Cerebellar cognitive affective syndrome after bilateral caudal paramedian midbrain infarction

Excerpt

A 71-year-old man complained of sudden-onset vertigo, unsteady gait and slurred speech with gradual worsening in one day. Upon admission to the hospital, neurological examination revealed dysarthria, vertical nystagmus, adduction impairments of both eyes and bilateral cerebellar ataxia. Cerebellar functions were semi-quantified by International Cooperative Ataxia Rating Scale (ICARS) and Brief Ataxia Rating Scale (BARS) with scores of 56/100 and 26/30 separately. Besides, somnolence, obvious memory loss and attention impairments were also noted through clinical examination. On the first night of admission, the patient developed more neuropsychic symptoms, including disorientation, emotional instability, and impulsive behavior. In the next few days, the patient’s mental state fluctuated daily, with new manifestations such as depression and persecutory delusion. His deficits in cerebellar function, cognition and affect reminded us the possibility of cerebellar cognitive affective syndrome (CCAS). This patient with an educational level of 15 years scored 61/120 in CCAS scale [1], and failed in six items including phonemic fluency, category switching, cube draw and copy, verbal recall, similarities and affect, supporting a diagnosis of definite CCAS. The cranial magnetic resonance imaging, performed 2 days after onset of the neurological symptoms, showed an acute infarction in bilateral paramedian region of caudal midbrain without any supratentorial lesion (Fig. 1a and b). To clarify the cause of his mental disorder, ¹⁸F-fluorodeoxyglucose (FDG) PET was conducted and significant bilateral cerebellar hypermetabolism and frontal hypometabolism were disclosed (Fig. 1c and d). During hospitalization, antipsychotic medications (sertraline and quetiapine) provided some symptomatic relief for emotional instability and delusion. Two weeks later, the patient was discharged from the hospital to the rehabilitation center for further rehabilitation therapy.

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