Reversible palinacousis from intracranial metastases

Palinacousis in amyloidosis: exploring the hallucinatory phenomenon in brain pathology-a case report

BACKGROUND

Hereditary transthyretin amyloidosis, caused by transthyretin gene mutations, progresses with systemic impact and often presents peripheral neuropathy. Recent research reveals central nervous system involvement, marked by leptomeningeal amyloid accumulation and transient focal neurological episodes displaying cortical dysfunction.

CASE PRESENTATION

A 47-year-old Caucasian man with hereditary transthyretin amyloidosis presented with motor aphasia, right hemiparesis, fever, and an altered state of consciousness. Tests ruled out stroke or infection. While improving, the patient reported an ongoing auditory repetition phenomenon for 48 hours despite efforts to shift focus or introduce new stimuli.

CONCLUSION

This represents the first known case report documenting palinacousis in hereditary transthyretin amyloidosis attributed to central nervous system involvement. This case highlights the complexities in assessment and management of patients when neurological and psychiatric symptoms overlap.

[Auditory phenomena as differential diagnostics to tinnitus]

INTRODUCTION

In the auditory system, subjective tinnitus is known as phantom perception. Humans also report illusionary misperceptions of real listening impressions and complex scene-like acoustic fantasies without external hearing stimulus. The exact pathophysiological relationships of the auditory phenomena are still unclear. Important comorbidities include hearing loss, brain disease and mental disorders.

METHODS

In a literature search in the PubMed database, publications were evaluated until March 2021 on the search terms tinnitus, palinacousis, pareidolia, synesthesia, aura, acoustic hallucination with regard to similarities and differences to subjective tinnitus.

RESULTS

Subjective tinnitus can occur together with other auditory phenomena in an individual. Diagnostically important is the relationship between hearing loss and tinnitus as well as between tinnitus and hearing loss in the corresponding frequency range. With hearing loss, other auditory phenomena may occur.

CONCLUSION

The occurrence of various auditory phenomena simultaneously in a person suggests an auditory perceptual continuum with common physiological processing structures. People with hearing loss should be asked about the various auditory phenomena. For all auditory phenomena, audiometric examination should be part of the diagnostic standard.

Palinacousis: an eloquent symptom of temporal lobe lesion

A 24-year-old woman was referred to us for an intracranial haemorrhage in the left temporal lobe caused by a ruptured cavernous malformation; the bleeding extended over the left Heschl's gyrus and Wernicke area. On admission, the patient had global aphasia. A few days later, she spontaneously improved but remained with mild residual comprehensive dysphasia. She reported hearing, in her right ear, recently heard words, which is consistent with palinacousis. Auditory acuity testing was normal. EEG showed focal slowing in the left temporal region with no epileptiform activity. During awake surgery for resection of the cavernous malformation, stimulation of the superior temporal gyrus did not provoke palinacousis. The patient made good recovery with complete resolution of the aphasia and no recurrence of palinacousis. We aimed to review this phenomenon and to provide a systematic review of the current literature.

Palinacousis-Auditory Perseveration

Palinacousis is an auditory illusion rarely reported in cases of temporal lobe dysfunction. After reviewing the literature and comparing our clinical experience, we believe that palinacousis can occur as an aura, a simple partial seizure, a complex partial seizure, and/or a postictal event. Palinacousis maybe more common than recognized in patients with receptive aphasias or diffuse cerebral dysfunction, whose language deficits preclude adequate description. We report the case of a 71 years old man with the previously diagnosis of an infarction of left middle cerebral artery and valvular heart disease who presented with the symptoms of palinacousis. He was not diagnosed psychotic diseases. An electroencephalography showed normal wave. He was diagnosed as temporal lobe epilepsy with palinacousis due to post-stroke. Palinacousis was completely reversed after treatment with antiepileptic drug. We report that palinacousis as an epileptic phenomenon can help localized potential lesions and can improve patient care.