Pallidotomy in Parkinson's disease increases supplementary motor area and prefrontal activation during performance of volitional movements an H2(15)O PET study

Supplementary motor area and right dorsal prefrontal cortex activation in Parkinson's disease is selectively impaired during volitional limb movements. Since posteroventral pallidotomy improves motor performance in Parkinson's disease patients 'off' medication (i.e. off medication for 9-12 h), we hypothesized that it would also concomitantly increase supplementary motor area and dorsal prefrontal cortex activation. Six Parkinson's disease patients with a median total motor Unified Parkinson's Disease Rating Scale (UPDRS) of 52.5 (range 34-66) 'off' medication underwent unilateral right posteroventral pallidotomy. The patients had H2(15)O PET when 'off' medication before and 3-4 months after surgery. Each PET study comprised four to six measurements of regional cerebral blood flow either at rest or while performing regularly paced joystick movements in freely selected directions (forward, backward, left or right) using the left hand. Pre- and postoperative scans were performed in an identical manner and the associated levels of activation were compared using statistical parametric mapping. After pallidotomy, the median total motor UPDRS score 'off' medication decreased by 34.7% (P = 0.03) and mean response times of joystick movements following the pacing tones improved by 13.8% (P = 0.08). Relative increases in activation of the supplementary motor area and right dorsal prefrontal cortex were observed during joystick movements (P < 0.001). Decreased activation was seen in the region of the right pallidum (P = 0.001). We conclude that pallidotomy reduces pallidal inhibition of thalamocortical circuits and reverses, at least partially, the impairment of supplementary motor area and dorsal prefrontal cortex activation associated with Parkinson's disease.

The female tetraplegic: an admission of urological failure

OBJECTIVE

To present the long-term follow-up of female patients with tetraplegia managed in our unit, many of who require permanent indwelling catheters or urinary diversions that lead to significant complications and associated morbidity.

PATIENTS AND METHODS

Eighty-four female tetraplegics (mean age 31 years, range 13-81) were followed for a mean of 9 years (range 2-30). Three groups of patients were identified, depending on their neurology; 27 patients had complete lesions (Frankel A), 20 had incomplete lesions with poor functional recovery (Frankel B/C) and 37 had incomplete lesions with good function (Frankel D/E).

RESULTS

The patients with complete lesions (Frankel A) were difficult to manage, with 23 of the 27 (85%) treated using indwelling catheters. Three patients underwent diversion and for one patient, the carer performs clean intermittent catheterization (CIC). Of the 20 patients with Frankel B/C lesions, 14 have permanent indwelling catheters, three are able to perform CIC and three void by controlled triggering of detrusor contractions (reflex voiding). The 37 patients with Frankel D/E lesions fared better and only three (8%) require permanent catheters. Of the others, four (11%) use CIC (one following a cystoplasty) and most (30, 81%) use reflex voiding. Most of the 40 patients with permanent catheters had significant problems with bladder stones (55%), leakage and by-passing (35%), and recurrent symptomatic infections (33%). Patients performing CIC fared better, with most needing anticholinergic therapy or subtrigonal phenol; patients who used reflex voiding also needed these two treatments at some stage. Four patients (two with ileal loops and two with indwelling catheters) developed dilated upper tracts.

CONCLUSIONS

The urological status of female patients following cervical cord injury depends on the level of injury and recovery. Most patients with Frankel A-C lesions have permanent indwelling catheters and most patients with Frankel D or E lesions void with controlled triggering or use CIC. Although upper tract dilation was seen in only 5%, patients had significant morbidity related to the bladder.

Bowel problems after enterocystoplasty

OBJECTIVES

To document the changes in bowel habit in patients who have undergone enterocystoplasty.

PATIENTS AND METHODS

Sixty-nine patients with neuropathic (NP) and 44 with non-neuropathic (NNP) bladder dysfunction (mean age 26 years, range 13-61, 93.6% socially continent), followed for at least 36 months after cystoplasty, were assessed using a questionnaire addressing faecal frequency, consistency, method of evacuation and incontinence episodes before and after surgery.

