P50 variations in Behcet`s patients without neurologic findings

OBJECTIVE

In the present study, subclinical lesion involvement was investigated using the P50 component in Behcet`s patients without neurological manifestation.

METHODS

We performed this clinical research in Erciyes University, Faculty of Medicine between December 2000 and November 2001. The studies were carried out on 18 Behcet`s patients without neurologic findings and 18 volunteers for control. Standard Ag/AgCl electrodes in plastic cups were used for monopolar EEG derivations. They were attached with electrode paste and tape at the Cz (vertex) according to the 10-20 system. The auditory stimuli were delivered in pairs. The P50 waves, which may be taken from approximately 50 msec from the stimuli, were collected by computer system. Amplitudes and latencies of the P50 components were measured in the same system.

RESULTS

This study showed that the suppression of P50 responses performed by the test stimuli, was significantly more decreased in Behcet`s patients than the control subjects.

CONCLUSION

The decrease of the suppression of the auditory P50 response to repeated stimuli reflects a deficit in the central nervous system`s ability, such as attention, cognition, and sensory input in Behcet`s patients and can be used as a neurophysiological marker in subclinical lesions in these patients.

Evidence for theory of mind deficits in euthymic patients with bipolar disorder

OBJECTIVE

i) To investigate the subtle ToM (theory of mind) deficits in euthymic patients with bipolar disorder. ii) To investigate the impact of non-ToM cognitive deficits on ToM abilities.

METHOD

Forty-three euthymic patients with bipolar disorder and 30 healthy control subjects were involved in this study. ToM was assessed by the Eyes test and the Hinting task. Both groups were also evaluated with a comprehensive neuropsychological battery including tasks for basic emotion and face recognition.

RESULTS

The patient group was impaired on both of the ToM tasks. The patient group also showed impairment in many cognitive tasks including tasks related to sustained attention.

CONCLUSION

Even euthymic patients with bipolar disorder may be impaired in advanced ToM tasks. Executive dysfunction and some other cognitives deficits such as basic emotion recognition may be at least partly responsible for this result.