Patrick M. Foy

Do prophylactic anticonvulsant drugs alter the pattern of seizures after craniotomy

A total of 276 patients with a high risk of developing postoperative seizures were randomised to treatment with carbamazepine or phenytoin for six or 24 months, or to no treatment. No significant differences were found (though the confidence limits were fairly wide) between the regimes in respect of the incidence of seizures or death. In a substantial proportion of the patients postoperative epilepsy remained a continuing disability. A high incidence of drug-related side effects was found in the treatment groups. Prophylactic anticonvulsants cannot therefore be recommended routinely following supratentorial craniotomy.

Acute traumatic CSF fistulae: the risk of intracranial infection

The management of acute traumatic cerebrospinal fluid (CSF) fistulae is still a matter of debate and hinges about what is perceived to be the risk of subsequent intracranial infection. We have therefore carried out a retrospective analysis of 160 cases of traumatic CSF leaks to assess the incidence, cumulative risk and prognosis of intracranial infection. The overall incidence of meningitis in this group before surgical dural repair was 30.6% (49/160), the cumulative risk exceeded 85% at 10 years follow-up and the meningitis was fatal in 4.1% (2/49). The recurrence of CSF leakage after initial spontaneous cessation was 7% and meningitis was recurrent in 30.6% (15/49). Prophylactic antibiotics had reduced the risk of meningitis from 61 to 34%. The commonest pathogen was pneumococcus and the CSF leakage had stopped within 7 days in 60% of those who developed meningitis and in 50% of those who did not develop meningitis. Meningitis is still a serious complication of post-traumatic CSF fistulae and is potentially fatal despite modern therapeutic agents.

Serum anticonvulsant concentrations and the risk of drug induced skin eruptions.

In two prospective studies of anticonvulsant therapy there was a high incidence of drug-induced skin reactions to phenytoin (7%) and carbamazepine (16.6%). High initial serum concentrations of these drugs appeared to be a factor influencing the occurrence of such skin reactions.

The prognosis of primary intracerebral tumours presenting with epilepsy: the outcome of medical and surgical management.

It is not known whether conservative or early aggressive (resective surgery with or without radiotherapy) management is better for tumours presenting with epilepsy. The prognosis of 560 patients with a clinical and CT diagnosis of intrinsic supratentorial tumour was examined retrospectively. Epilepsy was the first symptom in 164 patients. Histological confirmation of diagnosis was available in 391 (70%) of cases. Median survival was 37 months in the group presenting with epilepsy and six months in those presenting with other symptoms (p less than 0.0001). Patients presenting with epilepsy were more likely to have a normal clinical examination, a non-enhancing low density lesion on CT scan and a low grade tumour. From Coxs stepwise proportional hazards model, significant independent variables adversely affecting prognosis were increasing age, focal neurological signs and enhancing CT lesions at diagnosis, non-resective surgery and male sex. Of those presenting with epilepsy 80 patients had surgical treatment within two months of CT diagnosis. The Coxs model failed to identify any beneficial effects for either early resective surgery or radiotherapy. In primary intracerebral tumours with presentations other than epilepsy, resective surgery and radiotherapy were amongst the important factors associated with prolonged survival. Primary intracerebral tumours presenting with epilepsy are relatively benign and their outcome appears to be chiefly determined by clinical factors.

Post-traumatic CSF fistulae, the case for surgical repair

The management of acute post-traumatic CSF fistulae is still a matter of controversy. A long-term analysis of 160 patients with acute post-traumatic non-iatrogenic dural fistulae was undertaken to establish the value of surgical dural repair. One hundred and forty-nine patients underwent dural repairs following traumatic CSF rhinorrhoea. The risk of meningitis following surgical dural repair was 4%. The operative mortality was 1.3% (2/151), as was the negative exploration rate. The first dural repair was successful in 90% and a second dural repair was required in 10%. These results are in favour of surgical dural repair which can be undertaken with a low morbidity and mortality and is highly successful in preventing meningitis following traumatic CSF rhinorrhoea.

Smoking and subarachnoid haemorrhage: A case control study

Retrospective and epidemiological studies have suggested that smoking increases the risk of developing aneurysmal subarachnoid haemorrhage (SAH). During 1990, 217 patients presenting to the Mersey Regional Neurosurgical unit with spontaneous SAH were prospectively studied. Smoking habits of patients with SAH were compared with age, sex and occupation matched controls. The relative risk of spontaneous aneurysmal SAH for smokers was twice that of non-smokers (p < 0.001). Management outcome at 6 months following aneurysmal SAH was similar for smokers and non-smokers (p = 0.43) but smokers had more postoperative pulmonary complications requiring ventilation. Significance was tested with chi-square tests.

Pituitary tumours presenting in the elderly: management and outcome

In elderly patients there are few data on the efficacy and safety of pituitary surgery and radiotherapy (DXT). The aim of the present study was to assess the mode of presentation, treatment and outcome of patients >64 years with a pituitary tumour presenting to a regional neuroendocrine service.

Pituitary enlargement and hyperprolactinaemia due to primary hypothyroidism: Errors and delays in diagnosis

Two young women with pituitary gland enlargement and hyperprolactinaemia were referred for pituitary surgery. Both had received bromocriptine (one patient for 13 years) for presumed prolactinoma. Mild clinical signs of hypothyroidism were present and endocrine tests revealed primary autoimmune thyroid failure. Following thyroxine replacement treatment, the pituitary enlargement and hyperprolactinaemia completely resolved. In both patients the hyperprolactinaemia was relatively mild and menorrhagia had been present for many years. A third patient, a 61-year-old man presenting with bitemporal hemianopia due to pituitary enlargement underwent transphenoidal pituitary surgery. The results of thyroid function tests on admission were not available until after surgery. Although the patient was clinically euthyroid, these revealed primary hypothyroidism and his considerable pituitary enlargement may also have been secondary to thyroid failure. Urgent thyroid function tests should be performed in all patients with pituitary enlargement prior to surgery to exclude hypothyroid induced pituitary swelling.

Differences between neurological and neurosurgical approaches in the management of malignant brain tumours.

The management and outcome in 205 patients diagnosed as having cerebral gliomas over five years were reviewed. Patients referred to neurologists and neurosurgeons had similar clinical features and similar results on computed tomography. Patients referred to neurologists underwent burr hole biopsy less often and had better short term morbidity than patients referred to neurosurgeons, although final outcome was the same in both groups. Few patients underwent other surgical procedures. Referral for radiotherapy was usually by neurosurgeons, although this did not significantly affect long term survival. The implications for the management of patients with primary malignant brain tumours and the need for prospective studies are discussed.

The effectiveness of prophylactic anticonvulsants following neurosurgery

SummaryOne hundred and two patients who underwent supratentorial procedures for neurosurgical conditions, which are known to carry a high incidence of postoperative seizures, have been given prophylactic anticonvulsant medication. This preliminary analysis has failed to demonstrate any dramatic effect on the postoperative incidence of seizures in the first six months as the result of this policy. There has been a high incidence of serious side effects, but compliance has not been a major problem. This long-term study is continuing, though with a modified protocol.