Intraspinal oxidised cellulose (Surgicel) causing delayed paraplegia after thoracotomy--a report of three cases.

Oxidised regenerated cellulose (Surgicel) is a commonly used haemostatic agent in neurosurgery, thoracic surgery, and orthopaedics. We present three cases of paraplegia after thoracic surgery during which oxidised cellulose had been used during thoracotomy for haemorrhage control, and was later found to have passed through the intervertebral foramen causing spinal cord compression. In all intraspinal and perispinal procedures, the over-liberal use of Surgicel should be avoided, and attempts made to remove all excess Surgicel once adequate haemostasis is obtained.

Bilateral trigeminal neuralgia: a therapeutic dilemma.

In order to illustrate the inherent problems of managing bilateral trigeminal neuralgia a retrospective study of the 16 cases of bilateral trigeminal neuralgia, out of just over 300 cases of trigeminal neuralgia, treated over a 14-year period, has been performed. All the patients, presented with a typical history of trigeminal neuralgia and underwent surgical exploration. Pain relief was initially achieved in all cases; however, only four remained cured, three have become pain free after additional rhizotomy, a further one after peripheral cryotherapy and four with medical treatment. Four patients have had bilateral operations for trigeminal neuralgia, but in two cases the pain was relieved on one side only. Bilateral trigeminal neuralgia presents special problems of management with respect to underlying neuropathology (e.g. multiple sclerosis), the need for the limitation of the use of ablative techniques in order to minimise the disability of bilateral sensory and motor dysfunction, and the relatively poor response to microvascular decompression. These factors emphasize the multifactorial nature of the cause of trigeminal neuralgia. Magnetic resonance tomographic angiography is now available and is important in determining the range of therapeutic options for this group of patients.

Microvascular decompression for trigeminal neuralgia in Charcot-Marie-Tooth disease.

The authors report on three patients suffering from coexistent trigeminal neuralgia (TGN) and Charcot-Marie-Tooth disease who, based on preoperative magnetic resonance tomographic angiography findings, underwent microvascular decompression. All patients had demonstrable neural compression and all experienced immediate postoperative pain relief. Symptoms recurred in one patient and required a second procedure in the form of a neurotomy. Two patients suffered from bilateral TGN. When a patient with TGN suffers coexistent neurological disease and experiences bilateral symptoms, preoperative imaging and subsequent decompressive surgery may avoid the unacceptable risk of morbidity associated with bilateral ablative procedures.

Spontaneous chronic and subacute subdural haematoma in young adults.

Spontaneous subacute and chronic haematoma in young adults is rare. It has not been previously reported in this age group. We present three cases of chronic and subacute subdural haematoma in young adults, in one of whom the diagnosis was certainly delayed. All three patients underwent burrhole evacuation and made a full neurological recovery. A cause for the haematoma was never established. The literature on the subject, which is scanty, is reviewed and the condition is briefly discussed. The aetiology remains obscure.

Heterotopic bone formation causing recurrent donor site pain following iliac crest bone harvesting.

An unusual case of recurrent iliac crest donor site pain secondary to heterotopic bone formation is described. The literature is reviewed with a special emphasis on the aetiology and treatment of this entity.

Long-term outcome of percutaneous thermocoagulation for trigeminal neuralgia.

A retrospective analysis of long-term efficacy of percutaneous radiofrequency thermocoagulation of the trigeminal ganglion or root for the relief of trigeminal neuralgia was carried out in our unit. From the medical records and questionnaires, outcomes of 108 procedures performed in 81 patients from January 1986 to December 1990 were obtained with a follow-up period of 6-11 years. The initial success rate was 87% and the probability of remaining pain-free 1, 2 and 11 years after the procedure was 65, 49 and 26%, respectively. Patients with typical symptoms had a better long-term efficacy than those with atypical presentations, and patients who had not undergone a previous surgical procedure also had a better outcome. There was no mortality in this series. Common adverse effects included dysaesthesia in 20 patients, corneal numbness in 12 patients and masseter weakness in three patients.

Improvement in adult-onset Rasmussen's encephalitis with long-term immunomodulatory therapy.

