Out of hours magnetic resonance imaging for suspected cauda equina syndrome: lessons from a comparative study across two centres.

BACKGROUND: Cauda equina syndrome, a rare but disabling spinal surgical emergency, requires prompt investigation, ideally using magnetic resonance imaging as patients may require decompressive surgery. Out of hours access to magnetic resonance imaging is only routinely available in major trauma centres and neurosurgical units. Patients in regional hospitals with suspected cauda equina syndrome may require transfer for diagnostic imaging. We retrospectively studied the proportion of patients referred with suspected cauda equina syndrome who required out of hours transfer for magnetic resonance imaging and decompressive surgery. MATERIALS ANDS METHODS: Retrospective cohort study of patients referred using online referral platforms with suspected acute cauda equina syndrome and transferred out of hours between 6pm to 8am on weekdays and all day on weekends to two of the largest neurosurgical units in the UK in Birmingham and Cambridge. RESULTS: A total of 441 patients were referred across both sites with a suspicion of acute cauda equina syndrome; 339 patients were transferred for diagnostic scans and only 16 of them (4.7%) were positive for cauda equina compression, necessitating prompt decompressive surgery. Of the patients with negative magnetic resonance scans, 50% had their discharge or transfer back to referring hospitals delayed by more than 24 hours. CONCLUSIONS: Over 95% of patients who were transferred for imaging did not undergo emergency decompression. The authors propose a greater role for the provision of out of hours magnetic resonance imaging in all hospitals admitting emergency patients to streamline management.

Fitness to fly post craniotomy--a survey of medical advice from long-haul airline carriers.

Commercial airline passengers are subject to numerous medical risks while in transit. Seventeen long-haul airline companies were questioned concerning fitness to travel and the case of a patient wishing to travel post craniotomy. Three airline companies gave satisfactory medical information, while the remaining airlines felt it was the decision of the operating surgeon rather than the airline company. A literature review shows that post operative pneumocephalus and the risk of tension pneumocephalus is the major medical concern when transporting patients post craniotomy. Evidence is contradictory with respect to the importance of this potentially life threatening problem. Postoperative 100% oxygen may improve the rate of pneumocephalus absorption. Airline companies have an unstandardised approach to unique medical problems, resulting in increased responsibility for the attending surgeon who may be ill equipped to deal with poorly researched aviation medicine.

Traumatic spinal subarachnoid hematoma: report of a case with MRI.

BACKGROUND: Spinal subarachnoid hematoma (SAH) is uncommon following traumatic injury to the spine. There are few case reports of neurologic deficit secondary to traumatic spinal SAH. CASE DESCRIPTION: This 6-year-old boy was injured in a vehicular accident from which he became paraplegic and presented to us 1 week later. Plain X rays were normal and a myelo-computed tomography (CT) scan demonstrated an irregular intradural lesion from D10-L2. The magnetic resonance imaging (MRI) revealed an SAH at D11-12 level, posterior to the cord, which was surgically evacuated. The patient did not improve neurologically. CONCLUSION: Significant cord injury and neurologic deficit can occur without obvious abnormalities on plain X rays or CT scan. MRI is very useful in detecting these lesions and can help in their management.

Supraorbital microcraniotomy for acute aneurysmal subarachnoid haemorrhage: results of first 50 cases.

For the past 50 years the pterional craniotomy has been the standard approach for anterior circulation aneurysms. However, this is a major procedure. As the trend is towards minimally invasive surgery generally, we have been developing a minimally invasive approach for anterior circulation aneurysms - the supraorbital microcraniotomy. We present first 50 patients who underwent this operation after an aneurysmal subarchnoid haemorrhage. The data were collected prospectively between 2001 and 2004. A total of 60 aneurysms were clipped (10 patients had two aneurysms). Forty-one of fifty patients (82%) were good grade (WFNS I and II) and 9/50 (18%) were poor grade (WFNS III - V) at the time of surgery. Anterior communicating aneurysms were the commonest (37%), but aneurysms at all of the usual anterior circulation sites were included, apart from ophthalmic aneurysms, as none presented during this period, and pericallosal aneurysms, which were not appropriate for it. Five patients (10%) also had an intracerebral haematoma on presentation. The overall management mortality for this series was 3/50 (6%) with 82% achieving a favourable outcome on the Glasgow Outcome Scale (GOS). For those in good grade at surgery, the mortality was 1/41 (2.4%) with 87.7% achieving a favourable outcome on the GOS.

Changes in plasma phenytoin level following craniotomy.

Phenytoin is often used to prevent postcraniotomy seizures, but is not always effective. We investigate changes in plasma phenytoin level ([phenytoin]) following craniotomy. The [phenytoin] in 28 patients who were receiving phenytoin (oral/ intravenous) and undergoing a craniotomy were prospectively measured 24 h preoperatively, immediately pre- and postcraniotomy, 24 and 48 h postoperatively. Factors examined included patients' age, sex, pathology, preoperative [phenytoin], operative duration and blood loss. Fifteen patients had [phenytoin] concentrations outside the therapeutic range. Twenty-five patients experienced a decrease in [phenytoin] immediately postcraniotomy: pre-, post- and 24 h postcraniotomy mean [phenytoin] were 13.4, 10.0 and 12.9 mg/l, respectively. Preoperative [phenytoin], operative duration and blood loss had significant correlation with the decrease in [phenytoin] (p < 0.05). In conclusion, < 50% of the patients had therapeutic preoperative [phenytoin]. In most patients, [phenytoin] decreases by 26% after craniotomy and returns to preoperative level within 24 h. These may contribute to early postoperative seizure development.

Stereotactic radiosurgery and vestibular schwannoma: hydrocephalus associated with the development of a secondary arachnoid cyst: a report of two cases and review of the literature.

Stereotactic radiosurgery for vesibular schwannoma requires long-term follow-up with complete MR imaging. We report two cases of a large secondary arachnoid cyst developing in the cerebellopontine angle following stereotactic radiosurgery. In one case this was associated with progressive ventriculomegaly and the onset of symptomatic hydrocephalus requiring emergency treatment. The second patient had ventriculomegaly at diagnosis, but developed an arachnoid cyst following treatment. Although both arachnoid cysts and hydrocephalus may also occur spontaneously in patients with vestibular schwanomma, the incidence is higher after stereotactic radiosurgery. As both complications may be associated with sudden clinical deterioration, follow-up with full cranial T1 and T2 weighted MR imaging is required to reveal these complications, in addition to assessing tumour response.