was induced with pneumococcal cell walls (PCW). Increase of ICP and brain water content were significantly inhibited (P < 0.05) by intravenous treatment with ICAM-1 mAb (TM-8, 1 mg/kg). Furthermore, ICAM-1 mAb treatment profoundly attenuated (P < 0.05) rCBF increase and WBC invasion into the CSF. These results suggest that the ICAM-1 pathway is critically involved in the early phase of bacterial meningitis.     

Mild cognitive impairment after viral meningitis in adults

Objective To evaluate cognitive outcome in unselected patients with previously diagnosed viral meningitis. Methods Twenty-one unselected patients were examined neurologically, psychiatrically, and psychometrically 25±12 months after the acute stage of viral meningitis. The results were compared with the results of twenty-one healthy controls. Results Despite of a very good clinical outcome in the post-meningitis group patients performed significantly worse on tasks concerning non-verbal memory functions (BVRT), attention and speed of cognitive performance (WMS-3) even when there was no sign of parenchymal involvement. Forty percent of the patients were categorised as suffering from mild to moderate cognitive impairment. Conclusions Viral meningitis in adults results in mild cognitive impairment in a significant proportion of patients that is not identified by clinical examination or cognitive screening tests. Nevertheless, even mild deficits in non-verbal learning and cognitive speed might lead to overstrain and handicap in complex situations of daily living and working. We therefore recommend that the neuropsychiatric evaluation of all patients with intracranial infections include neuropsychological testing. Received: 8 April 2001, Received in revised form: 21 September 2001, Accepted: 8 October 2001     

Raised intracranial pressure,the syndrome of inappropriate antidiuretic hormone secretion,and arginine vasopressin in tuberculous meningitis

Intracranial pressure (ICP) monitored shortly after admission over a period of 1 h in 31 children with tuberculous meningitis (TBM) was significantly higher (median 22.5 mm Hg, range 8.4–50.9 mmHg) in 19 children with laboratory evidence of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) than in 12 children without such evidence (median 16.2 mmHg, range 5.8–42.5 mmHg; P = 0.027). Neither plasma nor cerebrospinal fluid arginine vasopressin (AVP) was related to ICP (r = 0.33 and 0.13 respectively). Mean arterial pressure (MAP) was measured in 23 children and a moderate correlation was found with plasma AVP (r = 0.62; P = 0.0019). In TBM, plasma AVP may be secreted as a response to raised ICP in an effort to raise MAP and maintain cerebral perfusion pressure. In this setting excess fluid may be inappropriately retained, leading to hyponatremia and hypo-osmolemia.     

Pediatric intracranial pressure monitoring in hypoxic and nonhypoxic brain injury

We reviewed the results of all pediatric patients undergoing intracranial pressure (ICP) monitoring in a 2-year period at our institution. The outcome of patients suffering hypoxia or ischemic injuries (HII) is compared to those suffering non-hypoxic or non-ischemic injuries (NHII). Thirty-four patients had ICP monitors placed during the study period. Inconplete patient information led to the exclusion of 5 patients. An additional 5 patients were excluded because no measures to control ICP were taken after the monitor was placed. Twenty-four patients required treatment for raised ICP (hyperventilation, 24; mannitol, 19; barbiturate coma, 6). Admission Glasgow Coma Score in patients suffering HII (median score 5) and NHII (median score 6) were not significantly different (Mann-Whitney U Test). Only 2 of 8 patients with HII were near-drowning vietims. The remaining 6 had HII from other causes (5 survivors of various forms of asphyxia and 1 of cardiac arrest). All 8 patients had poor outcomes (1 severely disabled; 7 died). The 16 patients with NHII had a variety of diagnoses (6 trauma, 5 encephalitis, 4 bacterial meningitis, 1 diabetic ketoacidosis). Among these, 6 had good outcomes and 10 poor outcomes (2 severely disabled, 2 vegetative, and 6 died). The difference in outcome between patients with NHII and HII is significant at P=0.059 (Fischer Exact test). Patients with NHII may benefit from ICP monitoring. Patients with HII from near-drowning and other causes did not appear to benefit from ICP monitoring and interventions directed at controlling ICP.     

