Saccade behaviour in migraine patients.

BACKGROUND: Voxel-based morphometry studies in migraine patients showed significant grey matter volume reduction in regions involved in the control of saccadic eye movements. We hypothesized that these changes would be reflected in dysfunctional saccadic behaviour. METHODS: Saccades were recorded by infrared oculography using three different paradigms (pro-saccade with gap, pro-saccade overlap and anti-saccade with gap). We compared the results for migraine patients (n = 80) with those for controls (n = 87). RESULTS: No significant differences were found between migraine patients with (n = 46) and without (n = 34) aura. Migraine patients showed a saccadic behaviour that differed from controls in three respects. In migraine patients, the latencies in the pro-saccade with gap paradigm were borderline significantly longer. Moreover, in both the pro-saccade with gap and the pro-saccade overlap paradigm we observed a larger intra-individual variation of the latency in migraine patients. However, the biggest difference was that the patients who received migraine prophylactic therapy made significantly more anti-saccade errors in the anti-saccade with gap paradigm, suggesting that inhibitory saccade control is impaired in migraine patients depending on the severity of the migraine. CONCLUSION: We suggest a deficient inhibitory control, reflecting an executive dysfunction in the dorsolateral prefrontal cortex or a dysfunction in the cingulate cortex, is present in migraine patients.

Diagnostic and therapeutic trajectory of cluster headache patients in Flanders.

OBJECTIVE: A fraction of cluster headache (CH) patients face diagnostic delay, misdiagnosis, undertreatment and mismanagement. Specific data for Flanders are warranted. METHODS: Data on CH characteristics, diagnostic process and treatment history were gathered using a self-administered questionnaire with 90 items in CH patients that presented to 4 neurology outpatient clinics. RESULTS: Data for 85 patients (77 men) with a mean age of 44 years (range 23-69) were analysed. 79% suffered from episodic CH and 21% from chronic CH. A mean diagnostic delay of 44 months was reported. 31% of patients had to wait more than 4 years for the CH diagnosis. 52% of patients consulted at least 3 physicians prior to CH diagnosis. Most common misdiagnoses were migraine (45%), sinusitis (23%), tooth/jaw problems (23%), tension-type headache (16%) and trigeminal neuralgia (16%). A significant percentage of patients had never received access to injectable sumatriptan (26%) or oxygen (31%). Most prescribed preventative drugs after the CH diagnosis were verapamil (82%), lithium (35%), methysergide (31%) and topiramate (22%). Despite the CH diagnosis, ineffective preventatives were still used in some, including propranolol (12%), amitriptyline (9%) and carbamazepine (12%). 31% of patients had undergone invasive therapy prior to CH diagnosis, including dental procedures (21%) and sinus surgery (10%). CONCLUSION: Despite the obvious methodological limitations of this study, the need for better medical education on CH is evident to optimize CH management in Flanders.

Cerebral oedema in episodic ataxia.

We report a patient with episodic ataxia (presumably of type 2) who developed cerebral oedema secondary to a common infection (presumably viral). Cerebral oedema may be a part of the clinical spectrum of familial episodic ataxia and argues for an overlap with hemiplegic migraine. It is suggested to consider a diagnosis of episodic ataxia or familial hemiplegic migraine in catastrophic reactions to apparent trivial trauma or infection.

Saccadic ping pong gaze in coma.

In this report, we describe the peculiar eye movements of a young man who became comatose after a head injury. The eyes moved rhythmically from one side to another, without pausing in the lateral positions. This phenomenon has been described as "ping pong gaze" (PPG), referring to short-cycling periodic alternating gaze with smooth eye deviations. In the present patient, however, a saccadic type of PPG could be confirmed by oculography. Possible clinical and pathophysiological implications are discussed.

False perception of visual verticality in multiple sclerosis.

We wanted to investigate to what extent patients with multiple sclerosis (MS), not complaining of dizziness or disequilibrium, may have problems with the estimation of gravidity. Therefore, we studied the static 'subjective visual vertical' (SVV), a test that is thought to reflect mainly otolith function. Further, we correlated SVV measures with the degree of disease disability. A group of outpatients was compared with a group of age- and sex-matched healthy volunteers. The deviations of SVV in patients were significantly larger than in controls. Overall, SVV was abnormal in 48% of individual patients. There was a significant correlation between SVV and the global disability score. The same held true for correlation with the subscores of brainstem and cerebellar complaints. The SVV test proved to be a simple method that was well tolerated by the patients. It can be considered a complementary otoneurological tool for evaluating MS patients. Further, these findings suggest that misperception of the verticality parallels the disability in MS patients.

