Gabapentin Superadded to a Pre-Existent Regime Containing Amytriptyline for Chronic Sciatica.

SETTING: There is currently a gross lack of evidence base guiding the medical management of chronic sciatica (CS). Only scant previous studies have assessed gabapentin (GBP) in CS. Extrapolating NICE-UK guidelines, prescribing authorities often insist on trialling anti-depressants (e.g., amytriptyline, AMP) as a first line for neuropathic pain states such as CS. When super-adding second-line agents, such as GBP, NICE-UK encourages overlap with first-line agents to avoid decreased pain-control. No study has reflected this practice. OBJECTIVE: Evaluate efficacy and side effects (SE) of GBP superadded to a pre-existent regime containing AMP for CS. SUBJECTS AND METHODS: Prospective cohort of patients with unilateral CS attending a specialist spine clinic. Eligible patients had experienced partial benefit to a pre-existent regime containing AMP: none had significant SE. No drugs other than GBP were added or discontinued (the latter was considered inequitable) for 3 months. Visual analog pain score (VAS), Oswestry disability index (ODI), and SE were recorded. RESULTS: Efficacy: in 56% (43/77) there were reductions in VAS (5.3 ± 3.6→2.8 ± 2.7, P < 0.0001) and ODI (42.8 ± 31.1→30.7 ± 25.2, P = 0.008). SE: Eighty-two SE (23 types) were reported in 53% (41/77). Efficacy was less in those with SE: a trend existed for a lesser reduction in VAS (2.0 ± 2.4 v 3.0 ± 2.7, P = 0.08), which proved significant for ODI (8.1 ± 11.4 v 16.7 ± 18.2, P = 0.01). Thirty-four percent (26/77) discontinued GBP all within 1 week (i.e., during titration). CONCLUSION: This is the first prospective cohort study of GBP super-added to a pre-existent regime containing AMP for CS, as per routine clinical practice and NICE-UK principles. Super-added GBP demonstrated further efficacy over the previous regime in 56%; however, SE were frequent (53%) and diverse (23 types), and 34% abruptly discarded GBP. Although SE were associated with decreased efficacy, 37% nevertheless tolerated GBP despite SE.

Posttraumatic Amnesia: A Systematic Review and Meta-Analysis. Proposal for a New Severity Classification.

BACKGROUND: Posttraumatic amnesia (PTA) duration is used to predict outcome after traumatic brain injury (TBI): however, no meta-analysis exists. METHODS: A systematic review was performed following PRISMA reporting guidelines. The databases Scopus-1966, PubMed/MEDLINE, CINAHL, PsycINFO, and Embase were searched for relevant texts. Random effects meta-analysis derived pooled estimates of the odds ratio of outcomes of interest and sensitivity and specificity of PTA at different cutoffs, and subsequently a summary receiver operating curve was derived. PTA prediction of Glasgow Outcome Scale (GOS) and Glasgow Outcome Scale-Extended (GOSE) scores was assessed both qualitatively and quantitatively by pooled odds ratio regarding both a good outcome (GO: GOS-5 or GOSE-7/GOSE-8) and a severe disability outcome (SDO: GOS-3 or a GOSE-3/GOSE-4). Summary receiver operating curve analysis was performed in the prediction of composite of a moderate disability outcome (MDO: GOS-4 or GOSE-5/GOSE-6) and SDO. RESULTS: Twenty-four studies were included in qualitative synthesis, and 9 (12,386 patients; males, 64%-84%) in meta-analysis. The odds of a GO and SDO were significantly different between PTA >56 days and PTA <7 days (P = 0.04 and P = 0.03). PTA <7 days (mild TBI) excluded MDO/SDO and SDO alone with 87% and 90% sensitivity. PTA of 43-86 days (severe TBI) predicted MDO/SDO or SDO with 90%-96% and 80%-90% specificity. However, PTA of 7-42 days (moderate TBI) predicted MDO/SDO or SDO with only 38%-89% and 30%-80% specificity. CONCLUSIONS: PTA duration was reliable in predicting outcome when <7 days, and especially when >42 days but was often unreliable between 7 and 42 days duration.

Effect of Gabapentin vs Pregabalin on Pain Intensity in Adults With Chronic Sciatica: A Randomized Clinical Trial.

