Diffuse Calvarial Hyperostosis and Spontaneous Intracranial Hypotension: A Case-Control Study.

BACKGROUND AND PURPOSE: Diagnosing spontaneous intracranial hypotension and associated CSF leaks can be challenging, and additional supportive imaging findings would be useful to direct further evaluation. This retrospective study evaluated whether there was a difference in the prevalence of calvarial hyperostosis in a cohort of patients with spontaneous intracranial hypotension compared with an age- and sex-matched control population. MATERIALS AND METHODS: Cross-sectional imaging (CT of the head or brain MR imaging examinations) for 166 patients with spontaneous intracranial hypotension and 321 matched controls was assessed by neuroradiologists blinded to the patient's clinical status. The readers qualitatively evaluated the presence of diffuse or layered calvarial hyperostosis and measured calvarial thickness in the axial and coronal planes. RESULTS: A significant difference in the frequency of layered hyperostosis (31.9%, 53/166 subjects versus 5.0%, 16/321 controls, P < .001, OR = 11.58) as well as the frequency of overall (layered and diffuse) hyperostosis (38.6%, 64/166 subjects versus 13.2%, 42/321 controls, P < .001, OR = 4.66) was observed between groups. There was no significant difference in the frequency of diffuse hyperostosis between groups (6.6%, 11/166 subjects versus 8.2%, 26/321 controls, P = .465). A significant difference was also found between groups for calvarial thickness measured in the axial (P < .001) and coronal (P < .001) planes. CONCLUSIONS: Layered calvarial hyperostosis is more prevalent in spontaneous intracranial hypotension compared with the general population and can be used as an additional noninvasive brain imaging marker of spontaneous intracranial hypotension and an underlying spinal CSF leak.

Prevalence of cerebral vein thrombosis among patients with spontaneous intracranial hypotension.

BACKGROUND AND PURPOSE: Cerebral venous sinus thrombosis (CVST) is a rare condition but an important complication of spontaneous intracranial hypotension (SIH). We reviewed our experience of patients with SIH and assessed for the presence of CVST. METHODS: We reviewed the medical records and imaging studies from our tertiary referral institution, assessing patients with clinically suspected SIH as well as imaging findings of intracranial hypotension. All relevant brain MRIs were reviewed for the presence of brain sag, pachymeningeal enhancement, and CVST. RESULTS: Among 563 patients with a clinical diagnosis of SIH, 431 (76%) demonstrated brain sag. In the overall patient cohort, a total of 5 patients had CVST (0.9%) and all 5 of these patients demonstrated findings of brain sag. Of the patients with CVST, 3 had significant complications, including dural arteriovenous fistulas (2 patients) and lobar hemorrhage with seizure (1 patient). CONCLUSION: SIH is a risk factor for the development of CVST. In our review of 563 patients with clinical and/or imaging findings of SIH, 0.9% of patients were diagnosed with CVST and 3 of these patients (60%) had additional severe complications.

Pediatric Intracranial Hypotension and Post-Dural Puncture Headache.

Pediatric intracranial hypotension can occur acutely following iatrogenic dural puncture for diagnostic or therapeutic purposes, or chronically from cerebrospinal fluid leak. The incidence of intracranial hypotension in children is not fully known. However, many steps can be taken to reduce the risk of a child developing a post-dural puncture headache. Other causes of intracranial hypotension, such as spontaneous intracranial hypotension or CSF fistulas, are rare and with little pediatric data to guide evaluation and management. This manuscript reviews the risk factors, diagnostic evaluations, and treatments for post-dural puncture headache, as well as a limited discussion of spontaneous intracranial hypotension as it may pertain to children and adolescents.

Risk factors for nonresponsive hydration in patients with spinal cerebrospinal fluid leakage.

