Intense and recurrent déjà vu experiences related to amantadine and phenylpropanolamine in a healthy male

The Déjà Vu Illusion

The déjà vu illusion occurs when a person has an inappropriate feeling of familiarity in a situation that is objectively unfamiliar or new. The amorphous nature of this experience has made identifying its etiology challenging, but recent advances in neurology and understanding of implicit memory and attention are helping to clarify this cognitive illusion. More specifically, déjà vu may result from (a) a brief change in normal neural transmission speed causing a slightly longer separation between identical messages received from two separate pathways, (b) a brief split in a continuous perceptual experience that is caused by distractions (external or internal) and gives the impression of two separate perceptual events, and (c) the activation of implicit familiarity for some portion (or all) of the present experience without an accompanying conscious recollection of the prior encounter. Procedures that involve degraded or occluded stimulus presentation, divided attention, subliminal mere exposure, and hypnosis may prove especially useful in elucidating this enigmatic cognitive illusion.

Reduplicative paramnesia: a review

BACKGROUND

Reduplicative paramnesia (RP) is a content-specific delusional misidentification syndrome (DMS) which has received little attention in the research literature relative to other DMS. RP is thought to result from an organic rather than psychiatric cause distinguishing it from other DMS. Our systematic review examines the research literature investigating the prevalence, symptomatology and potential neurologic mechanisms underlying RP.

SAMPLING AND METHODS

MEDLINE, PsycINFO, and the Cochrane Library were searched (from 1966 to February 10, 2012) with the reference lists of relevant articles examined. Case reports, clinical studies and post-mortem studies focusing on, or referring to, RP were included.

RESULTS

There is a paucity of literature regarding the potential mechanisms underlying the psychological, cognitive and neurological aspects of RP. The available literature is limited by the lack of systematic clinical studies and in vivo investigations with current findings remaining only speculative. However, there does appear to be a consensus that RP may have a neurologic rather than psychiatric cause and that right and bifrontal lesions as well as the cognitive dissonance associated with memory, visuospatial and impaired conceptual integration are common factors in RP presentation.

CONCLUSIONS

This area requires further extensive systematic research with supplementary in vivo data. Current studies suggest that focal lesions within the frontal lobe may account for the onset of RP.

Recognition without identification, erroneous familiarity, and déjà vu

Déjà vu is characterized by the recognition of a situation concurrent with the awareness that this recognition is inappropriate. Although forms of déjà vu resolve in favor of the inappropriate recognition and therefore have behavioral consequences, typical déjà vu experiences resolve in favor of the awareness that the sensation of recognition is inappropriate. The resultant lack of behavioral modification associated with typical déjà vu means that clinicians and experimenters rely heavily on self-report when observing the experience. In this review, we focus on recent déjà vu research. We consider issues facing neuropsychological, neuroscientific, and cognitive experimental frameworks attempting to explore and experimentally generate the experience. In doing this, we suggest the need for more experimentation and a more cautious interpretation of research findings, particularly as many techniques being used to explore déjà vu are in the early stages of development.

Neuroimaging and cognitive changes during déjà vu

OBJECTIVE

The cause or the physiological role of déjà vu (DV) in healthy people is unknown. The pathophysiology of DV-type epileptic aura is also unresolved. Here we describe a 22-year-old woman treated with deep brain stimulation (DBS) of the left internal globus pallidus for hemidystonia. At certain stimulation settings, DBS elicited reproducible episodes of DV.

METHODS

Neuropsychological tests and single-photon-emission computed tomography (SPECT) were performed during DBS-evoked DV and during normal DBS stimulation without DV.

RESULTS

SPECT during DBS-evoked DV revealed hyperperfusion of the right (contralateral to the electrode) hippocampus and other limbic structures. Neuropsychological examinations performed during several evoked DV episodes revealed disturbances in nonverbal memory.

CONCLUSION

Our results confirm the role of mesiotemporal structures in the pathogenesis of DV. We hypothesize that individual neuroanatomy and disturbances in gamma oscillations or in the dopaminergic system played a role in DBS-elicited DV in our patient.

Déjà vu experiences in schizophrenia: relations with psychopathology and antipsychotic medication

To clarify why patients with schizophrenia show déjà vu experiences less frequently, we studied déjà vu experiences in 113 schizophrenic patients in relation to psychopathologies and antipsychotic medication. Déjà vu experiences were observed in 53.1% of the schizophrenic patients. Patients with increased negative symptoms (blunted affect, motor retardation, emotional withdrawal, conceptual disorganization, and mannerisms) had déjà vu experiences less frequently. The other psychopathologies were not significantly associated with presence of déjà vu experiences. The dosage of antipsychotic drugs was significantly correlated with the frequency of déjà vu experiences. This correlation was not affected by their psychopathologies at the time of examination. The decreased frequency of déjà vu experiences in patients with schizophrenia may be mainly due to the negative symptoms. The positive relation between frequency of déjà vu experiences and the dosage of neuroleptics remains uncertain.

