Adenosine A1 receptors modulate anxiety in CD1 mice.

The effect of the selective adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine (CCPA) was investigated in CD1 mice by the elevated plus-maze and the light/dark test, two models for measuring anxiety in rodents. CCPA, administered i.p., had an anxiolytic effect at 0.3 nmol/kg in the elevated plus-maze and at 1 nmol/kg in the light/dark test. Brain levels of 22 nM were found after administration of 100 nmol/kg CCPA, as measured by ex vivo binding experiments. These values are consistent with the occupancy of adenosine A1 but not A2 receptors by CCPA, and suggest that the anxiolytic-like action of CCPA may be mediated by centrally located adenosine A1 receptors. Both CPT, a selective adenosine A1 receptor antagonist, and IBMX, a non-selective adenosine antagonist, had an anxiogenic effect in the two tests. It is thus possible that purinergic neurons may be involved in the tonic modulation of affective state in mice.

Staging of supratentorial hemispheric glioma using tumour extension, histopathological grade and extent of surgical resection.

A 'TGS' classification for supratentorial brain glioma is proposed, based on three parameters: tumour extension (T), histopathological grade (G) and extent of surgical resection (S). Two groups of patients were analysed: the first (n = 137) had tumour submitted to stereotactic biopsy; the second (n = 60) had malignant glioma operated on by craniotomy and tumor resection. All three staging parameters significantly influenced survival. Histopathological grade was the most significant factor, and the only independent variable on multivariate analysis, followed by extent of tumour and then extent of surgical resection. The data support the applicability of the proposed parameters for a staging classification of hemispheric brain glioma.

Intraoperative real-time ultrasonography in the microsurgical removal of subcortical or deep-seated brain tumors.

Seventy-three patients with subcortical or deep-seated brain tumours have been operated on with the aid of intraoperative ultrasonography. Forty-one had metastases and thirty-two primitive neuroepithelial neoplasms. In all cases ultrasonography allowed an easy and precise localization of the tumours. The removal was gross total in 45 cases (61.6 per cent), subtotal in 17 (23.3 per cent) and partial in 11 (15.1 per cent). Preservation or improvement of the Karnofsky Performance Status was obtained in 63 patients (86.3 per cent), with a morbidity and mortality rate of 11 and 2.7 per cent respectively. Our results indicate that ultrasound guided microsurgery represents a handy, reliable and relatively low risk procedure for the treatment of intra-axial brain tumours.

Interstitial irradiation for newly diagnosed or recurrent malignant gliomas: preliminary results.

The preliminary results obtained in 19 patients treated with interstitial irradiation for malignant gliomas are reported. Three different groups are included in the study: I Newly diagnosed tumours not suitable for surgery: 13 cases (10 anaplastic astrocytomas (AA) and 3 glioblastomas (GBM), mean volume 46.56 cc, source Ir 192) were implanted permanently (n = 11, mean peripheral dose 93.54 Gy) or temporarily (n = 2, 50 Gy = 0.5 Gy/hr). External beam irradiation was additionally applied in all cases. II Residual or recurrent tumours: 5 patients (2 AA and 3 GBM, mean volume 7.2 cc, source Ir 192) received temporary implants (150 Gy peripheral dose = 1.5 Gy/hr) after surgery and conventional radiotherapy. III Newly diagnosed surgically removable tumours: only one patient with AA (15 cc volume, source Ir 192) received temporary implantation with the same dose regimen used in Group II before surgery and external beam irradiation. A median survival time of 26.75 mos (34.62 mos for AA, with 3 long-term survivors) was observed in the patients of Group I. Three patients of Group II are still alive after 8, 12 and 12 mos after brachytherapy, the other 2 (GBM) survived 7 and 12 mos. The single patient so far included in Group III is still alive after 6 mos. Although the study is still in progress, these preliminary data seem to indicate that interstitial radiotherapy can be effective in prolonging survival of patients with malignant gliomas.

Spinal cord stimulation (SCS) in deafferentation pain.

Spinal cord stimulation is considered to be ineffective in relieving deafferentation pain. We have retrospectively analyzed the results obtained in a series of 41 patients. Sixteen suffered from pain associated with an incomplete traumatic spinal lesion, 15 from a posttherapeutic neuralgia, and 10 from pain due to root and/or nerve damage. At the end of the test period, 43.7% of the patients with paraplegic pain, (40% of those with peripheral deafferentation pain and 66.6% of the ones with postherapeutic neuralgia), reported satisfactory pain relief and were connected to a chronic stimulation system. At mean follow-up (15 months), only 20% of the patients of the first two groups reported sufficient pain relief. In the postherapeutic group the figure of responders was unchanged. The mean analgesia achieved was 70%. From this analysis we conclude that the results achieved in the postherapeutic pain patients, although positive in only 66% of them, are remarkably stable with time. Therefore, we recommend a percutaneous test trial of SCS in every case of postherapeutic pain resistant to medical treatment.

Spinal cord stimulation (SCS) in spastic hemiparesis.

Thirteen patients with post-stroke spastic hemiparesis underwent a percutaneous test trial of spinal cord stimulation (SCS) in order to modify their motor disturbances. Clinical evaluation based on Albert's motor scale and neurophysiological evaluation consisting of surface EMG during voluntary, involuntary, and reflex motor activity were performed before and during SCS. At the end of the test period, eight patients showed a significant improvement in their motor performance. The EMG analysis confirmed the clinical data. SCS was followed by a reduction or disappearance of synergic coactivation with better agonist-antagonist coordination, a decrease of clonus both in duration and spreading, and better endurance. The effect on motor control did not increase with time after the first month of SCS, but was long lasting (mean follow-up: 2 years). There was a correlation between sensory deficit and motor outcome suggesting that the enhancement of sensory input put into play by SCS and the consequent development of new sensory-motor integration might be responsible for the improvement in motor performance.

Spinal cord stimulation (SCS) in the treatment of postherpetic pain.

SCS is considered to be of poor value in treating postherpetic pain. We have retrospectively analyzed the results obtained in 10 patients suffering from postherpetic neuralgia. An epidural electrode was implanted, aiming the tip in a position where stimulation could produce paraesthesiae over the painful area. At the end of the test period 6 out of 10 patients reporting a mean analgesia of 52.5% underwent a permanent implant. At mean follow-up (15 months) all the 6 patients were still reporting a satisfactory pain relief (74% of mean analgesia). These figures remained unchanged at the next follow-ups (max 46 months). The result of SCS in our patients, although positive in only 60% of them, are remarkably stable with time. We therefore recommend a percutaneous test trial of SCS in every case of postherpetic neuralgia resistent to medical treatment.