BACKGROUND: Spinal cerebrospinal fluid (CSF) leakage is frequently encountered clinically after lumbar puncture or spontaneous events. Although some patients recover without treatment or after intensive hydration, some require an epidural blood patch (EBP). The risks of nonresponsive hydration remain unknown. Therefore, we identified the risk factors for patients with spinal CSF leakage nonresponsive to hydration. METHODS: We retrospectively reviewed patients diagnosed with spinal CSF leakage between January 2010 and March 2021. Clinical data, including patient age, sex, etiology, and radiological indications in magnetic resonance imaging, were compared between patients who were responsive and non-responsive to hydration. RESULTS: Of the 74 patients with spinal CSF leakage, 25 were responsive to hydration and 49 required EBP. Patients who were nonresponsive to hydration were older (39.27 vs. 34.32 years, P = 0.01), had a higher percentage of spontaneous intracranial hypotension (93.88% vs. 68.00%, P = 0.005), had more spinal CSF leakage (12.04 vs. 8.04, P = 0.01), and had a higher percentage of dural sinus engorgement (81.63% vs. 60.00%, P = 0.044). Spontaneous intracranial hypotension (odds ratio [OR]: 4.63; 95% confidence interval [CI]: 1.00-21.38) and having ≥9 spinal CSF leakages (OR: 3.29; 95% CI: 1.08-10.01), as indicated by magnetic resonance myelography, are considered risk factors for noneffective hydration. CONCLUSIONS: Patients with spinal CSF leakage who have spontaneous intracranial hypotension and those with ≥9 spinal CSF leakages are considered at risk for noneffective hydration. EBP should be considered early in these patients.

Spinal subdural hygroma.

A spinal subdural hygroma is a rare entity. In this review, we try to contribute to the pooling of current knowledge about spinal subdural hygroma, from embryology and physiology until radiological detection and treatment. The relevant articles in the literature regarding spinal subdural hygroma were reviewed, using a sensitive search strategy on Internet databases. A spinal subdural hygroma is associated with trauma, iatrogenic causes, spontaneous intracranial hypotension headache, and probably meningitis. MR imaging is the golden standard for diagnosis. Treatment of the hygroma is almost always conservative and surgery is seldom necessary, however treating the underlying cause is important. The physiology, in spite of numerous suggestions and hypotheses in literature, remains unclear. The prevalence of spinal subdural hygroma is also still unknown. Only a few articles deal with spinal subdural hygroma, because it is an uncommon entity, without specific symptoms. Probably it is often not diagnosed because of the frequent association with other cranial or spinal pathologies and the need for high-resolution imaging. More research is required to examine the prevalence, importance, and pathophysiology of spinal subdural hygroma.

Diffuse Calvarial Hyperostosis in Patients with Spontaneous Intracranial Hypotension.

BACKGROUND: Diagnosis of spontaneous intracranial hypotension (SIH) may be delayed due to nonspecific symptoms and variable imaging findings. Cases of hyperostosis in children who are overshunted, a process that may be physiologically analogous to adults with SIH, have been reported by others and observed in our practice. The purpose of this retrospective study was to assess the frequency and pattern of calvarial hyperostosis in patients with SIH. METHODS: We retrospectively reviewed computed tomography and magnetic resonance imaging examinations from consecutive patients who underwent myelography for the evaluation of SIH to assess for the presence of generalized calvarial thickening or development of a secondary layer of bone. Patients with typical benign hyperostosis frontalis were excluded. Patient demographics and clinical factors were evaluated for association with hyperostosis. RESULTS: Among 285 patients with SIH, 40 (14.0%) demonstrated diffuse calvarial hyperostosis on imaging. Most of these patients (32/40; 80.0%) demonstrated a distinct circumferentially layered appearance to the skull, whereas 8 of 40 (20.0%) had generalized calvarial thickening without layering. CONCLUSIONS: Diffuse calvarial hyperostosis, particularly the concentrically layered form that we term "layer cake skull," is a relatively common imaging feature in patients with SIH. In the appropriate clinical context, this finding will allow the possibility of SIH to be raised based on computed tomography imaging, which is otherwise of limited utility in the initial diagnosis of this condition.