RESULTS

Of the patients with NP bladder dysfunction, 26 (38%) had more and seven (10%) less frequent bowel action after surgery, with 36 (52%) unchanged; 38 (55%) of patients had unchanged consistency, 26 (38%) were looser and five (7%) more constipated; 41 (59%) opened their bowels as before, 16 (23%) needed more help and 12 (17%) less help to evacuate; 16 (23%) patients had more and 17 (25%) less episodes of incontinence; 21 (30%) patients felt their bowels had not become normal after their operation and only 24 (35%) that they had returned to normal within 3 months of their operation. The bowel segment used was ileum in 44 patients, ileocaecal in 11 and sigmoid cystoplasty in 14. Patients with intact ileum did not have the same degree of diarrhoea, with only three of the 14 patients with a sigmoid cystoplasty being adversely affected. Of the patients with NNP bladder dysfunction, 18 patients (41%) had a more and five (11%) a less frequent bowel action; 20 (46%) had more loose and five (11%) less loose bowel action; similar numbers (five and four) needed either an increase or a decrease in laxatives or enemata: surprisingly, 12 patients (27%) felt they had an increase in the episodes of incontinence; 17 (39%) patients felt their bowels returned to normal within 3 months of surgery and 30% felt their bowels had not become normal after surgery. Only one patient in this group had a sigmoid cystoplasty and she did not find that the operation interfered with her bowel function.

CONCLUSIONS

Ileal resection results in malabsorption of bile acids, maldigestion of fat and an imbalance of water and electrolytes. Patients with neurogenic bladders are finely balanced between acceptable bowel function and choas, and surgery often tips this balance the wrong way. In 30% of the present patients, bowel problems persisted after surgery, with 38% having increased frequency. 38% having looser consistency and 23% more incontinence episodes following surgery. More surprisingly, a high percentage of NNP patients had bowel problems after cystoplasty.

Supravesical diversion for incontinence: a long-term follow-up

OBJECTIVES

To report the long-term follow-up of patients with an ileal conduit urinary diversion, constructed for intractable incontinence in patients with benign disease where the native bladder was left in situ, and to determine the fate of the bladder and the effects on the upper tracts.

PATIENTS AND METHODS

Ninety-three patients (mean age at operation 50 years, range 8-78) were followed for a minimum of 2 (mean 5) years after undergoing an ileal conduit urinary diversion. Seventy-one patients (76%) had neurological disease (18 traumatic and 53 non-traumatic) and the single largest group of patients (28) suffered from disseminated sclerosis. Twenty-two patients with no obvious neurological disease underwent the procedure for unmanageable incontinence or intractable bladder symptoms or for interstitial cystitis. The patients were assessed for problems in the bladder remnant, stomal problems and upper tract changes following surgery.

RESULTS

Forty-eight patients (52%) had recurrent vesical infections and pyocystis and of these, 23 (48%) required admission for in-patient bladder irrigations. To control recurrent bladder problems, five patients required creation of a vesico-vaginal fistula; this did not suffice in two and they subsequently underwent cystectomy; in total, five patients underwent cystectomy. Twenty-nine patients (31%) had stomal problems, those with the skin being commonest. Parastomal hernia repair was required in 10 (10%) patients and three had further surgery for recurrence. Of 83 patients with normal upper tracts before diversion, post-operative radiological assessment showed upper tract dilatation in 28 (34%) and in 10 (12%) this was bilateral. In one patient with a neuropathic bladder, the ileal diversion resulted regression of the dilated upper tracts.

CONCLUSIONS

Supravesical diversion is safe and well tolerated but assessing the long-term follow-up, the incidence of bladder problems in over half these patients and upper tract changes in over a third suggests an indefinite follow-up is mandatory. Despite these problems, most patients are delighted with the outcome of their surgery.

