Hemilaminectomy for large spinal extradural meningeal cysts: A case report and review of surgical techniques.

Spinal extradural meningeal cysts (SEMC) are uncommon causes of back pain. The literature contains only case reports of this pathology, and treatment remains controversial due to its rarity. We present a case of SEMC and describe an approach via hemilaminectomy, with the choice of side guided by radiological imaging, followed by complete excision of the cyst and repair of the underlying dural defect.

Are we justified in doing blood tests 'routinely' for all neurosurgical patients?

To ensure continuing patient care in a cost effective and efficient manner and to determine the importance of routine pre-op bloods in patients undergoing spine surgery, a retrospective audit of 170 patients was carried out in the Neurosurgery Department at Cork University Hospital. There were 94 males and 76 females. No test had less than 87.4% normal results. There were 17 (10.7%) abnormal haemoglobin levels, 13 (8.2%) abnormal white cell count levels, 14 (8.9%) abnormal creatinine levels and of sodium and potassium levels, 5 (3.2%) and 3 (2%) were abnormal respectively. Of the abnormal results, the majority fell close to reference range. 95% of the total cost incurred in performing the procedure was attributed to normal blood results. Abnormal blood results in this cohort of patients did not alter management. We conclude that routine blood tests, including coagulation screen, may not be necessary in healthy individuals undergoing elective spine surgery.

Extraskeletal myxoid chondrosarcoma of the cerebellopontine angle presenting during pregnancy.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft-tissue sarcoma, which usually occurs in the lower extremities. It is often associated with chromosomal translocations. The clinical, radiological and pathological findings in extraskeletal myxoid chondrosarcoma, with an origin in the cerebellopontine angle, are described along with the issues associated with management of this tumour presenting acutely in a 26-year-old woman who was 20 weeks pregnant.

Dural AVM supplied by the ophthalmic artery.

Dural arteriovenous malformations in the anterior cranial fossa are rare and are especially prone to haemorrhage. These lesions are usually treated by surgical excision. We report the embolization of an anterior cranial fossa DAVM using an endovascular approach via the ophthalmic artery.

Pseudoaneurysm of the occipital artery: an unusual cause of persisting headache after minor head injury.

Post-traumatic pseudoaneurysms of the extracranial arteries in the scalp are uncommon sequelae of head injury. We report on a patient who presented four weeks after a minor head injury with a tender, pulsating and enlarging mass in the course of the left occipital artery. There was associated headache radiating to the vertex. Computed tomographic angiography confirmed the lesion to be a pseudoaneurysm of the occipital artery. The lump was resected with complete resolution of symptoms.

Traction and television for reduction of unilateral childhood rotatory atlanto-axial subluxation.

We report the use of television in maintaining unilateral rotation of the head in a child being treated conservatively for a delayed rotatory atlanto-axial subluxation.

Spinal epidural abscess: the importance of early diagnosis and treatment.

OBJECTIVES: To remind clinicians of the dangers of delayed diagnosis and the importance of early treatment of spinal epidural abscess. METHODS: A review of the literature on spinal epidural abscess and a comparison of the published literature with local experience. RESULTS: Imaging with MRI or CT enables early diagnosis of spinal epidural abcess and optimal therapy is surgical evacuation combined with 6-12 weeks (median 8 weeks) of antimicrobial chemotherapy. Clinical features are fever, pain, and focal neurological signs and may be associated with preceding and pre-existing bone or joint disease. The commonest aetiological organism is S aureus. CONCLUSION: Early diagnosis and appropriate early antimicrobial chemotherapy with surgery is associated with an excellent prognosis.

Cervical spondylotic myelopathy with syringomyelia.

Syringomyelia may complicate cervical spondylotic myelopathy (CSM). We describe a case of CSM with instability at C3/4 and a cervicothoracic syrinx which was demonstrated using magnetic resonance imaging. Decompression and stabilization, without drainage of the syrinx, were adequate surgical treatment.

Thecal repair in post-surgical pseudomeningocoele.

