Growing Skull Fracture and the Orbitocranial Variant: Nuances of Surgical Management.

AIMS: Growing skull fracture (GSF) is a rare complication resulting from diastatic enlargement of a pediatric skull fracture. Orbitocranial GSF is a distinct variant with more complex management issues due to the displacement of the globe. This study aims to discuss surgical considerations in the management of GSF, with particular reference to orbitocranial variants. METHODS: We conducted a retrospective analysis of 7 children operated for GSFs at our institute from 2008 to 2015. RESULTS: Four boys and 3 girls were operated during this period. The mean age at initial trauma was 2 years, and most of them sustained falls. The most frequent symptoms of GSF were progressive scalp swelling and proptosis. The most common location was the orbitofrontal region. Duraplasty with cranioplasty was performed in 5 patients, while duraplasty alone was only required in 2 patients. A postoperative complication was noted in 1 patient and managed successfully. Good cosmetic results were obtained in all of the cases. CONCLUSIONS: Duraplasty is essential in the repair of GSF and should be followed by cranioplasty to prevent recurrent leptomeningeal herniation. We recommend the use of autologous bone from the surgical site for cranioplasty. Orbital roof repair is advisable for good visual and cosmetic outcome in orbitocranial variants of GSF.

Growing skull fractures: guidelines for early diagnosis and surgical management.

BACKGROUND: Growing skull fracture (GSF) is a rare complication of pediatric head trauma and causes delayed onset neurological deficits and cranial defect. GSF usually develops following linear fracture with underlying dural tear resulting in herniation of the brain. Early diagnosis and treatment are essential to avoid complications. However, there are no clear-cut guidelines for the early diagnosis of GSF. The present study was conducted to identify the criteria for the early diagnosis of GSF. MATERIAL AND METHODS: From 2010 to 2015, all pediatric patients of head trauma with linear fracture were evaluated. Patients of age <5 years with cephalhematoma, bone diastasis of 4 mm or more with underlying brain contusion were subjected to contrast brain MRI to find out the dural tear and herniation of the brain matter. Patients with contrast MRI showing dural tear and herniation of the brain matter were considered high risk for the development of GSF and treated surgically within 1 month of trauma. Patients with contrast brain MRI not showing dural tear and herniation of the brain matter were regularly followed for any signs of GSF. RESULTS: A total of 20 patients were evaluated, out of which 16 showed dural defects with herniation of the brain matter and were subjected to duraplasty. Four patients in which MRI did not show dural tear and herniation of the brain matter were regularly followed-up and have not shown any sign of GSF later on follow-up. CONCLUSION: Early diagnosis of GSF can be made based on the four criteria, i.e., (1) age <5 year with cephalhematoma, (2) bone diastasis 4 mm or more (3) underlying brain contusion (4) contrast MRI showing dural tear and herniation of the brain matter. Dural tear with herniation of the brain matter is the main etiopathogenic factor for the development of GSF. Early diagnosis and treatment of GSF can yield a good outcome.

[SIMULTANEOUS MEASUREMENT OF INTRAVENTRICULAR AND PARENCHYMAL INTRACRANIAL PRESSURE IN PATIENTS WITH SEVERE TRAUMA BRAIN INJURY].

INTRODUCTION: "Standard" assessment of ICP by measuring liquor ventricular pressure recently questioned. THE OBJECTIVE OF THE STUDY: Compare the values of ventricular and parenchymal ICP against the closure of open liquor drainage and during active CSF drainage. MATERIALS AND METHODS: Examined 7 patients with TBI and intracranial hypertension syndrome, GCS 5.6 ± 1.2 points, 4.2 ± age 33 years. Compared parenchymal and ventricular ICP in three time periods: 1--during closure of ventricular drainage, 2--during of the open drains and drainage at the level of 14-15 mmHg, 3--during the period of active drainage. When comparing two methods of measurement used Bland-Altman method. RESULTS: 1. During time period of the closed drainage correlation coefficient was r = 0.83, p < 0.001. Bland-Altman method: the difference of the two measurements is equal to the minimum and 0.7 mm Hg, the standard deviation of 2.02 mm Hg 2. During time period of the open drainage was reduction of the correlation coefficient to r = 0.46, p < 0.01. Bland-Altman method: an increase in the difference of the two measurements to -0.84 mmHg, standard deviation 2.8 mm Hg 3. During time period of the active drainage of cerebrospinal fluid was marked difference between methods of measurement. Bland-Altman method: the difference was 8.64 mm Hg, and a standard deviation of 2.6 mm Hg. CONCLUSIONS: 1. During the closure of the ventricular drainage were good correlation between ventricular and parenchymal ICR 2. During open the liquor drainage correlation between the two methods of measuring the intracranial pressure is reduced. 3. During the active CSF drainage correlation between the two methods of measuring intracranial pressure can be completely lost. Under these conditions, CSF pressure is not correctly reflect the ICP 4. For an accurate and continuous measurement of intracranial pressure on the background of the active CSF drainage should be carried out simultaneous parenchymal ICP measurement.