Traumatic vs Spontaneous Cerebrospinal Fluid Hypotension Headache: Our experience in a series of 137 cases.

OBJECTIVES: To analyze and compare differences between epidemiological and clinical aspects, as well as radiologic findings and treatment, in a series of adult patients with traumatic intracranial hypotension (TIH) and spontaneous intracranial hypotension (SIH) treated at our institution in order to identify predictors of recurrence. BACKGROUND: Cerebrospinal fluid hypotension headache (CSF-HH) is often caused by orthostasis and relieved by recumbency. Etiology can be either traumatic or spontaneous. Indirect signs of CSF hypotension are often observed on brain MRI. The most common therapeutic approach is conservative management and, when necessary, the use of an epidural blood patch. METHODS: Medical history and brain MRI of adult patients consulting our institution with a diagnosis of CSF-HH between January 2010 and March 2019, were retrospectively reviewed. Clinical criteria as per the International Classification of Headache Disorders, 3rd edition, were applied. Presence of typical MRI findings were assessed by two experienced neuroradiologists, previously informed of patients' clinical characteristics. Patients were divided into two different groups, namely: Group A: Spontaneous Intracranial Hypotension (SIH) and Group B: Traumatic Intracranial Hypotension (TIH). Recurrence was defined as return of symptoms after one month of remission. In order to find predictors of recurrent intracranial hypotension the patients were divided into three groups: Recurrent Orthostatic headache (ROH); (33 cases; 25%); Non-Recurrent Orthostatic headache (NROH) (84; 61%) and Patients missing follow-up (20; 15%). The latter were excluded from the regression analysis. RESULTS: 137 patients with CSF-HH were identified: 80 traumatic (54 women, age 33.8 ±â€¯10.4 years) and 57 spontaneous (31 women, age 43.9 ±â€¯15.2 years). Median follow-up was 35 months (range: 8 months-9 years). Compared with TIH, patients with SIH showed lower frequency of orthostatic headache and higher frequency of aural fullness. Also, in patients with SIH, brain MRI showed a higher frequency of pachymeningeal enhancement, ventricular collapse, cisternal obliteration, posterior fossa crowding, brainstem distortion, and a more likely presence of subdural collections. Patients with SIH required an epidural blood patch treatment more often, showed higher recurrence rates, and were more prone to develop subdural hematomas. RECURRENCE: As more days elapsed between headache onset and clinical consultation, the presence of spontaneous intracranial hypotension, tinnitus, and thoraco-lumbo-sacral pain were all more common in patients with recurrence. Findings on brain MRI suggesting higher recurrence rates in patients included: ventricular collapse, brainstem distortion, and posterior fossa crowding. Patients treated with invasive therapy (epidural blood patch) presented a higher recurrence rate. In the multivariate regression analysis, the only independent predictor of recurrence after adjusting for age, sex and traumatic vs spontaneous cause of IH, was brainstem distortion diagnosed on MRI (OR 5.13, 95% CI: 1.2-21.7; p = 0.026). CONCLUSIONS: SIH and TIH can no longer be likened, since there is considerable variability in clinical presentation, imaging findings, response to treatment and recurrence rates. Anatomical abnormalities underlying SIH leaks are often complex and not simply a disruption of normal structures as encountered in TIH, which could explain why treatment success is poor and recurrence rates remain high.

Lumbar Drain for Temporary Cerebrospinal Fluid Diversion: Factors Related to the Risks of Complications at a University Hospital.