Importance: Optimal pharmacologic treatment for chronic sciatica (CS) is currently unclear. While gabapentin (GBP) and pregabalin (PGB) are both used to treat CS, equipoise exists. Nevertheless, pharmaceutical regulation authorities typically subsidize one drug over the other. This hinders interchange wherever the favored drug is either ineffective or ill-tolerated. Objective: To assess GBP vs PGB head to head for the treatment of CS. Design, Setting, and Participants: A preplanned interim analysis of a randomized, double-blind, double-dummy crossover trial of PGB vs GBP for management of CS at half the estimated final sample size was performed in a single-center, tertiary referral public hospital. A total of 20 patients underwent randomization from March 2016 to March 2018, and 2 were excluded with 1 lost to follow-up and the other requiring urgent surgery unrelated to the study. Patients attending a specialist neurosurgery clinic with unilateral CS were considered for trial recruitment. Chronic sciatica was defined as pain lasting for at least 3 months radiating into 1 leg only to, at, or below the knee level. Imaging (magnetic resonance imaging with or without computed tomography) corroborating a root-level lesion concordant with symptoms and/or signs was determined by the trial clinician. Inclusion criteria included patients who had not used GBP and PGB and were 18 years or older. Analyses were intention to treat and began February 2018. Interventions: Randomly assigned participants received GBP (400 mg to 800 mg 3 times a day) then PGB (150 mg to 300 mg twice daily) or vice versa, each taken for 8 weeks. Crossover followed a 1-week washout. Main Outcomes and Measures: The primary outcome was pain intensity (10-point visual analog scale) at baseline and 8 weeks. Secondary outcomes included disability (using the Oswestry Disability Index) and severity/frequency of adverse events. Results: The total trial population (N = 18) consisted mostly of men (11 [61%]) with a mean (SD) age of 57 (16.5) years. A third of the cohort were smokers (5 [28%]), and more than half consumed alcohol (12 [67%]). Gabapentin was superior to PGB, with fewer and less severe adverse events. Both GBP (mean [SD], 7.54 [1.39] to 5.82 [1.72]; P < .001) and PGB (mean [SD], 7.33 [1.30] to 6.38 [1.88]; P = .002) displayed significant visual analog pain intensity scale reduction and Oswestry Disability Index reduction (mean [SD], 59.22 [16.88] to 48.54 [15.52]; P < .001 for both). Head to head, GBP showed superior visual analog pain intensity scale reduction (mean [SD], GBP: 1.72 [1.17] vs PGB: 0.94 [1.09]; P = .035) irrespective of sequence order; however, Oswestry Disability Index reduction was unchanged. Adverse events for PGB were more frequent (PGB, 31 [81%] vs GBP, 7 [19%]; P = .002) especially when PGB was taken first. Conclusions and Relevance: Pregabalin and GBP were both significantly efficacious. However, GBP was superior with fewer and less severe adverse events. Gabapentin should be commenced before PGB to permit optimal crossover of medicines. Trial Registration: anzctr.org.au Identifier: ACTRN12613000559718.

Early Postoperative Morbidity After Chronic Subdural Hematoma: Predictive Usefulness of the Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity, American College of Surgeons National Surgical Quality Improvement Program, and American Society of Anesthesiologists Grade in a Prospective Cohort.

BACKGROUND: Although chronic subdural hematoma (CSDH) is generally benign, long-term survival (LTS) after CSDH is poor in a significant subgroup. This dichotomy has been compared to fractured neck of femur. However, although early postoperative mortality (within 30 days of CSDH) is well recorded with CSDH and similar to fractured neck of femur (4%-8%), scant accurate data exist regarding early postoperative morbidity (POMB). POMB, which prolongs length of stay (LOS) after major nonneurosurgery, is associated with decreased LTS. One recent CSDH study suggested a POMB standard of 10% i.e., notably less than with fractured neck of femur (45%). METHODS: POMB was recorded in a novel prospective single-center cohort after CSDH. The POSSUM (Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity), American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) score, and American Society of Anesthesiologists (ASA) grade were assessed as tools for potentially predicting POMB. Receiver operating characteristic (ROC) curves were calculated. RESULTS: Early postoperative mortality (within 30 days of CSDH) occurred in 3 of 114 patients (3%). Seventy-one POMB events occurred in 54 of 114 patients (47%), with 27 of 54 (50%) having a Clavien-Dindo grade ≥2. Most POMB was neurologic (n = 47/71, 66%). Age (P = 0.01), Glasgow Coma Scale (GCS) score (P = 0.001), Markwalder grade (P = 0.01), hypertension (P = 0.047), and/or ≥1 preexistent comorbidity (P = 0.041) were predictive. LOS (P = 0.01) and discharge modified Rankin Scale score (P < 0.001) were significantly associated. Predicted and observed POMB with POSSUM were significantly disparate (χ2 = 15.23; P = 0.001): POSSUM area under ROC (AUROC = 0.611) was also nondiscriminatory. ACS-NSQIP (χ2 = 18.51; P < 0.001; AUROC = 0.629) and ASA grades (P = 0.25) were also nonpredictive. CONCLUSIONS: POMB was frequently disabling, mostly neurologic, and as frequent and diverse as with fractured neck of femur. POMB was significantly correlated with LOS and discharge modified Rankin Scale score. Surprisingly, POSSUM, ACS-NSQIP, and ASA grades were not predictive and would not aid consent. Simple parameters (age, Glasgow Coma Scale, Markwalder grade, hypertension, and/or ≥1 other comorbidity) were instead predictive. Longitudinal follow-up will determine whether POMB affects LTS. CSDH, like fractured neck of femur, is distinct.

