Göran Blomstedt

Infections in neurosurgery: A retrospective study of 1143 patients and 1517 operations

SummaryThe files of 1143 neurosurgical patients, operated on between November 1, 1979 and June 4, 1981 were examined for records of post-operative infections. Eighty-three patients had developed infections (7%). In addition there were 33 instances of aseptic meningitis. Patients with a shunt were prone to infection (12%). Bone flap infections accounted for more than half of all infections after supratentorial craniotomy. Bacterial meningitis accounted for more than half of all infections after suboccipital craniotomy and translabyrinthine operations. In these patients bacterial meningitis was six times more common, and aseptic meningitis three times more common than in those who had had supratentorial operations. Shunt infection was more common after repeated shunt operations in quick succession. Craniotomy increased the risk of a shunt becoming infected.Antibiotic prophylaxis should be used not only in shunt operations but in all operations performed on patients with a shunt. If bacteria are recovered in a suspected shunt infection, immediate removal of the shunt is the best treatment. However, if the shunts removal or replacement is exceptionally difficult intraventricular antibiotic treatment may be tried. The age of the patient, the duration of the operation, the individual surgeon and the number of operations did not affect the rate of infection. Clinical signs and conventional laboratory tests, apart from bacterial culture, cannot differentiate between bacterial and aseptic meningitis, but a drop in the level of consciousness suggests bacterial meningitis.

Magnetoencephalography in presurgical evaluation of children with the Landau-Kleffner syndrome

Summary: Purpose: Our aim was (a) to localize the primary epileptogenic cortex for possible multiple subpial transsection in four children with the Landau‐Kleffner syndrome (LKS), and (b) to evaluate the impact of magnetoencephalography (MEG) in the localizing process.

The effect of surgery in encephalopathy with electrical status epilepticus during sleep

Purpose:  We analyzed clinical and electroencephalography (EEG) outcomes of 13 patients with pharmacoresistant encephalopathy with electrical status epilepticus during sleep (ESES) following epilepsy surgery.

Combined use of non-invasive techniques for improved functional localization for a selected group of epilepsy surgery candidates.

Invasive cortical mapping is conventionally required for preoperative identification of epileptogenic and eloquent cortical regions before epilepsy surgery. The decision on the extent and exact location of the resection is always demanding and multimodal approach is desired for added certainty. The present study describes two non-invasive preoperative protocols, used in addition to the normal preoperative work-up for localization of the epileptogenic and sensorimotor cortical regions, in two young patients with epilepsy. Magnetoencephalography (MEG) was used to determine the primary somatosensory cortex (S1) and the ictal onset zones. Navigated transcranial magnetic stimulation (nTMS) was used to determine the location and the extent of the primary motor representation areas. The localization results from these non-invasive methods were used for guiding the subdural grid deployment and later compared with the results from electrical cortical stimulation (ECS) via subdural grids, and validated by surgery outcome. The results from MEG and nTMS localizations were consistent with the ECS results and provided improved spatial precision. Consistent results of our study suggest that these non-invasive methods can be added to the standard preoperative work-up and may even hold a potential to replace the ECS in a subgroup of patients with epilepsy who have the suspected epileptogenic zone near the sensorimotor cortex and seizures frequent enough for ictal MEG.

Functional Plasticity of the Motor Cortical Structures Demonstrated by Navigated TMS in Two Patients with Epilepsy

BACKGROUND Recently, navigated transcranial magnetic stimulation (nTMS) has been suggested to be useful in preoperative functional localization of motor cortex in patients having tumors close to the somatomotor cortex. Resection of tumors in anatomically predicted eloquent areas without adverse effects have emphasized functional plasticity elicited by intracranial pathology. OBJECTIVE To describe functional plasticity of motor cortex indicated by nTMS in two patients with epilepsy. METHODS nTMS, functional MRI (fMRI), diffusion-tensor (DT)-tractography and magnetoencephalography (MEG) were utilized to preoperatively localize motor cortical areas in the workup for epilepsy surgery. The localizations were compared with each other, with the cortical anatomical landmarks, and in one patient with invasive electrical cortical stimulation (ECS). RESULTS In two out of 19 studied patients, nTMS identified motor cortical sites that differed from those indicated by anatomical landmarks. In one patient, nTMS activated preferentially premotor cortex rather than pathways originating from the precentral gyrus. MEG and fMRI localizations conformed with nTMS whereas ECS localized finger motor function into the precentral gyrus. Resection of the area producing motor responses in biphasic nTMS did not produce a motor deficit. In the other patient, nTMS indicated abnormal ipsilateral hand motor cortex localization and confirmed the functionality of aberrant motor cortical representations of the left foot also indicated by fMRI and DT-tractography. CONCLUSION nTMS may reveal the functional plasticity and shifts of motor cortical function. Epileptic foci may modify cortical inhibition and the nTMS results. Therefore, in some patients with epilepsy, the nTMS results need to be interpreted with caution with regard to surgical planning.