Brachioradial pruritus--a peculiar neuropathic disorder.

The case is presented of a middle-aged woman who suffered from lancinating itch on the dorsolateral aspect of the upper arm after a loco-regional injury, first on the right and later on the left side. Brachioradial pruritus (BRP) was diagnosed. Neurophysiologic examination was compatible with a neuropathy at the C5-C6 level, while a negative nerve root block supported an additional central impact. The presumed pathophysiology of BRP is discussed in terms of a neuropathic disorder. We suggest that damage from whatever cause from either the cutaneous nerves or from the more proximal sensory pathways may be the causative physiopathologic basis for this enigmatic disorder. BRP was refractory to different therapeutic approaches, except to lamotrigine. As BRP presents a therapeutic challenge, it seems important to report lamotrigine as a potential new therapy.

Carotid artery aneurysm in human immunodeficiency virus infection.

The case is reported of a patient with human immunodeficiency virus (HIV) infection presenting with isolated headache as the presumed manifestation of a cavernous carotid aneurysm. The relationship between HIV and aneurysms is discussed. Clinicians should be aware of the possibility of carotid aneurysms in HIV-positive patients, even in areas where HIV is not endemic and when no neurological deficit is present. Magnetic resonance imaging is recommended as the initial diagnostic study.

Treatment of anterior canal benign paroxysmal positional vertigo by a prolonged forced position procedure.

This report presents a therapeutic procedure for refractory benign paroxysmal positional vertigo (antBPPV) of the anterior canal. Two patients with refractory antBPPV were treated by a prolonged forced position procedure (PFPP). The technique is based on the assumption that the pathophysiological mechanism of antBPPV is similar to that generating posterior canal canalolithiasis. The patients recovered from refractory antBPPV after one or more PFPPs. The rationale for this therapy is that when the patient lies in the proposed forced position, the affected anterior canal is uppermost in an almost gravitationally vertical position. If the patient remains in this position for several hours, the floating particles lying in the non-ampullary arm of the canal can gradually slip out of the canal towards the vestibule due to gravity. We recommend trying PFPP when the side of lithiasis cannot be determined, in cases that are resistant to particle repositioning canal manoeuvres, and before considering canal plugging for refractory antBPPV.

Abnormal psychophysical visual perception in Parkinson's disease patients.

Several visual dysfunctions in Parkinson's disease (PD) are described. Most of them are subtle or only demonstrated by stimulus-specific electrophysiologic or psychophysical testing. However, these minor deficits are thought to be of clinical relevance as they are related to direct or indirect complaints. Special emphasis is laid on visual hallucinations. These are most likely of multifactorial origin. The relation between hallucinations in PD and in dementia with Lewy bodies has to be elaborated further. Visual loss, as a possible and reversible cause of visual hallucinations should be actively sought and corrected as far as possible. An underlying role of dopaminergic retinal cells in visual dysfunction of PD patients is widely recognised. However, whether the basic abnormality resides also in the visual cortex remains to be elucidated. Other neurotransmitters may also be involved. It has not been answered whether visual dysfunction might distinguish PD from other forms of parkinsonism.

Parkinsonism in patients with vascular dementia: clinical, computed- and positron emission-tomographic findings.

PURPOSE: The present study investigates the vascular nature of parkinsonian features in patients with 'probable' vascular dementia. PATIENTS AND METHODS: Forty patients with vascular dementia were studied with positron emission tomography (PET) using the steady state technique with (15)O in order to assess regional cerebral blood flow (rCBF), regional oxygen extraction rate (rOER) and regional metabolic rate for oxygen (rCMRO(2)) in different brain regions. The findings in 10 patients with (VaDP) were compared to 30 without parkinsonism (VaD). RESULTS: The clinical and computed tomographic findings in the parkinsonian patients were similar to those described in the literature as probable vascular parkinsonism. The PET results showed decreased rCBF and rCMRO(2) in the frontal and parietal cortices and in the striatum of the VaDP compared to the VaD group. The decrease of rCBF and rCMRO(2) in frontal and parietal cortices is due to the more severe mental changes in the VaDP group. In the VaDP patients rCBF and rCMRO(2) were more decreased and rOER increased in the striatum contralateral to the most affected parkinsonian side. CONCLUSION: Our PET findings show that local ischemic changes in the striatum contribute to parkinsonism in vascular dementia patients.

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.