S-100ß in chronic subdural haematoma: Prospective cohort study.

Chronic subdural haematoma (CSDH) is invariably classified as 'neurotrauma'. However, whilst a history of trauma/fall is frequent, it is usually distant, mild or even absent. Serum S-100ß > 1.38 µg/L is associated with a 100% specificity for mortality/poor outcome acutely after moderate-severe neurotrauma. Serum S-100ß > 0.10 µg/L is used to screen mild neurotrauma cases for emergent neuro-imaging. Serum S-100 in controls is 0.057 µg/L. S-100ß in serum or CSDH fluid (CSDHf) has not been studied. No normal 'subdural fluid' exists to compare CSDHf. We measured serum and CSDHf S-100ß at surgical drainage in a novel prospective single-centre cohort. Of n = 86/86 (100%, M65, age 73 ±â€¯13yrs), n = 66 (76%) reported mild trauma/fall 31 ±â€¯23 days previously. N = 54 (63%) presented with good clinical Markwalder Grade (MG: 0-1). Paired serum and CSDHf S-100ß samples were obtained in n = 45. CSDHf S-100ß (n = 80) was elevated (0.9 ±â€¯0.6 µg/L), was significantly higher than serum S-100ß (n = 51) (0.33 ±â€¯0.05 µg/L, P = 0.002), and was significantly correlated with midline-shift (r = 0.43, P = 0.005) and CSDH volume (r = 0.225, P = 0.046). CSDHf S-100ß was not significantly associated with any demographic factor, co-morbidity or outcome measure. CONCLUSIONS: Despite expectations, S-100ß was elevated in serum CSDH, but was significantly higher in CSDHf. Indeed, CSDHf S-100ß approached serum levels associated with a poor prognosis after acute-neurotrauma. However, CSDHf S-100ß did not represent a biomarker for trauma nor functional outcome. Whilst the non-traumatic source for on-going S-100ß release could not be determined, prolonged compression of an atrophic brain, subsequent CSF leakage, or 'subdural-space' meningeal disruption/proliferation, represent theoretical possibilities. Elevated S-100ß may therefore not be specific for mild-moderate-severe acute neurotrauma. Alternative non-traumatic intra-cranial mechanisms evidently also exist.

Long-term health outcomes in survivors after chronic subdural haematoma.

Chronic subdural haematoma (CSDH) is the most common neurosurgical presentation among the elderly. Although initially considered a non-threatening event, recent studies have highlighted poor long-term survival post-CSDH. Currently, there is a paucity of information regarding long-term health outcome in survivors after CSDH post-intervention. The objective of this research was to assess long-term functional, cognitive, and mental health outcome after CSDH. CSDH patients were administered a telephone-based assessment including a Demographic Questionnaire, Functional Activities Questionnaire (FAQ), Cognitive Telephone Screening Instrument (COGTEL), Mental Health Continuum-Short Form (MHC-SF), and the Geriatric Depression Scale (GDS). Results were obtained in n = 51 patients. CSDH patients were assessed at 5.5 + 2.1 years after CSDH and results were compared to age/gender matched controls (n = 52). Comorbidities were significantly greater in CSDH patients at the time of assessment (χ2 = 35.47, P < .01). CSDH patients demonstrated a significant reduction in functional independence (FAQ, P < .001) and Verbal Short-Term Memory (COGTEL, P = .048). Potential negative trends were observed for Verbal Long-Term Memory (P = .06) and Inductive Reasoning (P = .07). CSDH patients also demonstrated significantly poorer emotional, psychological and social well-being (MHC-SF: Emotional, P = .003; Psychological, P = .001; and Social, P < .001), with increased depressive symptomatology (GDS, P < .001). In addition to known decreased long-term survival, CSDH survivors demonstrated poorer long-term functional, cognitive and mental health outcomes than controls. Pre-existent comorbidities were also more prevalent. CSDH is therefore a sentinel health event: survivors represent a vulnerable group who require long-term, comprehensive, person-centred care. This is the first study of long term CSDH health outcomes.

