When does too little pressure become too much? A case of spontaneous intracranial hypotension presenting with acute loss of consciousness.

Background: We present a unique case of spontaneous intracranial hypotension (SIH) presenting with acute collapse and loss of consciousness. Case Description: The affected patient suffered an abrupt decline in level of consciousness several weeks after initial diagnosis. The patient was urgently transferred to a specialist neurosurgical unit. Imaging showed bilateral subdural fluid collections with significant associated local mass effect. The treating team faced a clinical conundrum with a lack of clarity as to whether this sudden deterioration was secondary to the local pressure effect on brainstem traction from reduced intracranial pressure. A decision was made to proceed with urgent burr-hole decompression of the bilateral subdural fluid collections. Conclusion: After a protracted, complex postoperative course, the patient recovered to full functional independence. To the author's knowledge, this is the first case in literature describing successful surgical management of SIH, with bilateral burr-hole evacuation to relieve the paradoxical mass effect of bilateral subdural fluid collections.

Cauda equina syndrome.

Aims: Patients with cauda equina syndrome (CES) require emergency imaging and surgical decompression. The severity and type of symptoms may influence the timing of imaging and surgery, and help predict the patient's prognosis. Categories of CES attempt to group patients for management and prognostication purposes. We aimed in this study to assess the inter-rater reliability of dividing patients with CES into categories to assess whether they can be reliably applied in clinical practice and in research. Methods: A literature review was undertaken to identify published descriptions of categories of CES. A total of 100 real anonymized clinical vignettes of patients diagnosed with CES from the Understanding Cauda Equina Syndrome (UCES) study were reviewed by consultant spinal surgeons, neurosurgical registrars, and medical students. All were provided with published category definitions and asked to decide whether each patient had 'suspected CES'; 'early CES'; 'incomplete CES'; or 'CES with urinary retention'. Inter-rater agreement was assessed for all categories, for all raters, and for each group of raters using Fleiss's kappa. Results: Each of the 100 participants were rated by four medical students, five neurosurgical registrars, and four consultant spinal surgeons. No groups achieved reasonable inter-rater agreement for any of the categories. CES with retention versus all other categories had the highest inter-rater agreement (kappa 0.34 (95% confidence interval 0.27 to 0.31); minimal agreement). There was no improvement in inter-rater agreement with clinical experience. Across all categories, registrars agreed with each other most often (kappa 0.41), followed by medical students (kappa 0.39). Consultant spinal surgeons had the lowest inter-rater agreement (kappa 0.17). Conclusion: Inter-rater agreement for categorizing CES is low among clinicians who regularly manage these patients. CES categories should be used with caution in clinical practice and research studies, as groups may be heterogenous and not comparable.

A case of chronic dysaesthesia in the torso and upper limbs: lessons from a cervical spinal cord subependymoma.

INTRODUCTION: Subependymomas are slow growing WHO grade 1 tumours, typically attached to the ventricular wall of the fourth or lateral ventricles. Spinal subependymomas are rarer still and experience of their biological characteristics remains limited. CASE PRESENTATION: A 29-year-old lady presented with chronic attacks of itchy dysaesthesia involving the left hand, neck and trunk, and associated with ipsilateral leg spasms. Recent symptomatic change involved occasional limping and left sided facial numbness but no pain. MRI showed an intradural mass surrounding most of the cervical spinal cord, which appeared scalloped extrinsically, rather than diffusely expanded, by a seemingly extramedullary lesion. At operation, the cord appeared expanded, with no clear margin or distinction between tumour and cord tissue; and the tumour was found to be intramedullary with an exophytic component, rather than extramedullary. Moderate reduction of the left abductor pollicis brevis evoked potential led to a pause in surgery. There was transient hand weakness postoperatively with full recovery, and no radiological change in the tumour morphology for a further 6 years. DISCUSSION: An intramedullary tumour such as a spinal cord subependymoma can be mistaken radiologically for an extramedullary tumour, such as an epidermoid. If a subependymoma is suspected, given its indolent course and long-term survival, caution in the extent of surgical resection is advisable in order to avoid surgical morbidity.

Spinal subependymoma surgery: do no harm. Little may be more!

OBJECTIVE:  Outline the reported diagnostic and operative findings, and evaluate the surgical treatment outcome to clarify the best available recommendations. METHODS:  Ovid Medline, Embase and PubMed central databases were searched from inception until January 2019 using the terms (subependymoma and (spinal or cervical or thoracic)). The articles were reviewed for reported spinal subependymoma cases perioperative management and treatment outcomes. RESULTS:  A total of 49 papers provided data on 105 cases. 47 cases were reported in the last 5 years. The reported cases were two medullary-cervical, 35 cervical, 32 cervicothoracic, 21 thoracic, 12 thoracolumbar and three lumbar. Spinal subependymomas typically arise from within the central spinal canal, giving the appearance of an intramedullary mass, usually eccentric to one side. Symptoms at presentation ranged between 1 month to 17 years, (mean 3.5 years, median 2 years) and were over 3 years in 36, and over 8 years in 12 cases. Sensory symptoms are the most frequent 75(80%), followed by weakness in 60(64%), pain in 45(48%) and sphincter disturbance in 24(25%). Postoperative neurological function was reported in 78 cases, and worsening was reported in 40 cases (51%), of which, 29 (72%) had complete resection, 6 (15%) had subtotal resection and 5 (12%) had partial resection. Neurological status remained the same in 24 (30%) and improved in 14 (18%). CONCLUSION:  The reviewed cases report a rate of 65% total resection of which 57% had worsened function after surgery. There were no reports of malignant transformation; therefore, long-term survival is expected, and surgical caution should be exercised where there is minimal symptom progression.