Acute vasospasm following transcallosal resection of a xanthogranulomatous colloid cyst of the 3rd ventricle.

We present the first case of a 57 year old man who developed severe, acute vasospasm following transcallosal resection of an unusual, xanthogranulomatous colloid cyst. The 16 year history of growth of this cyst may have resulted in its unusual pathology, and the subsequent vasospastic reaction to its excision. We discuss the potential pathological relationship between the inflammatory nature of the cyst, chemical meningitis and vasospasm, and what this implies about vasospasm in general. The severe, life-threatening vasospasm affected all four major vessels and required aggressive management by endovascular injection of nimodipine and angioplasty, with good recovery. The case illustrates a previously undescribed sequel of surgery for this condition, demonstrates an effective treatment and offers possible insights into the pathogenesis of vasospasm

Acute foramen magnum syndrome from acquired Chiari I malformation relieved by ventriculoperitoneal shunt revision.

An adult case of shunt malfunction presenting with acute quadriparesis as a manifestation of foramen magnum syndrome with acquired Chiari type I malformation is described in this study. The corticospinal function was restored after shunt revision. MRI showing considerable ascent of cerebellar tonsils after surgery is shown. Theories regarding the formation of acquired Chiari I malformations, alongside the possible synergistic roles of intracranial pathologies and cerebrospinal fluid drainage in the development of this entity are discussed

Investigation of prevalence of MRSA in referrals to neurosurgery: implications for antibiotic prophylaxis.

In order to establish the appropriateness of our current prophylactic antibiotic regimen we analysed the prevalence of MRSA in emergency referrals to our unit. MRSA screening records for all emergency admissions for a 3-month period were analysed. One-hundred-and-seventy-five patients were admitted as transfers from another hospital. Evidence of screening was found in 61% (107 patients). Of the screened patients, 15% (16) were MRSA positive. Source of referral or length of inpatient stay after referral to the time of transfer were not predictive for MRSA status. Gentamicin is active against more than 95% of MRSA strains cultured in our hospital and against 87% of MRSA strains cultured in the neurosurgery unit. A number-needed-to-treat (NNT) analysis showed that, with MRSA prevalence at 15%, cefuroxime plus gentamicin at induction could prevent one MRSA infection per 421 treated patients compared with cefuroxime alone. Vancomycin had minimal additional benefit over cefuroxime plus gentamicin (NNT: 1684). We conclude that MRSA carriage is common in patients referred as emergencies from other hospitals. Cefuroxime plus gentamicin can be used as antibiotic prophylaxis in this group. Vancomycin can be reserved for patients known to be colonized with MRSA (NNT: 51)

Idiopathic normal pressure hydrocephalus: an important differential diagnosis.

Idiopathic normal pressure hydrocephalus, an uncommon but important differential diagnosis for ataxia, cognitive impairment and urinary incontinence, is surgically treatable, unlike many of its differential diagnoses. This article discusses its assessment, investigation and therapeutic interventions

Posterior occipitocervical instrumented fusion for dropped head syndrome after deep brain stimulation.

We describe dropped head syndrome in a patient with Parkinson's disease receiving subthalamic nucleus deep brain stimulation (DBS). Posterior occipitocervical instrumented fusion after transarticular screw fixation of an odontoid fracture is shown and its rationale explained. Pedunculopontine nucleus DBS as treatment for fall-predominant Parkinson's disease, and globus pallidus interna DBS for dystonia-predominant Parkinson's disease, are discussed

Internal fixation for osteomyelitis of cervical spine: the issue of persistence of culture positive infection around the implants.

BACKGROUND: We describe the management of osteomyelitis of the cervical spine, utilizing internal fixation with subsequent removal and culture of the implants. Four out of five patients had evidence of bacterial colonisation in close proximity to the internal fixation device. METHODS: Five consecutive patients (all female, ranging in age from 50 to 74 yrs) presenting with unstable cervical osteomyelitis were treated by surgical decompression, primary internal fixation followed by three months of intravenous antibiotics. The internal fixation was removed in 4 out of 5 cases within a year of stopping the intravenous regime. The remaining patient was deemed medically unfit for further operation. Multiple specimens from the screw sites were taken at the time of metal removal. A final course of oral antibiotics was prescribed based on the results of these specimens. FINDINGS: Four patients, who had removal of the implants, had positive cultures growing different bacteria from the primary infection, at the time of removal of the implant. None of the patients developed instability after removal of the implant. INTERPRETATION: Asymptomatic bacterial colonisation of a metallic implant has profound management implications. We recommend long-term oral antibiotic regimes after insertion of internal fixation devices in the face of infection and eventual removal of these implants and microbiological re-sampling

Abnormal cerebral blood volume in regions of contused and normal appearing brain following traumatic brain injury using perfusion magnetic resonance imaging.