Growth and Resorption of Chronic Subdural Hematomas: Gardner, Weir, and the Osmotic Hypothesis Revisited.

BACKGROUND: To explain why some chronic subdural hematomas (CSDHs) grow and/or resorb, a physically decreasing outer membrane (OM) surface area (SA) to CSDH volume (V) ratio has been reexplored, and a critical CSDH size inferred (OM SA ≈ V). Gardner showed that since CSDH protein exceeded cerebrospinal fluid (CSF) protein, CSF→CSDH osmosis occurred across a semipermeable inner membrane (n = 1). By contrast, Zollinger and Gross demonstrated that serum→CSDH osmosis could also occur across the OM (n = 1). Notably, Weir refuted Zollinger and Gross by finding equal CSDH and serum total protein (n = 20); however, Weir did not refute Gardner. Although all extant mechanisms, especially rehemorrhages, explain CSDH growth, only OM SA ≥ V simultaneously permits resorption. We aimed to reevaluate the osmotic hypothesis. METHODS: Paired serum and CSDH samples were measured in a prospective cohort. RESULTS: Results were consecutively obtained in 116 patients (87 men; mean age, 73 ± 13 years). Serum osmolality and CSDH osmolality were similar (285.70 ± 7.99 vs. 283.85 ± 7.52 mmol/kg, respectively; P = 0.11) and significantly correlated (r = 0.75, P < 0.0001). Serum total protein significantly exceeded CSDH total protein (66.6 ± 6.8 vs. 43.68 ± 20.24 g/L, P < 0.0001) as did serum albumin (35.62 ± 4.46 vs. 30.85 ± 8.5 g/L, P < 0.0001) and serum total globulins (31.5 ± 6 vs. 18.6 ± 11.4 g/L, P < 0.0001). Serum and CSDH proteins were not correlated (total protein: r = 0.003; albumin: r = 0.08; globulins: r = 0.21). CONCLUSIONS: Only crystalloids equilibrated. CSDH colloids were significantly decreased. CSDH dilution or colloidal flocculation is implied. CSDH dilution (by CSF→CSDH inner membrane [IM] osmosis or OM transudation/exudation) could favor CSDH growth, as would repeated OM hemorrhages. Contrariwise, isolated colloidal flocculation could favor CSDH shrinkage by OM CSDH→serum osmosis. The latter may result in OM SA ≥ V favorable for ultimate resolution. Our results refute Weir and Zollinger and Gross, but not Gardner. Osmotic gradients simultaneously exist for both CSDH growth and resorption. Each equilibrium could depend on each gradient relative to each IM/OM semipermeability.

Primary erector spinae pyomyositis causing an epidural abscess: case report and literature review.

BACKGROUND CONTEXT: Primary pyomyositis (PM) is a rare bacterial infection of skeletal muscle usually restricted to tropical zones. Typically caused by Staphylococcus aureus, primary staphylococcal PM associated with an epidural abscess has not been reported before. PURPOSE: We present the first case of staphylococcal PM associated with an epidural abscess. STUDY DESIGN: Case report. PATIENT SAMPLE: A 56-year-old woman. OUTCOME MEASURES: Clinical follow-up at 9 months. METHODS: This 56-year-old woman presented with a sudden onset of left lumbar back pain and sciatica without prior illness. She was pyrexial on admission, with elevated inflammatory markers but with no obvious systemic source of sepsis. RESULTS: Spinal magnetic resonance imaging and subsequent surgery revealed an erector spinae abscess causing an epidural abscess via the left L4/5 intervertebral foramen. Both back pain and sciatica were immediately improved postoperatively. Culture revealed S aureus as the sole organism sensitive to flucloxacillin. Intravenous therapy was converted to oral after 12 days once the erythrocyte sedimentation rate had normalized and she was asymptomatic. She remains asymptomatic and without clinical signs at the 9-month follow-up. CONCLUSION: Spinal infection must always be considered when back pain and sciatica are associated with clinical signs of sepsis. We present the first case of staphylococcal PM associated with an epidural abscess.

Subsidence and malplacement with the Oblique Maverick Lumbar Disc Arthroplasty: technical note.

