Visual evoked potential abnormalities in dementia with Lewy bodies.

OBJECTIVES: Visuo-perceptual deficits and visual hallucinations (VHs) are common disturbances in patients with dementia with Lewy bodies (DLB) and those with Parkinson's disease (PD). In particular, delays in visual evoked potential (VEP), reversed by l-dopa administration, have previously been observed in PD patients. Impairment in metabolic functions of dopaminergic amacrine cells within the inner plexiform layer of the retina has been largely documented and has been posited as the underlying cause of visual and retinal alterations in PD. The aims of the present study were to investigate the presence of VEP abnormalities in DLB patients, as compared to a PD control group, and to assess the presence of significant correlations between neurophysiological measures and clinical symptoms (i.e., presence of visuospatial deficits and/or visual hallucinations). METHODS: Fifteen DLB patients and fifteen matched PD patients underwent pattern reversal before and after l-dopa administration, and a short neuropsychological assessment. RESULTS: In DLB patients, we observed delay of the P100 latency to foveal stimuli in both eyes compared to normative values. Compared to PD, DLB patients showed higher values of the P100 latency for foveal stimulation from the right eye prior to l-dopa administration (p = 0.018). No correlations between VEP alterations, visuo-spatial deficit and visual hallucinations were found. DISCUSSION: Our findings demonstrated a longer P100 delay in DLB than in PD patients, especially along the right visual pathway. In contrast to previous studies, which focused on a dopaminergic pre-geniculate impairment of visual pathways, our evidence suggests that other mechanisms, possibly relying on thalamic involvement, which is known to be dysfunctional in DLB, can interfere with VEP abnormalities.

Asymptomatic carotid acute dissection following focal status epilepticus.

•CAD is one of the most important predisposing factors of cerebral ischaemia in young adults.•Focal motor seizures with the involvement of the neck may represent a risk condition of developing CAD•A heightened awareness for CAD should be recommended in patients affected by epilepsy, carotid dopplers may confirm the clinical suspicion in case of significant neck trauma associated with seizures.

Lateralized periodic discharges in insular status epilepticus: A case report of a periodic EEG pattern associated with ictal manifestation.

OBJECTIVE: Insular lobe seizures generally represent a misconceived ictal phenomenon characterized by specific neurological signs. Aphasia can be a rare presenting sign associated with insular lobe epilepsy which could be easily mistaken for a manifestation of other acute brain diseases. METHOD: We describe an insular status epilepticus (SE) characterized by sudden onset of language disturbance associated with hypersalivation and paraesthesia. A concomitant EEG recording showed the presence of Lateralized Periodic Discharges plus superimposed fast activity (LPDs + F). After an adequate acute endovenous anti-seizure treatment, a normalization of the EEG abnormalities with a complete resolution of all the neurological symptoms was achieved. DISCUSSION: Language disturbances can be usually found in various pathological acute pictures involving the dominant frontal and temporal lobes. The presence of certain EEG pattern, could rise the suspect of aphasia as a critical manifestation. LPDs pattern is usually correlated with structural lesions. The association between LPDs and seizure is controversial but it seems to be more consistent when they are associated with "Plus modifiers" and with an high periodic frequency. CONCLUSION: Our case underlines the importance of considering focal SE in the differential diagnosis of patients presenting aphasia, even in the absence of previous history of epilepsy. We describe how LPDs can be associated with SE in a patient affected by a brain tumour, supporting the idea that some characteristic periodic patterns could be associated with seizure occurrence.