Neurocognitive features distinguishing primary central nervous system lymphoma from other possible causes of rapidly progressive dementia

Objective: Define the neurocognitive features of primary central nervous system lymphoma (PCNSL) presenting with dementia, and compare with other causes of rapidly progressive dementia (RPD). Background: PCNSL can present as an RPD. Differentiating PCNSL from other RPDs is critical because lymphomatous dementia may be reversible, and untreated PCNSL is fatal. Methods: We performed a meta-analysis of case reports of dementia from PCNSL (between 1950 and 2013); 20 patients (14 with lymphomatosis cerebri) met our criteria. We compared these patients to a case series of patients with RPD from Creutzfeldt-Jakob disease and other non-PCNSL etiologies (Sala et al, 2012. Alzheimer Dis Assoc Disord. 26:267-271). Results: Median age was 66 years (range 41 to 81); 70% were men. Time from symptom onset to evaluation was <6 months in 65%. No patients had seizures; 5% had headaches; 45% had non-aphasic speech difficulty. There was significantly more memory impairment in patients with PCNSL than other RPDs and significantly less myoclonus and parkinsonism. Behavioral changes and cerebellar signs were not significantly different. Significantly more patients with PCNSL than other RPDs had white matter changes; significantly fewer had atrophy. Elevated CSF protein and pleocytosis were more frequent in PCNSL; patients with other RPDs tended to have normal CSF±14-3-3 protein. Conclusions: Unlike patients with RPD from other causes, those with PCNSL commonly present with impaired memory, apathy, and abnormal speech and gait, without headache, seizure, or myoclonus. White matter changes and CSF abnormalities predominate. Improved clinical awareness of PCNSL can prompt earlier diagnosis and treatment.