Mental Illness 2018; volume 10:7586

Peduncular hallucinosis associ- ized, a medical work-up was performed due ated with a pontine cavernoma to the patient’s recent weight loss. A CT Correspondence: Robert G. Bota, University brain identified a pontine cavernoma of California Irvine, 101 City Drive, Orange, prompting the patient to be transferred to CA, USA. Michael Couse, Todd Wojtanowicz, UC Irvine (UCI) for a neurosurgical evalu- Tel.: +1.229.815.0219. Sean Comeau, Robert Bota ation nine days after her suicide attempt. E-mail: [email protected] University of California Irvine, CA, USA At UCI, the patient experienced both Key words: Peduncular hallucinosis, pontine auditory (AH) and visual cavernoma. (VH); most commonly the hallucinations presented as members of her family. She Contributions: the authors contributed equally. Abstract was observed numerous times to be con- Peduncluar hallucinosis is a rare neuro- versing with imaginary family members Conflict of interest: the authors declare no logical disorder characterized by visual hal- and informed staff that she saw these family potential conflict of interest. lucinations, often described to be vivid and members in her room on several occasions. dream-like. While the exact pathophysiolo- Additionally, the VH and AH were not Funding: none. gy has yet to be elucidated, most cases to always experienced together. For example, date have suggested an etiology stemming she experienced AH of a family member’s Received for publication: 18 January 2018. from lesions to the thalamus or . voice emanating from another room result- Accepted for publication: 18 January 2018. Here presented is a case of a 54-year-old ing in confusion, disorientation and eliciting This work is licensed under a Creative female with peduncular hallucinosis sec- a strong emotional response. She was also Commons Attribution-NonCommercial 4.0 ondary to a pontine cavernoma hemorrhage seen to be interacting with her VH; for International License (CC BY-NC 4.0). in the setting of essential hypertension. The example, she was seen knitting with imagi- patient’s vivid visual and auditory halluci- nary needles and petting an imaginary dog. ©Copyright M. Couse et al., 2018 nations aligned temporally with the lesion’s The patient’s hallucinations occurred once Licensee PAGEPress, Italy discovery and resolved after pharmaceutical or twice daily and occurred mostly at night. Mental Illness 2018; 10:7586 treatment. This case represents a rare form In between these episodes, the patient was doi:10.4081/mi.2018.7586 of peduncular hallucinosis secondary to a appropriately oriented, demonstrated a lin- pontine cavernoma hemorrhage leading to ear, organized thought process and had no vasospasm in the arteries feeding the brain- abnormal thought content. The patient was stem. able to describe many of her hallucinations Discussion in detail, often depicting them as being sur- The patient described above reported real and dream-like. During this time the new onset hallucinations that became patient also complained of , diffi- noticeable to the medical staff shortly after Introduction culty with ocular movements and vertigo. she was stabilized following a suicide On ophthalmic exam, an impairment Peduncular hallucinosis (PH) is a rare attempt. In keeping with the current litera- was noted with her ocular motility. Using a characterized by vivid ture, her hallucinations were vivid, complex 9 point ocular motility scale ranging from - visual hallucinations (VH) which are often and centered on persons familiar to her; 4 to 4, she demonstrated a -2 restriction in 2 associated with disturbances of sleep and specifically members of her family. Other all directions in her right eye and -1 restric- oculomotor function.1,2 PH is associated characteristics of her hallucinations were in tion in all directions except -2 restriction of with a range of different pathologies of the accordance with previously published cases abduction in her left eye. No other abnor- 6 central nervous system including: vascular of PH, including: VH combined with AH, malities were noted on her ophthalmic, and infectious lesions of the midbrain, pons active interaction by the patient with her physical and neurological exam. 1,7 and thalamus; local subarachnoid hemor- hallucinations, and the hallucinations pre- Work up conducted at UCI included a 2,4,8 rhage; compression by local and distal dominately occurring at night. When not complete metabolic panel, complete blood tumors; basilar ; basilar vascular actively hallucinating, the patient demon- count, urine toxicology screen, thyroid hypoplasia and following regional surgical strated insight into the nature of her halluci- stimulating hormone level and a urine or angiographic interventions.3 Due its rari- nations, which correlates with some but not analysis, all of which were within normal 2,8,9 ty and the array of conditions associated all reports of PH. Benke et al. proposed limits. An MRI brain revealed a 1.2 cm with its development, diagnosing PH pres- that the discrepancy in insight is due to the region of hemorrhage within the posterior differences in the manner by which patients ents a rare and unique challenge to the clini- pons. Neurosurgery determined that the best are interrogated about the episodes as well cian. Here, we hope to add to the conditions course was to monitor the hemorrhagic as the time lag between the associated with PH by presenting an excep- lesion in lieu of evacuation. A diagnosis of and the evaluation by clinical staff. This tional case of PH resulting from a pontine peduncular hallucinosis was made and, in may explain why our patient demonstrated hemangioma hemorrhage. accordance with previous case reports, the insight only once her hallucinations had patient was started on 5 mg at subsided. In addition to hallucinations, PH bedtime.3-5 The patient was also started on often presents with ocular motor and sleep 20 mg fluoxetine daily for her depression, a disturbances;2,10 both of which our patient Case Report scopolamine patch for her vertigo and con- experienced while hospitalized. In a case A 54-year-old female with a past med- tinued on her home hydrochlorothiazide series of five PH patients, Benke et al. ical history of depression, anxiety, hypothy- and levothyroxine. Thereafter the VH reported that all five patients struggled with roidism and hypertension presented to an resolved within the next 24 hours and the recalling information provided to them in a outside hospital after attempting suicide by patient was eventually discharged home in mental status exam. This finding was noted cutting both of her wrists. While hospital- stable condition. in our case as the patient scored a 24 on her