Surgical treatment of patients with single and dual pathology: relevance of lesion and of hippocampal atrophy to seizure outcome

Modern neuroimaging can disclose epileptogenic lesions in many patients with partial epilepsy and, at times, display the coexistence of hippocampal atrophy in addition to an extrahippocampal lesion (dual pathology). We studied the postoperative seizure outcome of 64 patients with lesional epilepsy (median follow-up, 30 months) and considered separately the surgical results in the 51 patients with a single lesion and in the 13 who had dual pathology. In patients with a single lesion, 85% were seizure free or significantly improved (Engel's class I-II) when the lesion was totally removed compared with only 40% when there was incomplete resection (p < 0.007). All three patients with dual pathology who had both the lesion and the atrophic hippocampus removed became seizure free. In contrast, only 2 of the 10 patients with dual pathology undergoing surgery aimed at the lesion or at the hippocampus alone became seizure free (p < 0.05), although 4 of them showed significant improvement (Engel's class II). We conclude that the outcome in patients with single epileptogenic lesions is usually dependent upon the completeness of lesion resection. In patients with dual pathology, surgery should, if possible, include resection of both the lesion and the atrophic hippocampus.

Craniopharyngioma: improving outcome by early recognition and treatment of acute complications

PURPOSE

To assess the frequency, mode of presentation, treatment, and outcome of acute complications in patients with craniopharyngioma around the time of radiotherapy.

METHODS AND MATERIALS

A review was made of 188 patients with craniopharyngioma treated with conservative surgery and external beam radiotherapy at the Royal Marsden Hospital between 1950 and 1992.

RESULTS

Twenty six (14%) (95% confidence interval: 9-19%) patients with craniopharyngioma developed acute deterioration immediately before, during and 2 months after radiotherapy with visual deterioration (19 patients), hydrocephalus (7 patients), and global deficit (7 patients). Cystic enlargement with or without hydrocephalus was the most common cause of deterioration. No patient or disease characteristics were predictive of deterioration on univariate or multivariate analysis. Eighteen patients had surgical intervention at the time of deterioration and survived the immediate period. Six of seven patients who did not have surgical intervention died. All patients who survived the postcomplication period completed the full course of external beam radiotherapy. The 10-year progression-free survival of 162 patients without deterioration was 86%, and of 18 patients with acute deterioration who recovered after surgery, 77%.

CONCLUSION

Patients with craniopharyngioma develop acute deterioration around the time of radiotherapy owing to cystic enlargement and/or hydrocephalus which does not represent tumor progression. Early recognition and appropriate surgical treatment followed by conventional full-dose radiotherapy are associated with good long-term outcome.

Sellar tuberculoma: report of two cases

Hypophyseal tuberculomas are exceptionally rare. We report two patients with sellar tuberculoma but with no evidence of concurrent extrasellar disease. Although the lesion is often mistaken for adenoma, there are characteristic radiological features: intense enhancement on contrast CT and thickening of the pituitary stalk on MRI in 86% of cases. Accurate diagnosis is important because pituitary tuberculoma is curable.

Stereotactic thalamotomy in tremor-dominant Parkinson's disease: an H2(15)O PET motor activation study

Stereotactic thalamotomy is an effective treatment for severe drug-resistant tremor. The thalamus, however, facilitates motor activity, and thalamotomy would be predicted to inhibit movement-associated cortical activation. Two tremulous parkinsonian patients were studied with H2(15)O positron emission tomography before and after left ventralis intermedius thalamotomy. Subjects were scanned at rest and during performance of externally paced joystick movements in freely selected directions with the right hand. Thalamotomy relieved tremor but, as predicted, led to decreased activation of the left sensorimotor cortex, lateral premotor cortex, and parietal area 7 on hand movement.

