Optimizing and simplifying post-traumatic amnesia testing after moderate-severe traumatic brain injury despite common confounders in routine practice.

The duration of post-traumatic amnesia (PTA) following traumatic brain injury (TBI) is a key diagnostic and outcome indicator. However, concerningly, different PTA paradigms record different PTA durations: some over-estimate, others under-estimate, PTA. Thus, a compromise is implied. The potential effect of in-hospital confounders including opioids is unknown. Three clinical groups were prospectively recruited. Group-1: in-patients with moderate-severe-TBI (MS-TBI), considered likely 'in-PTA'. Group-2: patients rehabilitating after recent MS-TBI, considered 'out-of-PTA'. Group-3: orthopaedic in-patients without TBI undergoing elective surgery. Only Groups 1&3 were taking opioids. All were administered the Westmead Post-traumatic Amnesia Scale (WPTAS) and the Galveston Orientation and Amnesia Test (GOAT). Results were obtained in n = 56 (Group-1:n = 18, Group-2:n = 13 and Group-3:n = 25). On WPTAS, Groups 1&3 scored similarly, but significantly lower than, Group-2 (χ2 = 8.2, P = 0.017). Contrariwise, on GOAT, Group-1 scored significantly lower than Groups 2&3 (χ2 = 23.99, P < 0.001): however, no patient scored GOAT <75. WPTAS showed moderate sensitivity (72%) but poor specificity (40%) in distinguishing Group-1 from Groups 2&3. Contrariwise, GOAT showed 100% specificity but 0% sensitivity. WPTAS 'day of week' and 'pictures' combined with GOAT 'transport medium to hospital', 'anterograde amnesia' and 'retrograde amnesia' maximized sensitivity (100%), specificity (85-88%), PPV (77-83%) and NPV (100%) in distinguishing Group-1 from Groups 2&3. CONCLUSIONS: Confounders including opioids likely affected WPTAS overall, but not GOAT specificity. A merger, whereby WPTAS sensitivity augmented GOAT specificity, was therefore sought. Favourable items from WPTAS (4/12) and GOAT (3/10) together optimized, and yet simplified, PTA testing; despite prevalent clinical confounders. Less, not more, 'PTA' items would benefit both patients and staff alike.

Prospective randomized placebo-controlled double-blind clinical study of adjuvant dexamethasone with surgery for chronic subdural haematoma with post-operative subdural drainage: Interim analysis.

Most chronic subdural haematomas (CSDH) are successfully treated neurosurgically. However, operative recurrences occur with a frequency 3-30%, consume resources and potentially prolong length-of stay (LOS). The only adjuvant factor proven to significantly decrease CSDH recurrence rate (RR) is post-operative subdural drainage. Corticosteroids have been used to conservatively manage CSDH. One non-randomised study also compared dexamethasone (DX) as an adjunct to surgery without post-operative drainage: whilst a null effect was observed, the 'surgery-alone' group consisted of only n = 13. We present an interim analysis of the first registered prospective randomised placebo-controlled trial (PRPCT) of adjuvant DX on RR and outcome after CSDH surgery with post-operative drainage. Participants were randomised to either placebo or a reducing DX regime over 2 weeks, with CSDH evacuation and post-operative drainage. Post-operative mortality (POMT) and RR were determined at 30 days and 6 months; modified Rankin Score (mRS) at discharge and 6 months. Post-operative morbidity (POMB) and adverse events (AEs) were determined at 30 days. Interim analysis at approximately 50% estimated sample size was performed (n = 47). Recurrences were not observed with DX: only with placebo (0/23 [0%] v 5/24 [20.83%], P = 0.049). There was no significant between-group differences in POMT, POMB, LOS, mRS or AEs. CONCLUSIONS: In this first registered PRPCT, interim analysis suggested that adjuvant DX with post-operative drainage is both safe and may significantly decrease recurrences. A 12.5% point between-groups difference may be reasonable to power a final sample size of approximately n = 89. Future studies could consider adjuvant DX for longer than the arbitrarily-chosen 2 weeks.