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MOCA losing the majority of points in the in the interpeduncular cistern could also 6. Kulhari A, Manjila S, Singh G, et al. section requiring her to recall words pre- give rise to VH.5,13,14 In the case described Auditory hallucinosis as a presenting sented to her a few minutes earlier. by Harada, the authors argued that the two feature of interpeduncular lipoma with PH has been associated with a range of to three day delay in the onset of hallucina- proximal p1 segment fenestration: differing CNS pathologies;2,3,5,11,12 howev- tions was due to vasospasm rather than report of a rare case and review of liter- er, regardless of the etiology, lesions of direct damage to the . ature on peduncular hallucinosis. J Vasc midbrain and/or pontine structures appear Interv Neurol 2016;91:7-11. to be crucial for the characteristic cognitive 7. Dunn DW, Weisberg LA, Nadell J. defects. The mechanism for PH implicates Peduncular hallucinations caused by the brainstem , its thala- Conclusions brainstem compression. mic targets and the projections connecting In the case here presented it is difficult 1983;33:1360-1. the two. Briefly, excitatory, cholinergic pro- to know if subtler symptoms began prior to 8. Talih FR. A probable case of peduncular jections arise from the pontine tegmentum the pontine cavernoma hemorrhage was dis- hallucinosis secondary to a cerebral and inhibitory, serotonergic projections covered; however, what is clear is that there peduncular lesion successfully treated arise from the dorsal raphe nuclei. was a multiple day delay between the dis- with an atypical . Innov Projections from both of these centers influ- covery of the hemorrhage and presentation Clin Neurosci 2013;10:28-31. ence the dorsal lateral geniculate nucleus of hallucinations. Taken together, the pro- 9. Manford M, Andermann F. Complex (LGN) of the thalamus. Brainstem lesions posed pathophysiology of our case began visual hallucinations. Clinical and neu- may disrupt the serotonergic, inhibitory with hemorrhage from her pontine heman- robiological insights. Brain raphe nucleus inputs resulting in excitation gioma leading to vasospasm of the arteries 1998;121:1819-40. of the dorsal LGN and dysregulation of feeding the brainstem resulting in disrup- 10. Notas K, Tegos T, Orologas A. A case of LGN projections to visual cortical regions tion of the dorsal raphe nucleus and its peduncular hallucinosis due to a pontine leading to complex VHs. Similarly, lesions inputs onto the dorsal LGN ending in visual infarction: a rare complication of coro- involving thalamic nuclei may disrupt the hallucinations and PH. nary angiography. Hippokratia important processing function of these 2015;19:268-9. structures, resulting in impaired retinal sig- 11. Geddes MR, Tie Y, Gabrieli JDE, et al. nals and visual hallucinations. In addition to Altered functional connectivity in its involvement in inhibiting the LGN, the References dorsal raphe nuclei have been implicated in 1. Kölmel HW. Peduncular hallucinations. lesional peduncular hallucinosis with both the sleep-wake cycle and regulation of J Neurol 1991;238:457-9. REM sleep behavior disorder. Cortex REM and non-REM sleep.10 Due to this 2. Benke T. Peduncular hallucinosis: a 2016;74:96-106. relation it has been proposed that the visual syndrome of impaired reality monitor- 12. Dogan VB, Dirican A, Koksal A, experiences in PH are theoretically similar ing. J Neurol 2006;253:1561-71. Baybas S. A case of peduncular halluci- to those of REM sleep. 3. Mocellin R, Walterfang M, Velakoulis nosis presenting as a primary psychi- Pontine cavernomas are a collection of D. Neuropsychiatry of complex visual atric disorder. Ann Indian Acad Neurol malformed blood vessels and because of hallucinations. Aust N Z J 2013;16:684-6. their fragility, hemorrhage is a common 2006;40:742-51. 13. Yano K, Kuroda T, Tanabe Y, Yamada complication. Three previous reports have 4. Pascal de Raykeer R, Hoertel N, H. Delayed cerebral ischemia manifest- been published in which subarachnoid hem- Manetti A, et al. A case of chronic ing as peduncular hallucinosis after orrhage resulted in PH.5,13,14 In these cases, peduncular hallucinosis in a 90-year-old aneurysmal subarachnoid hemorrhage-- the proposed mechanism of PH onset woman successfully treated with olan- three case reports. Neurol Med Chir begins with free blood irritating blood ves- zapine. J Clin Psychopharmacol (Tokyo) 1994;34:593-6. sels leading to vasospasm resulting in 2016;36:285-6. 14. Harada Y, Ishimitsu H, Miyata I, et al. reduced cerebral perfusion in the midbrain. 5. O’Neill SB, Pentland B, Sellar R. Peduncular hallucinosis associated with The authors also proposed a less likely Peduncular hallucinations following ruptured basilar-superior cerebellar alternative, in which a more localized effect subarachnoid haemorrhage. Br J artery aneurysm--case report. Neurol of pressure on the midbrain due to tension Neurosurg 2005;19:359-60. Med Chir (Tokyo) 1991;31:526-8.

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