Post-operative aseptic meningitis

SummaryNeurosurgical patients with post-operative meningitis often present with negative bacterial cultures. The symptoms and signs as well as laboratory findings are identical to those with verified bacterial meningitis. The aim of this study was to find out whether we are dealing with a sterile reaction, and antimicrobial treatment can safely be stopped.24 patients with post-operative meningitis with negative bacterial cultures were randomized into two groups. Both were initially treated with chloramphenicol until the results of the bacterial cultures were available. Treatment was then withdrawn in one group and continued in the other. Chloramphenicol had no effect on the outcome and can therefore safely be stopped when adequate bacterial cultures are reported negative.

Sensitivity and specificity of seizure-onset zone estimation by ictal magnetoencephalography

Purpose:  Ictal video–electroencephalography (EEG) is commonly used to establish ictal onset‐zone location. Recently software development has enabled systematic studies of ictal magnetoencephalography (MEG). In this article, we evaluate the ability of ictal MEG signals to localize the seizure‐onset zone.

Deletion 3q27→3qter in an infant with mild dysmorphism, parietal meningocele, and neonatal miliaria rubra-like lesions

SummaryDeletion 3q27→3qter in an infant is described. A chromosomal abnormality was suspected because of minor facial dysmorphism and closed parietal meningocele. On the first day of life, a large exudative inflammation appeared on the skin of her back, which completely resolved after 1 week. Biopsy showed dilated sweat gland openings resembling miliaria rubra, which has not been previously reported in this age group. It is unclear if the skin change was due to the chromosomal abnormality. The meningocele was repaired at age 8 months. At age 20 months, slight neurodevelopmental delay was evident, the main features being hypertonicity and inability to walk without support. The patient has two healthy sisters, and prometaphase chromosome studies in both parents were normal. This infant represents the first example of del3q27→3qter and the first reported association of meningocele with an abnormality of chromosome 3.

Microsurgical treatment of temporal lobe cavernomas

BackgroundCavernomas of the temporal lobe occur in 10–20% of patients with cerebral cavernomas. They frequently cause epileptic seizures, some of which tend to become refractory to medical therapy. Surgical removal of safely achievable symptomatic lesions has been frequently consistent with good long-term outcome. In the present study, a postoperative outcome is assessed.MethodsOf our 360 consecutive patients with cerebral cavernomas, 53 (15%) had a single cavernoma in the temporal lobe. Forty-nine patients were treated surgically and were included in the study. All data were analyzed retrospectively. The cavernomas were allocated into three groups based on the temporal lobe site: medial, anterolateral, and posterolateral. To collect follow-up data, all available patients were interviewed by phone. Seizure outcome was assessed using the Engel classification and general outcome using the Glasgow Outcome Scale (GOS).ResultsPatients’ median age at presentation was 37 (range, 7–64) years, with a female/male ratio of 2.5:1. Epileptic seizures occurred in 40 patients (82%). Median duration of seizures preoperatively was 3 (range, 0.1–23) years. In addition, four patients (10%) had memory disorder. Three patients without history of seizures (6%) complained of headache and two (4%) had memory problems. Three patients (6%) had an incidental cavernoma. Hemorrhage occurred in nine patients (18%) preoperatively. Median postoperative follow-up time was 6 (range, 0.2–26) years. Favorable seizure outcome (Engel class I and II) was registered in 35 patients (90%). Ten patients (25%) who had only a single seizure before surgery were seizure free during postoperative follow-up. Good general outcome (GOS, 4.5) was detected in 46 patients (96%). Two patients (4%) developed a new mild memory deficit after surgery, and in two patients existing memory deficits worsened.ConclusionsMicrosurgical removal of temporal lobe cavernomas is a safe and effective method to improve seizure outcome in patients with medically intractable epilepsy and to prevent deterioration caused by hemorrhage.

Infections in Neurosurgery: A Randomized Comparison Between Silk and Polyglycolic Acid

SummarySilk or polyglycolic acid (PGA) was chosen at random for 1,011 patients operated on in the department during a 19 month period in 1981. There was no difference in the incidence of serious infections between the two groups. A significantly higher incidence of suture fistulas in the silk group indicates the use of PGA for buried sutures.