OBJECTIVE: To study the immediate and chronic effects of high-dose, long-term human i.v. immunoglobulin (h i.v.Ig) therapy in two patients with advanced adult-onset Rasmussen's encephalitis (RE). BACKGROUND: Despite advances in our understanding of the autoimmune pathogenesis of RE, medical options for chronic treatment are limited. METHODS: In an open-label treatment trial, treatment started with monthly cycles of high-dose h i.v.Ig (0.4 g/kg/d for 5 days) followed by maintenance therapy (0.4 g/kg 1 day each month) after the patients' conditions began to improve. Outcome measures included clinical, psychological, functional, and laboratory assessments before and at relevant intervals throughout 1 year of treatment. RESULTS: In both patients, unrelenting pretreatment deterioration halted, and after this they displayed striking improvements in seizure control, hemiparesis, and cognition that produced useful recovery of function. Improvements were delayed until after 2 to 4 monthly cycles of high-dose h i.v.Ig and continued when patients switched to maintenance treatment. Their recoveries were accompanied by increased cerebral perfusion on interictal SPECT and suppression of inflammatory markers in CSF. CONCLUSIONS: h i.v.Ig can be a useful, possibly disease-modifying, long-term therapy for adult-onset RE that should be considered before radical surgery is performed. Because improvements can be delayed, we propose guidelines for intensive and prolonged trials of immunomodulatory therapy in adults with this syndrome.

The C-terminal tetrapeptide of beta-endorphin (MPF) enhances lymphocyte proliferative responses.

Human MPF (Lys-Lys-Gly-Glu) stimulates the proliferative response of human lymphocytes to the T-cell mitogen concanavalin A by 121-751% in the concentration range 10(-11)-10(-4) M; the peak effect is at 10(-8) M, lower or higher concentrations eliciting reduced responses, i.e. the dose-response curve is bell-shaped. Species specificity is high. Human MPF similarly stimulates rat lymphocytes, but the peak effect is seen at a 100-fold higher dose (10(-6) M). Rat MPF (Lys-Lys-Gly-Gln) has a peak effect at 10(-6) M with human lymphocytes, but the peak effect with rat lymphocytes is at a 1000-fold lower dose (10(-9) M). Truncated forms of the MPFs (Gly-Glu, Gly-Gln, Gly, Glu, Gln) and opioid peptides (beta-endorphin, [Leu] and [Met]enkephalin) show insignificant or only weak stimulatory or inhibitory effects. These results suggest that MPF acts via specific non-opioid receptors located on lymphocytes and that endogenously released MPF may have an important role in the functioning of the immune system.

The differential effect of the level of spinal cord stimulation on patients with advanced peripheral vascular disease in the lower limbs.

Percutaneous spinal cord stimulation (SCS) (Medtronic model 3487A PISCES-Quad lead) was carried out in 10 patients with rest pain from advanced peripheral vascular disease of the lower limb, who were unsuitable for conventional treatment. Trial stimulation ranged from 1-20 weeks and was associated with pain relief in nine of the patients. Claudication distance was improved in six patients. Trophic lesions improved in one patient with small artery disease. Spinal cord stimulation did not reverse the course of acute gangrenous lesions. The distal arterial pressure measured by Doppler Ankle/Brachial Pressure Index, (ABPI), showed no change. The capillary blood flow and skin temperature of both feet, measured, respectively, by Laser Doppler flowmetry and skin thermistor, showed a tendency to decrease when the stimulation was at the higher level, above T10, compared with an increase when the stimulation was at the lower level T12. Transcutaneous oxygen tension monitoring of the symptomatic foot showed an increase in four out of five patients. Pain relief was not dependent on circulatory changes, but it was more significant when the circulatory changes showed an impressive increase in the blood flow. The mechanism of these circulatory changes is probably by modulation of the sympathetic nervous system. Recognition of the optimal sitting of SCS may be critical in the clinical use of this technique, which seems to be a valuable option in the treatment of patients with advanced peripheral vascular disease (PVD).

Persistent facial pain following microvascular decompression of the trigeminal nerve.

