Pure surgical treatment of 109 aneurysms.

AIM: Target of this study was to investigate outcomes after pure surgical treatment of intracranial aneurysms. METHODS: Patients with intracranial supratentorial circle aneurysms were retrospectively reviewed between July 1994 and October 1998. Studied cases were admitted at the Department of Neurosurgery of S. Maria-Hospital, Terni, a Government supported General Hospital. One hundred and nine Hunt and Hess Grade 0 to III patients with supratentorial circle aneurysms was studied in order to determine whether advances in the surgical management of intracranial aneurysms have improved surgical outcomes and which factors may predict outcome. All patients were managed only with standard neurosurgical aneurysms clipping procedures. Outcomes evaluation was made at patients' discharge and classified on the base of the Glasgow Outcome Scale (GOS). Surgical timing, SAH grading, pre and post surgical symptomatic vasospasm, temporary clipping, and intraoperative aneurysm rupture were correlated with outcomes. RESULTS: Surgical results showed a 75% excellent outcome. Mortality rate was 3%. Hunt and Hess grade 0 highly influenced outcome. Differences in outcomes among grades I to III were not significant. No differences in outcomes related to temporary clipping were noted. A low rate of intraoperative aneurysm rupture is reported: 5 out of 109 cases. In all these cases outcome was good, with neither mortality or morbidity. CONCLUSIONS: Results indicate a progressive improvement in surgical outcomes, suggesting that there still exist margins for improvements in pure surgical management of intracranial aneurysms.

[Transcranial Doppler sonography in neurotraumatology: hemodynamic monitoring of diffuse axonal injury]. / Il Doppler transcranico in neurotraumatologia: monitoraggio emodinamico della lesione assonale diffusa.

Six patients with diffuse axonal injury, ranging in age 8 to 29 years, hospitalized in emergency in our Polyclinic with a Glagow coma score under 8, were examined. Patients were intubated and connected to an automatic respirator. They underwent serial cranial CT and transcranial Doppler sonography recordings using the temporal window with insonation of the two middle cerebral arteries. During the period of observation, the metabolic processes and systemic hemodynamics were maintained within the limits of homeostasis. In all cases and at different times, osmotic diuretics (18% mannitol), barbiturates and hyperventilation therapy were administered. In 5 patients over 6 (80%) increased blood flow, variously sensitive to barbiturates, was detected associated to increased resistance index secondary to intracranial hypertension. Based on Doppler findings four patients underwent surgical treatment: ventriculostomy for monitoring of intracranial pressure or decompressive craniectomy. According to this experience, the use of transcranial Doppler US is mandatory for a correct identification of the hemodynamic injury associated to diffuse axonal injury, for planning the medical and/or surgical approach and for assessment of the successful results of therapeutic management.

"Filtering effect" of cerebrospinal fluid on spinal somatosensory evoked potentials: case report.

A 31-year-old man presented complaining of radicular (L4) pain. MRI and myelo-TC of the thoraco-lumbar spine showed the presence of an extradural CSF cyst extending from Th6 to L2, posterior to the cord. The patient underwent a Th12 laminectomy, the cyst was opened and drained. A recording electrode was placed epidurally, dorsal to the cyst, at the level of the Th12 vertebral body, and the potentials evoked by stimulation of the tibial and saphenous nerves were monitored during surgery. After cyst drainage the epidural potentials were significantly larger (x5) in amplitude and more defined in shape than those recorded in the presence of the cyst. Our case demonstrates the "filtering effect" of CSF on spinal somatosensory evoked potentials.

Spinal cord stimulation in the treatment of paraplegic pain.

Twenty-five patients suffering from intractable pain due to a chronic spinal cord lesion underwent a percutaneous test of spinal cord stimulation. At the end of the test period, 40.9% of the patients reported a mean of 65% pain relief and these patients were selected for ongoing stimulation. At a mean follow-up time of 37.2 months the success rate, based on the number of patients with more than 50% pain relief, had fallen to 18.2%. Pain relief rates were analyzed in relation to quality of pain, neurological status, level and extent of the lesion, and electrode level to identify prognostic factors that could improve the clinical usefulness of spinal cord stimulation. Patients experiencing painful spasms or a constrictive type of pain and with incomplete thoracic lesions were found to be the best candidates for spinal cord stimulation.

Increase of cerebral blood flow and improvement of brain motor control following spinal cord stimulation in ischemic spastic hemiparesis.

A 64-year-old man had an ischemic stroke in the left parietotemporal cortical-subcortical areas. He developed a severe right spastic hemiparesis and dysphasia. An angiographic study showed left internal carotid artery occlusion and right internal carotid artery stenosis. A right internal endoarteriectomy was performed without any clinical improvement. After 1 year the patient was a candidate for cervical spinal cord stimulation (SCS) for the treatment of his spastic hemiparesis. An epidural electrode (Medtronic Sigma 3483) was positioned at the cervical level, mediodorsal to the cord. Clinical and neurophysiological studies (surface polyelectromyography, PEMG, for evaluation of brain motor control) were performed before and after 7 days of SCS (0.2 ms, 80 c/s, intensity for paresthesiae, continuous mode). A transcranial Doppler (TCD) study of both middle cerebral arteries (MCA) at rest and during SCS was performed on two occasions. SCS was followed by improvement of voluntary movement, decrease of spasticity and better endurance. The clinical findings were confirmed by the PEMG recordings. TCD examination showed an increase of flow velocities on both the right MCA (+43%) and the left MCA (+130%) during SCS. Such a TCD pattern, suggesting an increase of cerebral blood flow (CBF) during SCS, was reproducible. This case confirms efficacy of SCS in the treatment of ischemic hemiparesis and the increase of CBF following cervical SCS in man. The marked increase of CBF, particularly evident on the ischemic side, may play a role in mediating the improvement of motor control in our patient together with a possible arousal of the so-called 'sleeping neurons' of the penumbra zone.