Barbiturate therapy for patients with refractory intracranial hypertension following severe traumatic brain injury: its effects on tissue oxygenation, brain temperature and autoregulation.

The aim of this study was to explore the effects of barbiturate coma on cerebral tissue oxygen tension and cerebrovascular pressure reactivity (PRx), as an index of cerebral autoregulation in severe head injury patients. This was a prospective observational clinical study of 12 patients with severe traumatic brain injury, carried out at a tertiary-level neurosurgical intensive care unit between April 2002 and May 2005. All patients received standard neurosurgical intensive care and monitoring. Probes for intracranial pressure (ICP), brain temperature (BT) and brain tissue oxygenation (PTiO2) were inserted into (noncontused) normal-looking white matter. Cerebrovascular PRx was measured as a moving correlation between ICP and arterial blood pressure. Barbiturate coma was instituted when ICP became refractory (ICP>20 mmHg). All data from the multimodal monitoring were digitally extracted and statistically analysed. The mean ICP decreased with barbiturate coma in eight of the 12 patients (75% of the patients), but only four achieved a value below 20 mmHg. Of eight patients with prebarbiturate PTiO2 levels above 10 mmHg, six had a further improvement in oxygenation. Thus, concordant favourable changes in ICP, PRx and PTiO2 with barbiturate coma were seen in those who survived. Effective response to barbiturates can be detected by improved PTiO2 and autoregulation (PRx) in severe head injury patients.     

Serial lumbar CSF pressure measurements and cranial computed tomographic findings in childhood tuberculous meningitis

Intracranial pressure (ICP) was monitored in 218 consecutive children with hydrocephalus secondary to tuberculous meningitis (TBM). All children underwent cranial computerized tomographic (CT) scanning and continuous lumbar cerebrospinal (CSF) pressure monitoring on admission. Noncommunicating hydrocephalus (37 children), as determined by air encephalography, was treated by ventriculoperitoneal (VP) shunting and communicating hydrocephalus (181 children), by means of daily acetazolamide and frusemide. Response of ICP to treatment in the group with communicating hydrocephalus was assessed by means of repeated CSF pressure monitoring and CT scanning. One hundred and eighty-five of the 218 patients survived the 1st month of treatment. The aim of this study was the retrospective determination of (1) the relationship between ICP measurements and CT findings on admission and (2) the characteristics of the ICP recording which correlated best with the CT criteria of compensated hydrocephalus after the 1st month of treatment. No relationship was found between the level of baseline CSF pressure and the degree of hydrocephalus, as demonstrated by CT scanning, on admission. Seventy-five per cent of the patients with communicating hydrocephalus that survived the 1st month of treatment complied with the CT criteria for compensated hydrocephalus. All these patients had a baseline CSF pressure below 15 mmHg and absence of high-amplitude B waves on the pressure recording done at the end of the 1st month. In this study repeated lumbar CSF pressure monitoring proved to be an effective instrument to assess the response of communicating tuberculous hydrocephalus to medical treatment and also accurately predicted the timing of compensation of the hydrocephalus. Received: 19 January 1999 Revised: 20 March 1999     

Meningitis following basal skull fracture in two in-line skaters

Introduction In-line skating has been reported to cause severe head injury. Basilar skull fracture (BSF) is associated with a high risk of complication.Case report We report two children who had bacterial meningitis following seemingly trivial in-line skating injuries. In both, anterior BSF was diagnosed retrospectively following occurrence of Streptococcus pneumoniae meningitis.Discussion The clinical signs indicating BSF depend on the fracture location. Plain skull radiography and computed tomography (CT) are not sensitive enough to detect thin fractures in the anterior cranial fossa. We argue that high resolution multiple-plane CT and coronal T2-weighted magnetic resonance imaging are indicated to diagnose BSF.     

