Accepted Manuscript Water-level sign: A vivid pictorial expression for a known neuroradiological phenomenon hitherto differently unclearly described Josef G. Heckmann, Stefan Ernst, Dieter Woischneck PII: DOI: Reference: S0022-510X(18)30012-1 doi:10.1016/j.jns.2018.01.009 JNS 15735 To appear in: Journal of the Neurological Sciences Received date: Revised date: Accepted date: 22 November 2017 22 December 2017 9 January 2018 Please cite this article as: Josef G. Heckmann, Stefan Ernst, Dieter Woischneck , Waterlevel sign: A vivid pictorial expression for a known neuroradiological phenomenon hitherto differently unclearly described. The address for the corresponding author was captured as affiliation for all authors. Please check if appropriate. Jns(2018), doi:10.1016/ j.jns.2018.01.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. ACCEPTED MANUSCRIPT Letter to the Editor Water-level sign: A vivid pictorial expression for a known neuroradiological phenomenon hitherto differently unclearly described PT Josef G. Heckmann1, Stefan Ernst2, Dieter Woischneck3 1 RI Department of Neurology, Municipal Hospital Landshut, Germany 2 SC Department of Radiology, Municipal Hospital Landshut, Germany 3 NU Department of Neurosurgery, Municipal Hospital Landshut, Germany Correspondence to: MA Prof. Dr. Josef G. Heckmann (MME), Department of Neurology, Municipal Hospital Landshut, Robert-Koch Str. 1, 84034 Landshut, Germany ED Telephone: +49 871 698 3719, Fax: +49 871 698 3467, E-mail: josef.heckmann@klinikum- Word count: AC C References: EP T landshut.de 895 10 Keywords: Blood-fluid level; fluid-blood level; fluid-fluid level; chronic subdural hematoma; spinal hemorrhage; cerebral metastasis; hemorrhagic space-occupying pituitary process ACCEPTED MANUSCRIPT Dear Editor, Cranial computed tomography (CCT) represents one of the most important contributions to neurological and neurosurgical practice. First reports on blood-fluid -, fluid-blood -, or fluidfluid level in CCT go back to 1979 [1]. These signs can be seen in cerebral hemorrhage PT related to tumors, trauma, amyloid angiopathy, arteriovenous malformations, and bleeding disorders [1-6]. In this report, the “water-level sign” is proposed as a superordinate term to RI describe the heterogeneous architecture of some fluid-containing cerebral and spinal SC processes. The fluid components behave literally like a water-level, allowing different parts of NU the fluid to be identified contributing to diagnosis and therapy. 1. Clinical presentation MA An 86-year-old woman was admitted with headache, dizziness, and slight left-sided weakness. Some days earlier, she had fallen. In the emergency department, she was found ED to have dysarthria, cognitive impairment, and frailty. Her head computed tomography (CT) scan showed a chronic subdural hematoma with heterogeneous compounds (Figure 1A). EP T Neurosurgical care was ordered, and the neurological findings were finally stabilized. A 78-year-old man who had been prescribed apixaban (2.5mg bid) and clopidogrel (75 mg AC C daily) reported on severe back pain. He showed a pronounced positive Lasègue test without focal abnormalities. Magnetic resonance imaging (MRI) of his spine demonstrated a marked hyperintense fluid level at the height of the second sacral vertebral body (Figure 1B), while MRI of his brain showed cortical superficial siderosis (CSS). The lumbar puncture revealed extensively hemorrhagic cerebrospinal fluid (CSF). As the complete imaging of the neuroaxis did not show another identifiable cause, a spinal subarachnoid hemorrhage in the context of CSS complicated by anticoagulant therapy in combination with clopidogrel was diagnosed. With conservative therapy, the patient recovered within three weeks. The clinical condition of this patient has been discussed elsewhere [7]. ACCEPTED MANUSCRIPT A 57-year-old woman was found at home having suffered an epileptic seizure. In the emergency department, she was slow to respond, did not follow commands, and was weaker on her right side than on her left side. Her medical records revealed a history of metastatic adenocarcinoma of the lung. A head CT scan showed cerebral metastasis (Figure 1C), in PT which the tumors revealed a partially hemorrhagic component with a level inside. As a RI progressed disease was diagnosed, palliative therapy was implemented. SC A 17-year-old woman reported blurred vision predominantly in her left eye. In addition, she developed a frontal headache. A galactorrhoea had been noted for about 16 months. NU Ophthalmologically, the vision in her left eye was strongly reduced (0.05), and there was no significant visual field restriction in the Goldman perimetry. Endocrinologically, prolactin was MA elevated (16 451 µU/ml). The MRI showed a hemorrhagic space-occupying pituitary process (Figure 1D). Via transsphenoidal surgery, the cystic hemorrhagic process was removed, and ED histologically, prolactioma was diagnosed (Figure 1D). The visual disorder markedly 2. Discussion In EP T diminished postoperatively, and cabergolin was prescribed. describing neuroradiological findings, visual metaphors are powerful aids for AC C understanding clinical associations [8]. Often metaphors are realigned to the objects they resemble, such as Mount Fuji, the peace symbol, animals, hot cross buns, and many others [8-10]. A water-level is a handcrafter’s tool used in masonry and carpentry to identify the horizontal direction. The integrated water, oil, or air pearl indicates the