Metabolic and Toxic Myelopathies.

OBJECTIVE: This article reviews the clinical presentation, diagnostic evaluation, and treatment of metabolic and toxic myelopathies resulting from nutritional deficiencies, environmental and dietary toxins, drugs of abuse, systemic medical illnesses, and oncologic treatments. LATEST DEVELOPMENTS: Increased use of bariatric surgery for obesity has led to higher incidences of deficiencies in nutrients such as vitamin B12 and copper, which can cause subacute combined degeneration. Myelopathies secondary to dietary toxins including konzo and lathyrism are likely to become more prevalent in the setting of climate change leading to drought and flooding. Although modern advances in radiation therapy techniques have reduced the incidence of radiation myelopathy, patients with cancer are living longer due to improved treatments and may require reirradiation that can increase the risk of this condition. Immune checkpoint inhibitors are increasingly used for the treatment of cancer and are associated with a wide variety of immune-mediated neurologic syndromes including myelitis. ESSENTIAL POINTS: Metabolic and toxic causes should be considered in the diagnosis of myelopathy in patients with particular clinical syndromes, risk factors, and neuroimaging findings. Some of these conditions may be reversible if identified and treated early, requiring careful history, examination, and laboratory and radiologic evaluation for prompt diagnosis.

Diagnostic and prognostic significance of preoperative evoked potential tests in degenerative cervical myelopathy.

BACKGROUND CONTEXT: Decompression surgery is a treatment option for patients with degenerative cervical myelopathy (DCM). Surgical decisions primarily depend on clinical symptoms and radiological examinations. The diagnostic and prognostic significance of evoked potential tests for surgical outcomes in patients with DCM has not been thoroughly examined. PURPOSE: To identify the diagnostic and prognostic significance of preoperative evoked potential tests in patients with DCM who underwent decompression surgery. STUDY DESIGN: This was a retrospective observational study. PATIENT SAMPLE: One hundred two consecutive patients who underwent evoked potential tests and surgical treatment between January 2016 and December 2020 in a single spine center and had a minimum follow-up of 6 months. OUTCOME MEASURES: Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery. METHODS: This study evaluated the preoperative central motor conduction time (CMCT), somatosensory evoked potentials, and Japanese Orthopedic Association (JOA) scores obtained preoperatively and 6 months after surgery. RESULTS: Abnormal CMCT findings were observed in 94 patients (92.2%). Abnormal somatosensory evoked potentials were observed in 77 patients (75.5%). There was a statistically significant correlation between preoperative JOA score and abductor pollicis brevis (APB)-CMCT (r=-0.546, p=.001), tibialis anterior (TA)-CMCT (r=-0.517, p<.001), median nerve (MN)-SSEP (r=-0.353, p=.001), and tibial nerve (TN)-SSEP (r=-0.349, p=.003). There were significant differences in recovery rates associated with diabetes mellitus (DM), preoperative severity of myelopathy, TA-CMCT, MN-SSEP, and TN-SSEP. Stepwise multiple regression analysis showed that the major factors affecting the clinical outcomes were TN-SSEP (ß=0.327, p=.004), preoperative JOA score (ß=0.278, p=.012), and DM (ß=0.241, p=.025). CONCLUSIONS: Evoked potential testing is a functional diagnostic tool that can indicate the severity of myelopathic symptoms in patients with DCM. Additionally, preoperative TN-SSEP may have significant prognostic value in predicting postoperative clinical outcomes. Thus, preoperative evoked potential tests could be helpful for determining suitable surgical treatment candidates and forecasting postoperative prognosis.

Subclinical respiratory dysfunction and impaired ventilatory adaptation in degenerative cervical myelopathy.