Detection of cerebral spinal fluid-associated chemokines in birth traumatized premature babies by chip-based immunoaffinity CE.

A major concern in treating premature infants with birth-associated head trauma is the rapid determination of reliable biomarkers of neuroinflammation. To this end a chip-based immunoaffinity CE device has been applied to determine the concentrations of inflammation-associated chemokines in samples of cerebral spinal fluid collected from such subjects. The chip utilizes replaceable immunoaffinity disks, to which reactive antibody fragments (FAb) of six antichemokine-specific antibodies were immobilized. Following injection of a sample into the device, the analytes were captured by the immobilized FAbs, labeled in situ with a red laser dye, chemically released and separated by CE. Each resolved peak was measured on-line by LIF detection and the results compared to standard curves produced by running known chemokine standards through the immunoaffinity system. The complete processing of a sample took 10 min with separation of all six analytes being achieved in less than 2 min. The system compared well to commercial ELISA, analysis of the results by linear regression demonstrating r(2) values in the range of 0.903-0.978, and intra and interassay CV of the migration times and the measured peak areas being less than 2.3 and 5%, respectively. Application of the system to analysis of cerebrospinal fluid from head traumatized babies clearly indicated the group with mild trauma versus those with severe injury. Additionally, CE analysis demonstrated that the severe trauma group could be divided into individuals with good and poor prognosis, which correlated with the clinical finding for each patient.

Mitigating effects of external ventricular drain usage in the management of severe head injury.

BACKGROUND: Cerebrospinal fluid (CSF) drainage has been variably employed to lower intracranial pressure (ICP) in patients with severe head injury. The efficacy of this manoeuvre remains under-explored (Brain Trauma Foundation Recommendation-optional treatment). This work seeks to report the results of CSF drainage via external ventricular drain (EVD) in severe head injury in comparison to other treatment options. METHODS: Retrospective observational comparative study of all consecutive patients admitted to a major trauma centre with severe traumatic brain injury over a period of 12 months. RESULTS: Out of a total 139 patients, 33 had delayed elevation of ICP despite conventional medical therapy, 16 patients were treated with EVD insertion (4 placed under AxiEM image guidance [Medtronic]) and 17 received either decompressive craniectomy or barbiturate coma. Subsequently, two patients with decompression had further ICP elevation and needed EVD. Two patients with EVD had raised ICP-one underwent decompression and the other was treated with barbiturate coma. One patient with EVD developed infection, which was successfully treated. Patients treated with EVD had a lower risk of needing definitive treatment for ICP control, i.e. decompressive craniectomy or barbiturate coma. CONCLUSIONS: EVD was a safe and less invasive procedure, and achieved sustained control of ICP in this patient group.

Imaging of skull-base cephalocoeles and cerebrospinal fluid leaks.

Skull-base cephalocoeles and cerebrospinal fluid (CSF) leaks may be congenital, spontaneous, or secondary. A classification of congenital lesions is formulated and the imaging features are illustrated. The concept of spontaneous skull-base CSF leaks and the significance of aberrant arachnoid granulations in imaging these patients are explored. The majority of secondary lesions relate to trauma; however, other potential causes of secondary skull-base cephalocoeles and CSF leaks are discussed. Imaging evaluation in these clinical scenarios may be complex and the role of each imaging method is reviewed.

[Intracranial pressure-volume relationship. Physiology and pathophysiology]. / Intrakranielle Druck-Volumen-Beziehung. Physiologie und Pathophysiologie.

