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Background: Magnetic resonance imaging may suggest spinal cord compression and structural lesions in degenerative cervical myelopathy (DCM) but cannot reveal functional impairments in spinal pathways. We aimed to assess the value of contact heat evoked potentials (CHEPs) in addition to MRI and hypothesized that abnormal CHEPs may be evident in DCM independent of MR-lesions and are related to dynamic mechanical cord stress., Methods: Individuals with DCM underwent neurologic examination including segmental sensory (pinprick, light touch) and motor testing. The presence or absence of hyperintense signal on T2-weighted MRI (T2-positive/negative) was assessed. Phase-contrast MRI was used to assess spinal cord motion as an indicator of dynamic mechanical stress. Dermatomal somatosensory evoked potentials and CHEPs were recorded after stimulation of dermatomes C6, C8, and T4 (CHEPs only) to assess spinal cord integrity., Results: Of 138 individuals included in this study (age 56 ± 13 years), 35% (N = 48) presented with T2-positive and 65% (N = 90) presented with T2-negative DCM. Abnormal CHEPs were present in T2-positive DCM (C6:41%; C8:32%; T4:24%) and T2-negative DCM (C6:35%; C8:54%; T4:26%). Multisegmental CHEP abnormalities at C6 and C8 were related to increased spinal cord motion (p = 0.030; ϵ 2  = 0.072), and reduced upper extremity pinprick (p = 0.046; ϵ 2  = 0.063) and motor scores (p = 0.005; ϵ 2  = 0.108)., Conclusions: CHEPs revealed distinct patterns of spinal cord impairment independent of structural T2-positive lesions, which were associated with measures of cord motion. CHEPs thus provide valuable complementary diagnostic insights into spinal cord integrity beyond MRI. This is especially important in incipient myelopathy to inform early diagnosis and timely interventions before the development of definite cord lesions., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background and Purpose: In 1916, Hans H. G. Queckenstedt (1876-1918) was the first to describe a test aimed at detecting spinal cerebrospinal fluid (CSF) space obstruction through lumbar CSF pressure measurements in paraplegic patients. For this test, bilateral jugular vein compression was applied during lumbar puncture and consecutive changes in lumbar CSF pressure were then observed. Findings were rated as normal, or indicative of incomplete or complete spinal block. This test, known as Queckenstedt's test, became widely adopted and further developed in the field., Methods: This systematic literature review provides an overview of the milestones in research using Queckenstedt's test., Results: Clinical research involving Queckenstedt's test was widely disseminated across the globe. In 1922, the proof of concept for Queckenstedt's test was provided by James B. Ayer (1882-1963) through simultaneous cisternal and lumbar CSF pressure measurements. He found that the cisternal (in contrast to lumbar) pressure remained responsive in cases with spinal block. The test was further refined up until the 1960s, and was considered a routine diagnostic procedure for testing of spinal canal obstruction. Developments in non-invasive spinal computed tomography and magnetic resonance imaging led to a significant decline in interest in Queckenstedt's test, and the test eventually disappeared from textbooks and clinical routine. However, at the beginning of the 21st century there was renewed interest in revealing the biomechanical properties of the CSF through advanced recording and computational techniques to complement spinal imaging., Conclusion: Spine and spinal cord physicians should be familiar with Queckenstedt's test, which not only represented a milestone in spinal diagnostics, but provided a physiological framework for the appreciation of spinal cord compression that is still valid today., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background and Purpose: The timing of decision-making for a surgical intervention in patients with mild degenerative cervical myelopathy (DCM) is challenging. Spinal cord motion phase contrast MRI (PC-MRI) measurements can reveal the extent of dynamic mechanical strain on the spinal cord to potentially identify high-risk patients. This study aims to determine the comparability of axial and sagittal PC-MRI measurements of spinal cord motion with the prospect of improving the clinical workup., Methods: Sixty-four DCM patients underwent a PC-MRI scan assessing spinal cord motion. The agreement of axial and sagittal measurements was determined by means of intraclass correlation coefficients (ICCs) and Bland-Altman analyses., Results: The comparability of axial and sagittal PC-MRI measurements was good to excellent at all cervical levels (ICCs motion amplitude: .810-.940; p < .001). Significant differences between axial and sagittal amplitude values could be found at segments C3 and C4, while its magnitude was low (C3: 0.07 ± 0.19 cm/second; C4: -0.12 ± 0.30 cm/second). Bland-Altman analysis showed a good agreement between axial and sagittal PC-MRI scans (coefficients of repeatability: minimum -0.23 cm/second at C2; maximum -0.58 cm/second at C4). Subgroup analysis regarding anatomic conditions (stenotic vs. nonstenotic segments) and different velocity encoding (2 vs. 3 cm/second) showed comparable results., Conclusions: This study demonstrates good comparability between axial and sagittal spinal cord motion measurements in DCM patients. To this end, axial and sagittal PC-MRI are both accurate and sensitive in detecting pathologic cord motion. Therefore, such measures could identify high-risk patients and improve clinical decision-making (ie, timing of decompression)., (© 2022 The Authors. Journal of Neuroimaging published by Wiley Periodicals LLC on behalf of American Society of Neuroimaging.)