The Zeitraffer phenomenon, akinetopsia, and the visual perception of speed of motion: a case report.

The Zeitraffer phenomenon is the altered perception of the speed of moving objects. A single case is reported using the subject's own description of a transient alteration of the visual perception of motion. The literature on the subject is reviewed. The Zeitraffer phenomenon probably arises from dysfunction of brain networks subserving visual perception of speed. It shares characteristics with akinetopsia, the loss of visual ability to perceive motion.

The relationship between schizophrenia and frontotemporal dementia.

Schizophrenia is a relatively common disorder diagnosed by the presentation of psychotic symptoms in the absence of identifiable neurologic or other organic cause. Frontotemporal dementia (FTD) is a relatively rare progressive neurodegenerative disorder that can present with a multitude of cognitive and behavioral symptoms including psychosis. At times, this phenotypic overlap can mean that schizophrenia and FTD are 2 possibilities in the differential diagnosis of a psychotic presentation. In this article, we systematically review the literature on the relationship between schizophrenia and FTD including case reports that highlight the potential for diagnostic confusion, clinical studies examining the relationship between the disorders, and the molecular evidence of shared pathophysiologic mechanisms. Although a relationship between the disorders is not definitively supported by the current literature, we identify the characteristics of a psychotic presentation that should alert the clinician to the possibility of FTD and describe the areas where further research is needed to clarify the pathophysiologic relationship.

Psychiatric aspects of epilepsy.

Patients who have epilepsy face many challenges resulting from their illness and have frequent psychiatric comorbidities. Recognition of these disorders is increasing and is having a positive impact on patients' quality of life. Recent recommendations about a new classification system for psychiatric disorders related specifically to epilepsy and based on the relationship of symptoms to seizures, antiepileptic medications, and EEG changes should further research and treatment. Especially insofar psychiatric syndromes specific to epilepsy can be identified, correlation of clinical phenomena with relatively well-understood pathophysiology in epilepsy will allow advances in the understanding of psychiatric illness. This progress should move the treatment of patients who have epilepsy toward a comprehensive biopsychosocial model that focuses on the whole person rather than simply on the disease process.

Seeking reversibility and treatability in dementia.

The search for "reversible causes" in the patient presenting with dementia has become a routine part of medical care. This article reviews evidence as to the prevalence of reversibility and concludes that actual reversal of dementia by treatment is rare. In this context, the utility of specific laboratory investigations is discussed, and commonly sought conditions, such as normal-pressure hydrocephalus and B12 deficiency, are reviewed. Overemphasis on reversibility risks neglect of the assistance physicians can provide to patients suffering from irreversible conditions and their families.

The three cognitive examinations.

Cognitive dysfunction is a core feature of neuropsychiatric illness. We offer a framework or conceptualizing cognitive function and discuss bedside examination and neuropsychological assessment, as well as the limitations of these tools. We stress the clinical importance of executive cognitive dysfunction, and we provide guidance or its assessment.