Posttraumatic increase of intracranial pressure (ICP) is a strong prognostic factor for the outcome of patients after traumatic brain injury. After exhausting all compensatory mechanisms ICP increases exponentially, where ICP(norm)=(CSF production*CSF flow resistance)+venous pressure((sinus sagittalis))=10-15 mmHg. The ICP curve is influenced by the compliance (DeltaV/DeltaP) and elasticity (DeltaP/DeltaV) of the brain. Marmarou could demonstrate that the non-linear cranio-spinal pressure-volume relationship describes a logarithmic, mono-exponential, strongly linear relationship between pressure and volume and named this the pressure volume index (PVI=log ICP/DeltaV). The pressure volume index describes the volume necessary to increase ICP by a factor of 10. Additionally to PVI the measurement of volume-pressure response (VPR) was introduced. The continuous intracranial compliance could be determined on the principle of pulsatile volume increases as an equivalent of very small intra-cranial volume increases. However, to ascertain functional status of the injured brain a combination of measurements of different parameters, such as tissue oxygen partial pressure (p(ti)O2), cerebral blood flow (CBF), microdialysis and electrocorticography (ECoG) is recommended.

S100B protein and its clinical effect on craniocerebral injury.

OBJECTIVE: To explore the role of S100B protein in the early diagnosis, treatment, and prognosis judgement of craniocerebral injury. METHODS: In this study, we reviewed the domestic and foreign research reports about the relationship between S100B protein and craniocerebral injury. RESULTS: The concentration of S100B protein had a different increase based on the degree of injury in early stage after craniocerebral injury, and the increasing degree of S100B protein showed a positive correlation with the grading of pathogenetic condition and prognosis of craniocerebral injury. CONCLUSIONS: S100B protein may be taken as a specific index of early diagnosis, grading of pathogenetic condition, and prognosis judgement after craniocerebral injury. To grasp and regulate the mechanism of neurotoxicity and to elucidate the therapeutic effect of S100B protein will be a research direction in clinical treatment of craniocerebral injury.

[Differential diagnosis of subdural liquor accumulation in recurrent craniocerebral injury].

Criteria are proposed for the diagnosis of the origin and time- lapse of subdural accumulations of liquor in patients with repeated craniocerebral injury. The set of this criteria includes specific features of association and relative position of subdural liquor accumulations, their volume, and intracranial manifestations of primary and repeated craniocerebral injuries. Algorithms and nomograms have been developed in the course of the study allowing for accurate differentiation between subdural liquor accumulations as consequences of primary and repeated craniocerebral injuries. The results of the study have implications for practical forensic medical evaluation of repeated craniocerebral injuries with subdural liquor accumulation.

Prolonged elevation of magnesium in the cerebrospinal fluid of patients with severe head injury.

OBJECTIVES: Several works have investigated the role of serum magnesium (Mg) concentrations in traumatic brain injury. However, there is restricted information about cerebrospinal fluid (CSF) levels of Mg in patients with severe head injury (SHI). We assessed the changes of Mg concentrations in CSF and serum in patients with SHI during the first 10 days after the trauma. METHODS: Eleven patients with SHI were studied prospectively on days 1-3, 5 and 10 with analysis of CSF and serum levels of Mg and Ca. The control group consisted of nine patients with hydrocephalus. RESULTS: CSF levels of Mg were significantly higher in patients than controls in the corresponding time points except on days 5 and 10 of trauma. The CSF Mg levels tended to decrease and the highest level was found on day 1 after trauma (2.81 +/- 0.65 mg/dl). In the control group, the CSF level of Mg was 1.95 +/- 0.66 mg/dl. No significant difference can be detected between controls and patients regarding serum Mg and Ca levels. In addition, significantly higher values of Ca in the CSF were observed in all time points after trauma in patients with SHI than in the controls. There was no correlation between the CSF and serum levels of Mg and Ca levels. DISCUSSION: Our study demonstrates that in patients with SHI, CSF levels of Mg and Ca are elevated during the whole observation period. Further works should be designed in order to show the role and importance of CSF levels of ionized Mg in outcome of patients with SHI.

High-sensitivity C-reactive protein levels in cerebrospinal fluid and serum in severe head injury: relationship to tumor necrosis factor-alpha and interleukin-6.

Recent studies have demonstrated the role of high-sensitivity C-reactive protein (hsCRP) in inflammatory diseases; however, it is unclear whether this molecule has a role after severe head injury (SHI). Our aim was to evaluate the levels of hsCRP in both cerebrospinal fluid (CSF) and serum from patients after SHI. The study focused on 11 patients with SHI, and evaluated CSF and serum levels of hsCRP, tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in a 10-day period following the head trauma. The values were compared with those from nine control patients, who had normal pressure hydrocephalus. In the CSF and serum of the patients after SHI, HsCRP was found to be significantly higher, at all times, than in the controls; TNF-alpha and IL-6 levels were also higher in these patients. However, hsCRP levels did not correlate with either TNF-alpha or IL-6. TNF-alpha and IL-6 increased during the period immediately following the SHI, and intrathecal levels were always higher than those of the serum. This study demonstrates for the first time that hsCRP reaches high levels in both CSF and serum in patients with SHI, and it may therefore be used as an inflammatory index. This finding suggests a need for further studies in this area, which are larger in scope than the present study.

