[Intracranial abscess and empyema: neurosurgical management]

Brain abscesses and empyemas are severe infections with lethal outcomes in the case of inappropriate treatment. The files of 34 patients with brain abscesses, and nine with intracranial empyemas treated over eight years (1990-1997) were analyzed retrospectively. Cases were evaluated for treatment and compared with data from the literature. Patients with brain abscess underwent either aspiration of the lesion through a burr hole (79.5% of the cases), or craniotomy and excision (8.8% of the cases); 11.7% were treated only with antibiotics. The operative mortality was 2.9% and the outcome was satisfactory in 85% of patients. These results are in agreement with data from the literature. Prognosis is strongly related to the initial clinical status. Current methods of treatment include surgical aspiration of large abscesses with a mass effect, and are usually associated with a poor clinical status. Excision is suggested whenever aspiration procedures have failed, or in the presence of foreign material or fungal abscess. Medical treatment is indicated for small and deeply located abscesses in patients with satisfactory clinical states. Empyemas in our series were treated with burr hole and pus aspiration. The mortality rate was 11%, and 62.5% of the patients made a good recovery. In agreement with other reported studies, the method of treating subdural empyema is much less significant than an aggressive early drainage of the infection. Although brain abscesses and empyema remain a significant neurosurgical concern, aggressive treatment can result in an excellent outcome in the majority of patients.

[Ataxic crural hemiparesis caused by posterior spinal arterial infarction]

Infarction in the territory of the posterior spinal arteries is uncommon, giving rise to a softening of variable extend in the peripheral arterial system. In the reported case, the lesion was restricted to a posterior column and produced a syndrome of crural ataxic hemiparesis.

[Traumatic spinal complications of cervical arthrosis]

OBJECTIVES

Cervical spondylotic myelopathy is usually a chronic and progressive disease. In a few cases, however, dramatic tetraplegia sometimes occurs after even minor injury.

METHODS

We report seven patients (6 males, 1 female, aged from 41 to 63), who suffered from acute myelopathy after an injury.

RESULTS

In 5 cases, the injury revealed the cervical spondylotic myelopathy. A hyperextension of the cervical spine was found in 5 cases. The injury was severe in only one case, but there was no bony abnormalities, except arthrosis. The most common cause was a fall. In contrast, severe tetraplegia was found in 4 cases. Spontaneous, but incomplete, recuperation occurred in 4 patients. In all 7 cases, CT scan and MRI showed congenital cervical stenosis associated with cervical spondylosis. The level of disco-osteophytic changes was mainly in C4, C5, C6. On T2-weighted spin-echo image, an increased signal intensity was present in the cord of 3 patients, but was not correlated with the severity of the symptoms, nor with improvement. Surgical treatment was performed in 6 cases: 3 laminectomies, 3 anterior or antero-lateral approaches. Improvement after operative decompression was observed in all but one case, even when the motor or sensory deficit persists for more than one year. Motricity of the inferior limbs improved better than the other deficits, perhaps because of the location of non-reversible lesions in the spinal gray matter.

CONCLUSION

The acute medullary syndrome of cervical spondylotic myelopathy is serious and can cause major handicaps. This complication justifies a preventive surgical attitude when medullar signs are moderate, and cervical imagery shows a spondylotic compression of the cord with congenital stenosis.

[Neurosurgical aspects of Rendu-Osler disease. Apropos of 6 recent cases and review of the literature]

Six patients with neurological complications in Rendu-Osler-Weber disease were reviewed. There were 4 patients (3 int the same family) with a brain abscess, one patient with a brain abscess and a spinal cord subarachnoid hemorrhage, one patient with a recurrent intracerebral hemorrhage due to a vascular malformation. The infectious complications are related to the presence of pulmonary arterio-venous fistula, which should be treated, whenever diagnosed. Because of the potentially severe outcome of these neurological complications of the Rendu-Osler-Weber disease, screening of the patient's relatives is highly recommended.