A randomized trial on dose-response in radiation therapy of low-grade cerebral glioma: European Organization for Research and Treatment of Cancer (EORTC) Study 22844

PURPOSE

Cerebral low-grade gliomas (LGG) in adults are mostly composed of astrocytomas, oligodendrogliomas, and mixed oligoastrocytomas. There is at present no consensus in the policy of treatment of these tumors. We sought to determine the efficacy of radiotherapy and the presence of a dose-response relationship for these tumors in two multicentric randomized trials conducted by the European Organization for Research and Treatment of Cancer (EORTC). The dose-response study is the subject of this article.

METHODS AND MATERIALS

For the dose-response trial, 379 adult patients with cerebral LGGs were randomized centrally at the EORTC Data Center to receive irradiation postoperatively (or postbiopsy) with either 45 Gy in 5 weeks or 59.4 Gy in 6.6 weeks with quality-controlled radiation therapy. All known parameters with possible influences on prognosis were prospectively recorded. Conventional treatment techniques were recommended.

RESULTS

With 343 (91%) eligible and evaluable patients followed up for at least 50 months with a median of 74 months, there is no significant difference in terms of survival (58% for the low-dose arm and 59% for the high-dose arm) or the progression free survival (47% and 50%) between the two arms of the trial. However, this prospective trial has revealed some important facets about the prognostic parameters: The T of the TNM classifications as proposed in the protocol appears to be one of the most important prognostic factors (p < 0.0001) on multivariate analysis. Other prognostic factors, most of which are known, have now been quantified and confirmed in this prospective study.

CONCLUSION

The EORTC trial 22844 has not revealed the presence of radiotherapeutic dose-response for patients with LGG for the two dose levels investigated with this conventional setup, but objective prognostic parameters are recognized. The tumor size or T parameter as used in this study appears to be a very important factor.

Assay of anticancer drugs in tissue culture: comparison of a tetrazolium-based assay and a protein binding dye assay in short-term cultures derived from human malignant glioma

Because of the methodological difficulties associated with the MTT assay in screening short-term cultures derived from human malignant glioma, a chemosensitivity assay based on the protein staining using sulforhodamine B (SRB) has been optimized for use with these cells. SRB at a fixed dye concentration achieved maximal staining density at 20 min for most cell lines and this intensity was not further increased by using dye concentrations above 0.2%. A delay in staining after fixation did not significantly decrease staining intensity, but delay in dye extraction after fixation and staining did. There was an excellent quantitative and qualitative linear relationship between cell number determined by either the SRB assay or by cell counting, but not with the MTT assay which consistently underestimated the number of cells in assay plates. The MTT assay appeared to be incapable of detecting less than about 150 cells/well, while these small numbers of cell were readily detectable by either cell counting or SRB staining. There was a close correlation between chemosensitivity values derived from the MTT and SRB assays for procarbazine, CCNU and vincristine when the endpoint is taken as either the ID25, ID50 or ID75. The results indicate that the SRB is capable of producing broadly similar results to the MTT assay, but is more sensitive in the detection of small numbers of cells with a linear relationship between cell number and SRB staining intensity over a wide range of cell numbers. It is capable of producing data from short-term cultures from malignant glioma and offers technical advantages over the MTT assay in that plates may safely be stored at certain points during the assay without the need for immediate processing. The SRB assay provides a useful alternative to the MTT assay for determining the sensitivity of short-term cultures of human glioma to cytotoxic drugs.

Acquired immune deficiency syndrome (AIDS) and cerebral astrocytoma

The presence of cerebral lesions in patients affected by the acquired immune deficiency syndrome (AIDS) has been estimated to be around 10%, with the majority being infective lesions or primary central nervous system lymphomas. The co-occurrence of a cerebral glioma in such patients is rare. The aim of this report is to present four more cases, discussing their clinical and neuroradiological features, as well as the outcome and the possible pathogenesis.