Pain in the face following microvascular decompression (MVD) can be due to persisting trigeminal neuralgia (TGN) or a variety of other facial pain syndromes. If magnetic resonance tomoangiography (MRTA) indicates continuing vascular compression and the patient has true persistent TGN, then the patient can be relieved of pain by repeating the MVD. When the MRTA is negative for continuing compression alternative techniques may be employed; section of the nerve at the pons may be the treatment of choice for true persistent TGN in the absence of neurovascular compression. In some cases the pain is dysaesthetic in nature and not persistent TGN. This is always associated with previous destructive lesions to the nerve, usually radio-frequency thermocoagulation. When this component to the pain is recognized pre-operatively the patient must be warned not to expect relief of this same component of the pain from MVD. When it is not possible to classify the facial pain clinically, improvement does not occur following MVD even when there is clear evidence of vascular compression on MRTA.

Idiopathic syringomyelia and the importance of occult arachnoid webs, pouches and cysts.

Syringomyelia is the condition in which longitudinal cavities are found within the spinal cord. The use of drainage procedures has been widely practised with good short term results. However, the long-term results in some large series have been less favourable. There are many associated conditions and in most forms a blockage to the normal flow of CSF, either at the foramen magnum or in the spinal canal, can be identified. Most surgeons would now direct their efforts to the establishment of normal CSF flow rather than a shunting procedure. In a certain group of patients, even with the advent of sophisticated MRI, no associated abnormality or CSF block is easily identified. This type of syringomyelia is often termed idiopathic. We report 10 patients with symptomatic syringomyelia without readily recognized predisposing factors. In eight patients preoperative myelography revealed a block to the flow of contrast compatible with subarachnoid obstruction. Eight patients underwent laminectomy and division of the obstructing arachnoid webs. Five experienced good improvement and three only moderate improvement. Two of the patients underwent syrinx shunting procedures only, which resulted in a worsening of their symptoms. At operation one patient was found to have an arachnoid cyst. We believe that patients with idiopathic symptomatic syringomyelia may need myelography to identify such arachnoid abnormalities. Subsequent surgery should be directed at the establishment of normal CSF flow by laminectomy and excision of the offending lesion.

Trigeminal neuralgia: a quantitative sensory perception threshold study in patients who had not undergone previous invasive procedures.

The authors investigated 28 patients with "idiopathic" trigeminal neuralgia who had undergone no previous invasive procedures; together these patients had a total of 50 affected trigeminal divisions. Quantitative sensory perception thresholds were measured before operation. Preoperative measurements in the affected divisions indicated raised thresholds for touch (von Frey filaments) and temperature, but not for pinprick or heat pain, in agreement with the findings of Nurmikko. Only the tactile threshold was also significantly affected in the unaffected divisions on the affected side. The authors discuss their findings in relation to the pathophysiology of trigeminal neuralgia, concluding that the origin of the condition is almost certainly central to the gasserian ganglion.

Sensory effects of microvascular decompression in trigeminal neuralgia.

Nineteen patients with "idiopathic" trigeminal neuralgia, who had not undergone any previous interventional procedures, possessed a vessel or vessels compressing the preganglionic nerve root that was demonstrated by magnetic resonance tomographic angiography. Pain was relieved immediately in all of these patients after they underwent microvascular decompression without observed nerve damage. Although preoperative measurement of sensory perception thresholds showed elevations in the thresholds for touch (von Frey filaments) and warmth and coolness sensations, these thresholds normalized during the postoperative period. An apparent deficit in the pinprick (sharpness) sensation appeared postoperatively, but the deficit gradually regressed and completely disappeared by 1 year after surgery; this phenomenon may have been a statistical anomaly. The patients' pain disappeared immediately postoperatively and remained absent throughout the follow-up period. The authors conclude that damage to the nerve or nerve root is not essential for the relief of trigeminal neuralgia.

Trophic effects of melanotropin-potentiating factor (MPF) on cultures of cells of the central nervous system.

MPF is a tetrapeptide (structure Lys-Lys-Gly-Glu) that elicits a variety of neurotrophic effects in vivo consistent with a role in neuronal regeneration. In support of this role, we now show that MPF stimulates the proliferation of cultured astrocytes and neurite outgrowth from cultures of neocortical cholinergic and mesenchephalic dopaminergic neurons. The dose-response relationships are biphasic ("bell shaped"), maximal responses being obtained with 10(-6) M concentrations of MPF. MPF and nerve growth factor seem to act on different receptors, because their effects on cholinergic neurons are synergistic.