Degenerative cervical myelopathy (DCM) is a debilitating neurological condition characterized by chronic compression of the cervical spinal cord leading to impaired upper and lower limb function. Despite damage to areas of the cervical spinal cord that house the respiratory network, respiratory dysfunction is not a common symptom of DCM. However, DCM may be associated with respiratory dysfunction, and this can affect the ventilatory response to respiratory challenges during emergence from anesthesia, exercise, or pulmonary disease. Surgical spinal cord decompression, which is the primary treatment for DCM, leads to improved sensorimotor function in DCM; yet its impact on respiratory function is unknown. Here, using a clinically relevant model of DCM, we evaluate respiratory function during disease progression and assess adaptive ventilation to hypercapnic challenge before and after surgical intervention. We show that despite significant and progressive forelimb and locomotor deficits, there was no significant decline in eupneic ventilation from the early to late phases of spinal cord compression. Additionally, for the first time, we demonstrate that despite normal ventilation under resting conditions, DCM impairs acute adaptive ventilatory ability in response to hypercapnia. Remarkably, akin to DCM patients, surgical decompression treatment improved sensorimotor function in a subset of mice. In contrast, none of the mice that underwent surgical decompression recovered their ability to respond to hypercapnic ventilatory challenge. These findings underscore the impact of chronic spinal cord compression on respiratory function, highlighting the challenges associated with ventilatory response to respiratory challenges in individuals with DCM. This research highlights the impact of cervical spinal cord compression on respiratory dysfunction in DCM, as well as the persistence of adaptive ventilatory dysfunction after surgical spinal cord decompression. These results indicate the need for additional interventions to enhance recovery of respiratory function after surgery for DCM.

Management of mild degenerative cervical myelopathy and asymptomatic spinal cord compression: an international survey.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: Currently there is limited evidence and guidance on the management of mild degenerative cervical myelopathy (DCM) and asymptomatic spinal cord compression (ASCC). Anecdotal evidence suggest variance in clinical practice. The objectives of this study were to assess current practice and to quantify the variability in clinical practice. METHODS: Spinal surgeons and some additional health professionals completed a web-based survey distributed by email to members of AO Spine and the Cervical Spine Research Society (CSRS) North American Society. Questions captured experience with DCM, frequency of DCM patient encounters, and standard of practice in the assessment of DCM. Further questions assessed the definition and management of mild DCM, and the management of ASCC. RESULTS: A total of 699 respondents, mostly surgeons, completed the survey. Every world region was represented in the responses. Half (50.1%, n = 359) had greater than 10 years of professional experience with DCM. For mild DCM, standardised follow-up for non-operative patients was reported by 488 respondents (69.5%). Follow-up included a heterogeneous mix of investigations, most often at 6-month intervals (32.9%, n = 158). There was some inconsistency regarding which clinical features would cause a surgeon to counsel a patient towards surgery. Practice for ASCC aligned closely with mild DCM. Finally, there were some contradictory definitions of mild DCM provided in the form of free text. CONCLUSIONS: Professionals typically offer outpatient follow up for patients with mild DCM and/or asymptomatic ASCC. However, what this constitutes varies widely. Further research is needed to define best practice and support patient care.

[The differential diagnosis of inflammatory and non-inflammatory myelopathy].

The differential diagnosis of inflammatory and non-inflammatory myelopathy can be challenging. Clinical information such as age, gender, speed of onset and progression, systemic symptoms, spinal cord and brain MRI, autoantibodies, and cerebrospinal fluid findings are necessary. The speed of onset is particularly important for differentiation. Inflammatory myelopathy typically follows an acute/subacute course, while spinal cord infarction presents with a hyperacute course, and intramedullary tumors often have a chronic progressive course. Spinal dural arteriovenous fistula usually shows a chronic progressive course, but it can present with fluctuating symptoms in the early stages and may appear as an acute onset. It is essential to definitively exclude compressive myelopathy for the diagnosis of inflammatory myelopathy. Even if a definitive diagnosis cannot be made, regular reevaluation during treatment is necessary.

Demographics, clinical findings and diagnoses of cranial thoracic myelopathies (T1-T6 vertebrae) in cats.