Measurement of exposure to nutrients: an approach to the selection of informative foods

Frequently, epidemiologic questionnaires are designed to measure several individual level exposures, including exposure to one or more nutrients. Although most nutrients are contained in a large number of foods, constraints on questionnaire length permit the inclusion of only a subset of these. In this paper, the authors review the two common methods of food selection, and they propose two new methods. When the intent is to estimate the effect of the nutrient on disease risk using a logistic regression model, the authors show that their Max_r method is optimal. With the use of case-control data, they examine the assumption of non-differential measurement error that is essential to the validity of all analyses that rely on shortened questionnaires. They conclude by combining the statistical considerations developed for judging adequacy of a selection method with their empirical results and suggest new goals for dietary questionnaires and a new approach to questionnaire construction consistent with those goals.

Subependymoma of the cervical cord

Subependymomas are benign lesions of the central nervous system. Their occurrence in the spinal cord is rare. It is important to recognize these lesions because their total surgical excision is feasible and leads to long term symptom remission-a case of a spinal subependymomas localized in the cervical region is discussed and a review of the relevant literature is presented.

Artificial urinary sphincter for post-prostatectomy incontinence

OBJECTIVE

To assess the role of the artificial urinary sphincter in the management of patients with post-prostatectomy incontinence.

PATIENTS AND METHODS

The study comprised 28 patients (mean age 71 years, range 45-81) with post-prostatectomy incontinence caused by sphincter deficiency who underwent implantation of an artificial sphincter and were followed for a mean of 41 months (range 6-79).

RESULTS

Twenty-one (75%) patients had a bulbar cuff and seven (25%) had a membranous urethral cuff implanted. Problems with the bulbar urethral cuff included persistent stress leakage in six, system failure in two and infection in one patient. Nine patients with the bulbar urethral cuff and one patient with the membranous urethral cuff required revision. Of the nine re-operations in those fitted with a bulbar urethral cuff, five required a higher pressure balloon, one a smaller cuff, two had system failures replaced and one had a membranous urethral cuff implanted because of infection. Three of these nine patients needed a third operation and in all of these a membranous urethral cuff was inserted. A total of 33 operations were performed in 21 patients with bulbar urethral cuffs (a re-operation rate of 57%) and eight operations were carried out in seven patients with membranous urethral cuffs (a re-operation rate of 14%). Three patients needed anticholinergic therapy and one needed a clam cystoplasty for intractable instability. Twenty-four patients (86%) are dry and fully continent, three (11%) have occasional stress leakage and one patient had a cerebro-vascular accident 9 months after surgery and now has an indwelling catheter.

CONCLUSIONS

Patients who had artificial sphincters implanted to treat post-prostatectomy incontinence achieved a social continence rate of 96%. With bulbar urethral sphincters there was a high incidence of post-implantation incontinence and a high re-operation rate to achieve this success.

Artificial urinary sphincter in patients with neurogenic bladder dysfunction

OBJECTIVE

To assess the role of the artificial urinary sphincter (AUS) in the management of sphincter weakness incontinence in neuropathic patients.

PATIENTS AND METHODS

Ninety patients (75 male and 15 female, mean age 26 years, range 13-62) with neurogenic bladder dysfunction (71 with congenital and 19 with acquired cord lesions) who underwent implantation of an AUS were reviewed. All patients were followed up for a minimum of one year after the initial implantation of the sphincter (mean 4 years, range 1-10). Pre-operative video-urodynamics demonstrated sphincter weakness incontinence in all patients, with 24 patients having an acontractile-type bladder. Of 66 patients with intermediate-type bladders, 52 underwent cystoplasty.

RESULTS

Eighty-three patients (92%) were continent both night and day, three were occasionally damp and controlled by pharmacotherapy, and four had a persistent poor result. Of the 66 patients with detrusor hyper-reflexia, 52 (79%) required a cystoplasty to achieve continence and 14 (21%) were controlled with anti-cholinergic therapy. The re-operation rate was 28% (25/90) and complications included six infections, seven erosions, eight system failures, two pump failures, one sheered tube and one rectal and one bladder perforation. Seventy (78%) of the patients currently perform intermittent catheterization to treat high post-voiding residual urine volumes.