[Pituitary apoplexy]

Pituitary apoplexy results from necrosis or haemorrhage of a pituitary adenoma. This rare complication occurs in 2 to 10% of operated adenomas. The acute form results from massive intrapituitary bleeding leading to violent headache, meningeal signs, impaired conscience and ophthalmology signs, basically bilateral blindness. Associated signs are frequent including paralysis of the oculomotor nerves, epilepsy seizure, hemiplegia. Diabetes insipidis is exceptional. In less acute forms, the sudden nature of the headache and ophthalmology signs can suggest diagnosis. Standard X-ray reveals destruction of the sella turcica. Computed tomography shows either a haematoma or a cystic cavity in the pituitary gland which must be perfectly described together with the integrity of the bone structures due to the risk of lysis. Magnetic resonance imaging is an essential technique which can be used to describe the volume and suprasellar extension of the tumour, its texture, possible compression of adjacent structures and determine the age of the haemorrhage. This imaging technique can also isolate rare optochiasmatic apoplexia requiring intracranial evacuation. Emergency surgery is mandatory for most all authors. Rhinal-septal decompression is usually used, but the intracranial route may be preferred for very large suprasellar tumours. Medical treatment alone may be successful for small prolactin adenomas. Outcome depends on the time lapse to decompression. Optic nerve recovery is usually possible if the delay is less than 7 days. Cranial nerve recovery is less dependent on the time interval. In all cases hormone substitution is required.

Pharmacokinetics and tissue distribution of 99mTc-labelled enoxaparin in the rat: evaluation of dosimetry parameters

A low molecular weight heparin, enoxaparin, was labelled with 99mTc and the characteristics of the labelled compound determined. In vitro the stability, and labelling efficiency (98%) of the labelled drug were excellent. Rats were injected with 99mTc-enoxaparin to study pharmacokinetics and distribution. The results were used to calculate dosimetric estimates which are a prerequisite for pharmacokinetic studies on labelled LMWH (low molecular weight heparin) in human subjects. Biodistribution studies showed preferential liver and spleen accumulation. But the doses absorbed by these target organs remained below the upper limits of the dose received by a patient undergoing hepatic scintigraphy.

99m Technetium labelled heparin: potential value as a tracer of heparin activity in pharmacokinetic and biodistribution studies

Pharmacokinetics and biodistribution of 99m Technetium (99mTc) labelled heparin were studies to assess its value as a tracer of heparin kinetics in comparison with unlabelled heparin. In vitro, the stability and labelling efficiency (98%) of the labelled drug were excellent and elution was minimal. In vivo, after I.V. infusion of the drug, there was no difference in the same animal between anticoagulant activity measurements and radioactive countings, both displaying a plasmatic biexponential pattern (T1 = 2.9 minutes, T2 = 76 minutes). Biodistribution studies showed primarily liver, spleen and kidney accumulation, with no thyroid uptake. The advantages of this technetium labelling may therefore be used for the heparin drug in various experimental and pathological situations even in humans.

[Surgical approach to the 3rd segment of the vertebral artery by a paramedian posterior route]

Following an anatomical study of the lateral suboccipital region, the authors have devised an approach to the third segment of the vertebral artery, from C2 to the foramen magnum, which enabled them to treat an arteriovenous fistula in C1 while preserving the vertebral artery. The different operative stages and anatomical features are described. The simplicity and safety of this approach should encourage surgeons to use it.

[Peroperative rupture of the lumbar dura mater with nerve root hernia. Management]

Rupture of the dura mater during lumbar laminectomy may result in destruction of the herniated sacral and lumbar nerve roots. This can be avoided by a simple but immediate surgical procedure, details of which are presented here.

[Cerebral ischemia, treatment by vascular micro surgical technique: intra-extra cranial anastomosis (author's transl)]

The introduction of vascular micro-surgical techniques has allowed to treat cerebral ischemia, through extra-intra-cranial anastomosis, when the causative arterial lesions have a surgically unfavorable location. Thirty patients underwent brain revascularization through extra-intra-cranial micro-anastomosis between the superficial temporal artery (branch of the external carotid artery) and a cortical branch of the middle cerebral artery. Twenty five patients had definite sensitive and motor deficits. Five patients, on the other hand, underwent preventive surgery because of transient cerebral ischemia. In our series, the global rate of the microanastomosis patency is 78%. When the anastomosis is patent, 85% of the cases with motor deficits are cured or improved. The results are even more favorable in case of transient cerebral ischemia, for the anastomosis in such cases was always patent. None of these later patients had ischemia attacks with a one-year follow-up.