OBJECTIVES: The aim of the study was to describe the patient demographics, clinicopathological features and presumptive or final diagnoses in cats with myelopathies between the T1 and T6 vertebrae. METHODS: This retrospective multicentre case study enrolled cases between 2015 and 2022 that were diagnosed with myelopathies between the T1 and T6 vertebrae as the primary cause for the presenting clinical signs. RESULTS: A total of 21 cases matched the inclusion criteria, 13 males (11 castrated and 2 entire) and 8 spayed females (median age 93 months; range 5-192). Most of the cases presented with a chronic and progressive history (76% and 86%, respectively), with a median duration of 29 days (range 1-2880). At the time of presentation, 90% of the cases were localised to the T3-L3 spinal cord segments based on neurological examination. The most common underlying pathology was neoplasia (42.9%), followed by inflammatory (24%), anomalous (19%), degenerative (9.5%) and vascular (4.8%) disorders. The most common location was T3-T4 (29%), followed by T2-T3 and T5-T6 (19% each). The cutaneous trunci reflex was normal in 86% of the cases and most of the cases (71%) did not show spinal discomfort upon admission. CONCLUSIONS AND RELEVANCE: Neoplasia was the most common cause of cranial thoracic myelopathy in this study. The lack of pathognomonic clinical signs for this specific region highlights the importance of assessing the entire thoracolumbar region up to and including at least the T1 vertebra when investigating cases with signs consistent with a T3-L3 myelopathy.

A screening method for cervical myelopathy using machine learning to analyze a drawing behavior.

Early detection of cervical myelopathy (CM) is important for a favorable outcome, as its prognosis is poor when left untreated. We developed a screening method for CM using machine learning-based analysis of the drawing behavior of 38 patients with CM and 66 healthy volunteers. Using a stylus pen, the participants traced three different shapes displayed on a tablet device. During the tasks, writing behaviors, such as the coordinates, velocity, and pressure of the stylus tip, along with the drawing time, were recorded. From these data, features related to the drawing pressure, and time to trace each shape and combination of shapes were used as training data for the support vector machine, a machine learning algorithm. To evaluate the accuracy, a receiver operating characteristic curve was generated, and the area under the curve (AUC) was calculated. Models with triangular waveforms tended to be the most accurate. The best triangular wave model identified patients with and without CM with 76% sensitivity and 76% specificity, yielding an AUC of 0.80. Our model was able to classify CM with high accuracy and could be applied to the development of disease screening systems useful outside the hospital setting.

Blood spinal cord barrier disruption recovers in patients with degenerative cervical myelopathy after surgical decompression: a prospective cohort study.

The pathophysiology of degenerative cervical myelopathy (DCM) is characterized by chronic compression-induced damage to the spinal cord leading to secondary harm such as disruption of the blood spinal cord barrier (BSCB). It is therefore the purpose of this study to analyze BSCB disruption in pre- and postoperative DCM patients and to correlate those with the clinical status and postoperative outcome. This prospectively controlled cohort included 50 DCM patients (21 female; 29 male; mean age: 62.9 ± 11.2 years). As neurological healthy controls, 52 (17 female; 35 male; mean age 61.8 ± 17.3 years) patients with thoracic abdominal aortic aneurysm (TAAA) and indication for open surgery were included. All patients underwent a neurological examination and DCM-associated scores (Neck Disability Index, modified Japanese Orthopaedic Association Score) were assessed. To evaluate the BSCB status, blood and cerebrospinal fluid (CSF) samples (lumbar puncture or CSF drainage) were taken preoperatively and in 15 DCM patients postoperatively (4 female; 11 male; mean age: 64.7 ± 11.1 years). Regarding BSCB disruption, CSF and blood serum were examined for albumin, immunoglobulin (Ig) G, IgA and IgM. Quotients for CSF/serum were standardized and calculated according to Reiber diagnostic criteria. Significantly increased preoperative CSF/serum quotients were found in DCM patients as compared to control patients: AlbuminQ (p < .001), IgAQ (p < .001) and IgGQ (p < .001). IgMQ showed no significant difference (T = - 1.15, p = .255). After surgical decompression, neurological symptoms improved in DCM patients, as shown by a significantly higher postoperative mJOA compared to the preoperative score (p = .001). This neurological improvement was accompanied by a significant change in postoperative CSF/serum quotients for Albumin (p = .005) and IgG (p = .004) with a trend of a weak correlation between CSF markers and neurological recovery. This study further substantiates the previous findings, that a BSCB disruption in DCM patients is evident. Interestingly, surgical decompression appears to be accompanied by neurological improvement and a reduction of CSF/serum quotients, implying a BSCB recovery. We found a weak association between BSCB recovery and neurological improvement. A BSCB disruption might be a key pathomechanism in DCM patients, which could be relevant to treatment and clinical recovery.