BACKGROUND: The A-Mav (Medtronic, Sofamor Danek, Memphis, TN) is a well-established lumbar total disc arthroplasty device. The O-Mav (Medtronic) is a more recent innovation designed to minimize the potential vascular complications associated with A-Mav insertion at L4/5. No study has hitherto studied the relative accuracy or safety of the two techniques. PURPOSE: To compare the accuracy of lumbar disc arthroplasty placement by using the anterior technique (A-Mav) with the oblique (O-Mav) technique. STUDY DESIGN: Technical report. PATIENT SAMPLE: Fourteen patients. OUTCOME MEASURES: Implant placement accuracy on high-resolution computed tomography scan. Comparative morbidity, mortality, blood loss, and operating time were also assessed. METHODS: Patients were considered for lumbar disc arthroplasty who had suffered chronic discogenic low back pain unresponsive to nonoperative management for at least 6 months. All patients were operated on at the L4/5 level. A-Mavs were inserted in 7 patients and O-Mavs in 7. Implant placement was analyzed postoperatively by using computer software on high-resolution computed tomography scan with respect to four parameters: (1) off-center malplacement, (2) axial rotational malplacement, (3) coronal tilt, and (4) vertebral body susbsidence. Comparative morbidity, mortality, blood loss, and operating time were also assessed. RESULTS: Subsidence, off-center malplacement, and rotational malplacement were significantly increased in O-Mavs compared with A-Mavs (4.3+/-0.6 mm vs. 1.6+/-0.6 mm, p=.008; 3.1+/-0.4 mm vs. 1.3+/-0.4 mm, p=.006; 6.5 degrees +/-1.2 degrees vs. 3.8 degrees +/-0.4 degrees , p=.046). No significant differences were found between O-Mavs and A-Mavs in tilt, operating time, blood loss, or morbidity and mortality. CONCLUSIONS: O-Mav insertion appears to be complicated by significantly greater vertebral body subsidence and malplacement than A-Mav insertion. A-Mav insertion therefore appears to be more accurate and less complicated yet equally as safe as O-Mav insertion.

Lumbar total disc arthroplasty: coronal midline definition and optimal TDA placement.

It is a general principle with arthroplasty insertion that precise implant centering is critical for long term function and outcome. Whilst some authors have proclaimed that lumbar total disc arthroplasty (TDA) may be different, and that off -centre placement may be functionally well tolerated, these claims are premature: significantly worse clinical results have already been reported with poorly placed TDA at 2 years. Accurate TDA placement requires a precise and consistent definition of the desired coronal midline target (which is currently lacking), as well as a procedural mechanism to optimize placement at that target. We summarize our experience, as well as others', in achieving these two requirements. Long-term outcomes after lumbar TDA insertion should only be compared with results from fusion where TDAs have been implanted accurately.

Spontaneous Resolution of Lumbar Facet Joint Cyst.

BACKGROUND: Juxtafacet cysts (JFCs) are uncommon spinal lesions that can cause neural compression and are typically managed surgically. Rarely, JFCs can spontaneously resolve. CASE DESCRIPTION: We present the case of a spontaneously resolving right L4/5 JFC in an otherwise fit and well 60-year-old female. She presented with progressive chronic lower back pain and intermittent sciatica. She had no neurologic deficit. The patient was keen to avoid surgical intervention. After 19 months her symptoms had significantly improved, and repeat magnetic resonance image demonstrated complete resolution of the lesion. CONCLUSIONS: While surgery to remove a JFC ± spinal stabilization remains the mainstay and definitive treatment for symptomatic JFCs, patients without neurologic deficit may be safely managed conservatively pending possible spontaneous resolution. Spontaneous resolution may reflect the natural history of the condition.

Utility of Retrograde Amnesia Assessment Alone, Compared with Anterograde Amnesia Assessment in Determining Recovery After Traumatic Brain Injury: Prospective Cohort Study.