CONCLUSIONS

A rate of continence > 90% was achieved in these neurogenic patients after implantation of an AUS and we recommend a simultaneous cystoplasty in patients with detrusor overactivity.

Randomized trial of bolus phenylephrine or ephedrine for maintenance of arterial pressure during spinal anaesthesia for Caesarean section

Thirty-eight healthy women undergoing elective Caesarean section under spinal anaesthesia at term were allocated randomly to receive boluses of either phenylephrine 100 micrograms or ephedrine 5 mg for maintenance of maternal arterial pressure. The indication for administration of vasopressor was a reduction in systolic pressure to < or = 90% of baseline values. Maternal arterial pressure (BP) and heart rate (HR) were measured every minute by automated oscillometry. Cardiac output (CO) was measured by cross-sectional and Doppler echocardiography before and after preloading with 1500 ml Ringer lactate solution and then every 2 min after administration of bupivacaine. Umbilical artery pulsatility index (PI) was measured using Doppler before and after spinal anaesthesia. The median (range) number of boluses of phenylephrine and ephedrine was similar; 6 (1-10) vs 4 (1-8) respectively. Maternal systolic BP and CO changes were similar in both groups, but the mean [95% CI] maximum percentage change in maternal HR was larger in the phenylephrine group (-28.5 [-24.2, -32.9]%) than in the ephedrine group (-14.4 [-10.6, -18.2]%). As a consequence atropine was required in 11/19 women in the phenylephrine group compared with 2/19 in the ephedrine group (P < 0.01). Mean umbilical artery pH [95% CI] was higher in the phenylephrine group (7.29 [7.28-7.30]) than in the ephedrine group (7.27 [7.25-7.28]). The results of the present study support the use of phenylephrine for maintenance of maternal arterial pressure during spinal anaesthesia for elective Caesarean section.

Interstitial cystitis: involvement of the intestine

Two patients with intractable interstitial cystitis are presented. Both have had substitution enterocystoplasty and in both, unabated symptoms have resulted in ileal loop diversion. In both patients the excised neobladder had shown extensive changes of interstitial cystitis involving all layers, including the muscle layers of the explanted intestine. Also in one of these patients, symptoms suggestive of interstitial cystitis persisted and biopsies taken from the ileal loop have shown histological changes characteristic of interstitial cystitis. The presentation of interstitial cystitis in the intestine is discussed and we conclude that interstitial cystitis does manifest in the intestine.

Craniotomy guidance using a stereo-video-based tracking system

In open intracranial neurosurgery, it is desirable to minimize exposure and to approach the target in the most accurate way possible. The VISLAN system described here employs a completely passive hand-held locator which is tracked by a video system and does not require a mechanical linkage nor cables. The system also tracks easily recognizable, constant, anatomical landmarks of the patient. By this means the initial registration of pre-operative imaging and the detection of, and correction for, patient movement can be accomplished. High-resolution MRI segmented interactively is used to define external surface and brain anatomy. Thus, a pre-operative patient representation (POPR) is planned. During the surgical procedure the patient's head is illuminated by structured light and stereo-video pictures obtained from two television cameras mounted above the head. The system is calibrated and registered with the POPR using a chamfered matching algorithm. The locator is also tracked in space by the video system, and its tip position shown in relation to the POPR on the video monitor.

Intramedullary spinal cord abscess: case report

Intramedullary spinal cord abscesses are rare lesions with a poor prognosis unless diagnosed and treated promptly. We report a case of a Nigerian man with tuberculous meningitis that was complicated by an intraspinal cord abscess and was treated surgically. The literature regarding this uncommon clinical entity is reviewed.

Intermittent catheterization following enterocystoplasty

OBJECTIVE

To assess the segment of bowel used in enterocystoplasty and the need to perform intermittent self-catheterization (ISC) after enterocystoplasty for the treatment of incontinence.