Prospective controlled cohort study of Troponin I levels in patients undergoing elective spine surgery for degenerative conditions: Prone versus supine position.

Prior studies have suggested that elevated serum Troponin-I (TnI) levels immediately after non-cardiac surgical procedures (8-40%) represent subclinical cardiac stress which independently predicts increased 30-day mortality. Routine post-operative TnI monitoring has therefore been suggested as a standard of care. However, no prior studies have focussed on elective degenerative spine surgery, whilst few have measured pre-op TnI. Further, prolonged prone positioning could represent an additional, independent, cardiac stress. We planned a prospective controlled cohort study of consecutive TnI levels in routine elective spine surgery for degenerative spine conditions, incorporating 3 groups: 'prone<2h', 'prone>2h' and 'supine' positioning. TnI levels (>0.04µg/L) were recorded immediately pre-/post-surgery, and by 24h of surgery. N=120 patients were recruited. Complete results were obtained in 92 (39 supine, 53 prone). No significant between-groups differences were observed in demographic or cardiovascular risk factors. Validated TnI-elevation by 24h was not observed in any group. Spurious elevations were recorded in one 'prone<2h' and one 'prone>2h'. One non-ST segment myocardial infarction (STEMI) occurred on day 7 without TnI elevation by 24h (prone>2h). There was no 30-day mortality. CONCLUSIONS: Despite a lower cut-off, no validated TnI elevation was observed in any group by 24h after surgery. One non-STEMI had not been associated with TnI-elevation by 24h. Immediately peri-operative cardiac stress therefore appeared comparatively rare in patients undergoing routine elective spine surgery. Further, prone positioning did not represent an additional, independent, risk. Routine immediately post-operative TnI monitoring in elective spine surgery therefore appears unjustified. Our study highlighted several caveats regarding consecutive TnI testing.

A clinical comparison of the quadhelix appliance and the nickel titanium (tandem loop) palatal expander: a preliminary, prospective investigation.

Maxillary expansion using either a quadhelix appliance (Qx) or a nickel titanium palatal expander (Nt) was prospectively compared in 28 consecutive new patients (19 female, nine male) presenting with posterior buccal segment crossbites. Study models taken at each activation were measured to determine the mean maxillary expansion efficacy (Emax) and the mean expansion rate (m(max)) across the first molars and first premolars. Patient discomfort was assessed using visual analogue scores, and cost-effectiveness was also considered. Neither Emax nor m(max) differed significantly between Qx and Nt across either the first molars or the first premolars. However, both Emax and m(max) were significantly greater across the first molars than across the first premolars only with Qx (Emax: 8.4 +/- 0.7 mm versus 5.1 +/- 0.6 mm, P = 0.001; m(max): 0.09 +/- 0.005 mm/day versus 0.05 +/- 0.006 mm/day, P = 0.0001). In addition, greater variance was apparent in m(max) with Nt than with Qx across both the first molars and the first premolars. Overall, Qx and Nt elicited similar discomfort. However, significantly less was reported with Nt on days 6 (P = 0.04) and 7 (P= 0.03) following the second 'activation'. These preliminary results suggest that Qx and Nt are equally efficacious maxillary expanders. However, Qx expansion appeared significantly more controlled, as well as more individually predictable in expansion rate. Overall, Qx and Nt probably elicit similar discomfort, but significantly less discomfort may be seen with Nt following the second activation. Finally, because more than one appliance is invariably required with Nt, Qx expansion is potentially less costly.

Fibrous dysplasia of the cervical spine presenting as a pathological fracture.