A postsurgical pseudomeningocoele (PSPM) forms when cerebrospinal fluid extravasates through a dura-arachnoidal tear and becomes encysted within the wound. Patients may become symptomatic with wound swelling, headache and radiculopathy. A uniform method of repairing PSPMs is described which includes separation of the dura from the arachnoid, dural repair under operating microscope control, and the use of overlapped local flaps to reinforce the dura and obliterate the PSPM sac. Four recent cases are presented which were successfully treated using this method.

High thoracic disc prolapse in a rugby player: the first reported case.

Traumatic disc prolapse in the thoracic region is not common, and is rare above the T3 level. A case of a T1-T2 disc prolapse as a result of rugby injury is described.

Chronic post-traumatic erosion of the skull base.

Delayed post-traumatic erosion of the skull base is reported in three patients who presented as adults with cerebrospinal fluid fistulae and a history of recurrent meningitis. These skull defects were associated with herniation of the subarachnoid space into the diploe of the skull base, the paranasal sinuses and the orbit. This rare complication of head injury is assumed to have occurred as the result of a dural tear at the time of trauma. Its site probably determines whether a resulting meningocele widens the intradiploic space or broaches the cranial floor.

Effect of a new computed tomographic image transfer system on management of referrals to a regional neurosurgical service.

A computed tomographic image transfer system ('Image Link') was used to link scanners within the Oxford region, UK, to the regional neurosurgical service. 100 consecutive neurosurgical referrals were examined by this system; 43% of the emergency referrals did not require transfer, 31% were transferred electively, and 26% urgently. Most of the patients defined as potentially hazardous for transfer (10/11) did not require neurosurgical intervention. The delay by the use of the system was negligible and early detection of intracranial haematoma contributed to good outcome in some head injured patients. Overall, 3,170 miles of ambulance journey were avoided. Use of image link has led to substantial improvements in management of neurosurgical emergency referrals, cost-effectiveness of neurosurgical and ambulance facilities, and interhospital communication between doctors.

Upper limb emboli. A review of 55 patients managed surgically.

During an eleven years period 1976-1986, 55 patients with emboli to the upper limb were managed at St. Laurence's Hospital. The presentation was classical for acute limb ischaemia in the majority while 27% presented 48 hours or more after the onset of symptoms. Four patients presented with gangrene. In 41 patients a source of embolus was readily identified: atrial fibrillation (33), recent myocardial infarct (5), subclavian artery aneurysm (2), left atrial myxoma (1). In the remaining 14 patients the source of the embolus was not initially apparent but investigation by echocardiography, 24 hour Holter monitoring and coagulation studies suggested a source in eight. Embolectomy was performed in 51 patients and amputation as a primary procedure in two. The patients with subclavian artery aneurysms were not treated surgically. A normal circulation was restored both clinically and angiographically in 43 patients, four of whom later died from myocardial infarction. Four of the remaining eight patients had residual arm claudication, three required amputation and one had an ischaemic contracture. The failure to restore a normal circulation was uniformly associated with delayed presentation or failure to adequately anticoagulate the patient with heparin.

The vascularisation of the central-peripheral transitional zone of rat lumbar ventral rootlets: a morphological and morphometric study.

The blood vessels supplying the central-peripheral transitional zone of rat fifth lumbar ventral spinal nerve rootlets were examined during development and at maturity. At all stages all vessels were either capillaries or postcapillary venules. They lay in the spaces between the rootlets, being entirely absent from the endoneurial spaces. A proportion of these vessels communicated with those supplying the adjacent spinal cord. In this respect they differed from those supplying the dorsal rootlet transitional zone, at least in the cat, where no such communication occurs. During the first week after birth, at least one capillary was directly related to each rootlet, generally over about half the length of the transitional zone. Subsequently vascularity increased considerably. At three weeks postnatum, and subsequently, capillaries outnumbered rootlets by up to 50% and almost the entire length of the transitional zone was related to one capillary or more. This change was related to the maturation of the transitional nodes of gamma axons, which is likely to be related to increased alpha and gamma motoneuron activity. These changes were somewhat offset due to the fact that rootlet diameter increased with age. As a result, the distance between the capillary wall and the centre of the rootlet almost doubled between 20 and 300 days postnatum. The diameter of the capillaries did not change with age but that of the postcapillary venules increased.