PATIENTS AND METHODS

Of 123 patients undergoing enterocystoplasty, 77 (mean age 29.5 years, range 13-61) had neurogenic disease (NB group) and 46 (mean age 45.7 years, range 16-74) had non-neuropathic bladders (NNB group). The success of enterocystoplasty, with respect to the segment of bowel used and the need for ISC, was assessed during a follow-up of 6-125 months.

RESULTS

Ileum was used in 84 (63.8%), ileum and caecum in 19 (15.4%) and sigmoid in 20 (16.3%) patients. In the NB group, more patients had a sigmoid cystoplasty (24.7 vs 2.2%) and less (67 vs 80%) had an ileo-cystoplasty than in the NNB group. A total of 87 (71%) patients required ISC; 63 (82%) of the NB group and 24 (52%) of the NNB group. The influence of the intestinal segment was conspicuous in the NB group, with 82% and 95% of patients with ileocaecal and sigmoid cystoplasty needing ISC against 77% of those patients with ileal cystoplasty. The difference was not so evident in the NNB group.

CONCLUSIONS

A social continence rate of 93.6% in the NB and 84.8% in the NNB patients was achieved, partly due to the patients' success with ISC, a necessary skill to be mastered by all patients before undergoing enterocystoplasty.

Anorectal function in patients with complete spinal transection before and after sacral posterior rhizotomy

BACKGROUND/AIMS

The implantation of spinal stimulators to facilitate defecation in patients with complete spinal transection involves division of the posterior sacral nerve roots. The aim of this study was to investigate the role of spinal reflexes in anorectal function.

METHODS

Anorectal manometry and electromyography were performed in 14 patients with supraconal spinal cord transection (C6-T12) before and after complete sacral posterior rhizotomy and in 30 normal controls.

RESULTS

Patients with spinal transection lost conscious control of the external anal sphincter. Reflex responses to intra-abdominal pressure and to rectal distention were eliminated after rhizotomy, indicating that they are spinal reflexes. Rhizotomy also eliminated giant rectal contractions induced by rectal distention in these patients. In contrast, the exaggerated sphincter relaxation induced by rectal distention was not influenced by rhizotomy. Discriminant rectal sensation was lost, but patients with thoracic cord lesions perceived a dull pelvic sensation during rectal distention even after rhizotomy.

CONCLUSIONS

The exaggerated anorectal smooth muscle responses and absent conscious control of the anorectum may explain why patients with complete spinal transection experience uncontrollable reflex defecation, and the persistence of external anal sphincter contraction during straining may impair fecal expulsion. The elimination of these responses after posterior rhizotomy prevented reflex defecation while facilitating manual evacuation.

Stereotactically-guided craniotomy for cavernous angiomas presenting wit epilepsy

With the wider availability of magnetic resonance imaging cavernous malformations are being recognised with increasing frequency in those patients presenting with intractable epilepsy. Surgical resection is the treatment of choice. However, because these lesions are usually small and may be located in eloquent areas stereotactic resection should be considered. Stereotactically-guided resection of pathologically verified cavernous angiograms was performed in 10 patients in this series presenting with epilepsy (8 males, 2 females, mean age 32 years). Eight patients presented with medically intractable epilepsy (5 complex partial seizures, 3 grand mal seizures). Of the remaining patients one experienced multiple episodes of haemorrhage and the other headaches (with a non-diagnostic scan) both in association with epilepsy. Pre-operative localisation of the motor strip was determined in one case by functional MRI. Following resection of these lesions all patients experienced improved seizure control with a mean follow-up period of 22 months. The mean postoperative hospital stay was 5.1 days with no surgical complications recorded. We conclude that stereotactically-guided resection offers significant advantages in the management of cavernous malformations. Surgical indications for operative resection would include medically refractory epilepsy, repeated haemorrhage and those cases where there is diagnostic uncertainty.