Symptomatic secondary spinal arachnoid cysts: a systematic review.

BACKGROUND CONTEXT: Secondary spinal arachnoid cysts have rarely been reported but present significant challenges for management. These cysts could be anteriorly located with long rostral-caudal extensions and many are related to arachnoiditis, leading to difficult-to-treat disorders. Thus far, due to the scarcity of reports, the features of the disease and the optimal therapeutic strategies remain unclear. PURPOSE: To investigate clinical features and the optimal treatment modalities of secondary spinal arachnoid cysts compared with primary spinal arachnoid cysts. STUDY DESIGN: Systematic review. PATIENT SAMPLE: Systematic review identified 103 secondary cases from 80 studies and reports. OUTCOME MEASURES: Condition of symptom relief and duration of treatment response were analyzed. METHODS: An electronic literature search of the PubMed database was conducted for studies on secondary spinal arachnoid cysts between 1990 and 2022. Non-English publications, nonhuman studies, reports of a primary cyst, studies not including case details, and studies of nonsymptomatic cases were excluded. RESULTS: This systematic review included 103 secondary cases. The most commonly reported etiologies were iatrogenic factors, trauma, and subarachnoid hemorrhage, accounting for 88 intradural extramedullary, 11 extradural, one intradural/extradural, one interdural, and one intramedullary spinal arachnoid cyst after a median duration of 30, 12, and 9 months, respectively. Extradural cysts were more prone to occur at dorsal locations and affect thoracic segments (mean cyst length: 3.4 segments). Intradural cysts showed a relatively higher ventral/dorsal ratio (1:1.09, 1.75:1, and 3.50:1 for cysts occurring from iatrogenic factors, trauma, and subarachnoid hemorrhage, respectively) and thoracic distribution, with a mean cyst length of 4.3 segments (5.1 for ventral and 3.5 for dorsal cysts). For intradural cysts, recurrence risk was lower after surgical resection than after fenestration/marsupialization (12-month recurrence risk: 21.43% vs 50.72%, log-rank test: p=.0248, Gehan-Breslow-Wilcoxon test: p=.0126). In cases treated with shunting, one recurrence (1/8 cases) was noted after external shunting and two recurrences (2/5 cases) after internal shunting at a median follow up of 12 months. CONCLUSIONS: Secondary spinal arachnoid cysts, particularly intradural cysts, are rarer and more challenging to treat than primary spinal cysts. Although fenestration/marsupialization is the commonly adopted treatment, the recurrence rate is high. For unresectable cysts, shunting procedures, particularly shunting into a body cavity (eg, pleural or peritoneal cavity) away from the subarachnoid space, could be a therapeutic alternative besides fenestration/marupialization, yet its efficacy requires confirmation by more data.

Spinal arachnoid webs in adults: Clinical and imaging features in a multicenter study.

BACKGROUND AND PURPOSE: Spinal arachnoid webs (SAWs) are rare and can present with myelopathic symptoms. This study aims to add 85 more cases of SAWs to the literature so we can continue to analyze clinical and imaging trends of SAWs to better understand this entity and its natural history. METHODS: An institutional review board-approved retrospective review of SAW cases between 2016 and 2022 within a metropolitan, multihospital network was performed, searching for MR and CT reports that included "arachnoid web." Of 108 identified reports, 85 patients had imaging and/or pathologically proven arachnoid webs. Demographic and clinical data were collected. Images were analyzed for SAW level, point of maximum kyphosis, presence of cord expansion, and signal intensity. The electronic medical record (EMR) was reviewed for age, sex, symptom presentation and duration, management, and outcomes. RESULTS: Of 85 cases, the most common presenting chief complaint was back pain and weakness. All (100%) SAWs were in the dorsal thoracic subarachnoid space, with 87% (74/85) located from thoracic (T) 2 to T6. Spinal cord expansion and signal abnormality were present in 54.1% and 23.5%, respectively. Twenty-six underwent surgical resection with 20 showing improvement of at least one symptom. CONCLUSION: We present 85 additional cases of SAWs to the existing literature. Our cases all occurred in the dorsal thoracic subarachnoid space, predominantly from T2 to T6. Patients present with symptoms like other causes of cord compression, and spinal MR studies should be evaluated routinely for the findings of SAWs. Further research could focus on understanding SAW prevalence, risk factors, and pathophysiology.