Fibrous dysplasia (FD) is an uncommon benign fibro-osseous abnormality of bone, of unknown aetiology and equal sex incidence, which is most commonly restricted to one bone (monostotic FD: MFD, 70%). Less commonly multiple bones are affected (polyostotic FD: PFD, 27%). Vertebral involvement is uncommon (4%), but more common with PFD (7 - 24%) than MFD (1%). Of 20 cases of FD involving the cervical spine, only three have represented MFD. Unlike cases associated with PFD, all cases presented with acute neck pain without significant neurological impairment after minor trauma. We present the case of a 35-year-old male with MFD who developed a pathological fracture of C3 following minor trauma. Radiographs showed collapse and typical 'ground glass' lucency of C3. CT revealed replacement of C3 cancellous bone by hypodense tissue extending into the right lateral mass. The cortex was thinned and fractured, and encroached upon the right foramen transversarium and spinal canal. Magnetic resonance imaging demonstrated hypo-intensity on both T1 and T2, with uniform contrast enhancement. Subtotal excision was achieved via an anterior C3 corpectomy, with residual FD left within the right lateral mass. Stability was achieved utilizing an iliac crest strut autograft, C2-4 plate-and-screws, and mobilization in a halo frame for 3 months. At 18 months, he remained asymptomatic and without deficit. Radiography, CT and MRI confirmed graft fusion without FD invasion, but with residual right lateral mass FD unchanged in size.

Persistent absence of ring-enhancement on CT with an encapsulated brain abscess.

Ring-enhancement on CT (RECT) is generally considered a sine qua non in diagnosing a cerebral abscess. We describe a 16-year-old female who presented with headaches, vomiting and drowsiness, which over 2 weeks rapidly progressed to coma. CT demonstrated a moderately large left frontal extradural abscess, associated with contiguous left frontal osteomyelitis, and underlying frontal and ethmoidal sinusitis. In addition, there was a large circular low density area within the left frontal lobe associated with midline shift that, owing to negative RECT, was assumed to represent nascent ischaemic cerebritis. Despite emergency twist-drill drainage of the extradural abscess, and antibiotic/corticosteroids administration, her clinical condition continued to deteriorate and two episodes of uncal herniation were reversed medically. Repeated CT, however, continued to demonstrate negative enhancement within the left frontal low density, although significant enhancement continued to be apparent with recurrent contiguous extradural suppuration. At definitive craniotomy, a large, well-encapsulated abscess cavity was excised from the left frontal lobe corresponding precisely to the area of previously negative enhancement, along with drainage of the recurrent extradural abscess. Thus, in addition to well-known 'false-positives' for RECT with a cerebral abscess, our case highlights the rare occurrence of a 'false-negative'. A low density mass lesion on CT with persistent negative RECT can neither be assumed to represent early cerebritis nor to exclude a mature abscess.

Primary intracerebral mesenchymal chondrosarcoma with rhabdomyosarcomatous differentiation: case report and literature review.

Intracranial chondrosarcoma (Ch-S) is a slow-growing, locally recurrent, malignant cartilaginous tumour of the skull base. Intracranial mesenchymal chondrosarcoma (MsCh-S) is a rarer, more malignant variant associated with the supratentorial meninges. Only seven cases of Ch-S, and six of MsCh-S, that were primarily intraparenchymal in origin have been reported. Moreover, no case of intracranial Ch-S or MsCh-S has been reported in which rhabdomyosarcomatous differentiation was prominent. A 17-year-old Asian girl presented with a 4-week history of occipital headache, vomiting and paraesthesia in the left hand. She was drowsy with a left hemiparesis and had a dilated right pupil with bilateral papilloedema. CT demonstrated a large, partly calcified, contrast-enhancing mass in the right temporo-parietal region with oedema and midline shift. Through a large craniotomy, a tense brain was encountered with no apparent cortical abnormality. Despite a radical tumour excision, with excellent initial clinical recovery, a local recurrence rapidly occurred within weeks prior to the administration of any radiotherapy. Initial histopathological examination revealed a primary MsCh-S with osseous and rhabdomyosarcomatous differentiation, with an indistinct margin. After a second radical excision, a second recurrence rapidly occurred; however, this proved excessively vascular and inoperable. Radiotherapy was declined and death followed within 3 weeks. This is the seventh case of primary intracerebral MsCh-S to be reported and the first to demonstrate rhabdomyosarcomatous differentiation. It was characterized clinically by rapid, local recurrence with increased vascularity.

