MRI is the diagnostic procedure of first choice because of its potential to demonstrate the exact localisation, extent and relationship of the arachnoid cyst to the spinal cord. Cord atrophy secondary to compression can be visualised and used for prediction of neurological outcome. Myelography and CT-Myelography (CTM) are still of diagnostic value since they might demonstrate the communication between the subarachnoid space and the cyst, which is important for surgical planning. The aim of surgical treatment is neural decompression and prevention of refilling of the cyst which is best accomplished by complete resection of the cyst and closure of the communication between cyst and subarachnoid space.

A series of 31 patients with good neurological 6-month outcomes (Glasgow Outcome Scale = I) was examined with a battery of cognitive tests 1 to 5 years after aneurysmal subarachnoid hemorrhage (SAH) and early operation. The results showed a marked disability in 28 to 62% of these patients in the subtests of a complex choice reaction task. Short-term memory was impaired in 53% of the patients neuropsychologically examined, whereas 21% of them had a reduced long-term memory. Concentration was impaired in 7 to 16% of the SAH patients. Also, 10% of the patients rated Glasgow Outcome Scale = I had an indication for an aphasic language disturbance. Multivariate analysis proved significant harmful effects of the severity of the bleeding seen on computed tomographic scan (Fisher scale) on information processing and word-finding capacity. Patients who were older at the time of the SAH were significantly more disturbed in concentration, short-term memory, and information-processing capacity at follow-up. It can be concluded from these results that a good neurological outcome (Glasgow Outcome Scale = I) does not exclude persisting neuropsychological deficits. Therefore, the value of the clinical use of the Glasgow Outcome Scale is limited. As a consequence, a differentiated neuropsychological examination is proposed to evaluate the exact outcome of SAH patients.

Eighteen consecutive patients with olfactory groove meningiomas, with diameters ranging from 1.5 to 7 cm, underwent microsurgical tumour resection using a unilateral frontal interhemispheric approach. Unilateral frontal craniotomy, superior to the frontal sinus, exposing the superior sagittal sinus was performed. The ipsilateral frontal lobe was gently retracted laterally, and the tumour resected through the gap between the falx and the medial aspect of the frontal lobe, anteriorly to the genu of the corpus callosum. Gross total tumour resection was achieved in all the patients. There was no evidence of damage to the frontal lobes, the anterior cerebral arteries or the optic system. Compared with the more commonly applied subfrontal route, the interhemispheric approach has the advantages of sparing the frontal sinuses and providing excellent overview of the dissection of the anterior cerebral arteries and the optic system, as well as for the resection of tumour invading the frontal cranial base.

In a series of 10 patients with stereotactically treated basal ganglia haematoma rtPA was used to dissolve remaining clots. Pre-operative haematoma volume ranged between 39 and 111 cm3 (average 56 cm3). Stereotactic aspiration alone yielded an average volume reduction of 60% (range 23 to 78%). Haematoma cavity was instillated with rtPA repeatedly beginning 24 hours after the stereotactic intervention. At the end of rtPA therapy between 2 and 4 days after onset of the haemorrhage 67 to 92% (average 84%) of the initial haematoma was removed in all patients. More than 80% of the pre-operative clot could be removed in 8 out of 10 patients between day 2 and 4. There were no signs of rtPA related toxicity. At the end of the follow-up period (between 4 and 17 months--mean 8 months) 6 patients were awake, oriented and with a residual hemiparesis able to live in their familiar environment. It is concluded that local rtPA instillation is an effective additional treatment to further resolution of deep seated intracerebral haematomas after stereotactic aspiration.

A series of 31 patients with good neurological 6-month outcomes (Glasgow Outcome Scale = I) was examined with a battery of cognitive tests 1 to 5 years after aneurysmal subarachnoid hemorrhage (SAH) and early operation. The results showed a marked disability in 28 to 62% of these patients in the subtests of a complex choice reaction task. Short-term memory was impaired in 53% of the patients neuropsychologically examined, whereas 21% of them had a reduced long-term memory. Concentration was impaired in 7 to 16% of the SAH patients. Also, 10% of the patients rated Glasgow Outcome Scale = I had an indication for an aphasic language disturbance. Multivariate analysis proved significant harmful effects of the severity of the bleeding seen on computed tomographic scan (Fisher scale) on information processing and word-finding capacity. Patients who were older at the time of the SAH were significantly more disturbed in concentration, short-term memory, and information-processing capacity at follow-up. It can be concluded from these results that a good neurological outcome (Glasgow Outcome Scale = I) does not exclude persisting neuropsychological deficits. Therefore, the value of the clinical use of the Glasgow Outcome Scale is limited. As a consequence, a differentiated neuropsychological examination is proposed to evaluate the exact outcome of SAH patients.

These results suggest that intraventricular bleeding may cause impairment of cerebrospinal fluid circulation but that the mass effect of clots distending the ventricle walls is the most important mechanism responsible for HVD. This model closely imitates several prominent features of human IVH and may therefore be a useful tool for preclinical assessment of the efficacy and safety of treatment with TPA.

Twelve patients with severe intraventricular haemorrhage (IVH) underwent intraventricular thrombolysis with recombinant tissue plasminogen activator (rtPA). External ventricular drainage was performed in all patients within 24 hours of haemorrhage. Fibrinolytic therapy was started within 24 hours from the onset of symptoms in ten cases, and in two further cases after 48 hours and 5 days, respectively. Two to 5 mg of rtPA were injected via the ventricular catheter into one or both lateral ventricles. The injection was repeated at intervals ranging from 6 to 24 hours until CT scans demonstrated a substantial reduction of intraventricular blood. The total rtPA doses per patient ranged from 3 to 31 mg. CT scans showed a marked reduction of intraventricular blood and normalization of ventricular size within 24 to 48 hours from the beginning of the fibrinolytic therapy. Rapid reduction of elevated intracranial pressure by continuous diversion of cerebrospinal fluid could be achieved in all patients, because the ventricular catheters never became obstructed by clotted blood during the fibrinolytic therapy. During the period of treatment, the level of consciousness, as classified according to the Glasgow Coma Scale, improved from a mean value of 7 to 12. One fatal case of meningitis most probably due to the ventriculostomy was the only complication related to the treatment. This method of treatment might improve the prognosis in patients in whom a large intraventricular haematoma volume, ventricular dilatation, and impaired cerebrospinal fluid circulation are major determinants for the outcome.

Supratentorial complications of infratentorial surgery are rare. In the last 3 years we have operated on 187 patients with infratentorial lesions and have observed an incidence of 3.7% of supratentorial haemorrhages. Postoperative intracranial air, as shown by early postoperative CT control, was encountered mainly in a subdural frontal location and within the interhemispheric fissure. We performed no surgical decompression of the air accumulation because of the lack of clinical symptoms. Predisposing factors for the development of supratentorial complications remote from the surgical area are hypertonia, female sex, brain atrophy and preoperative shunting procedures. Measures to avoid these complications are discussed.