Melatonin-Responsive Complex Nocturnal Visual Hallucinations

Sleep-Related Hallucinations

The diagnostic category of sleep-related hallucinations (SRH) replaces the previous category of Terrifying Hypnagogic Hallucinations in the 2001 edition of International Classification of Sleep Disorders-R. Hypnagogic and hypnopompic hallucinations (HHH) that occur in the absence of other symptoms or disorder and, within the limits of normal sleep, are most likely non-pathological. By contrast, complex nocturnal visual hallucinations (CNVH) may reflect a dimension of psychopathology reflecting different combinations of etiologic influences. The identification and conceptualization of CNVH is relatively new, and more research is needed to clarify whether CNVH share common mechanisms with HHH.

Nocturnal visual hallucinations in patients with disorders of arousal: a novel behavioral and EEG pattern

AIM

To investigate clinical and video-polysomnography (VPSG) findings of hallucinatory experiences in patients suffering from disorders of arousal (DOA) in the absence of other pathologies.

METHODS

The authors retrospectively reviewed the records of 370 adults with DOA. Thirty (8.1%) patients concomitantly reported complex nocturnal visual hallucinations. VPSG recordings were scrutinized, and motor behavioral and electroencephalogram (EEG) patterns were classified according to previous descriptions of DOA.

RESULTS

Thirty DOA patients reported seeing images of objects, people, and animals; either distorted, static, or mobile. The images disappeared with increased illumination in 80% of patients, and 23.3% reported preceding dream imagery. In addition to the classical DOA patterns on VPSG, a distinct pattern of behavioral and EEG manifestation associated with complex hallucinatory episodes was identified in 16 (53.3%) DOA patients. This consisted of low-voltage mixed-frequency EEG activity before eye opening that persisted while patients were observed staring or visually tracking before the onset of motor behavior.

CONCLUSION

A novel, distinct behavioral and EEG pattern in patients with DOA and history of reported complex nocturnal visual hallucinations was identified. This may represent a unique phenotype of dissociation between sleep states that merits further investigation.

The man behind the bed: a case of peduncular hallucinosis treated with quetiapine and melatonin

An 81-year-old female presented with a right pontine infarct and later developed recurrent vivid hallucinations. After a workup for delirium and hallucinosis was unrevealing, a diagnosis of peduncular hallucinosis (PH) was proposed. Treatment with quetiapine and, later, adjunctive nightly melatonin resulted in return to cognitive baseline. An array of etiologies can be responsible for visual hallucinations, including PH. Herein, we review several disorders of hallucinosis and their diagnostic workup. Additionally, we explore the pathophysiology of PH and its association with the pontine-geniculate-occipital (PGO) pathway and propose why correction of the sleep-wake cycle may benefit patients with PH.

Parasomnias Occurring in Non-Rapid Eye Movement Sleep

PURPOSE OF REVIEW

This article discusses the clinical manifestations, diagnosis and differential diagnosis, pathophysiology, and management of parasomnias occurring in non-rapid eye movement (REM) sleep.

RECENT FINDINGS

Disorders of arousal are characterized by dissociated sleep, with wake and sleep phenomena intermingling, and local sleep, in which different areas of the brain exist simultaneously in different states of wakefulness or sleep. The frequency of arousals from slow-wave sleep with delta or mixed-frequency activity has a high sensitivity but relatively low specificity for the diagnosis of arousal parasomnias.

SUMMARY

Disorders of arousal (sleepwalking, sleep terrors, and confusional arousals) are characterized by incomplete awakenings from slow-wave sleep, limited recall of imagery, and partial or complete amnesia. They occur most frequently in childhood. Management includes correction of precipitating factors, attention to safety, behavioral techniques, and medications. Sleep-related eating disorder is a variant of arousal disorders and may be associated with the use of short-acting hypnotics and restless legs syndrome. Complex nocturnal visual hallucinations can occur with visual loss, dementia with Lewy bodies, use of β-adrenergic receptor antagonists, and anxiety. Exploding head syndrome occurs at wake-sleep transition or on waking during the night, is usually benign, and requires treatment only if significant sleep disruption occurs.