Meningitis due to viridans streptococci in adults

Seven patients are reported with meningitis due to viridans streptococci. These patients represented 5% of culture-proven cases of bacterial meningitis in adults participating in a prospective multicentre clinical trial evaluating the use of dexamethasone. Meningitis was iatrogenic in three patients: one patient had been treated with endoscopic sclerotherapy for oesophageal varices, and two patients had undergone thermocoagulation of the gasserian ganglion for trigeminal neuralgia in the previous days. Received: 8 January 1997 Received in revised form: 17 March 1997 Accepted: 3 April 1997     

Imaging of acquired cerebral herniations

The consequences of cerebral herniation are compression of the brain, cranial nerves, and blood vessels that may result in serious neurologic morbidity, coma, and even death. A thorough understanding of the various patterns of cerebral herniation is essential, and it is important to remember that many of these patterns of herniation overlap. CT and MR imaging are effective at establishing the diagnosis of cerebral herniation, which will guide important decisions regarding therapeutic options and prognosis.     

Cerebrovascular involvement in the acute phase of bacterial meningitis

Cerebral ischaemia is a common complication of bacterial meningitis. Although cerebrovascular involvement in the acute phase of inflammation may be particularly important for the still unacceptably high morbidity and mortality, only, a few studies have investigated cerebrovascular changes in bacterial meningitis. We prospectively investigated changes of intracranial cerebral blood flow velocities (CBFV) in 22 patients (12 men, 10 women, mean age 48 years, 19 years, SD) with bacterial meningitis, by means of transcranial Doppler sonography (TCD). According to previously published criteria the degree of arterial narrowing was assessed and related to the patients’ outcome. Elevated CBFVs in the middle cerebral artery were documented in 18/22 patients with markedly increased systolic peak velocities (CBFV of > 210 cm/s) in 7 patients. Serial examinations performed in 11 patients showed elevated CBFV as early as day 1, reaching peak CBFV between day 3 and day 6 after onset of symptoms in most cases. Furthermore, cerebrovascular involvement was also documented by disturbances of physiological slow spontaneous oscillations of blood flow velocities in 5/10 patients examined with TCD. Low Glasgow Coma Scales (< 7) on admission (29% vs 0%), focal cerebral ischaemic deficits (29% vs 7%) and, seizures (43% vs 7%) were more frequent in patients with CBFV of > 210 cm/s. Finally, a poor clinical outcome was significantly related to severe vascular involvement (P < 0.05). Received: 26 February 1996 Received in revised form: 16 July 1996 Accepted: 5 August 1996     

Level of transforming growth factor beta 1 is elevated in cerebrospinal fluid of children with acute bacterial meningitis

We investigated the levels of transforming growth factor beta 1 (TGF-β1) in cerebrospinal fluid (CSF) in children with meningitis, with a view to prognostic relevance. CSF TGF-β1 levels on admission were measured by a sandwich enzyme immunoassay in children with bacterial meningitis (n = 16), aseptic meningitis (n = 12), and control subjects without evidence of central nervous system (CNS) infection (n = 16). Patients were followed up for a mean duration of 13 months, and neurodevelopmental sequelae was determined for those with bacterial meningitis. On admission, CSF TGF-β1 levels were significantly higher in children with bacterial meningitis (mean, standard error, 32.92, 2.36 pg/ml) as opposed to those with aseptic meningitis (25.26, 1.72 pg/ml) (P = 0.0155), or control subjects (20.53, 1.05 pg/ml) (P < 0.0001). The CSF TGF-β1 levels in children with aseptic meningitis were higher than those in the control group, but without significance (P = 0.02). No apparent correlation existed between CSF TGF-β1 levels and CSF protein or cell counts in patients with bacterial meningitis. No significant difference in CSF TGF-β1 levels was found between patients with or without major sequelae following bacterial meningitis. Received: 19 March 1997 Received in revised form: 24 June 1997 Accepted: 20 August 1997     

Computed tomography in the assessment of raised intracranial pressure in non-traumatic coma