OBJECTIVE: Lumbar drains (LDs) are often used for temporary cerebrospinal fluid (CSF) diversion. However, limited data are available on the risk factors associated with complications. We reviewed our institutional LD data to identify the common indications and outcomes, including the risk factors associated with the occurrence of complications. METHODS: We performed a retrospective review of the patient medical records. All adult patients, who had an LD placed at our hospital during a 5-year period, were included in the present study. The Fisher Exact test and Mann-Whitney U test were used to compare the categorical data and continuous data, respectively; p ≤ 0.05 was considered to indicate statistical significance. RESULTS: During the study period, 211 patients had an LD placed and were included in the present study, of whom 133 were men (63.0%). The most common reason for LD placement was for an iatrogenic CSF leak and pseudomeningocele in 95 patients (45.0%). The mean duration of an indwelling LD was 3.7 ± 1.9 days. Meningitis was the most common complication after LD insertion, occurring in 12 patients (5.5%), followed by low pressure headaches in 10 patients (4.8%). Escherichia coli and Pseudomonas aeruginosa were the most common organisms on culture. Manipulation of the LD to draw CSF samples for analysis was a significant risk factor for the development of meningitis (p = 0.039). CONCLUSIONS: The most common complications in our institution were meningitis and low pressure headaches. Minimizing LD manipulation during CSF sampling could potentially decrease the risk of meningitis. Our protocol of continuing routine prophylactic antibiotics for patients with an indwelling LD might reduce the risk of meningitis; however, the results from a prospective cohort study would provide stronger evidence.

Identifying Incidence of and Risk Factors for Fluoroscopy-Guided Lumbar Puncture and Subsequent Persistent Low-Pressure Syndrome in Patients With Idiopathic Intracranial Hypertension.

BACKGROUND: To explore the incidence of and potential risk factors for developing persistent low-pressure syndrome after lumbar puncture (LP) in patients with idiopathic intracranial hypertension (IIH), as measured by use of blood patches. METHODS: A retrospective chart review was conducted of patients with definitively diagnosed IIH by clinical examination and LP, comparing them to patients with multiple sclerosis (MS) as controls who also received diagnostic LPs. Demographic, clinical, and radiological data were collected for each patient. The main outcome measure was the rate of post-LP blood patches in IIH patients compared with MS patients. Secondary outcome measures were the likelihood of undergoing an epidural blood patch related to age, body mass index, volume removed, opening pressure, the difference between opening and closing pressure, and the level of puncture within the IIH cohort. RESULTS: One hundred four IIH patients and 149 MS patients were included in the study. Among IIH patients, 12/104 (11.5%) underwent an epidural blood patch after LP as compared to 8/149 (5.4%) of the MS control patients (P = 0.086). Within the IIH population, none of the clinical or LP parameters were significantly correlated with increased risk of needing a blood patch. CONCLUSIONS: The incidence of low-pressure syndrome, as measured by blood patches, is similar in IIH patients and MS controls. This suggests that having elevated intracranial pressure before an LP is not protective against developing postpuncture low-pressure syndrome, contrary to common assumptions.

Cerebral Venous Thrombosis in Spontaneous Intracranial Hypotension: A Report on 4 Cases and a Review of the Literature.