Myelopathy disability index: establishing criteria for mild, moderate and severe impairment in patients with degenerative cervical myelopathy.

PURPOSE: To find the cut-off values in the Myelopathy Disability Index (MDI) that will allow us to classify the severity of Degenerative Cervical Myelopathy (DCM) into mild, moderate and severe. METHODS: Cross-sectional study with prospective data collection, with a total of 64 patients diagnosed with Degenerative Cervical Myelopathy (DCM). Anthropometric, diagnostic, neurological, functional and quality of life variables were collected. A Receiver Operating Curve (ROC) was performed. The cut-off points were validated by comparing the functional status of patients in the 3 groups and their Nurick scores. RESULTS: Sixty-four patients (23 women) with a mean age of 61.97 (SD 11.57) participated in this study. The majority of patients were Nurick I (28.13%) and Nurick II (32.81%). The medium MDI was 7.36 (SD 6.66) and the mJOA was 14.08 (SD 2.57). The mild-moderate cut-off value was between 4 and 5, with an Area Under the Curve (AUC) of 0.805, sensitivity of 0.853 and specificity of 0.6. For moderate-severe, the cut-off value obtained was between 7 and 8, with an AUC of 0.862, sensitivity of 0.857 and specificity of 0.684. Patients with greater severity had significantly lower functionality, with a P-value of 0.004 in the 30 Metre Walking Test and 0.005 in the Nine-Hole Peg Test. Established severity groups were also significantly related to the different categories of the Nurick score (P-value = 0.000). CONCLUSION: MDI values between 0 and 4 correspond to mild DCM, between 5 and 7 would be moderate DCM and from 8 to 30 indicate severe DCM.

[Spinal neurosurgery: radiculopathy and myelopathy]. / Spinal neurokirurgi på grund av radikulopati och myelopati.

The field of spinal neurosurgery covers degenerative conditions and trauma as well as tumors, malformations and vascular disorders of spine and spinal cord. This article focuses on the Swedish spinal neurosurgical care regarding radiculopathy and myelopathy. Disc herniation, foraminal stenosis, spinal stenosis and spinal cord compression due to degenerative disorders or tumors are discussed. Treatment options such as anterior cervical decompression and fusion, posterior forami-notomy, laminectomy and approaches to spinal intradural tumors are briefly presented. The aim is to present symptoms, diagnostics and treatment options of common conditions to facilitate early detection and referral to neurosurgical centers to avoid delayed dia-gnosis and neurological impairment.

Spinal intradural arachnoid cyst associated with diastematomyelia in an adult: a case report and review of literature.

We report a case of a spinal intradural arachnoid cyst in a thirty year old female with a previously undiagnosed and untreated diastematomyelia. The cyst was located exactly between the two hemi-cords of the split cord malformation. The patient was treated successfully by laminoplasty and total removal of the cyst. Additionally, sectioning of the filium terminale was done in the same sitting by a separate incision. This case posed a diagnostic dilemma. Though the clinical findings favoured an extramedullary lesion, the possibility of cystic degeneration in the spinal cord due to the tethered cord syndrome could not be completely negated. Spinal intradural arachnoid cysts have been reported in association with various neural tube defects, mainly in the paediatric age group. However, such a lesion associated with diastematomyelia in an adult, to the best of our knowledge, has not been reported previously.

Establishing mild, moderate and severe criteria for the myelopathy disability index in cervical spondylotic myelopathy.

