Maarten Goethals

Clinical Predictors of Late-Onset Seizures and Epilepsy in Patients with Cerebrovascular Disease

Background: Seizures and epilepsy are harmful and worsen the disability of stroke patients. There are currently no good clinical predictors of late-onset seizures and epilepsy in patients with cerebrovascular disease (CVD). Patients and Methods: 110 patients with delayed seizures after an ischaemic or a haemorrhagic stroke, a transient ischaemic attack or a subarachnoid haemorrhage (60 with a single seizure and 50 with epilepsy) and 366 without seizures were included in this retrospective study. The clinical syndrome, the stroke aetiology and the vascular risk factors were compared. The groups with a single seizure and with epilepsy were also analysed separately. Results: There were no differences in age, gender, aetiology and vascular risk factors between the groups with and without seizures. When comparing the incidence of the clinical syndromes, ischaemic partial anterior circulation syndrome (PACS) was significantly more and transient ischaemic attack less frequent in the group with seizures compared to the control group. The severity of the neurological impairment on admission and the degree of disability on discharge after a PACS was similar in those who developed late-onset seizures compared with those who did not. Also on the Cox proportional hazards analysis, PACS appeared to be the only clinical risk factor for development of seizures and epilepsy in patients with CVD. No differences were observed in clinical predictors between patients with a single seizure and those with epilepsy. Conclusion: PACS is the only independent predictor for the occurrence of late-onset seizures in patients with CVD.

Posterior cortical atrophy: two case reports and a review of the literature

We present two cases of progressive early-onset dementia with apraxia and visuospatial disability as initial manifestations. In the later stages of the illness Gerstmanns and Balints syndromes developed. Structural neuroimaging demonstrated parieto-occipital atrophy and functional imaging revealed bilateral hypometabolism and hypoperfusion in these areas. These cases fulfil the diagnostic criteria of posterior cortical atrophy (PCA). Frontal lobe involvement became evident as the disease progressed. Alzheimers disease also typically features this anterior spread and possibly this is the underlying pathological substrate for this clinical syndrome, although definite pathology is lacking. In this report, we describe longitudinal evolution in these two cases of PCA.

Eeg findings after a cerebral territorial infarct in patients who develop early- and late-onset seizures

Background: EEG findings are generally not considered to be very helpful for the diagnosis of poststroke seizures. Purpose: This retrospective study investigates the EEG characteristics in patients who develop seizures after a cerebral territorial infarct. Patients and Methods: The study population consisted of 110 patients with seizures after a cerebral territorial infarct (12 with early- and 98 with late-onset seizures) and 275 without. All 110 patients had an interictal EEG after their first seizure. The EEG patterns after the stroke were compared between those available from 69 patients who developed seizures and those from 275 who did not. Also the EEG patterns after the seizure (n = 110) were compared to those in the poststroke group without subsequent seizures. Results: Periodic lateralized epileptic discharges (PLEDs) on the EEG after stroke were only found in 5.8% of the patients with early- and late-onset seizures. They were absent in the stroke group without seizures. Frontal intermittent rhythmic delta activities (FIRDAs) were observed in 24.6% of the seizure group, compared to 1.1% in the control group. Diffuse slowing occurred also significantly more often in the former (21.7%) compared to the latter group (5.1%). Normal EEG findings were seen in 53.8% of the stroke patients without seizures, compared to 8.5% in those with seizures. The incidence of focal slowing was the same in both groups. Similar findings were observed when comparing the EEG patterns of the patients after the first poststroke seizure to those of the stroke group without subsequent seizures. In patients with early-onset seizures, PLEDs or FIRDAs were present in 25% each. FIRDAs and diffuse slowing were significantly more frequently observed on the poststroke EEGs of patients who developed late-onset seizures. Conclusions: FIRDAs, PLEDs and diffuse slowing are the most frequent EEG findings in patients with early-onset seizures. Patients with FIRDAs and diffuse slowing on the poststroke EEG have a high risk to develop late-onset seizures, while the chance is reduced in those with normal EEG findings.