Cerebrospinal fluid and serum levels of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 in patients with severe head injury.

BACKGROUND: The aim of this study is to present time course of insulin like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) levels in both cerebrospinal fluid (CSF) and serum of patients after severe head injury (SHI) and to compare with controls. METHODS: Our trauma and control groups included 11 consecutive patients with isolated SHI and 9 patients with hydrocephalus (one with normotensive and eight with hydrocephalus due to aqueduct stenosis), respectively. Both serum and cerebrospinal fluid levels of IGF-1 and IGFBP-3 were measured during post-traumatic days and we compared the levels with controls. RESULTS: Patients and controls showed undetectable levels of both IGF-1 and IGFBP-3 in their CSF. When considering serum levels, patients with SHI had always lower levels of both molecules than that of controls. CONCLUSION: Administration of IGF-1 during acute, as well as chronic phase of severe head trauma may provide beneficial effects and may decrease both mortality and morbidity in humans with SHI.

[Oxidative stress in victims with heavy combined cranium-facial trauma].

For acute posttraumatic period of heavy combined cranium-facial trauma (CFT) considerable activation of peroxide lipids oxidation in the liquor is typical beginning from the 1st day of posttraumatic period on the background of speedy and drastic depletion of fermentative and low-molecular antioxidant liquor system (in spite of introduction of antioxidants particularly a-tocopherol acetate). Non-adequate functioning of the system of antioxidant defense on the background of free radical activity splash can be considered as breakdown of the process of adaptive reaction forming. It leads to weighting the course of posttraumatic period of heavy combined cranium-facial trauma and its outcome as a whole.

Predictive (subtle or overlooked) initial head CT findings in patients who develop delayed chronic subdural hematoma.

With the aging population, the incidence of chronic subdural hematoma (CSDH) is expected to rise. Once symptomatic the morbidity from CSDH is not insignificant. We studied patients who had a minor head injury and CT brain scan prior to developing CSDH to determine if there were any predictors on these scans for subsequent development of a CSDH. A retrospective review was performed on all patients operated for CSDH over a 3-year period and a review performed on those who had imaging studies at the time of a preceding minor head injury. Seven of 37 patients had CT scans prior to developing CSDH. All had evidence of small increases in CSF intensity on the side or sides of the subsequent CSDH. In conclusion, in those patients with a history of minor head injury prior to developing a CSDH, CT brain demonstrated small increases in cerebral spinal fluid (CSF) intensity on the side or sides of the subsequent CSDH. Recognizing this finding may be helpful in monitoring these patients or initiating medical therapy.

Neurochemical aftermath of amateur boxing.

BACKGROUND: Little solid information is available on the possible risks for neuronal injury in amateur boxing. OBJECTIVE: To determine whether amateur boxing and severity of hits are associated with elevated levels of biochemical markers for neuronal injury in cerebrospinal fluid. DESIGN: Longitudinal study. SETTING: Referral center specializing in evaluation of neurodegenerative disorders. PARTICIPANTS: Fourteen amateur boxers (11 men and 3 women) and 10 healthy male nonathletic control subjects. INTERVENTIONS: The boxers underwent lumbar puncture 7 to 10 days and 3 months after a bout. The control subjects underwent LP once. MAIN OUTCOME MEASURES: Neurofilament light protein, total tau, glial fibrillary acidic protein, phosphorylated tau, and beta-amyloid protein 1-40 (Abeta([1-40])) and 1-42 (Abeta([1-42])) concentrations in cerebrospinal fluid were measured. RESULTS: Increased levels after a bout compared with after 3 months of rest from boxing were found for 2 markers for neuronal and axonal injury, neurofilament light protein (mean +/- SD, 845 +/- 1140 ng/L vs 208 +/- 108 ng/L; P = .008) and total tau (mean +/- SD, 449 +/- 176 ng/L vs 306 +/- 78 ng/L; P = .006), and for the astroglial injury marker glial fibrillary acidic protein (mean +/- SD, 541 +/- 199 ng/L vs 405 +/- 138 ng/L; P = .003). The increase was significantly higher among boxers who had received many hits (>15) or high-impact hits to the head compared with boxers who reported few hits. In the boxers, concentrations of neurofilament light protein and glial fibrillary acidic protein, but not total tau, were significantly elevated after a bout compared with the nonathletic control subjects. With the exception of neurofilament light protein, there were no significant differences between boxers after 3 months of rest from boxing and the nonathletic control subjects. CONCLUSIONS: Amateur boxing is associated with acute neuronal and astroglial injury. If verified in longitudinal studies with extensive follow-up regarding the clinical outcome, analyses of cerebrospinal fluid may provide a scientific basis for medical counseling of athletes after boxing or head injury.

