Descriptive Psychopathology: The Signs and Symptoms of ...

258 Section 3: Examination domainsExtracampine hallucinationsAn extracampine hallucination is a false perception outside the limits of thenormal sensory field (e.g. hearing plotters in another country). Extracampinehallucinations are associated with manic-depressive illness, seizure disorder, illicitdrug use, and delirium. 18Elementary hallucinationsElementary hallucinations are unformed. Flashes of light, undefined shapes andpatterns, and non-specific sounds such as buzzing, whirring, and clanking areexamples. These phenomena are associated with toxic states and migraine. Migrainescotomata include false perceptions of moving lights, zigzag lines, stars, shimmeringlights like the sun’s reflection off a body of water, and a gray or dark fog. Hallucinationsof well-defined geometric shapes are associated with cocaine intoxication. 19Functional hallucinationsA functional hallucination is elicited by an environmental stimulus in the samesensory modality. A particular pitch (e.g. the whine of a rusty faucet turned on)can trigger a hallucinated voice. A wallpaper pattern can change into the headsof demons or other false visual perceptions. Both the triggering stimulus andthe hallucination are perceived. Functional hallucinations are associated withdelirium and toxic states, seizure disorder, and focal brain vascular disease. 20A reflex hallucination is a form of synesthesia, the stimulus triggering the hallucinationin another sensory modality. For example, a patient hears footsteps andthen hallucinates lurking figures in the corner of the room.Palinacousis (auditory perseveration) and palinopsia (visual perseveration) arerare forms of functional hallucinations. Palinacousis is the hearing of words,sounds, and fragments of sentences continuously for minutes to hours after thestimulus is removed. 21 Palinopsia is seeing images continuously for minutes tohours after the visual stimulus is removed. The phenomena are associated withtemporal and occipital lobe dysfunction. Palinopsia is associated with LSD use. 22It is also reported in patients taking paroxetine, mirtazepine, and nefazodone,and this rare side-effect must be differentiated from endogenous psychosis. 23Experiential hallucinationsExperiential hallucinations were first described by the neurosurgeon WilderPenfield, who elicited them by stimulating various parts of the exposed cerebralcortex, particularly the temporal lobe, of his patients prior to neurosurgery.Penfield likened them to vivid memories. 24 Experiencing a telephone conversationwith a friend, a frightening situation, or a snippet of a family gathering areexamples.