AIM: Cervical Spondylotic Myelopathy (CSM) is a disabling condition arising from arthritic compression and consequent injury of the cervical spinal cord. Stratification of CSM severity has been useful to inform clinical practice and research analysis. In the UK the Myelopathy Disability Index (MDI) is a popular assessment tool and has been adopted by the British Spinal Registry. However, no categories of severity exist. Therefore, the aim of this study was to define categories of mild, moderate and severe. METHOD: An anchor-based analysis was carried out on previously collected data from a prospective observational cohort (N = 404) of patients with CSM scheduled for surgery and assessed pre-operatively and at 3, 12, 24 and 60 months post-operatively. Outcomes collected included the SF-36 version-1 quality of life measure, visual analogue scales for neck/arm/hand pain, MDI and Neck Disability Index (NDI). A Receiver Operating Curve (ROC) analysis, using the NDI for an anchor-based approach, was performed to identify MDI thresholds. RESULTS: Complete data was available for 404 patients (219 Men, 185 Women). The majority of patients underwent anterior surgery (284, 70.3%). ROC curves plotted to identify the thresholds from mild to moderate to severe disease, selected optimal thresholds of 4-5 (AUC 0.83) and 8-9 (AUC 0.87). These MDI categories were validated against domains of the SF36 and VAS scores with expected positive linear correlations. CONCLUSION: Categories of mild, moderate and severe CSM according to the MDI of 4-5 and 8-9 were established based on the NDI.

Determinants of quality of life in degenerative cervical myelopathy: a systematic review.

BACKGROUND: Degenerative cervical myelopathy (DCM) is the most common cause of chronic, progressive spinal cord impairment worldwide. Patients experience substantial pain, functional neurological decline and disability. Health-related quality of life (HRQoL) appears to be particularly poor, even when compared to other chronic diseases. However, the determinants of HRQoL are poorly understood. The objective was to perform a systematic review of the determinants of quality of life of people with DCM. METHODS: A systematic search was conducted in MEDLINE and Embase following PRISMA 2020 guidelines (PROSPERO CRD42018115675). Full-text papers in English, exclusively studying DCM, published before 26 March 2020 were eligible for inclusion and were assessed using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias 2 (RoB 2) tool. Study sample characteristics, patient demographics, cohort type, HRQoL instrument utilised, HRQoL score, and relationships of HRQoL with other variables were qualitatively synthesised. RESULTS: A total of 1176 papers were identified; 77 papers and 13,572 patients were included in the final analysis. A total of 96% of papers studied surgical cohorts and 86% utilised the 36-Item Short Form Survey (SF-36) as a measure of HRQoL. HRQoL determinants were grouped into nine themes. The most common determinant to be assessed was surgical technique (38/77, 49%) and patient satisfaction and experience of pain (10/77, 13%). HRQoL appeared to improve after surgery. Pain was a negative predictor of HRQoL. CONCLUSION: Current data on the determinants of HRQoL in DCM are limited, contradictory and heterogeneous. Limitations of this systematic review include lack of distinction between DCM subtypes and heterogenous findings amongst the papers in which HRQoL is measured postoperatively or post-diagnosis. This highlights the need for greater standardisation in DCM research to allow further synthesis. Studies of greater precision are necessary to account for HRQoL being complex, multi-factorial and both time and context dependent.

Surgical Outcome of Spinal Subdural Abscesses: A Report of Four Consecutive Patients and Brief Review of the Literature.

BACKGROUND AND STUDY AIMS: Spinal subdural abscesses (SSAs) are rare and have a poor prognosis, especially when they are diagnosed late. In the literature, most cases of SSAs have been reported as case reports and small case series. In this study, we aimed to evaluate the surgical outcomes of four consecutive SSA patients. MATERIAL AND METHODS: In this retrospective study, we reviewed the medical charts of four SSA patients who underwent surgical intervention at two neurosurgical centers from September 2012 to September 2019. RESULTS: Our series comprised four patients (three females and one male) with SSA (intradural-extramedullary) who were treated surgically. Holocord SSA was observed in two patients. The mean age was 15.1 ± 17.1 years. Unsteady gait and weakness of legs was the presenting symptom in all patients. The mean preoperative course was 5.3 ± 3.4 weeks. The causative pathogens were methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, and Mycobacterium tuberculosis. In the fourth case, the pathogen was non-M. tuberculosis. In the 44th postoperative month, the patient underwent surgery for an intramedullary abscess. The causative pathogen was E. coli. Except for one adolescent male who was paraplegic at presentation, improvement was observed in all patients at their last follow-up after 54.0 ± 35.9 months after surgery. CONCLUSION: Early diagnosis and urgent surgical intervention are essential for a good prognosis in SSA cases. We recommend drainage followed by appropriate antibiotics.