Spinal cord stimulation and cerebral blood flow: an experimental study.

Spinal cord stimulation (SCS) affects peripheral, coronary and cerebral blood flow (CBF) in humans. In 1986 Meglio et al. [Appl Neurophysiol 1986;49:139-146] advocated a functional reversible sympathectomy as one of the mechanisms of SCS in man. An experimental animal model was developed to study SCS effects on CBF and to investigate the possible mechanisms. Twenty-one white New Zealand rabbits were anesthetized with Fluothane; spontaneous ventilation was permitted. A steady hemodynamic and metabolic state was maintained. A small cervical laminectomy was performed and an electrode (Medtronic Sigma 3483) was placed in the epidural space over the posterior spinal cord. Both common carotid arteries were exposed and external carotid arteries were ligated. In 3 animals, the cervical symapthetic trunk (CST) was exposed and wrapped with bipolar hook-stimulating electrodes. SCS was performed for 20 min with electrical square waves of 210 microseconds duration, 80 cycles/s, at 2/3 motor threshold intensity. CST stimulation was delivered for 1 min with the following parameters: 10 V, 10 cycles/s, 0.5 ms duration. CBF velocities of both internal carotid arteries were measured by using a CW Doppler (in all the animals) and electromagnetic flowmeter (in 2 animals), at rest, during sympathetic trunk stimulation, during SCS, during simultaneous SCS and CST stimulation. During SCS, an increase of CBF was detected in 11 rabbits (52.4%); a decrease was observed in two cases (9.5%). No change was detected in the remaining 8 animals (38%). CST stimulation induced a decrease of CBF in all animals. Electromagnetic flowmetry confirmed velocitometric findings in the 2 cases studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Spinal cord stimulation in low back and leg pain.

We have reviewed our experience with spinal cord stimulation (SCS) in patients with low back and leg pain. 33 patients complaining of leg and low back pain underwent percutaneous tests of SCS. 28 patients had failed back surgery syndromes, 1 patient had pain related to an L1 vertebral body fracture, another from Tarlow cysts and the remaining 3 patients had lumbosacral spondyloarthrosis and osteoporosis without radiological signs of root compression. 28 patients showed mono- or pluriradicular deficits. At the end of the test period (5-65 days), 21 patients (63.6%) reported more than 50% of pain relief (mean analgesia 75%) and were submitted to chronic stimulation. The mean follow-up was 45.5 months. At maximum available follow-up, 40% of the patients (13 out of the 33 initial patients) were successfully using the stimulator (mean analgesia 66.6%).

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.

Clinical-electrophysiological correlations in a long-term case of subacute sclerosing panencephalitis with partial clinical improvement.

An electrophysiological follow-up was performed in a rare case of subacute sclerosing panencephalitis (SSPE) that from the vegetative stage had an extremely favourable course, lasting 4 years, in which clinical conditions passed, according to the Risk and Haddad scale, from stage 3 to stage 1. In this period of time, 5 CT scans and a series of EEGs, visual evoked potentials (VEPs) and brainstem auditory evoked potentials (BAEPs) were performed to investigate the correlation between clinical course and electrophysiological diagnostic data. The results showed a significant improvement in diagnostic results, directly correlated with the remission of clinical symptoms. Electrophysiological signs of improvement in VEPs were obtained before observable improvement was seen on CT scans. These results indicate that an accurate electrophysiological study (through cerebral evoked potentials) has an important role in investigating suspected cases of SSPE, in following the clinical evolution of this disease and providing prognostic data.

Congenital hydrocephalus: a new experimental model with histopathological study.

We describe a new experimental model of fetal hydrocephalus in the lamb. 14 sheep were operated on at 100-120 days gestation for the insertion of a catheter into the fetal aqueduct of Sylvius to block cerebrospinal fluid (CSF) flow. After the operation the intracranial pressure (ICP) was measured daily from the distal end of the catheter. The progress of ventricular dilatation was recorded by ultrasound. At ICP 100 mm/H2O the animals were killed for postmortem examination of the fetuses. Neuropathological examination showed massive dilatation of the ventricles. The ependymal cells appeared to be flat and the cellular lining disrupted. Growth of pseudocysts, cellular stratification and proliferation of the paraventricular germinal cells were observed also. With our new experimental model we were able to control the rise in ICP and correlate the evolution of the anatomical damage with the duration of high ICP and with the gestational age at which it began. Our model can also be used at early stages of gestation for reversing the development of hydrocephalus. It might therefore provide information on the suitability of fetal hydrocephalus surgery.