OBJECTIVE: Spontaneous intracranial hypotension is a risk factor for cerebral venous thrombosis. The occurrence of cerebral venous thrombosis in patients with spontaneous intracranial hypotension raises difficult practical questions regarding the management of the 2 conditions. We reviewed our experience and the relevant literature to evaluate these related questions. METHODS: We retrospectively studied the medical records and imaging studies of patients with spontaneous intracranial hypotension at a tertiary center from January 2007 through January 2017. The main search strategy was a literature review of journal articles in PubMed (1966 to January 2017). RESULTS: Among 374 patients with spontaneous intracranial hypotension, 4 were also diagnosed with cerebral venous thrombosis. A literature review yielded an additional 31 cases, including 21 men and 14 women with a mean age of 40.6 years. Of the 35 patients, 8 (22.8%) patients received anticoagulation therapy and epidural blood patch. Nineteen (54.3%) patients were given anticoagulant only. Seven (20%) patients were treated with epidural blood patch only. One (2.9%) patient did not receive epidural blood patch or anticoagulation therapy. There is no difference in terms of age, sex, diagnosis interval, association with other complications, and prognosis between the first 3 groups. Of the 19 patients who received anticoagulation therapy, 4 patients (21.1%) had intracranial hemorrhage or hematoma enlargement after anticoagulation, and one of these 4 patients died following further intracranial hemorrhage. Of the 8 patients who received both anticoagulation and epidural blood patch, 1 patient (12.5%, P = 0.528) developed subdural hematoma after anticoagulation. Of the 5 cases had intracranial hemorrhage aggravation after anticoagulation, 4 were subdural hematoma occurrence or enlargement. CONCLUSION: Cerebral venous thrombosis is a rare but important complication of spontaneous intracranial hypotension. The primary focus of treatment should be the treatment of intracranial hypotension. It could be possible that anticoagulation might increase the risk of intracranial hemorrhage in patients with spontaneous intracranial hypotension, although a firm conclusion could not be drawn based on the limited number of patients currently available. The use of anticoagulation therapy should be prudent and should be monitored carefully if initiated.

Hemodynamic Instability and Cardiovascular Events After Traumatic Brain Injury Predict Outcome After Artifact Removal With Deep Belief Network Analysis.

BACKGROUND: Hemodynamic instability and cardiovascular events heavily affect the prognosis of traumatic brain injury. Physiological signals are monitored to detect these events. However, the signals are often riddled with faulty readings, which jeopardize the reliability of the clinical parameters obtained from the signals. A machine-learning model for the elimination of artifactual events shows promising results for improving signal quality. However, the actual impact of the improvements on the performance of the clinical parameters after the elimination of the artifacts is not well studied. MATERIALS AND METHODS: The arterial blood pressure of 99 subjects with traumatic brain injury was continuously measured for 5 consecutive days, beginning on the day of admission. The machine-learning deep belief network was constructed to automatically identify and remove false incidences of hypotension, hypertension, bradycardia, tachycardia, and alterations in cerebral perfusion pressure (CPP). RESULTS: The prevalences of hypotension and tachycardia were significantly reduced by 47.5% and 13.1%, respectively, after suppressing false incidents (P=0.01). Hypotension was particularly effective at predicting outcome favorability and mortality after artifact elimination (P=0.015 and 0.027, respectively). In addition, increased CPP was also statistically significant in predicting outcomes (P=0.02). CONCLUSIONS: The prevalence of false incidents due to signal artifacts can be significantly reduced using machine-learning. Some clinical events, such as hypotension and alterations in CPP, gain particularly high predictive capacity for patient outcomes after artifacts are eliminated from physiological signals.

Impaired cerebrospinal fluid pressure.

Abnormalities of cerebrospinal fluid (CSF) pressure are relatively common and may lead to a variety of symptoms, with headache usually being the most prominent one. The clinical presentation of alterations in CSF pressure may vary significantly and show a striking similitude to several primary headache syndromes. While an increase in CSF pressure may be of primary or secondary origin, a pathologic decrease of CSF pressure is usually the result of a meningeal rupture with a resulting leakage of CSF. The pathophysiologic mechanisms of idiopathic intracranial hypertension (IIH) remain largely unknown. However recent evidence indicates that an abnormality in CSF outflow and absorption is likely to play a significant role. Treatment usually consists of a combination of weight loss and a pharmacologic approach using carbonic anhydrase inhibitors. Recent results of the first randomized, double-blind, placebo-controlled trial (RCT) with acetazolamide proved its efficacy in reducing headache and visual disturbances. Clinical evidence suggests efficacy for topiramate and furosemide but no RCT has been conducted to date to confirm these results. In contrast to IIH, spontaneous intracranial hypotension frequently remits spontaneously without specific treatment. If necessary, treatment options range from conservative methods to epidural blood or fibrin sealant patches and surgical interventions.