Normal patterns of déjà experience in a healthy, blind male: Challenging optical pathway delay theory

We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of déjà vu. The optical pathway delay theory of déjà vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of déjà vu is known to be experienced by blind individuals, we believe this to be the first reported application of this knowledge to the understanding of the phenomenon. Visual input is not present in MT, yet the experiences he describes are consistent with reports in the literature of déjà vu occurrence in sighted people. The fact that blind people can experience déjà vu challenges the optical pathway delay theory, and alternative causes are briefly discussed.

Epileptic consciousness: concept and meaning of aura

This research is based on previous publications that have analyzed certain neuropsychological phenomena that always have the same characteristic clinical features: a vivid experience of sudden onset and automatic development, accompanied by an intense sensation of strangeness. When these automatisms are accompanied by only mental symptoms, the designation paroxysmal psychic automatisms (PPAs) is proposed, and they should be interpreted as partial seizures (PSs) with a psychic content whenever they clearly exhibit the four features of suddenness, passivity, intensity, and strangeness. This interpretation is based on the existence of a wealth of scientific literature indicating an overlap between PPAs and PSs; moreover, bibliographic reviews indicate that the clinical signs just defined as characterizing PPAs are precisely those defining the epileptic consciousness.

Determination of serum amantadine by liquid chromatography-tandem mass spectrometry

BACKGROUND

Amantadine (1-adamantylamine) is used for treatment of influenza, hepatitis C, parkinsonism, and multiple sclerosis. Current amantadine analysis by HPLC or gas chromatography (GC) requires a laborious sample pretreatment with extraction and/or derivatization steps. We established an LC-MS/MS method without protein precipitation, centrifugation, extraction and derivatization steps.

MATERIAL AND METHODS

50 microl sample+50 microl of 0.4 mg/l 1-(1-adamantyl)pyridinium bromide as internal standard+1000 microl water (96-well plate). Of this 25 microl+500 microl water (96-well plate; final serum dilution 1:462). LC-MS/MS: Surveyor MS pump, Autosampler, triple-quadrupole TSQ Quantum mass spectrometer (Thermo Electron). Autosampling: 2 microl of each sample. Chromatography: isocratic water/acetonitrile (60/40 v/v) with 5 g/l formic acid, flow rate 0.2 ml/min, run time 3 min, Phenomenex Luna C8(2) (100 x 2.0 mm (i.d.); 3-microm bead size) column. Mass spectrometry: electrospray atmospheric pressure ionization, positive ion and selective reaction monitoring mode, ion transitions m/z 152.0-->135.1 (at 22 eV amantadine) and 214.1-->135.1 (at 26 eV internal standard).

RESULTS

Calibration curves were constructed with spiked serum samples (amantadine 50-1000 microg/l, r>0.99). No carry over (5000 microg/l). No ion suppression with retention times similar to those of amantadine (1.8 min) and the internal standard (2.1 min). Detection limit 20 mg/l, linearity 20-5000 mg/l, intra-assay/inter-assay CV<6%/<8%, recovery 99-101%. Method comparison: LC-MS/MS=1.23 x GC-45 (Passing-Bablok regression). No significant bias between GC and LC-MS/MS (Bland-Altman plot).

CONCLUSION

We consider the sample pretreatment without deproteination, derivatization and centrifugation steps and the specificity of the tandem mass spectrometry as the most important points of our amantadine analysis method.

A review of the déjà vu experience

For more than a century, the déjà vu experience has been examined through retrospective surveys, prospective surveys, and case studies. About 60% of the population has experienced déjà vu, and its frequency decreases with age. Déjà vu appears to be associated with stress and fatigue, and it shows a positive relationship with socioeconomic level and education. Scientific explanations of déjà vu fall into 4 categories: dual processing (2 cognitive processes momentarily out of synchrony), neurological (seizure, disruption in neuronal transmission), memory (implicit familiarity of unrecognized stimuli),and attentional (unattended perception followed by attended perception). Systematic research is needed on the prevalence and etiology of this culturally familiar cognitive experience, and several laboratory models may help clarify this illusion of recognition.