[Severe pediatric head injury: is there any optimal solution?]. / Sunki vaiku galvos smegenu trauma. Ar yra optimalus gydymo budas?

Traumatic brain injury in children is a worldwide problem. The incidence of trauma cases is increasing over the world, and in Lithuania it is several times higher than in the most developed European countries. The article reviews data about the most modern means of managing pediatric traumatic brain injury. The role of prehospital care, emphasizing on airway management, adequate ventilation, oxygenation, and perfusion in order to preclude secondary brain injury, which begins straight after trauma, is being noted. Establishing trauma system and patient's treatment in pediatric trauma centers, where child gets urgent and sufficient help, reduces mortality and improves outcomes. Pediatric patient's triage using patient's status scoring and trauma scoring systems is recommended. The role of intracranial pressure and cerebral perfusion pressure is crucial. Immediate management of intracranial pressure reduces mortality and improves outcomes. Techniques of intracranial pressure monitoring and management strategies of intracranial hypertension, their advantages and possible disadvantages are described.

Limitations of T2*-Gradient Recalled-Echo and Susceptibility-Weighted Imaging in Characterizing Chronic Subdural Hemorrhage in Infant Survivors of Abusive Head Trauma.

A possible misconception among radiologists is that chronic subdural hemorrhage should show some degree of blooming on T2*-gradient recalled-echo or susceptibility-weighted sequences such as SWI and susceptibility-weighted angiography, which is not necessarily true. We present 5 cases of chronic subdural hemorrhages in infants, demonstrating intensity near or greater than that of CSF with variable amounts of hemosiderin staining along the neomembranes. We review the physiology and MR imaging physics behind the appearance of a chronic subdural hemorrhage, highlighting that the absence of a BBB can allow hemosiderin to be completely removed from the subdural compartment. Finally, we stress the importance of reviewing all multiplanar sequences for the presence of neomembranes, which can be quite subtle in the absence of hemosiderin staining and are critical for making the diagnosis of chronic subdural hemorrhage.

Symptomatic narcolepsy, cataplexy and hypersomnia, and their implications in the hypothalamic hypocretin/orexin system.