Misdiagnosis of Spontaneous Intracranial Hypotension as a Risk Factor for Subdural Hematoma.

OBJECTIVE: This study aimed to evaluate the association between misdiagnosis of spontaneous intracranial hypotension (SIH) and subdural hematoma development. BACKGROUND: Although SIH is more prevalent than expected and causes potentially life-threatening complications including subdural hematoma (SDH), the association between misdiagnosis of SIH and SDH development is not yet evaluated. METHODS: Retrospective observational study was conducted between January 1, 2005, and December 31, 2014. Adult patients with spontaneous intracranial hypotension (age ≥ 18 years) were enrolled. RESULTS: Of the 128 patients with SIH, 111 (86.7%) were in no SDH group and 17 (13.3%) were in SDH group. Their clinical presentation did not show significant different between the two groups, except age, the days from symptom onset to correct diagnosis, and the number of misdiagnoses. Age (odds ratio [OR], 1.15; 95% confidence interval [CI], 1.07-1.23) and the number of times SIH was misdiagnosed (OR, 1.82; 95% CI, 1.03-3.21) were independent risk factors for the development of SDH in SIH patients by multivariate logistic analysis. The clinical outcomes, including length of hospital stay and revisit rate, were similar in the two groups. CONCLUSIONS: The number of times SIH was misdiagnosed was associated with the later development of SDH perhaps because of delay in correct diagnosis of SIH. Clinicians would prevent the later complication of SDH in SIH patients by increasing the awareness and a high index of suspicion of SIH.

Spontaneous Intracranial Hypotension: A Review and Introduction of an Algorithm For Management.

BACKGROUND: Spontaneous intracranial hypotension (SIH) is a condition of low cerebrospinal fluid volume and pressure caused by a leak of cerebrospinal fluid through a dural defect. Diagnosis and management can be difficult, often requiring coordination between multiple disciplines for myelography, blood patching, and possible surgical repair. Patients should be monitored closely, because they can deteriorate into a coma or even death. There are no widely accepted guidelines for the management of SIH. METHODS AND CONCLUSIONS: We review the existing SIH literature, illustrate management challenges via a case review, and propose an algorithm developed by neurosurgeons, radiologists, and anesthesiologists intended to simplify and streamline the management of SIH.

Intraoperative Secondary Insults During Orthopedic Surgery in Traumatic Brain Injury.

BACKGROUND: Secondary insults worsen outcomes after traumatic brain injury (TBI). However, data on intraoperative secondary insults are sparse. The primary aim of this study was to examine the prevalence of intraoperative secondary insults during orthopedic surgery after moderate-severe TBI. We also examined the impact of intraoperative secondary insults on postoperative head computed tomographic scan, intracranial pressure (ICP), and escalation of care within 24 hours of surgery. MATERIALS AND METHODS: We reviewed medical records of TBI patients 18 years and above with Glasgow Coma Scale score <13 who underwent single orthopedic surgery within 2 weeks of TBI. Secondary insults examined were: systemic hypotension (systolic blood pressure<90 mm Hg), intracranial hypertension (ICP>20 mm Hg), cerebral hypotension (cerebral perfusion pressure<50 mm Hg), hypercarbia (end-tidal CO2>40 mm Hg), hypocarbia (end-tidal CO2<30 mm Hg in absence of intracranial hypertension), hyperglycemia (glucose>200 mg/dL), hypoglycemia (glucose<60 mg/dL), and hyperthermia (temperature >38°C). RESULTS: A total of 78 patients (41 [18 to 81] y, 68% male) met the inclusion criteria. The most common intraoperative secondary insults were systemic hypotension (60%), intracranial hypertension and cerebral hypotension (50% and 45%, respectively, in patients with ICP monitoring), hypercarbia (32%), and hypocarbia (29%). Intraoperative secondary insults were associated with worsening of head computed tomography, postoperative decrease of Glasgow Coma Scale score by ≥2, and escalation of care. After Bonferroni correction, association between cerebral hypotension and postoperative escalation of care remained significant (P<0.001). CONCLUSIONS: Intraoperative secondary insults were common during orthopedic surgery in patients with TBI and were associated with postoperative escalation of care. Strategies to minimize intraoperative secondary insults are needed.