Cranial computed tomography (CT) scans and invasive intracranial pressure (ICP) measurements were reviewed for 34 children with non-traumatic coma from various causes. CT scan features including focal or generalised changes in density were noted and changes in cerebrospinal fluid (CSF) spaces were graded and correlated with the level of maximum ICP in the first 12 hours of treatment and monitoring. Seven patients had normal findings and 27 had abnormal scans. Nineteen of the 27 patients with abnormal scans had generalised abnormalities with varying degrees of loss of CSF space. Seventeen of these 19 patients had pressures greater than 15 mmHg. The highest pressures being found in those with the greatest degree of CSF space obliteration. In the remaining 8 patients, who had focal abnormalities either within the basal ganglia or cerebral hemisphere, there was no relationship between local CSF space obliteration and the level of ICP. In the 7 patients with normal scans three had ICPs of 20 mmHg or greater in the first 12 hours of monitoring and a further two also developed an ICP of this level 13-36 hours after the initiation of monitoring. In non-traumatic coma of various causes there is an association between loss of CSF space and increased ICP. However, there were two important exceptions to this; firstly in patients with focal abnormalities either within the basal ganglia or cerebral hemisphere, in whom the loss of adjacent CSF spaces was not a good indicator of generalised raised ICP; secondly some patients with normal scans, in whom this finding did not indicate normal ICP nor ensure that it remained at this level.     

Subdural intracranial pressure monitoring in craniosynostosis: its role in surgical management

In the management of craniosynostosis subdural intracranial pressure (ICP) monitoring has proved a useful and safe means of identifying those children with raised ICP who are at risk from its long-term sequelae and who would benefit from early surgical intervention. Overnight subdural ICP recordings have been obtained in 136 unoperated cases of craniosynostosis. Fifteen patients were studied both before and after cranial vault remodelling procedures. ICP was raised (>15 mmHg) in 35%, borderline (10–15 mmHg) in 27% and normal (<10 mmHg) in 27% of cases. Raised ICP was present in 28/53 of the syndromic craniofacial dysostosis cases and in 20/83 non-syndromic craniosynostosis cases investigated (P<0.001). Raised mean ICP and periodic plateaux of sustained ICP during sleep were particularly associated with the syndromic cases. Of the 15 patients studied following cranial vault surgery, 9 showed a reduction in ICP, 3 were unchanged and 3 had higher ICP postoperatively. The results of ICP monitoring can contribute significantly to formulating a rational and staged surgical management plan incorporating the need to normalise ICP and correct the frequently severe functional and cosmetic consequences of these disorders.     

Pneumococcal meningitis in infants

A review and follow-up study of 21 Chinese infants who had pneumococcal meningitis showed a mortality of 23.8% and high morbidity in survivors. Severe meningitis and delay in treatment as reflected by the presence of coma, pneumonia, disseminated intravascular coagulation, and lumbar CSF protein of over 368 mg% and glucose of lower than 10 mg% at the time of diagnosis were associated with fatality. Although the pneumococcus was sensitive to Penicillins which were given at usually recommended dosages and duration in these infants, the morbidity in survivors was high, and seemed to be associated with the presence of focal neurological abnormalities at the time of diagnosis, slow response in fever to treatment, short duration of afebrile period before discontinuation of antibiotics, and incompletely normal CSF parameters at the time of cessation of antibiotics. Serially sterile lumbar CSF did not guarantee against recrudescence of meningitis after cessation of antibiotics. The lack of uniformity in treating and monitoring these patients and suggested management are discussed.     