BACKGROUND: Posttraumatic amnesia (PTA) after traumatic brain injury (TBI) comprises anterograde amnesia (AA), disorientation, and retrograde amnesia (RA). However, RA is often neither assessed nor emphasized. A recent study demonstrated that although AA and disorientation were both present in non-TBI inpatients uniformly taking opioids, RA was absent. This suggests potentially significant utility with RA assessment alone since opioids are commonly prescribed post TBI. METHODS: We compared RA recovery with AA recovery in a prospective cohort post TBI. The Galveston Orientation and Amnesia Test (GOAT) represented a crude test for PTA (GOAT <75). AA was primarily assessed using the Westmead PTA Scale, and RA was assessed using the GOAT. All patients were prescribed oxycodone. RESULTS: Results were obtained (n = 31). While RA recovery coincided with a GOAT recovery in 19/31 (61%), AA recovery coincided with GOAT recovery in only 6/31 (19%), (χ2 = 11.5, P < 0.001). RA recovery preceded AA recovery in 15/31 (48%), while AA recovery preceded RA recovery in 7/31 (23%) (χ2 = 8.6, P = 0.003). Where RA recovery less frequently followed AA recovery, temporal lobe contusions were more frequent. RA recovery preceded/coincided with AA recovery in 100% of those who recovered when AA was defined as ×3 consecutive 12/12 scores (as is current widespread practice). AA recovery typically followed RA recovery with minimal delay. CONCLUSIONS: In the presence of potential in-hospital confounders including opioids, RA recovered significantly sooner after TBI than AA and was predictive of imminent AA recovery. RA assessment alone therefore had significant and novel utility in post-TBI assessment. RA assessment should be routinely recorded in all PTA assessment. Given its simplicity and resilience to common confounders, RA assessment should also be incorporated into the Glasgow Coma Scale.

Pregabalin versus gabapentin in the treatment of sciatica: study protocol for a randomised, double-blind, cross-over trial (PAGPROS).

BACKGROUND: There is currently an absence of high-grade evidence regarding the treatment of chronic sciatica (CS). Whilst gabapentin (GBP) and pregabalin (PGB) are both currently used to treat CS, equipoise exists regarding their individual use. In particular, no head-to-head study of GBP and PGB in CS exists. Despite equipoise, most countries' formulary regulatory authorities typically favour one drug for subsidy over the other. This hinders interchange wherever the favoured drug is either ineffective or not tolerated. The primary aim of this study is to conduct a head-to-head comparison of the efficacy of PGB versus GBP for CS based on outcomes on a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). METHODS/DESIGN: We are conducting a prospective, randomised, double-blind, double-dummy cross-over study. Included patients will be over 18 years old and have unilateral CS with radiological confirmation of corresponding neural compression/irritation. Pregnant women, those with major organ disease, or those with creatinine clearance < 60 ml/minute will be excluded. Patients will continue their current pain medication at study onset, conditional upon dosage consistency during the prior 30 days. Each drug will be titrated up to a target dose (GBP 400-800 mg three times daily, PGB 150-300 mg twice daily) and taken for 8 weeks. The first drug will then be ceased; however, cross-over will be deferred pending a 1-week washout period. Drug efficacy will be assessed using the VAS and ODI. Results of the Health Locus of Control Scale and side effect frequency/severity will be used to determine psychological functioning. Assuming the hypothesis that PGB will display a superior effect, the sample size required is n = 38 with 80% power and a 5% type I error rate. Results will be analysed via intention-to-treat methodology. DISCUSSION: This study will establish the efficacy of PGB compared with GBP in reducing pain in people with sciatica and lead to greater understanding of the treatment options available. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry, 12613000559718 . Registered on 17 May 2013.

Spontaneous bilateral carotid and vertebral artery dissections associated with multiple disparate intracranial aneurysms, subarachnoid hemorrhage and spontaneous resolution. Case report and literature review.

Spontaneous bilateral carotid and vertebral artery dissections (CADs and VADs) are rare. A 29-year-old female presented with a collapse, 4 weeks after a sudden onset of severe neck and shoulder pain. CT scan revealed diffuse subarachnoid hemorrhage (SAH) and early hydrocephalus. Angiography revealed bilateral CADs and VADs, along with multiple fusiform and saccular aneurysms. Systemic vessels - including the renal arteries - were normal, and no risk factors or underlying vasculopathy were apparent. The presumed source of SAH (a posterior cerebral artery aneurysm) was successfully clipped. Each dissection, by contrast, was managed conservatively with heparin prophylaxis; and spontaneous CAD and VAD resolution occurred within 6 months. We present a unique case of four-vessel dissection associated with multiple disparate saccular and fusiform aneurysms. We suspect that underlying vasculopathy - perhaps novel - may become apparent with time.

Subarachnoid hemorrhage emanating from a ruptured infundibulum: case report and literature review.