Sex- and Age-Related Differences in the Clinical and Neuroimaging Characteristics of Patients With Spontaneous Intracranial Hypotension: A Records Review.

BACKGROUND: The significance of sex- and age-related differences in the clinical course of spontaneous intracranial hypotension (SIH) was investigated. METHODS: We retrospectively studied 40 consecutive patients (female:male = 28:12, median age 41.5 years) treated under clinical diagnoses of SIH satisfying the International Classification of Headache Disorders 3rd edition criteria, including 37 patients (92.5%) with diffuse pachymeningeal enhancement. The patients were divided into two groups by age and sex, and the clinical and neuroimaging findings in each group were investigated. RESULTS: Acute onset (female:male = 82.1%:50.0%, P = .042), severe headache (75.0%:41.7%, P = .045) occurred with higher frequency in females than in males, and SDH occurred with lower frequency in females than in males (28.6%:75.0%, P = .006). Duration until the consultation (2:14 days, P = .022), SDH thickness (0:7.1 mm, P = .001), and iter displacement (1.6:7.1 mm, P = .004) was greater in males. Acute onset (Younger [≤40 years]: older [>40 years] = 94.1%:56.5%, P = .012), occurred with higher frequency in younger patients, and duration until the consultation (1:5 days, P = .001), frequency of SDH (17.7%:60.9%, P = .010), SDH thickness (0:5.9 mm, P = .003), in older patients. All nine patients with thunderclap headache were female, with median age of 37 years. CONCLUSIONS: More severe clinical symptoms with acute onset were observed in females and younger patients of SIH. Comparatively rare subdural hygroma/hematoma on magnetic resonance imaging might result from the shorter duration to diagnosis in females and younger patients. KEY WORDS: spontaneous intracranial hypotension, sex, age, magnetic resonance imaging, thunderclap headache.

Iatrogenic intracranial hypotension and cerebral venous thrombosis.

OBJECTIVE: To assess the manifestations of cerebral venous thrombosis (CVT) associated with intracranial hypotension (IH) following lumbar puncture (LP) or spinal anesthesia (SA). METHODS: Adult patients with acute CVT unrelated to infection, neurosurgery, or otolaryngological surgery were identified. CVT manifesting within 21days after LP/SA was considered associated with iatrogenic IH. Presentation of patients with and without associate IH was compared. RESULTS: 42 patients were included. 11/42 who had undergone LP/SA presented symptoms and imaging characteristics of IH; 31 had no evidence of IH. Those with IH were more often females (11/11 vs. 21/31, p=0.03), presented sooner after symptom onset (6.0±2.2 vs. 15.6±14days, p=0.002), and rates of venous infarction (45% vs. 23%) and seizures (27% vs. 10%) appeared somewhat elevated (p<0.15). Patients with CVT associated with IH had significantly more cortical vein thrombi (55% vs. 16%, p=0.02). Thrombi were significantly shorter in patients with IH (102±113mm vs. 246±133mm, p=0.002). CONCLUSION: Patients with CVT secondary to IH were typically younger females, and presented with a more acute and severe course with frequent venous infarcts. Although thrombi in the IH group were less extensive, they were more often symptomatic.

Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits.

