SIR: Degenerative cerebellar diseases have been associated with mostly personality changes, affective symptoms, and cognitive dysfunction, with only anecdotal reports of psychosis.1 A patient of sporadic olivopontocerebellar atrophy (OPCA) who developed a paranoid-hallucinatory psychosis is described. The concept of cerebellar "cognitive affective syndrome" is discussed, and inclusion of psychotic features to expand this concept is highlighted.
N.K., a 17-year-old right-handed girl, consulted the Western Psychiatric Institute and Clinic in the Spring of 2001. She had experienced illness for 3 years, characterized by sadness, crying spells interspersed with unprovoked laughter, fearfulness, feelings of unworthiness, and auditory hallucinations. Her crying spells were mostly in response to her fear and auditory hallucinations. As a result, she remained sad and aloof, and her sleep and appetite worsened. Her neurological examination revealed scanning speech, with child like quality and lack of prosody; gait ataxia; nystagmus; broken saccades; impaired finger nose test; dysdiadochokinesia; and impaired tandem walk. Muscle power and sensation were normal, and she had no parkinsonian features. On mental status examination, she had a depressed affect with ideas of worthlessness, referential and persecutory delusions, and second-person auditory hallucinations of derogatory content.
Previously, in 1995, the patient had a febrile illness that lasted one month and was characterized by altered sensorium, followed by an ataxic gait and intention tremors. A cranial computed tomography (CT) scan revealed a left-sided cerebellar abscess, which was a result of chronic otitis media in the left ear present since early childhood. For the next year, the patient showed gradual improvement in cerebellar signs and symptoms, but these worsened from 1996 onward. A repeat cranial CT scan, conducted in 1998 (after the onset of psychiatric symptoms), revealed generalized atrophy of both cerebellar hemispheres, vermis, pons, and inferior olivary nuclei. After a neurological consultation, the patient was diagnosed with sporadic olivopontocerebellar atrophy, in view of no family history. Her illness then progressed, with exacerbation of neurological signs and symptoms, as corroborated by more extensive atrophy of the cerebellum and brain stem on brain magnetic resonance imaging (MRI) performed in 2001. None of the scans showed any involvement of the cerebral cortex. Her electroencephalogram (EEG) was normal, and neuropsychological testing revealed major impairments in constructional ability, linguistic ability, and working memory. The patient was treated with 10 mg/day of fluoxetine, 4 mg/day of risperidone, and 2 mg/day of trihexyphenidyl, with resolution of both the depressive and psychotic symptoms within one month of starting treatment.
This case highlights the atypical psychiatric presentation in a patient of olivopontocerebellar atrophy (OPCA), which has traditionally been associated with dementia.2 Hallucinatory states have rarely been described in adults with OPCA, with or without dementia, with no such reports in children.3—5 Two of these patients demonstrated depression accompanying the paranoid-hallucinatory symptoms, as was present in this patient.3,4
The cognitive impairment and the psychiatric presentation, taken together, fit well into the cerebellar "cognitive affective syndrome."6,7 This syndrome includes executive, visuospatial, and linguistic dysfunction, along with psychiatric symptoms such as impaired regulation of affect, including irritability, impulsivity, disinhibition, and lability of affect, with poor attentional and behavioral modulation, withdrawal, apathy, and inconsolable whining. It has been shown that children with extensive vermis lesion are more likely to exhibit changes in affect regulation, while executive function impairment is more prominent with damage to the cerebellar hemispheres.7 This concurs with the reported case of the patient who exhibited both executive dysfunction and affect dysregulation and had both vermal and hemispheric atrophy. In addition, the presence of psychotic symptoms in this patient and in previous reports emphasizes the need to expand the concept of "cognitive affective syndrome" to "cognitive affective psychosis" syndrome. This concept is also favored by the increasingly recognized role of cerebellum in schizophrenia.8