A Rare Case of Idiopathic Spinal Cord Herniation Treated by DuraGen® Collagen Matrix Graft.

We report a rare case of idiopathic spinal cord herniation (ISCH) with a history of cerebrospinal fluid (CSF) leakage. ISCH is a protrusion of the spinal cord through a dural defect. Thin constructive interference in steady-state (CISS) images clearly demonstrated the herniated cord in the present case. The myelopathy worsened and the patient underwent surgery for reduction of herniated spinal cord; the dural defect was filled by placing collagen matrix graft (DuraGen®) between the inner and outer dural layers. The patient's symptoms have improved without relapse for 8 months since surgery. This method may be a good surgical option for cases of spinal cord herniation.

Salvage Surgery for Symptomatic Recurrence of Retro-Odontoid Pseudotumor after a C1 Laminectomy.

We provide the first report of successful salvage surgery for a post-C1 laminectomy symptomatic recurrence of a retro-odontoid pseudotumor (ROP) that caused myelopathy. The 72-year-old Japanese woman presented with an ROP causing symptomatic cervical myelopathy. With ultrasonography support, we performed the enucleation of the ROP via a transdural approach and fusion surgery for the recurrence of the mass. At the final observation 2-year post-surgery, MRI demonstrated the mass's regression and spinal cord decompression, and the patient's symptoms had improved. Our strategy is an effective option for a symptomatic recurrence of ROP.

Identification of specific causes of myelopathy in a large cohort of patients initially diagnosed with transverse myelitis.

BACKGROUND AND OBJECTIVES: Identifying the etiologic diagnosis in patients presenting with myelopathy is essential in order to guide appropriate treatment and follow-up. We set out to examine the etiologic diagnosis after comprehensive clinical evaluation and diagnostic work-up in a large cohort of patients referred to our specialized myelopathy clinic, and to explore the demographic profiles and symptomatic evolution of specific etiologic diagnoses. METHODS: In this retrospective study of patients referred to the Johns Hopkins Myelitis and Myelopathy Center between 2006 and 2021 for evaluation of "transverse myelitis", the final etiologic diagnosis determined after comprehensive evaluation in each patient was reviewed and validated. Demographic characteristics and temporal profile of symptom evolution were recorded. RESULTS: Of 1193 included patients, 772 (65%) were determined to have an inflammatory myelopathy and 421 (35%) were determined to have a non-inflammatory myelopathy. Multiple sclerosis/clinically isolated syndrome (n = 221, 29%) and idiopathic myelitis (n = 149, 19%) were the most frequent inflammatory diagnoses, while spinal cord infarction (n = 197, 47%) and structural causes of myelopathy (n = 108, 26%) were the most frequent non-inflammatory diagnoses. Compared to patients with inflammatory myelopathies, patients with non-inflammatory myelopathies were more likely to be older, male and experience chronic symptom evolution (p < 0.001 for all). Hyperacute symptom evolution was most frequent in patients with spinal cord infarction (74%), while chronic symptom evolution was most frequent in patients with structural causes of myelopathy (81%), arteriovenous fistula or arteriovenous malformation (81%), myelopathy associated with rheumatologic disorder (71%), and sarcoidosis-associated myelopathy (61%). CONCLUSIONS: Patients initially diagnosed with "transverse myelitis" are eventually found to have a more specific inflammatory or even non-inflammatory cause, potentially resulting in inappropriate treatment and follow-up. Demographic characteristics and temporal profile of symptom evolution may help inform a differential diagnosis in these patients. Etiological diagnosis of myelopathies would provide better therapeutic decisions.