Dumbbell hydatid cyst of the spine.

We describe a case of dumbbell hydatid cyst of the T(10) pedicle. This cyst had both extradural and retroperitoneal components,leading to spinal cord compression and abdominal pain. Following surgical excision and irrigation with hypertonic saline the patient made a full recovery, and is recurrence-free after 18 months follow-up.

Trigeminal neuralgia due to vascular compression in multiple sclerosis--post-mortem findings.

A 71-year-old male with multiple sclerosis and trigeminal neuralgia due to vascular compression underwent multiple radio-frequency nerve lesioning bilaterally. He was anaesthetic on the left side and required right microvascular decompression. He died after this procedure. The pathology of the pons and the effects of treatment are described.

Demonstration of neurovascular compression in trigeminal neuralgia with magnetic resonance imaging. Comparison with surgical findings in 52 consecutive operative cases.

Until recently, the inability to demonstrate neurovascular compression of the trigeminal nerve preoperatively resulted in surgery being offered only in cases of severe trigeminal neuralgia (TGN), frequently after a prolonged trial of medical treatment and following less invasive procedures, despite the fact that posterior fossa microvascular decompression gives long-term pain relief in 80% to 90% of cases. To assess whether vascular compression of the nerve could be demonstrated preoperatively, high definition magnetic resonance tomographic angiography (MRTA) was performed in 50 consecutive patients, five of whom had bilateral TGN, prior to posterior fossa surgery. The imaging results were compared with the operative findings in all patients, including two patients who underwent bilateral exploration. Vascular compression of the trigeminal nerve was identified in 42 of 45 patients with unilateral symptoms and on both sides in four patients with bilateral TGN. In the last patient with bilateral TGN, neurovascular compression was identified on one side, and on the other side the compressing superior cerebellar artery was separated from the nerve by a sponge placed during previous surgery. There was full agreement regarding the presence or absence of neurovascular compression demonstrated by MRTA in 50 of 52 explorations, but MRTA misclassified four vessels compressing the trigeminal nerve as arteries rather than veins. In two cases, there was disagreement between the surgical and MRTA findings. In the first of these cases, surgery revealed distortion of the nerve at the pons by a vein that MRTA had predicted to lie 6 mm remote from this point. In the second patient, venous compression was missed; however, this patient was investigated early in the series and did not have gadolinium-enhanced imaging. In nine cases, MRTA correctly identified neurovascular compression of the trigeminal nerve by two arteries. Moreover, MRTA successfully guided surgical reexploration in one patient in whom a compressing vessel was missed during earlier surgery and also prompted exploration of the posterior fossa in two patients with multiple sclerosis and one patient with Charcot-Marie-Tooth syndrome, in whom neurovascular compression was identified preoperatively. It is concluded that MRTA is an extremely sensitive and specific method for demonstrating vascular compression in TGN. As a result, open surgical procedures can be recommended with confidence, and microvascular decompression is now the treatment of choice for TGN at the authors' unit. They propose MRTA as the definitive investigation in such patients in whom surgery is contemplated.

Association between trigeminal neuralgia and multiple sclerosis: role of magnetic resonance imaging.

Seven consecutive patients with multiple sclerosis and trigeminal neuralgia were investigated with MRI to determine the occurrence of a lesion which would account for the patients' pain. Two patients had bilateral symptoms. In the patients with unilateral trigeminal neuralgia vascular compression of the nerve by an artery at the root entry zone on the symptomatic side was confirmed in three patients and an epidermoid tumour distorting the nerve on the symptomatic side was identified in one patient. A demyelinating plaque was identified in only one patient, affecting the trigeminal nerve at the root entry zone at the pons. In those with bilateral symptoms neurovascular compression was identified on both sides in one patient and on one side only in the remaining patient. Microvascular decompression cured the pain in two patients with neurovascular compression. The variable aetiology of trigeminal neuralgia is stressed even in patients with coexistent neurological conditions such as multiple sclerosis, which can cause trigeminal neuralgia independent of other causes.