horizontal level. In the patients presented here, we encountered a two-fluid level in different disease entities. In chronic subdural hematoma, such a finding is frequent and indicates a layered appearance with the heavier part of the fluid (fresh blood) sintering, and the lighter one (more xanthochromous) ACCEPTED MANUSCRIPT collecting at the top. In the case of spinal hemorrhage, the two fluid components are the hemorrhagic and normal CSF [7], and in the cases of cerebral metastasis and the spaceoccupying cystic pituitary process, the fluid components consist of blood and necrotic or liquefied tumor tissue. Hitherto such findings were described as blood-fluid -, fluid-blood -, or fluid-fluid level depending on the different components of the process [1-6]. Here we propose PT the superordinate term “water-level sign” to illustrate such a finding and to memorize it more easily. The “water-level sign” describes the heterogeneous architecture of such a condition in SC RI which different parts of the fluid behave literally like a water level. The term may be useful in neurological practice for several reasons. First, the appearance of NU density of different fluids enables conclusions about the duration of the disease. Fresh or nearly fresh blood indicates an acute disease (intracerebral hemorrhage with or without MA ventricular involvement) or a worsening of a chronic process (chronic subdural hematoma). Second, a process with different densities separated by a level is more likely to be identified, ED as a monomorphic process can be easily overlooked. Third, the detection of the different fluid parts of a disease process has implications for the neurosurgical planning. This concerns the EP T type of surgery (endoscopic or open), the positioning of boreholes or trepanation, and the preparation of surgical tools. A water-levelled process may allow the recognition of potential elevated pressure and therefor the anticipation of brain shifts after puncture. The AC C preoperative and precise characterization is also important for the assessment of the process during intraoperative ultrasound or magnetic resonance imaging (MRI). In addition, it gives information on potential malignancy or the risk of bleeding. 3. Conclusion To conclude, the presence of such a “water-level sign” can “tell a story” of the diseased patient and can support clinicians in their diagnostic and therapeutic work. In a broad sense, even “gas-fluid” and “fat-fluid” level can be subordinated to the water-level. ACCEPTED MANUSCRIPT Figure legends A. Chronic subdural haematoma with fluid level (arrow) separating heavier fluid (mixed with fresh blood) and lighter fluid (hygroma). B. Sagittal view of the lumbar spinal magnetic resonance imaging (T2 weighted) showing PT sedimentation of blood in the sacral dural sac (the arrow indicates the fluid level between hemorrhagic and normal cerebrospinal fluid). RI C. Axial CT of the head demonstrates two hemorrhagic metastases with the fluid level inside SC (arrow). The primary tumor was adenocarcinoma of the lung. D. Sagittal view of cerebral magnetic resonance imaging (T2 weighted) in a supine position NU showing a space-occupying pituitary cyst with the fluid level (arrow). MA Contributorship JGH and SE were involved in patients´ care and drafted the original manuscript. DW ED contributed a critical review and neurosurgical considerations. EP T Funding The work was not supported by a funder Obtained AC C Patients consent Competing interests None ACCEPTED MANUSCRIPT References 1. Dublin AB, Norman D. Fluid-fluid level in cystic cerebral metastatic melanoma. J Comput Assist Tomogr 1979;3:650-652. 2. Richmond T, Viraponse C, Sarwar M, Kier EL, Rothman S. Intraparenchymal blood PT fluid levels. AJNR 1981;2:577-579. 3. Livioni JP, McGahan JP. Intracranial fluid-blood levels in the anticoagulated patient. RI Neuroradiology 1983;25:335-337. SC 4. Zilkha A. Intraparenchymal fluid-blood level: a CT sign of recent intracerebral hemorrhage. J Comput Assist Tomogr 1983;7:301-305. NU 5. Ichikawa K, Yanagihara C. Sedimentation level in acute intracerebral hematoma in a patient receiving anticoagulation therapy: an autopsy study. Neuroradiology MA 1998;40:380-382. 6. Mittal MK, Burkholder DB, Wijdicks EF. Blood-fluid level on computed tomography ED head: a sign of warfarin-associated intraparenchymal haemorrhage. Am J Emerg Med 2012;30:2079.e1-2079.e2. EP T 7. Heckmann JG. Spinal subarachnoid haemorrhage in cortical superficial siderosis after apixaban and clopidogrel therapy. J Thromb Thrombolysis 2016;41:654-655. 8. Gocmen R, Guler E, Kose IC, Oguz KK. Power of the metaphor: forty signs on brain AC C imaging. J Neuroimaging 2015;25:14-30. 9. Heckmann JG, Ganslandt O. The Mount Fuji sign. New Engl J Med 2004;350:1881. 10. Heckmann JG, Oberst G. Peace sign in calcified idiopathic hypertrophic pachymeningitis. Can J Neurol Sci 2014;41:26. Fig. 1 AC C EP T ED MA NU SC RI PT ACCEPTED MANUSCRIPT ACCEPTED MANUSCRIPT Highlights PT RI SC NU MA  ED  EP T  Neuroradiologically heterogeneous architecture of fluid containing processes can present with a blood-fluid -, fluid-blood -, or fluid- fluid level. As a superordinate term “water-level sign” is proposed as the fluid components behave literally like a water-level. Chronic subdural hematoma, spinal subarachnoid hemorrhage, cerebral metastasis, or cystic pituitary process can reveal such a finding If such a finding can be identified, it can contribute to diagnosis and therapy. AC C 