Human narcolepsy is a chronic sleep disorder affecting 1:2000 individuals. The disease is characterized by excessive daytime sleepiness, cataplexy and other abnormal manifestations of REM sleep, such as sleep paralysis and hypnagogic hallucinations. Recently, it was discovered that the pathophysiology of (idiopathic) narcolepsy-cataplexy is linked to hypocretin ligand deficiency in the brain and cerebrospinal fluid (CSF), as well as the positivity of the human leukocyte antigen (HLA) DR2/DQ6 (DQB1*0602). The symptoms of narcolepsy can also occur during the course of other neurological conditions (i.e. symptomatic narcolepsy). We define symptomatic narcolepsy as those cases that meet the International Sleep Disorders Narcolepsy Criteria, and which are also associated with a significant underlying neurological disorder that accounts for excessive daytime sleepiness (EDS) and temporal associations. To date, we have counted 116 symptomatic cases of narcolepsy reported in literature. As, several authors previously reported, inherited disorders (n=38), tumors (n=33), and head trauma (n=19) are the three most frequent causes for symptomatic narcolepsy. Of the 116 cases, 10 are associated with multiple sclerosis, one case of acute disseminated encephalomyelitis, and relatively rare cases were reported with vascular disorders (n=6), encephalitis (n=4) and degeneration (n=1), and hererodegenerative disorder (three cases in a family). EDS without cataplexy or any REM sleep abnormalities is also often associated with these neurological conditions, and defined as symptomatic cases of EDS. Although it is difficult to rule out the comorbidity of idiopathic narcolepsy in some cases, review of the literature reveals numerous unquestionable cases of symptomatic narcolepsy. These include cases with HLA negative and/or late onset, and cases in which the occurrences of the narcoleptic symptoms are parallel with the rise and fall of the causative disease. A review of these cases (especially those with brain tumors), illustrates a clear picture that the hypothalamus is most often involved. Several cases of symptomatic cataplexy (without EDS) were also reported and in contrast, these cases appear to be often associated with non-hypothalamic structures. CSF hypocretin-1 measurement were also carried out in a limited number of symptomatic cases of narcolepsy/EDS, including narcolepsy/EDS associated with tumors (n=5), head trauma (n=3), vascular disorders (n=5), encephalopathies (n=3), degeneration (n=30), demyelinating disorder (n=7), genetic/congenital disorders (n=11) and others (n=2). Reduced CSF hypocretin-1 levels were seen in most symptomatic narcolepsy cases of EDS with various etiologies and EDS in these cases is sometimes reversible with an improvement of the causative neurological disorder and an improvement of the hypocretin status. It is also noted that some symptomatic EDS cases (with Parkinson diseases and the thalamic infarction) appeared, but they are not linked with hypocretin ligand deficiency. In contrast to idiopathic narcolepsy cases, an occurrence of cataplexy is not tightly associated with hypocretin ligand deficiency in symptomatic cases. Since CSF hypocretin measures are still experimental, cases with sleep abnormalities/cataplexy are habitually selected for CSF hypocretin measures. Therefore, it is still not known whether all or a large majority of cases with low CSF hypocretin-1 levels with CNS interventions, exhibit EDS/cataplexy. It appears that further studies of the involvement of the hypocretin system in symptomatic narcolepsy and EDS are helpful to understand the pathophysiological mechanisms for the occurrence of EDS and cataplexy.

Rapid, accurate and non-invasive detection of cerebrospinal fluid leakage using combined determination of beta-trace protein in secretion and serum.

BACKGROUND: beta-Trace protein (Btp) has been proposed as a valuable marker of cerebrospinal fluid (CSF) leakage overcoming the drawbacks of beta-2-transferrin (B-2Tr) determination. However, there is still controversy about the appropriate cut-offs to be used (range 0.35-6 mg/L). The aim of the study was to evaluate cut-offs of Btp determination for detection CSF leakage. Further, we assessed whether the Btp secretion to serum ratio (Btp-sec/ser-ratio) would add diagnostic value. METHODS: Prospective study in patients with suspected CSF leakage. Quantitative determination of Btp in secretion and serum (Dade-Behring) and qualitative measurement of B-2-Tr in secretion and serum. Results were assessed in view of clinical data. Cut-offs and diagnostic characteristics were determined by ROC analysis. RESULTS: A total of 176 samples were assessed originating from 105 patients. In 43 samples CSF leakage could be confirmed. Sensitivity of B-2-Tr was 84%, specificity amounted to 100%. The area under the curve (AUC) for Btp-measurement in secretion was 0.98. At a cut-off of 0.68 mg/L, sensitivity was 100% and specificity 91%. At a cut-off of 1.11 mg/L, the specificity was 100% with a sensitivity of 93%. The Btp-sec/ser-ratio has an AUC of 0.99. Combining a 0.68 mg/L cut-off in secretion with a Btp-sec/ser-ratio cut-off of 4.9 reveals a sensitivity of 99% and a specificity of 100%. CONCLUSIONS: Btp is a rapid and accurate marker for the presence of CSF leakage. Combining measurement of Btp in secretion together with determination of the Btp-sec/ser-ratio enhances the diagnostic characteristics of the Btp assay. Determination of Btp in both serum and secretion is thus recommended.

CSF lactate in diseases of the CNS.

The usefulness of the CSF lactate concentration in the diagnosis of bacterial meningitis was studied in 109 adults and children with a variety of infectious and neurologic diseases. A positive correlation was found between elevated lactate levels and the presence of leukocytes in the CSF. Elevations of the CSF lactate concentration with concomitantly negative Gram's stains and cultures were found in patients with infections at anatomic sites other than the CNS, accidental or neurosurgical head trauma, subarachnoid hemorrhage, and seizures due to alcoholism. When performed routinely on CSF, the positive predictive value was 31%, indicating that a diagnosis other than bacterial meningitis is more likely. We conclude that the CSF lactate concentration does not contribute to the diagnosis in children or adults with suspected meningitis.