BACKGROUND: Infundibula are frequently regarded as incidental anatomical variants that are of no pathogenetic significance. CASE DESCRIPTION: A 51-year-old man presented with a sudden onset of severe occipital headache. Computed tomographic scan revealed a predominantly perimesencephalic pattern of SAH with a slight bias toward the left side. Angiography demonstrated a left PCo-A IF as the sole abnormality. At craniotomy, the left PCo-A IF was found to represent the sole abnormality. The IF was markedly reddened posteriorly, contained a capping clot, and lay immediately adjacent to a mass of xanthochromatous tissue. The PCo-A was hypoplastic and lacked perforating vessels; therefore, the IF base was successfully clipped with a straight Sugita clip parallel to the left ICA. At discharge and at clinical follow-up, our patient was asymptomatic and lacked neurologic signs. CONCLUSIONS: Infundibula may rarely represent a direct source of rupture and SAH. Exploratory craniotomy is required to establish the diagnosis and to provide definitive treatment. To label a case of SAH as angiogram-negative may be unwise when an IF potentially colocalizes to the SAH source.

Lumbar extradural arteriovenous malformation: case report and literature review.

BACKGROUND CONTEXT: Most spinal arteriovenous malformations (AVMs) are dural arteriovenous fistulas in which a singularly intradural venous drainage emanates from an extradural nidus. A pure extradural spinal arteriovenous malformation (E-AVM), in the absence of a vertebral body (cavernous) hemangioma, is extremely rare, and full clinical, radiological, and operative descriptions are scant. PURPOSE: To fully document the rare occurrence of a symptomatic E-AVM producing spinal claudication. STUDY DESIGN: Case report. PATIENT SAMPLE: One patient. OUTCOME MEASURES: Radiological and functional. METHODS: This 62-year-old man presented with 6-month progressive spinal claudication, leg weakness, and diminished sensation. Electromyography revealed bilateral acute and chronic partial degeneration of L3-S1 nerve roots. Magnetic resonance imaging revealed moderate canal stenosis between L2-L4, with prominent epidural veins on the left at L3-L4. Spinal angiography was unsuccessful, and computed tomographic myelography merely confirmed minimal lumbosacral root filling. At decompressive L2-L4 laminectomy, inadvertent hemorrhage from varicose epidural veins released arterialized blood under considerable pressure. Only minor clinical improvement was noted after this procedure. Spinal angiography 6 weeks later subsequently confirmed an E-AVM on the left at L3-L4 which was successfully embolized. RESULTS: Follow-up at 8 weeks after this procedure confirmed significantly increased walking distance, improved distal sensation, and normal power in both legs, with insignificant claudication. CONCLUSIONS: When associated with canal stenosis, E-AVMs may exacerbate claudication by both compressive and venous-hypertensive mechanisms. Treatment should be by embolization, with laminectomy deferred.

Discal cysts.

Discal cysts are rare lesions that can result in refractory sciatica. Because they are so rare, their exact origin and details of the clinical manifestations are still unknown. The authors report on five men treated for discal cysts. The mean age of the patients at the time of the surgery was 32 years (range 25-38 years). All patients suffered from lower-extremity pain and the results of the straight leg-raising test were positive in all cases. Three patients reported motor weakness and four had sensory disturbance--symptoms similar to those found in patients with lumbar disc herniation. Magnetic resonance imaging demonstrated spherically shaped extradural lesions of various sizes with low and high signal intensities on T1- and T2-weighted images, respectively. Discography revealed obvious communication between the cyst and the intervertebral disc with reproducible leg pain in all patients. All patients underwent posterior decompression and excision of the cysts either with or without additional discectomy. The radicular symptoms were remarkably improved in all patients immediately after surgery, and no recurrent lesions were noted during follow up.

Reverse transformation of Modic type 2 changes to Modic type 1 changes during sustained chronic low-back pain severity. Report of two cases and review of the literature.

Modic Type 2 (MT2) neuroimaging changes are considered stable or invariant over time and relatively quiescent, whereas Modic Type 1 (MT1) changes are considered unstable and more symptomatic. The authors report two cases in which MT2 changes were symptomatic and evidently unstable, and in which chronic low-back pain severity remained unaltered despite a MT2-MT1 reverse transformation. Two women (41 and 48 years old) both presented with chronic low-back pain. Magnetic resonance (MR) images demonstrated degenerating discs at L5-S1 associated with well-established MT2 changes in adjacent vertebrae. Repeated MR imaging in these two patients after 11 months and 7 years, respectively, revealed reverse transformation of the MT2 changes into more florid MT1 changes, despite unaltered chronic low-back pain severity. Following anterior discectomy and disc arthroplasty, immediate abolition of chronic low-back pain was achieved in both patients and sustained at 3-year follow up. Modic Type 2 changes are therefore neither as stable nor as quiescent as originally believed. Each type can change, with equal symptom-generating capacity. More representative imaging-pathological correlates are required to determine the precise nature of MT changes.

