Cerebrospinal fluid neurone-specific enolase in mitochondrial encephalomyopathies.

Whether cerebrospinal fluid (CSF) neurone-specific enolase (NSE) contributes to the diagnosis of mitochondrial encephalomyopathies (MEMs) is unknown. Aim of the present study was thus to assess the validity of CSF-NSE in the diagnosis of MEM. CSF-NSE was determined in 24 controls, aged 28-88 years; and 23 MEM patients, aged 47-81 years. In controls, CSF-NSE was independent of sex (p = 0.849) and age (p = 0.346). Twenty-one MEM patients had clinical CNS involvement and two CNS abnormalities on imaging investigations exclusively. CSF cells were increased in 7, CSF protein in 17, CSF glucose in 1, and CSF lactate in 2 MEM patients. The upper reference limit of CSF-NSE was 14.66 ng/mL. CSF-NSE was elevated in 6 (26%) MEM patients. CSF-NSE was increased in a single MEM patient with subclinical CNS involvement. This study shows that CSF-NSE is elevated in only one quarter of the MEM patients. Determination of CSF-NSE appears to be of minor importance for the assessment of clinical or subclinical CNS involvement in MEM.