The sheaths surrounding the attachments of rat lumbar ventral roots to the spinal cord: a light and electron microscopical study.

The fifth lumbar ventral spinal nerve rootlets join to form a number of aggregated rootlet bundles. These in turn fuse to form the ventral root. Each rootlet is surrounded by a sheath which consists of a single fenestrated layer of cells and their attenuated cytoplasmic processes and which is open ended proximally. Immediately superficial to the spinal cord surface, rootlets are separated from one another by a labyrinth of inter-radicular spaces containing small blood vessels. Between adjacent rootlets the inter-radicular space tapers distally to an apex. The endoneurial space of the rootlet communicates with the subpial and inter-radicular spaces. Each aggregated rootlet bundle is surrounded by a multilayered sheath. Proximally, the outer layers of this sheath are continuous with the superficial layers of the pia mater. Both of these, as well as the root sheath with which the rootlet bundle sheaths are continuous distally, are complete and lack fenestrations. Accordingly, the endoneurial space, though continuous with the inter-radicular and subpial spaces, is isolated from the subarachnoid space.

The lumbar ventral root-spinal cord transitional zone in the rat. A morphological study during development and at maturity.

In the rat lumbar ventral spinal nerve rootlets, the central-peripheral transition occurs at the surface of a distal projection of central tissue into the rootlet. This changes considerably in appearance during development. In the first week after birth, it grows distally into the rootlet to form an irregular, tapering projection. In the second week after birth, it is retracted and becomes splayed out; its distal surface is irregular and lies just above the surrounding spinal cord. After this, it again grows distally into the rootlet. It forms a tapering projection which generally lies eccentrically in the rootlet, most often towards its dorsal surface. The central ends of the proximal transitional myelinated peripheral internodes generally lie in grooves on the surface of the central tissue projection. However, for a time during the second week after birth, many lie in invaginations into it. Occasional invaginations of the central tissue projection contain large numbers of collagen fibres rather than axons. A ring of collagen fibres surrounds the rootlet immediately distal to its attachment to the cord surface. Though the central tissue projection contains occasional astrocytic perikarya, it consists mostly of closely interwoven astrocyte processes derived from cell bodies situated at the cord surface surrounding the rootlet attachment. Changes in the form and size of the central tissue projection probably result largely from active growth and reorganisation of astrocyte processes. The barrier which these processes constitute probably prevents invasion of the cord by transitional Schwann cells. Before the central tissue projection develops, such invasion is probably prevented by the arrangement of transitional Schwann cells as a close-knit epithelium on the surface of the rootlet. The central tissue projection of ventral rootlets is smaller, more irregular in shape and less highly organised than that of dorsal rootlets. Central-peripheral transitional nodes lie close to the surface of the central tissue projection. They are therefore offset relative to one another and so are less likely to discharge one another. This arrangement may also protect the rootlet against mechanical damage due to traction.

The development of alpha and gamma motoneuron fibres in the rat. I. A comparative ultrastructural study of their central and peripheral axon growth.

The growth of alpha and gamma motoneuron axons was studied from late fetal life to maturity in the fifth lumbar ventral spinal root of the rat. Overall axon circumference distribution is unimodal up to three days postnatum and bimodal subsequently. Alpha and gamma fibre categories can be distinguished from one another before the bimodal distribution appears, since their degrees of segregation differ. By 3 days postnatum, the great majority of presumptive alpha axons are either promyelin or myelinated in form. The two populations follow separate maturation tracks subsequently, alpha axons making up between 60 and 70% of the total. Alpha axons grow most rapidly during the first week, gamma axons during the second and third weeks postnatum. The onset of myelination in both groups coincides with the most rapid period of growth. The delayed rapid growth of gamma fibres is due to a prolongation of their segregated stage; subsequent stages have a similar duration to those of alpha fibres. The periods of most rapid growth in both alpha and gamma fibres may be related to the formation of their respective terminal connections in the muscles. Myelination commences in relation to a smaller axon circumference in gamma than in alpha fibres. The former are therefore more myelinogenic than the latter.