Anterograde amnesia and disorientation are associated with in-patients without traumatic brain injury taking opioids. Retrograde amnesia (RA) is absent. RA assessment should be integral to post-traumatic amnesia testing.

The Glasgow Coma Scale (GCS) only assesses orientation after traumatic brain injury (TBI). 'Post-traumatic amnesia' (PTA) comprises orientation, anterograde amnesia (AA) and retrograde amnesia (RA). However, RA is often disregarded in formalized PTA assessment. Drugs can potentially confound PTA assessment: e.g. midazolam can cause AA. However, potential drug confounders are also often disregarded in formalized PTA testing. One study of medium-stay elective-surgery orthopaedic patients (without TBI) demonstrated AA in 80% taking opiates after general anesthesia. However, RA was not assessed. Opiates/opioids are frequently administered after TBI. We compared AA and RA in short-stay orthopaedic surgery in-patients (without TBI) taking post-operative opioids after opiate/opioid/benzodiazepine-free spinal anesthesia. In a prospective cohort, the Westmead PTA Scale (WPTAS) was used to assess AA (WPTAS<12), whilst RA was assessed using the Galveston Orientation and Amnesia Test RA item. Results were obtained in n=25 (60±14yrs, M:F 17:8). Surgery was uncomplicated: all were discharged by Day-4. All were taking regular oxycodone as a new post-operative prescription. Only one co-administered non-opioid was potentially confounding (temezepam, n=4). Of 25, 14 (56%) demonstrated AA: five (20%) were simultaneously disorientated. Mean WPTAS was 11.08±1.22. RA occurred in 0%. CONCLUSIONS: AA and disorientation, but not RA, were associated with in-patients (without TBI) taking opioids. Caution should therefore be applied in assessing AA/orientation in TBI in-patients taking opioids. By contrast, retrograde memory was robust and more reliable: even in older patients with iatrogenic AA and disorientation. RA assessment should therefore be integral to assessing TBI severity in all formalized PTA and GCS testing.

Membrane Surface Area to Volume Ratio in Chronic Subdural Hematomas: Critical Size and Potential Postoperative Target.

BACKGROUND: It is unknown why some chronic subdural hematomas (CSDHs) grow and require surgery, whereas others spontaneously resolve. Although a relatively small CSDH volume (V) reduction may induce resolution, V percent reduction is often unreliable in predicting resolution. Although CSDHs evolve distinctive inner neomembranes and outer neomembranes (OMs), the OM likely dominates the dynamic growth-resorption equilibrium. If other factors remain constant, one previous hypothesis is that resorption could fail as the surface area (SA) to V ratio decreases when CSDHs exceed a critical size. We aimed to identify a critical size and an ideal target, which implies resolution without recurrence. METHODS: Three-dimensional computed tomography CSDH SA to V ratios were obtained using computer software to compare CSDH SA to V between cases requiring surgery (surgical) and cases managed conservatively with spontaneous resolution (nonsurgical). RESULTS: Data were obtained in 45 patients (surgical: n = 28; nonsurgical: n = 17). CSDH risk factors did not significantly differ between surgical and nonsurgical cases. Surgical V was 2.5× the nonsurgical V (119.9 ± 33.1 mL vs. 48.4 ± 27.4 mL, respectively; P < 0.0001). Surgical total SA was 1.4× nonsurgical SA (256.63 ± 70.65 cm2 vs. 187.67 ± 77.72 cm2, respectively; P = 0.004). Surgical total SA to V ratio was approximately one half that of nonsurgical SA to V ratio (2.14 ± 0.90 mL-1 vs. 3.88±1.22 mL-1, respectively; P < 0.0001). Surgical OM SA (SAOM) was 120.63 ± 52 cm2, and nonsurgical SAOM was 94.10 ± 41 cm2 (P < 0.0001). Nonsurgical SAOM to V ratio was 1.94 mL-1, whereas surgical SAOM to V ratio was 1.005 mL-1 (i.e., surgical SAOM ≈ V). CONCLUSIONS: Because surgical total SA to V ratio was ≈2:1, one neomembrane may indeed dominate the dynamic growth-resorption equilibrium. CSDH critical size therefore appears to be when SAOM ≈ V, which is intuitive. Practically, subtotal CSDH evacuation which approximately doubles total SA to V ratio or SAOM to V ratio implies CSDH resolution without recurrence. This could guide subdural drain removal timing, discharge, or transfer. Prospective validation studies are required.