Unilateral fixed dilation of the pupil as a false-localizing sign with intracranial hemorrhage: case report and literature review.

OBJECTIVE AND IMPORTANCE: Although other focal signs may prove "false localizing," it is a neurosurgical axiom that unilateral fixed dilation of the pupil occurs ipsilateral to a supratentorial mass. CLINICAL PRESENTATION: A 25-year-old man collapsed with a dense right hemiplegia and a Glasgow Coma Scale score of 6 (eye opening, 1; motor, 4; verbal, 1) after rupture of a left middle cerebral artery aneurysm associated with an intrasylvian hematoma. Initially, both pupils had remained equal-sized and reactive: however, within hours, the right (contralateral) pupil became fixed and dilated (i.e., false localizing). For some time, the left (ipsilateral) pupil remained small and reactive; at emergency craniotomy, this also became fixed and equally dilated. INTERVENTION: After evacuation of the clot and wrapping of the aneurysm, both pupils rapidly became equal-sized and reactive. Twenty-four hours later, concurrent with massive left hemispheric swelling and a midline shift, the left (ipsilateral) pupil became unilaterally fixed and dilated (i.e., false localizing). Eventually, the right (contralateral) pupil also became fixed and dilated, concurrent with cardiovascular collapse. Death occurred within 10 hours. CONCLUSION: Unilateral fixed dilation of the pupil in patients with hemispheric mass lesions may be false localizing. Furthermore, disparate "herniating mechanisms" can arise despite mass effect emanating from the same side. Because such mechanisms cannot be witnessed, their nature remains speculative. An extensive review is contained in this article.

Bacillus cereus meningitis complicating cerebrospinal fluid fistula repair and spinal drainage.

Non-anthrax Bacillus species are rare, but serious causes of bacterial meningitis in those either immunocompromised or treated with CSF diversion. Although resistant to first-line antibiotics, they usually respond to chloramphenicol. We report a case of fulminant Bacillus cereus meningitis that complicated lumbar spinal drainage which proved resistant to all first-line antibiotics including chloramphenicol.

Idiopathic spinal cord herniation: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Idiopathic spinal cord herniation (ISCH) is a rare condition, reported in only 25 patients thus far, in which the thoracic cord is prolapsed through an anterior dural defect. It typically presents in middle age as either Brown-Sequard syndrome or spastic paraparesis. CLINICAL PRESENTATION: A 55-year-old woman initially presented at the age of 41 years with Brown-Sequard syndrome at the T8 disc space level on the left side. Investigations, including primitive magnetic resonance imaging, were deemed negative at that time. After a stepwise deterioration over 14 years, she presented again with spastic paraparesis and double incontinence, in addition to her previous spinothalamic dysfunction. Magnetic resonance imaging at this stage suggested either ISCH or a dorsal arachnoid cyst. INTERVENTION: Through a T7-T8 laminectomy, a left-of-midline ISCH was identified and easily reduced by gentle cord traction. No dorsal arachnoid cyst was identified. The anterior dural defect was repaired with a XenoDerm patch (LifeCell Corp., Woodlands, TX). After surgery, there was improved motor and sphincter function. However, there was continued sensory disturbance. CONCLUSION: ISCH is rare cause of thoracic cord dysfunction. Despite prolonged diagnostic delay, significant clinical improvement may be obtained with ISCH reduction and anterior dural repair.

The progression of an infundibulum to aneurysm formation and rupture: case report and literature review.

