The influence of levodopa and the COMT inhibitor on serum vitamin B12 and folate levels in Parkinson's disease patients.

Serum folate and vitamin B12 levels were measured in 67 consecutive Parkinson's disease patients treated either with levodopa + dopa decarboxylase inhibitor (DDC-i) plus catechol-O-methyltransferase inhibitors (COMT-i) or only with levodopa + DDC-i. The data were compared to 67 age-matched controls. Our findings show that levodopa-treated Parkinson's disease patients have low folate (p < 0.0007) and vitamin B12 levels (p < 0.0003). They also demonstrate that the addition of a COMT-i to levodopa + DDC-i treatment causes lower serum vitamin B12 (p < 0.03) and folate levels (p < 0.005) than levodopa + DDC-i treatment alone. We suggest supplementary treatment with vitamin B12 and folic acid in these situations.

Cognition in homozygous beta-thalassemia disease: a multichannel auditory event-related potential (P300) study.

Auditory Event-Related Potentials (AERP) were elicited in 25 beta-thalassemic patients, three days before and three days after a blood transfusion. The amplitude, latency and topographic distribution of P300 (P3) as well as N1, P2, N2 components were measured for the two assessment times. No significant differences in either amplitude, latency or topography were observed between the two situations, but thalassemic patients had significantly prolonged P3 latencies comparing to controls though none of them exceeded 3 standard deviations of the control mean values. Regarding P3 topography, 10 out of 25 patients showed a right centroparietal distribution area. It is concluded that information processing, as far as it is reflected in AERP components is impaired in thalassemic patients and blood transfusion have no significant influence in cognitive functions.

Cognitive function in non-demented individuals complaining of short-term memory disturbances: a study with event-related potentials (P 300) and brain CT scan.

Event-related potentials (ERPs) were elicited in 30, non-consecutive, non-demented individuals, complaining of short-term memory disturbances. Fifteen of them had a moderate diffuse cerebral atrophy on their brain CT and the other 15 had a negative brain CT. ERPs were also elicited in 15 age-matched controls with no reported memory disturbances and negative brain CTs. The statistical analysis showed that the group of individuals with cerebral atrophy had a significantly prolonged P300 (P3) latency and a decreased P3 amplitude compared to controls. It is concluded that among persons complaining of short-term memory disturbances, the individuals who show cerebral atrophy, taken as a group, have a P3 latency prolongation and/or low P3 amplitude a finding which reflects an impaired information processing.

A normative study of the trail making test A and B in Greek adults.

The purpose of this study was to explore the effects of age and education on the performance of the Trail Making Test (TMT), and to provide normative data in the Greek population. The TMT was administered to 643 healthy participants. All participants satisfied the criteria excluding dementia and other medical, psychiatric, and neurological disorders. Statistical analysis revealed that, age, education, and general level of intelligence significantly influence individual performance. Performance on TMT, especially part B, decreases with increasing age and lower levels of education. Current norms of the Greek version of TMT represent a useful set of norms for clinical practice.

Clinical applications of auditory event related potentials in neurology.

Auditory ERP (AERP) studies have been performed in 56 patients with central nervous system disturbances. Forty seven patients (90.5%), had AERP component abnormalities concerning mainly P300 topography alterations and secondarily P300 latency prolongation. It is concluded that P300 is a very useful tool in clinical neurology and that P300 topography or latency alterations are not specific of any cerebral disturbance but can be found in any disease whenever cognitive functions are impaired.

Cognition in epilepsy: a multichannel event related potential (P300) study.

Auditory event-related potentials (AERP) were elicited in 68 epileptic patients and 30 age-matched controls. Epileptic patients had significantly prolonged N2 and P300 (P3) latencies compared with controls. Seven patients were above the range of 3 standard deviations from the control mean values. Amongst epileptics, patients with temporal lobe epilepsy had significantly prolonged P3 latencies compared to patients with idiopathic generalized epilepsy. Patients with abnormal EEGs had significantly prolonged P3 latencies compared to those with normal EEGs. Patients on anticonvulsant monotherapy had shorter P3 latencies, compared to patients taking a combination of two or more anticonvulsants. Patients on shorter duration of treatment had less prolonged P3 latencies compared to those on longer anticonvulsant treatment.

Cognition in relapsing-remitting multiple sclerosis: a multichannel event-related potential (P300) study.

Auditory event-related potentials (AERP) were elicited in 47 patients with relapsing-remitting (RR) multiple sclerosis (MS) and 24 age-matched controls. MS patients had significantly prolonged N2 and P3 latencies as well as low P3 amplitude compared with controls. Seven of them exceeded 3 standard deviations from the control mean values. The observed N2 and P3 alterations are associated with the patients' disability status as it is defined by the Kurtzke expanded disability status scale (EDSS), but are not related to the duration of the disease. A possible cognitive decline as reflected in the observed AERP components alterations in MS patients is subsequently discussed.