The diagnostic value of EEG in Alzheimer disease: correlation with the severity of mental impairment.

The aim of our study was to analyze EEG changes in patients with Alzheimer disease (AD) and to determine how closely EEG reflects the progression of mental impairment in people with AD. Ninety-five patients with probable AD according to National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria treated in our Clinic for Memory Disorders were selected for this study. Patients were divided into three subgroups with mild, marked, and severe dementia according to the results of psychometric scales. The EEG findings were classified using an eight-degree scale according to the background activity, presence and amount of theta and delta waves, focal changes, lateralization of focal changes, synchronization, and presence of sharp and spike waves. A significant correlation between the degree of EEG abnormalities and cognitive impairment was found. We did not observe any correlation between the presence of delta waves and the results of neuropsychological tests. Our study revealed an important diagnostic value of EEG in the estimation of the severity of dementia parallel to psychometric scales.

Visual and brainstem auditory evoked potentials in hereditary motor-sensory neuropathy.

Visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) were recorded in 57 children and adults with hereditary motor-sensory neuropathy (HMSN); 37 of them were diagnosed as type I (demyelinating) and 20 as type II (axonal). None of the patients presented central nervous system involvement. The results were compared with VEP and BAEP records of 12 adults with Guillain-Barré syndrome (GBS) and 40 healthy controls. Above 30% of all patients with HMSN I showed delayed latency of the VEP. These abnormalities were less expressed in HMSN II. Abnormal BAEP were observed in almost 50% of patients with HMSN I and HMSN II with nearly the same frequency in both types but more pronounced in HMSN I. The most common feature was prolongation of the I-III interpeak latency (JPL). The VEP and BAEP changes could be present simultaneously in the same patient (mainly in HMSN I) or separately. More often the abnormalities were observed in the adult patients. Normal VEP and BAEP values were present in all patients with GBS. The results strongly suggest the subclinical optical and auditory pathways involvement in HMSN patients.

[Diagnosis of demyelination processes based on the visual evoked potential test using a checkerboard reversal pattern]. / Diagnostyka procesów demielinizacyjnych na podstawie wzrokowych potencjalów wywolanych przez odwracalny wzorzec szachownicy.

Visual evoked potentials in response to checkerboard reversal pattern were evaluated in 160 patients: 24 with isolated retrobulbar optic neuritis, 100 with unquestionable and probable multiple sclerosis, 36 with paraparesis or with disseminated changes of unestablished aetiology (degenerative or inflammatory) and in 80 healthy controls. Normal visual evoked potentials were obtained in all controls. In all cases of present or past optic neuritis abnormal potentials were observed, usually unilateral. In multiple sclerosis patients with unquestionable diagnosis abnormal potentials were present in 92% of cases, and in patients with probable multiple sclerosis they were found in 58%, and in cases without retrobulbar neuritis they were present in 71% and 48% of cases respectively. The abnormalities were found most frequently in both optic nerves. It was tried to find out other correlations making possible partial differentiation of the axonal and demyelinating type of damage to the anterior part of the visual pathways.

[Effect of diazepam on visual potentials evoked by reversible checkerboard pattern]. / Wplyw diazepamu na wzrokowe potencjaly wywolane przez odwracalny wzorzec szachownicy.

Visual potentials evoked by means of reversible checkerboard pattern were studied in 12 healthy subjects, 5 patients with probable multiple sclerosis and 3 patients with photosensitive epilepsy before and after intravenous injection of 10 mg of Valium. The most characteristic feature was lowering of the amplitude of the evoked visual potentials (in 75%) which appeared as a rule between 30 seconds and 4 minutes after Valium injection. Prolongation of Pmax latency was observed less frequently (in 65%) and this change was of low grade. In nearly half the cases sings of synchronization appeared with development of late multiphasic components of the visual evoked potential. No significant difference was noted in the effect of Valium on the latency and amplitude of the visual evoked potentials between healthy subjects and patients. The possible mechanisms of diazepam action on the conduction in visual pathways are discussed.

Gabapentin absorption: effect of mixing with foods of varying macronutrient composition.

OBJECTIVE: To compare the oral absorption profile of gabapentin following administration of the contents of opened capsules that were mixed with food vehicles of varied macronutrient (protein) composition. DESIGN: An unblinded, randomized, single-dose, four-way crossover pharmacokinetic study in nine healthy adult men and women volunteers. METHODS: Following an overnight fast, a single 600-mg dose of gabapentin (2 x 300-mg Neurontin capsules) was given either as an intact capsule swallowed with 120 mL of tap water (control, phase I), or after capsule contents were opened and mixed with; 4 oz. of applesauce (phase II), 120 mL of orange juice (phase III), or 4 oz. of fat-free chocolate pudding (phase IV). Subjects fasted for 4 hours following drug ingestion. Serial venous blood samples were obtained over 24 hours to determine gabapentin serum concentrations. Pharmacokinetic variables including AUC, maximum serum concentration (Cmax), and time to maximum serum concentration (tmax) were calculated by using standard noncompartmental methods. Subjects served as their own controls, and were randomly crossed over following a minimum 7-day washout period. Statistical analysis was performed by using ANOVA and Student's t-test where appropriate. RESULTS: No statistically significant differences in any kinetic variable were found between any study arm. A trend was noted for a modest increase in both Cmax and AUC in phase IV (chocolate pudding) compared with control (+18.6% and +13.2%, respectively). In a comparison of protein (phase IV) versus nonprotein phases (phases I-III), gabapentin AUC was 26% greater (47.28+/-14.65 vs. 37.43+/-9.78 microg/mL x h; p = 0.03), and Cmax was 32% higher (4.72+/-1.04 vs. 3.56+/-0.92 microg/mL; p = 0.003). CONCLUSIONS: Opening and mixing the contents of gabapentin capsules does not significantly impair drug absorption. This may be a viable administration option for patients who are unable to swallow intact capsules. Dietary macronutrient composition (i.e., protein) may favorably influence gabapentin oral absorption.