Peduncular hallucinosis associated with pontine hemorrhage in an adult patient

Peduncular hallucinosis refers to a rare neurophychiatric disorder presenting with vivid visual hallucinations, disturbances of sleep, and oculomotor dysfunction. It is typically caused by mesencephalic lesions. Nonetheless, a few cases have also been reported, in which the same syndrome was associated with thalamic and pontine lesions. We report the case of a 63-year-old male patient presenting to the Emergency Department of our hospital with irritability, gait difficulty, and diplopia of sudden onset two hours ago. Neurological examination revealed dysarthria, right facial palsy, bilateral gaze palsy, dysmetria of his left extremities, left-sided hemihypaethesia and extensory plantar response on the left. Brain computerized tomography (CT) showed a hemorrhagic lesion on the right lateral side of the pons. During his hospitalization at the Department of Neurology, he developed visual hallucinations, confusion, disorientation, insomnia, and strong emotional response. An extensive laboratory screening was performed and showed no abnormal findings. Suspecting peduncular hallucinosis due to the brainstem lesion, treatment with quetiapine and melatonin was administered to the patient and symptoms resolved completely within days. Subsequently, gradual neurological clinical improvement was also noted and two weeks after his admission, a repeated brain CT and a brain magnetic resonance imaging (MRI) showed partial absorption of the brainstem hemorrhage. The patient underwent rehabilitation for two months, showing further clinical improvement, and treatment with quetiapine and melatonin was discontinued without any further episodes being noted. A repeated brain MRI was performed two months after his admission to our hospital and showed no hemorrhage, but a mixed signal intensity core and a hypointense hemosiderin rim at the location of the absorbed hemorrhagic lesion, compatible with pontine carvenoma. Peduncular hallucinosis is most commonly associated with ischemic lesions of the posterior brain blood circulation, but different lesions have been reported, like vasospasm, brain tumors, encephalitis, hemorrhage associated with vascular malformations, such as a carvenoma, as seen in our case, representing a very rare form of peduncular hallucinosis.

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.

Illusions, hallucinations, and visual snow

Illusions and hallucinations are commonly encountered in both daily life and clinical practice. In this chapter, we review definitions and possible underlying mechanisms of these phenomena and then review what is known about specific conditions that are associated with them, including ophthalmic causes, migraine, epilepsy, Parkinson's disease, and schizophrenia. We then discuss specific syndromes including the Charles Bonnet syndrome, visual snow syndrome, Alice in Wonderland syndrome, and peduncular hallucinosis. The scientific study of illusions and hallucinations has contributed significantly to our understanding of how eye and brain process vision and contribute to perception. Important concepts are the distinction between topologic and hodologic mechanisms underlying hallucinations and the involvement of attentional networks. This chapter examines the various ways in which pathological illusions and hallucinations might arise in relation to the phenomenology and known pathology of the various conditions associated with them.

Peduncular hallucinosis after debulking of a third ventricular pilocytic astrocytoma: Case report and review of the literature

Peduncular hallucinosis is a rare clinical syndrome manifesting as complex visual hallucinations and sleep-wake dysregulation after injury to deep neural structures, most commonly the midbrain and diencephalon. Initially reported after ischaemic and haemorrhagic stroke, an increasing range of pathologies and procedures have been described as causative of peduncular hallucinosis. We present a novel case of peduncular hallucinosis following debulking of a third ventricular pilocytic astrocytoma as well as a review of the existing literature.

Peduncular hallucinosis according to Jean Lhermitte

Peduncular hallucinosis (PH) is a rare clinical syndrome with dream-like visual hallucinations intruding normal consciousness. It was initially reported in a 72-year-old woman by Jean Lhermitte in 1992. We uncovered the medical file of this patient with handwritten notes by Lhermitte and commented on it in the light of neurological knowledge that was common at that time. All along his career, Lhermitte has always been fascinated by consciousness disturbances, dreams and hallucinations. He had here the brilliant intuition of linking PH to awareness mechanisms located in the mesencephalic area. This PH case represented a good opportunity to him to emphasize the close relationships between neurology and psychiatry.

Peduncular hallucinosis associated with a pontine cavernoma

Peduncluar hallucinosis is a rare neurological disorder characterized by visual hallucinations, often described to be vivid and dream-like. While the exact pathophysiology has yet to be elucidated, most cases to date have suggested an etiology stemming from lesions to the thalamus or midbrain. Here presented is a case of a 54-year-old female with peduncular hallucinosis secondary to a pontine cavernoma hemorrhage in the setting of essential hypertension. The patient’s vivid visual and auditory hallucinations aligned temporally with the lesion’s discovery and resolved after pharmaceutical treatment. This case represents a rare form of peduncular hallucinosis secondary to a pontine cavernoma hemorrhage leading to vasospasm in the arteries feeding the brain-stem.

Complications after obliteration of the superior petrosal vein: Are they rare or just underreported?

Dandy first described the course of the superior petrosal vein (SPV) and its importance during surgery in 1929. Although it has been reported that this vein can be sacrificed without complication, unfavourable outcomes may occur after dividing the SPV. We review these consequences, which may include peduncular hallucinosis and hearing loss, or even hemorrhage, and discuss factors that may contribute to complications. Preservation of the SPV should be attempted whenever possible to increase the safety of surgery.