ICTAL HALLUCINATION

The term ictal hallucination is indebted to the Latin nounictus, which means blow or thrust. In neurology the term ictus is used to denote a paroxysmal epileptic seizure. The term ictal hallucination refers to a hallucination occurring in the context of an *aura or a partial epileptic seizure, but it also applies to hallucinations evoked by means of cortical probing. Phe-nomenologically, ictal hallucinations tend to be complex or * compound in nature. As the American neurologist Maitland Baldwin (1918-1970) maintains, "Each ictal hallucination is cinemas-copic. It may unreel as a very detailed scene or present as a simple part of the more complex whole." The British neurologists John Hughlings Jackson (1835-1911) and Charles Beevor (18541908) are commonly credited with opening up the study of ictal hallucinations through their 1889 case report of a woman experiencing * visual and olfactory hallucinations.In the authors' description: "The patient was a cook. In paroxysm the first thing was tremor of the hands and arms; she saw a little black woman who was always actively engaged in cooking; the spectre did not speak. The patient had a very horrible smell (so-called subjective sensation of smell which she could not describe)... She never believed that the spectre was a real person! The patient proved to have a tumour of the right temporo-sphenoidal lobe." Tumours such as the one described by Jackson and Beevor, as well as other neoplastic lesions, are thought to mediate ictal hallucinations by causing epileptogenic processes in the affected lobe. Ictal hallucinations are often accompanied by *metamorphopsias (i.e. distortions of visual perception), and/or *illusions of sound and colour (i.e. 'unnaturally bright' or 'sharp' sense perceptions). Pathophysiologically, ictal hallucinations are traditionally associated with partial epileptic seizures affecting the temporal lobe. However, the parietal and occipital lobe may also be involved in their mediation. Moreover, ictal hallucinations presenting in the form of * reperceptions have been linked to aberrant activity in the lim-bic system. The term ictal hallucination is used in opposition to the term *non-ictal hallucination, and - from a different vantage point - * ictal illusion.

Baldwin, M. (1962).Hallucinations in neurologic syndromes.In: Hallucinations'.Edited by West, L.J. New York, NY: Grime & Stratton.

Jackson, J.H., Beevor, C.E. (1889). On a case of epileptic attacks with an olfactory aura from a tumour in the right temporosphenoidal lobe.Lancet, 1, 381.

Mauguière, F. (1999). Scope and presumed mechanisms of hallucinations in partial epileptic seizures.Epileptic Disorders, 1, 81-91.

Sowa, M.V., Pituck, S. (1989). Prolonged spontaneous complex visual hallucinations and illusions as ictal phenomena.Epilepsia, 30, 524-526.