Following traumatic brain injury, there may be secondary alterations in cerebrovascular parameters leading to ischemia and further cellular damage. To assess possible subacute hemodynamic disturbances following traumatic brain injury, we used conventional and perfusion magnetic resonance imaging (MRI) in 18 patients, on average 10 days following injury. Six of the 18 patients had focal contusions or edema visible on conventional MRI. These six patients had a significantly reduced normalized regional cerebral blood volume (rCBV) in the regions of focal pathology compared to equivalent areas in control subjects (patients 0.47 +/- 0.20 [means +/- SD], controls 1.02 +/- 0.11, p < 0.001). In addition, four of these six patients had an increased rCBV (outside control range) in the region of normal appearing brain immediately surrounding the contusion. These six patients were more significantly injured and had a worse clinical outcome compared to the remaining patients (p = 0.004,p = 0.03, respectively). There were five patients who had a region of reduced rCBV (outside control range) in a quadrant of normal appearing white matter, away from any visible abnormality, who were not more significantly injured than the remaining patients but went on to have a significantly poorer clinical outcome (p = 0.27, p = 0.01, respectively). Traumatic brain injury is a heterogeneous insult causing a variety of pathology, not all of which is visible using conventional imaging methods. The current study has shown that regions of both normal appearing and contused brain may have an abnormal rCBV and that alterations in rCBV may play a role in determining the clinical outcome of patients

Effect of insulin on intracellular pH and phosphate metabolism in human skeletal muscle in vivo.

1. 31P nuclear magnetic resonance spectroscopy and the hyperinsulinaemic-euglycaemic clamp were used simultaneously to assess the effect of insulin on intracellular pH and the major phosphorus-containing metabolites of normal human skeletal muscle in vivo in four normal subjects. 2. Insulin and glucose were infused for 120 min. Plasma insulin increased approximately 10-fold over preclamp levels (5.6 +/- 0.9 m-units/l pre-clamp and 54 +/- 5 m-units/l over the last hour of infusion; mean +/- SEM, n = 4). Plasma glucose concentration did not change significantly (5.4 +/- 0.2 mmol/l pre-clamp and 5.5 +/- 0.1 mmol/l over the last hour of infusion). 3. Insulin and glucose infusion resulted in a decline in the intracellular pH of forearm muscle of 0.027 +/- 0.007 unit/h (P less than 0.01), whereas in control studies of the same subjects, pH rose by 0.046 +/- 0.005 unit/h (P less than 0.001). 4. In the clamp studies, intracellular inorganic phosphate concentration rose by 18%/h, whereas ATP, phosphocreatine and phosphomonoester concentrations did not change. In plasma, inorganic phosphate concentration was 1.16 +/- 0.05 mmol/l before infusion, and this decreased by a mean rate of 0.14 mmol h-1 l-1. No change was observed in any of these intracellular metabolites in the control studies. 5. The results show that, under physiological conditions, insulin does not raise intracellular pH in human muscle, and thus cannot influence muscle metabolism by this mechanism. The results also suggest that insulin causes a primary increase in the next flux of inorganic phosphate across the muscle cell membrane

Altered cellular metabolism following traumatic brain injury: a magnetic resonance spectroscopy study.

Experimental studies have reported early reductions in pH, phosphocreatine, and free intracellular magnesium following traumatic brain injury using phosphorus magnetic resonance spectroscopy. Paradoxically, in clinical studies there is some evidence for an increase in the pH in the subacute stage following traumatic brain injury. We therefore performed phosphorus magnetic resonance spectroscopy on seven patients in the subacute stage (mean 9 days postinjury) following traumatic brain injury to assess cellular metabolism. In areas of normal-appearing white matter, the pH was significantly alkaline (patients 7.09 +/- 0.04 [mean +/- SD], controls 7.01 +/- 0.04, p = 0.008), the phosphocreatine to inorganic phosphate ratio (PCr/Pi) was significantly increased (patients 4.03 +/- 1.18, controls 2.64 +/- 0.71, p = 0.03), the inorganic phosphate to adenosine triphosphate ratio (Pi/ATP) was significantly reduced (patients 0.37 +/- 0.10, controls 0.56 +/- 0.19, p = 0.04), and the PCr/ATP ratio was nonsignificantly increased (patients 1.53 +/- 0.29, controls 1.34 +/- 0.19, p = 0.14) in patients compared to controls. Furthermore, the calculated free intracellular magnesium was significantly increased in the patients compared to the controls (patients 0.33 +/- 0.09 mM, controls 0.22 +/- 0.09 mM, p = 0.03)). Proton spectra, acquired from similar regions showed a significant reduction in N-acetylaspartate (patients 9.64 +/- 2.49 units, controls 12.84 +/- 2.35 units, p = 0.03) and a significant increase in choline compounds (patients 7.96 +/- 1.02, controls 6.67 +/- 1.01 units, p = 0.03). No lactate was visible in any patient or control spectrum. The alterations in metabolism observed in these patients could not be explained by ongoing ischemia but might be secondary to a loss of normal cellular homeostasis or a relative alteration in the cellular population, in particular an increase in the glial cell density, in these regions