PURPOSE: Intracranial hypotension has been reported as a complication of accidental drainage after surgical treatment in several cases. Application of negative pressure systems (wound drains, VAC(®)-therapy, chest tube drainage) had typically led to severe intracranial hypotension including intracranial hemorrhage and tonsillar herniation. In the last year the authors observed 2 cases of accidental spinal drainage of CSF in patients with neurological deficits, regressing after reduction of the device suction. MATERIAL AND METHODS: We conducted a systematic PubMed-based research of the literature to study the variety and frequency of the reported symptoms from 1st of January 1980 until 1st of October 2015. RESULTS: Reviewing the literature 24 relevant citations including 27 reported cases of posttraumatic or postoperative loss of CSF leading to neurological symptoms were identified. All 15 reported cases in which a negative pressure suction device had been applied showed severe neurological and radiological symptoms such as coma or brain herniation and intracranial hemorrhage. In all cases patients recovered rapidly after removal of the suction device. Milder symptoms were observed in the patients without negative pressure suction, mainly only presenting with headaches or cranial nerve involvement.Additionally, we give an overview about current recommendations regarding cranial and spinal imaging to rule out dural laceration and cranial hypotension. CONCLUSION: Patients with dural laceration complicated by accidental drainage of CSF can present with life-threatening conditions. Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis. A precise radiological examination can help to rule out dural laceration and intracranial hypotension. KEY POINTS: • Undetected dural laceration complicated by negative pressure suction drains can induce life-threatening symptoms.• Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis for radiologists Citation Format: • Sporns PB, Schwindt W, Cnyrim CD et al. Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits. Fortschr Röntgenstr 2016; 188: 451 - 458.

How common is normal cerebrospinal fluid pressure in spontaneous intracranial hypotension?

Objectives To determine the proportion of patients with spontaneous intracranial hypotension (SIH) who had a cerebrospinal fluid (CSF) pressure >6 cm H2O and to investigate the clinical and imaging variables associated with CSF pressure ( PCSF) in this condition. Methods We retrospectively reviewed 106 patients with SIH. PCSF was measured by lumbar puncture prior to treatment. Clinical and imaging variables - including demographic data, brain imaging results, symptom duration, and abdominal circumference - were collected. Univariate and multivariate analyses were performed to determine the correlation of these variables with PCSF. Results Sixty-one percent of patients had a PCSF between 6 and 20 cm H2O; only 34% had a PCSF ≤6 cm H2O. The factors associated with increased PCSF included abdominal circumference ( p < 0.001), symptom duration ( p = 0.015), and the absence of brain magnetic resonance imaging findings of SIH ( p = 0.003). A wide variability in PCSF was observed among all patients, which was not completely accounted for by the variables included in the model. Conclusions Normal CSF pressure is common in patients with SIH; the absence of a low opening pressure should not exclude this condition. Body habitus, symptom duration, and brain imaging are correlated with PCSF measurements, but these factors alone do not entirely explain the wide variability in observed pressures in this condition and this suggests the influence of other factors.

Intracranial hypotension: clinical presentation, imaging findings, and imaging-guided therapy.

PURPOSE OF REVIEW: To illustrate clinical presentations, imaging findings, and diagnostic and therapeutic approaches associated with various conditions of intracranial hypotension. RECENT FINDINGS: Intracranial hypotension occurs spontaneously, following (lumbar) dural puncture, accidental dural opening, or excessive surgical cerebrospinal fluid drainage. The typical clinical manifestation - orthostatic headache - may be masqueraded by atypical clinical findings, including coma, frontotemporal dementia, leptomeningeal hemosiderosis-associated symptoms, and others. MRI signs are highly specific, but the imaging strategy to search for spinal cerebrospinal fluid leaks (none, computed tomography myelography, magnetic resonance myelography with gadolinium, digital subtraction myelography) is a matter of debate. The same is true for the mode of treatment (bed rest, blind, fluoroscopy or computed tomography-guided epidural blood patching, fibrin patching, surgery). SUMMARY: Clinical presentation as well as diagnostic and therapeutic approaches in intracranial hypotension are very heterogenous.