Delayed visual P3 in unilateral thalamic stroke

Abstract

The P3 potential is accepted as a neurophysiological correlate of memory and attention. Delayed latencies were reported in different forms of dementias. Although the generator sites are still under debate, the thalamus may play a crucial role. The aim of this study was to investigate the influence of an unilateral thalamic ischaemic infarction on P3 generation. The event-related P3 component of six patients (2 male, four female; mean age 47 years, range 22-63 years) with unilateral thalamic ischaemic infarction was studied and compared to age-matched controls (five male, nine female; mean age 45.8 years; range 22-69 years). All patients underwent full clinical examination, CCT, and MRI scan. P3 potentials were recorded with a visual three stimulus discrimination paradigm. The mean P3 latency of the patient group to the target stimulus was delayed (469.7 ms, SD = 36.8) compared with the controls (378.8 ms, SD = 51.5; P < 0. 05). The mean P3 latency to the unexpected stimulus was delayed in patients with thalamic infarction compared with controls [477 ms (SD = 46.6) vs. 381.2 ms (SD = 48.5); P < 0.001). Delayed P3 components of the event-related potential (ERP) were recorded in six patients with unilateral thalamic infarction, suggesting an important role of the thalamus in the generation of the P3 potential.

Cognitive and Neurophysiological Effects of Non-invasive Brain Stimulation in Stroke Patients after Motor Rehabilitation

“…In previous reports, the authors measured P300 latencies at Pz or Cz (Trinka et al, 2000 ; Alonso-Prieto et al, 2002 ; Yamagata et al, 2004 ; Stahlhut et al, 2014 ) while in our study we used a finer setup and ERP latencies has been computed at F3, F4, F7, F8, C3, C4, P3, P4, T3, T4. No significant difference has been observed in P300 latency values measured on right or left hemisphere's electrodes.…”

“…Event Related Potentials (ERP) are a reproducible electrophysiological response to an external stimulus (visual or auditory), representing the brain activity associated with various cognitive processes such as selective attention, memory, or decision making. Interestingly, ERP can be valuable in the diagnosis of cognitive impairment and are able to track the cognitive changes during the follow-up in stroke patients (Trinka et al, 2000 ; Alonso-Prieto et al, 2002 ; Yamagata et al, 2004 ; Stahlhut et al, 2014 ).…”

Multimodal P3 under different attentional states in mesial temporal lobe epilepsy

“…Although the generators of the P3 in humans are not known, studies from depth electrodes in epileptic patients suggest local generation of the P3 by mesial temporal lobe structures (limbic P3) (Halgren et al ., 1986; McCarthy and Wood, 1987; Smith et al ., 1990; Grunwald et al ., 1995, 1998, 1999) and the temporoparietal junction (Knight et al ., 1989). However, the contribution of subcortical (Onofrj et al ., 1992a; Trinka et al ., 2000a) and mesial temporal structures to scalp P3 is uncertain (Johnson 1986; Johnson and Fedio, 1988; Daruna et al ., 1989; Rugg et al ., 1991; Puce and Bladin, 1991; Onofrj et al ., 1991, 1992b; Polich and Squire, 1993; Nishitani et al ., 1999; Trinka et al ., 2000b). Nelson and coworkers demonstrated alterations of the scalp recorded P3 using a complex visual language discrimination task in patients with mesial temporal lobe epilepsy (mTLE), but lateralization of the seizure focus was not obtained in this study (Nelson et al ., 1991).…”