Antisaccadic effects of a dopamine agonist as add-on therapy in advanced Parkinson's patients.

We wanted to compare clinical neurological and antisaccadic behavior before and after addition of a dopamine agonist to the usual antiparkinsonian drugs in advanced Parkinson's disease. Parkinson's patients in stage 3 and 4 of Hoehn and Yahr not yet taking a dopamine agonist were selected. In 20 patients, the treating neurologist decided to add pergolide. The dose of pergolide was adjusted by the treating neurologist according to clinical response. Antisaccades were studied by infrared oculography before and after addition of pergolide. Antisaccades are voluntary saccades in the opposite direction of an unanticipated visual target. The patients made more errors, i.e. they glanced to the target or they made no eye movement at all. In contradistinction to the global neurological improvement and the better motor scores, antisaccadic disturbances did not improve significantly with pergolide, except in younger patients. These findings suggest that antisaccadic alterations in patients with advanced Parkinson's disease could be multifaceted. Not only depletion of dopamine, but also non-dopaminergic dysfunctions could contribute. Cortical frontal lesions must also be taken into account.

MRI of the brain in cerebrotendinous xanthomatosis (van Bogaert-Scherer-Epstein disease).

The clinical, biochemical and magnetic resonance imaging findings of two patients with cerebrotendinous xanthomatosis are reported. This is a rare hereditary disease. Early recognition of this entity is important in view of the existing treatment possibilities. Magnetic resonance imaging findings typically include a bilateral and almost symmetrical increase of the signal intensity on the T2-weighted images in the cerebellar and periventricular cerebral white matter, the basal ganglia, the dentate nuclei and the brainstem as well as cerebellar and cerebral atrophy.

Antisaccades and remembered saccades in mild traumatic brain injury.

The most common site of focal lesions after mild traumatic brain injury (MTBI) is the frontal lobe. This lobe, however, is difficult to examine clinically. Neuroimaging is not performed routinely and usually shows normal results in uncomplicated trauma. Antisaccades (AS) and remembered saccades (RS) are neuro-ophthalmological tests of frontal function. This study examined whether there are disturbances of latency time or error rate of AS and RS in patients within 24 h after MTBI. Eye movements were studied with infrared-oculography. Data were obtained prospectively from 25 patients. An additional group of 6 patients with MTBI and alcohol intoxication were also examined. No statistical differences in AS or RS, either for errors or for latency time, were found between a group of age-matched controls and the patients, except in the group of alcohol-intoxicated MTBI patients. Our findings indicate that visual reflex inhibition and initiation of voluntary saccades were not disturbed in the nonintoxicated patients. It is hypothesized that the responsible frontal area was not affected. It is concluded that error rate and latency time of AS and RS are inappropriate measures for evaluating acute MTBI.

The effect of cognitive load on saccadic eye movements.

The present study tested the hypothesis that, unlike prosaccades, antisaccades require controlled processing, due to the prepotent response that needs to be inhibited. The effect of the Random time Interval Generation (RIG) task (Vandierendonck, A., De Vooght, G., & Van der Goten, K. (1998). European Journal of Cognitive Psychology, 10, 413-444) on these saccade latencies and errors was studied. This task has the advantage that it loads executive processes, with only minimal interference with verbal or visuo-spatial components. A first experiment compared saccade performance within the prosaccade and the antisaccade task, executed alone and in combination with the RIG task and fixed tapping (added to exclude possible motor component interference explanations). A second experiment investigated the influence of task characteristics on the effects found. Although it was shown that antisaccades are more prone to interference of an executive interference task, it seems that prosaccades are also vulnerable. Interference on prosaccades could originate from a controlled execution of these saccades. A third experiment confirmed that endogenously generated prosaccades are susceptible to dual-task interference and showed that controlled saccade execution, without the need to inhibit a prepotent response, is sufficient to produce interference.

Impaired early visual processing in disorganised schizophrenia.

Topographic differences in flash/pattern shift VEP data are evaluated in paranoid (n: 38), disorganized (n: 23) and residual (n: 23) schizophrenic subtypes and compared to normal controls. Increased early P1 and a restricted diffusion of the late P2 responses suggest dopaminergic over- and cholinergic underactivity in paranoid and residual schizophrenia. A distinctive pattern N145 reflects well-preserved attentional resources in the paranoid subtype. Latency increase and amplitude decrease of the pattern N145 concur with abnormal antisaccades documented in disorganized behaviour. VEP-data might help differentiate between schizophrenic subtypes.