Antimicrobial activity and phytochemical studies of some lichens from south of Spain.

The antimicrobial activity of some lichens from south Spain has been studied and some of plant constituents were identified. Activity against some Gram (+) bacteria has been observed in lichens containing usnic acid.

The use of stereotactic radiosurgery in the management of meningiomas.

This is a systematic review of a consecutive series of 309 meningiomas treated with gamma knife stereotactic radiosurgery between 1994 and 2000. There was an extreme selection bias towards lesions unfavourable for surgery, determined by the patients referred for treatment: 70% of tumours involved the skull base, 47% specifically the cavernous sinus: 15% of patients had multiple meningiomatosis or type 2 neurofibromatosis. Tumour histology was the main determinant of growth control (p < 0.001), the 5-year actuarial control rates being 87% for typical meningiomas, 49% for atypical tumours and 0% for malignant lesions. Complications from radiosurgery were rare, occurring in 3% of tumours, and were most frequently trigeminal and eye movement disturbances treating cavernous sinus meningiomas. Given the problems inherent in managing these tumours, radiosurgery is a valuable strategy and adjuvant treatment for these meningiomas.

Treatment options for von Hippel-Lindau's haemangioblastomatosis: the role of gamma knife stereotactic radiosurgery.

Haemangioblastomas secondary to von Hippel-Lindau (VHL) disease can be difficult to manage surgically, which has lead to an interest in the use of stereotactic radiosurgery. Retrospectively reviewed here are 30 tumours treated in 14 patients with a mean +/- SD follow-up of 34 +/- 24 months. During this time, three of the 14 patients (21%) died, two of generalized progressive disease. Before radiosurgery, the median time between interventions for cranial haemangioblastomas was 3 years (mean 3.9 +/- 5.0 years). After radiosurgery, the tendency for cranial disease progression was similar, 50% of patients developing further disease by 5 years. Local tumour control was achieved in the majority of cases and estimates of this are included. Radiosurgery is a useful palliative measure controlling the majority of haemangioblastomas, although its efficacy in these patients is limited by the tendency of further disease to develop or progress intracranially.

Gamma knife radiosurgery for cerebral arteriovenous malformations.

Since its introduction, gamma knife radiosurgery has become an important treatment modality for cerebral arteriovenous malformations. This paper is a brief overview of the technique used, of the clinical results achieved and of the experience gained in Sheffield.

Gamma knife stereotactic radiosurgery for unilateral acoustic neuromas.

OBJECTIVE: To evaluate the clinical results achievable using current techniques of gamma knife stereotactic radiosurgery to treat sporadic unilateral acoustic neuromas. METHODS: A retrospective review of 234 consecutive patients treated for unilateral acoustic neuromas between 1996 and 1999, with a mean (SD) follow up of 35 (16) months. Tumour control was assessed with serial radiological imaging and by the need for surgical intervention. Hearing preservation was assessed using Gardner-Robertson grades. Details of complications including cranial neuropathies and non-specific vestibulo-cochlear symptoms are included. RESULTS: A tumour control rate in excess of 92% was achieved, with only 3% of patients undergoing surgery after radiosurgery. Results were less good for larger tumours, but control rates of 75% were achieved for 35-45 mm diameter lesions. Of patients with discernible hearing, Gardner-Robertson grades were unchanged in 75%. Facial nerve function was adversely affected in 4.5%, but fewer than 1% of patients had persistent weakness. Trigeminal symptoms improved in 3%, but developed in 5% of patients, being persistent in less than 1.5%. Transient non-specific vestibulo-cochlear symptoms were reported by 13% of patients. CONCLUSIONS: Tumour control rates, while difficult to define, are comparable after radiosurgery with those experienced after surgery. The complications and morbidity after radiosurgery are far less frequent than those encountered after surgery. This, combined with its minimally invasive nature, may make radiosurgery increasingly the treatment of choice for small and medium sized acoustic neuromas.

Clinical experience with gamma knife stereotactic radiosurgery in the management of vestibular schwannomas secondary to type 2 neurofibromatosis.

OBJECTIVE: To evaluate the results of stereotactic radiosurgery treating vestibular schwannomas secondary to type 2 neurofibromatosis. METHODS: A retrospective review of 122 type 2 neurofibromatosis vestibular schwannomas consecutively treated in 96 patients. Tumour control was assessed by recourse to surgical intervention, by serial radiological imaging, and by the calculation of relative growth ratios in patients (n=29) habouring untreated contralateral tumours to act as internal controls. Hearing function was assessed with Gardner-Robertson grades and with averaged pure tone audiogram thresholds. Other complications are detailed. RESULTS: Applying current techniques, eight years after radiosurgery it was estimated that 20% of patients will have undergone surgery for their tumour, 50% will have radiologically controlled tumours, and in 30% there will be some variable concern about tumour control, but up to that time they will have been managed conservatively. Relative growth ratios one and two years after treatment indicate that radiosurgery confers a significant (p=0.01) advantage over the natural history of the disease. Analysis of these ratios beyond two years was precluded by the need to intervene and radiosurgically treat the contralateral control tumours in more than 50% of the cases. This growth control was achieved with 40% of patients retaining their Gardner-Robertson hearing grades three years after treatment, (40% having some deterioration in grade, 20% becoming deaf). Pure tone audiogram results suggest some progressive long term hearing loss, although interpretation of this is difficult. Facial and trigeminal neuropathy occurred in 5% and 2%. CONCLUSIONS: Radiosurgery is a valuable minimally invasive alternative treatment for these tumours. For most patients, it controls growth or defers the need for surgery, or both. There is a price in terms of hearing function, although this may compare favourably with the deafness associated with the natural history of the disease, and with surgery. In deciding on therapy, patients should be aware of this treatment option.