Effect of repetitive transcranial magnetic stimulation on saccades in depression: a pilot study.

Therapeutic repetitive transcranial magnetic stimulation (rTMS) in depression is applied over the prefrontal cortex. This brain region is known to play an important role in the control of saccades. We wanted to investigate whether the fast rTMS procedure affected saccadic activity in depression. Reflexive saccades (RS) and voluntary saccades were studied in 11 patients before and after therapeutic rTMS for depression. Two types of voluntary saccade tasks were used: a voluntary prosaccade (VpS) task and an antisaccade (AS) task. Eye movements were registered by infrared oculography. Latency and directional error rate were analyzed. rTMS was applied over the left dorsolateral prefrontal cortex (DLPFC). RS and VpS parameters were unchanged after 10 sessions of rTMS. However, the latency of antisaccades (AS) was significantly shorter after rTMS than before rTMS. It can be concluded that rTMS over the left DLPFC cortex in depression seems to have no important effect on reflexive saccades, while antisaccade activity is clearly favored by shortening of latency. As voluntary prosaccades were not significantly influenced, our findings may indicate that not merely the voluntary triggering of saccades but the inhibition of unwanted reflexive saccades is influenced by fast rTMS delivered over the DLPFC. These results suggest the intriguing possibility that rTMS might differentially affect specific aspects of saccade behavior.

ARE BETTER EYE MOVEMENTS AN ADVANTAGE IN BALL GAMES? A STUDY OF PROSACCADIC AND ANTISACCADIC EYE MOVEMENTS '

The aim of this study was to compare prosaccadic and antisaccadic eye movements of experts in ball sports and controls. In the prosaccadic and antisaccadic task, subjects made saccades respectively towards and away from a suddenly appearing stimulus. By means of infrared-oculography, we compared horizontal eye movements of experts (n = 18) and controls (n = 20). Experts had shorter overall saccadic latencies, but significantly shorter latencies occurred only on the antisaccade task, not on the prosaccade task. Our findings seem to support the concept that prosaccades and antisaccades have different underlying mechanisms and that expertise in ball games mainly improves antisaccadic performance in terms of latency and variability.

Saccadic eye movements and finger reaction times of table tennis players of different levels

Building upon the finding that athletes have faster saccadic eye movements than controls (Lenoir et al., Percept Motor Skills 2000;91:546-552), the aim of this study was to compare prosaccadic and antisaccadic eye movements in table tennis players of different levels. Saccadic latency, error rate, and reaction time on a visuomotor task (key press) were measured. Saccadic latency and error rate did not decrease with an increasing level of expertise. Finger reaction times correlated positively with antisaccadic latencies, but not with prosaccadic latencies. It is concluded that in an active population, saccadic performance does not allow the discrimination between recreational, moderate, and top players because of a ceiling effect. The relation between eye and finger movements is discussed in the framework of common brain areas during movement preparation.

Latanoprost in hemifacial spasm.

An empirical observation that the prostaglandin derivate latanoprost quited facial spasms in patients with glaucoma prompted us to study latanoprost in non-glaucomatous patients with hemifacial spasms [HFS]. This explorative trial followed an open-label, prospective treatment design. At short term, most patients showed no or only mild improvement and subsequently needed therapy with Botulinum toxin A. Although these results are not impressive, latanoprost could be considered as an interesting alternative in the treatment of patients with HFS and with concomitant glaucoma. A role for prostaglandins in the trigeminofacial reflex is hypothesised.

Voluntary saccades in fast ball games

In this princeps study of voluntary eye movements in fast ball games, a group of experienced sportsmen is compared with a group of inexperienced controls on an antisaccade task. The experienced players did not make more anticipatory eye movements or wrongly directed antisaccades. Their antisaccadic latency time was shorter than that of the controls. These results suggest that frontal control of saccades is favored in fast ball games. The findings are discussed in terms of a two-process model of eye movements and attention.