Palinacusis, or "auditory perseveration", is a rare condition in which sounds repeat even after they are inaudible. It is related to another rare neurological condition - -palinopsia, in which visual images repeat or cause trails. It is a type of auditory hallucination.
All reported causes of palinacusis have involved brain -- temporal lobe -- dysfunction. The temporal lobe of the brain contains auditory cortex -- brain tissue that processes sound.
There have only been 3 published papers (as of 2007) concerning palinacusis.
Patterson et al (1988) reported a a 50-year-old woman presented with nausea, vomiting, and global dysphasia, followed by two generalized seizures. Examination was otherwise normal, and computed tomography showed a small area of enhancement near the left sylvian fissure; there was a left temporal focus on the electroencephalogram. Treatment with phenytoin was instituted, and speech improved, with residual fluent dysphasia. Three days postictally, the patient complained of "echoing voices" in her right ear. Words or fragments of sentences recently uttered by the patient or others were perceived to recur unaltered for minutes to hours. Sounds other than speech were also affected. One week later the voices had disappeared, but a ticking sound was present; this also faded subsequently. The palinacousis never recurred; the patient was later found to have a Grade IV astrocytoma of the left temporal lobe, which caused her demise 8 months later.
Auzou et al (1995) reported another case in a 78-year-old patient with a left temporo parietal astrocytoma. The patient complained of "echoing voice" in his right ear. Palinacousis was associated with sensitive partial seizures. Neuropsychological investigations revealed hemianacusia with normal performance for phonological discrimination and verbal repetition. They suggested that these preserved abilities allowed emergence of palinacousis.
The author has encountered several patients with palinacusis in the course of his practice at Chicago Dizziness and Hearing. One especially instructive case involved a woman who had a contusion to her inferior colliculus area, as a result of a major head trauma. She was initially deaf, then as hearing returned began to experience auditory hallucinations that changed according to what she heard.
More papers have been written about auditory hallucinations than palinacusis.
Auditory hallucinations are common in psychiatric disorders including both schizophrenia and affective disorders (McAbee and Feldman-Winter 1999, Shinn, Pfaff et al. 2012, Shinn, Heckers et al. 2013). They also are reported in migraine (Rubin, McAbee et al. 2002) and epilepsy (Hauf, Wiest et al. 2013, Serino, Heydrich et al. 2014).
Similar to the Charles Bonnet syndrome where visual hallucinations occur after blindness, auditory hallucinations may occur in individuals with hearing loss (C, Marchie et al. 2004, Spiegel, Jafri et al. 2012; Goycoolea et al, 2006; Tanriverdi et al, 2001)
Common features to many of these reports are temporal lobe damage and hearing loss.
Palinacusis is a rare central auditory symptom. Most reported cases have been associated with temporal lobe lesions. It seems likely to us that this symptom is due to a loss of normal inhibition of auditory cortex, or due to irritibility of auditory cortex. Reduced hearing probably contributes by providing impetus to the brain to increase its sensitivity, as the pattern of reduced hearing and a brain abnormality is a common one.
Brain imaging and and EEG may be productive investigations.