OBJECTIVE AND IMPORTANCE: Infundibula (IFs) are funnel-shaped symmetrical enlargements that occur at the origins of cerebral arteries and are apparent on 7 to 25% of otherwise normal angiograms. They are frequently considered as normal anatomic variants of no pathogenic significance. CLINICAL PRESENTATION: We report the case of a ruptured posterior communicating artery aneurysm that had developed at the site of a previously known IF in a 49-year-old hypertensive woman. She had a poor conscious level at admission, with widespread subarachnoid hemorrhage and obstructive hydrocephalus. INTERVENTION: The patient was immediately ventilated, and an external ventricular drain was inserted. The aneurysm was successfully clipped; however, secondary hemorrhage occurred both before and during craniotomy. She developed marked hypernatremia and subsequently died. CONCLUSION: This is the 11th case of IF-to-aneurysm progression reported. It suggests that in certain cases, serial investigations may be indicated with IFs to detect aneurysm formation and preempt rupture.

Increased efficacy of sodium nitroprusside in middle cerebral arteries following acute subarachnoid hemorrhage: indications for its use after rupture.

Sodium nitroprusside (SNP) is commonly used for controlled systemic hypotension during aneurysm surgery after acute subarachnoid hemorrhage (SAH). Few experimental studies have assessed cerebrovascular responsiveness to SNP acutely after a representative SAH (i.e., following arterial rupture within the subarachnoid space). Instead, most studies have focused on delayed reactivity after slow injections of unpressurized blood throughout several days. In the authors' study, SAH was created by endovascular rupture in spontaneously breathing rats under urethane anesthesia without craniotomy. After 3 hours, proximal middle cerebral arteries (MCAs) were harvested and mounted as ring preparations in vitro. After preconstriction with 30 mM prostaglandin F2a, concentration-response curves were generated to express SNP's sequential relaxation of preconstricted tone. The effective concentration of SNP for 50% relaxation was significantly lower after SAH (p < 0.001) as compared with non-operated and sham-operated controls. There was also a significantly greater maximum percentage relaxation from preconstricted tone (p < 0.001) with SNP. The results of this study suggest that SNP is a potent and efficacious dilator of MCAs in the hours immediately after acute SAH.

Cushing's 'variant' response (acute hypotension) after subarachnoid hemorrhage. Association with moderate intracranial tensions and subacute cardiovascular collapse.

BACKGROUND AND PURPOSE: Hypertension is considered common and appropriate with subarachnoid hemorrhage (SAH), maintaining cerebral perfusion. Hypotension, in contrast, is considered rare and detrimental. This study was designed to assess the frequency of each in both acute and subacute phases of primary SAH. METHODS: SAH was created by arterial rupture in spontaneously breathing rats under urethane anesthesia without craniotomy (n = 32). Arterial pressure and intracranial pressure (ICP) were monitored invasively. RESULTS: After extensive extravasation, the mean ICP rose acutely from 8 +/- 1 to 53 +/- 4 mm Hg over 2.4 +/- 0.3 minutes. Acute pressor changes occurred transiently in 71%. The most common acute response was hypotension (63%). Hypertension, in contrast, was rare (6%); the remainder was invariant (29%). Hypertension was associated with significantly lower maximum ICP values (39 +/- 4 versus 69 +/- 4 mm Hg, P < .001) with a negative correlation between hypotension and delta ICP (r = -.7, P < .01). Distinct and independent of acute responses, hypotension also occurred subacutely as a cardiovascular collapse (38%). CONCLUSIONS: In contrast to popular belief, the most common acute response with SAH is hypotension; hypertension is rare. This, in fact, is in full agreement with Cushing: hypertension was seen only with gradual delta ICPs. In contrast, a "variant" to the classic response (hypotension) occurred with sudden delta ICPs. In the present study, hypotension stanched SAH at lower maximum ICP values, and thus with less cerebral compression. Despite this, cardiovascular collapse developed in a large proportion irrespective of acute change. Such collapse without prior hypertension (94%) implies a nonadrenergic etiology.