Abnormalities of cerebral blood flow in the acute phase of bacterial meningitis in adults

Summary The frequency, course and clinical significance of changes in regional cerebral blood flow (rCBF) during bacterial meningitis were investigated in 14 adult patients. The results of^99mTc-hexamethylpropylene amine oxime (HMPAO) single photon emission computed tomography (SPECT) were compared with the clinical signs and findings using cerebral angiography and conventional CT. HMPAO SPECT was performed 2–15 days (median 4.5 days) after the onset of neurological disease. Decreased HMPAO accumulation was detected in 13 patients. SPECT studies revealed focal hypoperfusion cor responding to the clinical symptoms in 6 patients suffering from hemiparesis or hemiataxia. Conventional cranial CT disclosed brain infarction in only 1 patient. Focal hypoperfusion was also found in 7 of 8 patients without clinical evidence of focal neurological deficits. In 6 patients, HMPAO SPECT findings were abnormal although cerebral angiography was normal. At follow-up examinations 3–45 weeks after the acute disease, abnormalities revealed by HMPAO SPECT had improved or had even disappeared in all patients studied. Our results indicate that reduced rCBF is a frequent finding in bacterial meningitis in the adult. In most patients it probably represents a functional and reversible disorder without structural lesion detectable on CT.     

Necrotizing Bacillus cereus infection of the meninges without inflammatory reaction in a patient with acute myelogenous leukemia: a case report

A 64-year-old man in a severely immunocompromised state due to acute myelogenous leukemia died, respirator-unaided, about 10 h after the abrupt onset of coma. An earlier blood culture had yielded Bacillus cereus. The autopsy, performed 2 h after death, demonstrated diffuse subarachnoid hemorrhage without berry aneurysms, and the formalin-fixed brain was tinged with gray-brownish discoloration. The sections of the brain presented a whitish tint of the surface layer of all portion of the cerebral cortices, even those in the sulci. Histological examination of the brain revealed leptomeningeal B. cereus dissemination, and widespread necrosis of the leptomeninges and arachnoid vessels without inflammatory cell reaction. The grossly recognizable whitish surface layer of the cerebral cortex showed overt hyperchromatism, and contained neurons more degenerative than those located in the deeper cortical layer. The total absence of inflammatory reaction may be explained by a combination of the immunocompromised state of the patient and the character of B. cereus infection, which in itself induces little inflammatory reaction. The prominent lesions were confined to the cerebral surface layer and leptomeningeal tissue including the arachnoid vessels, which were all bathed in the cerebrospinal fluid, suggesting that some necrotizing toxins had been secreted into the fluid by the B. cereus. The necrosis of arachnoid vessels is thought to have in turn caused diffuse subarachnoid hemorrhage and marked disturbance of the cerebral blood flow, resulting in the terminal coma. Received: 4 April 1996 / Revised, accepted: 8 September 1996     

An infant mouse model of brain damage in pneumococcal meningitis

Bacterial meningitis due to Streptococcus pneumoniae is associated with an significant mortality rate and persisting neurologic sequelae including sensory-motor deficits, seizures, and impairments of learning and memory. The histomorphological correlate of these sequelae is a pattern of brain damage characterized by necrotic tissue damage in the cerebral cortex and apoptosis of neurons in the hippocampal dentate gyrus. Different animal models of pneumococcal meningitis have been developed to study the pathogenesis of the disease. To date, the infant rat model is unique in mimicking both forms of brain damage documented in the human disease. In the present study, we established an infant mouse model of pneumococcal meningitis. Eleven-days-old C57BL/6 (n = 299), CD1 (n = 42) and BALB/c (n = 14) mice were infected by intracisternal injection of live Streptococcus pneumoniae. Sixteen hours after infection, all mice developed meningitis as documented by positive bacterial cultures of the cerebrospinal fluid. Sixty percent of infected C57BL/6 mice survived more than 40 h after infection (50% of CD1, 0% of BALB/c). Histological evaluations of brain sections revealed apoptosis in the dentate gyrus of the hippocampus in 27% of infected C57BL/6 and in 5% of infected CD1 mice. Apoptosis was confirmed by immunoassaying for active caspase-3 and by TUNEL staining. Other forms of brain damage were found exclusively in C57BL/6, i.e. caspase-3 independent (pyknotic) cell death in the dentate gyrus in 2% and cortical damage in 11% of infected mice. This model may prove useful for studies on the pathogenesis of brain injury in childhood bacterial meningitis.