Changing utilization of stereotactic radiosurgery in the UK: the Sheffield experience.

Recognizing a change in our workload and variabilities in referral patterns, we reviewed our previous activity from 1994 to 2000 retrospectively and examined prospectively formal referrals to the Unit in 2001. Arteriovenous malformations still constitute 30% of referrals and treatments, although as a proportion of our workload, this has declined. Radiosurgery is increasingly being chosen as a first line treatment for small and moderate-sized acoustic neuromas, although referral rates vary widely, some neuroscience units referring all and others none of their acoustic neuromas at least for a radiosurgical opinion. About 100 meningiomas, mainly skull-base and/or recurrent tumours after previous surgery, are now treated per year. Compared with other units world-wide, very few pituitary adenomas and cerebral metastases are treated. The implications of this are discussed.

Optimising imaging parameters for post mortem MR imaging of the human brain.

PURPOSE: MR imaging of post mortem brains has the potential to yield volumetric information and define the extent of structural changes prior to pathological examination. Although standard T2-weighted clinical imaging sequences have been used for the examination of formalin-fixed brains, these protocols may not yield optimum contrast. We examined the effect of varying durations of formalin fixation on the transverse relaxation time (T2) and the tissue spin density. MATERIAL AND METHODS: Three post mortem brains were examined weekly during formalin fixation from the unfixed state to 35 days fixation. Standard MR spin-echo imaging was used at 5 echo times (20-100 ms) to calculate transverse relaxation time (T2) and spin density. RESULTS: T2 decreased significantly (ANOVA, p<0.001) in both grey and white matter by 7 days fixation and there was a further (but non-significant) trend towards lower values between 7 and 35 days. Grey and white matter T2 times converged with fixation. Conversely, the grey to white matter spin density ratio increased from 1.19+/-0.01 to 1.54+/-0.06 over five weeks of fixation. CONCLUSION: Our results suggest that spin density-weighted imaging sequences would provide improved grey to white matter contrast over T2-weighted sequences.

Endovascular treatment of intracranial aneurysms: a minimally invasive approach with advantages for elderly patients.

An endovascular approach, embolizing intracranial aneurysms with electrolytically detachable coils, is a new minimally invasive treatment of aneurysms. Reviewing our experience with 13 patients aged 70 years or more, 12 patients were treated successfully. Over an average follow-up period of 8 months, there was only one death which might be attributed to an intracranial aneurysm. This compares favourably with mortality rates approaching 50% for either conservative or traditional surgical management of aneurysms presenting with subarachnoid haemorrhage in this age group. Coil embolization, avoiding craniotomy, may offer particular advantages in managing intracranial aneurysms in the elderly patient.

Haemodynamic consequences of embolizing aneurysms: a transcranial Doppler study.

Twenty patients with aneurysms were studied with transcranial Doppler before, during and after endovascular treatment with Guglielmi detachable coils. Catheterization of the anterior circulation decreased middle cerebral artery velocities by 15-20%. Inserting coils into the aneurysms increased pulsatility indices modestly, reflecting a stiffening of the cerebral circulation. Pre- and posttreatment velocities were not significantly different, and there was no evidence of coil embolization precipitating vasospasm. The haemodynamic stability, seen during and after therapy, suggests that coil embolization may prove a safe alternative way of treating acutely ruptured aneurysms.

A common carotid artery aneurysm causing severe dysphagia.

Extracranial carotid artery aneurysms are rare, but are occasionally recognized as causing dysphagia. These aneurysms generally occur at or above the bifurcation. Here we present what we believe is a unique case: a common carotid artery aneurysm compressing the upper oesophagus, and mimicking the obstruction of a post-cricoid carcinoma.

[Additional contribution to the study of the antimicrobial activity and identification of lichenic substances in some lichens from southern Spain]. / Nouvelle contribution à l'étude de l'activité antimicrobienne et identification des substances lichéniques de quelques lichens du sud de l'Espagne.

Antimicrobial activity in some lichens from south Spain has been studied. Some lichenical substances are also identified. A very hight activity has been observed in lichens with usnic acid.

Sporotrichosis.

Forty-nine patients with culture-proven sporotrichosis were treated between 1957 and 1986. Infections were lymphocutaneous in 36 patients, pulmonary in two, intraarticular in four, and involved multiple deep tissues in seven. Thirty-six infections involved an upper extremity. Five patients with deep infection had some evidence of being immunocompromised. Delay in diagnosis after presentation averaged 4 months overall and 25 months for those with deep infection. Ten of 12 joint infections resulted in significant functional impairment. Treatment with saturated potassium iodide solution was effective for lymphocutaneous infection. Four patients with infection of deeper tissues remain infected despite multiple operations and systemic courses of antifungal medication.

[Antibacterial activity of some lichens from southern Spain]. / Contribution à l'étude de l'activité antibactérienne de quelques lichens du sud de l'Espagne.

Antibacterial activity of some lichens from south Spain has been studied. High activity against Gram+ bacteria has been observed, although Parmelia caperata, Evernia prunastri and Usnea sp. are also active against Gram- bacteria.