Cognitive evaluation of patients with chronic neurolathyrism

The object of the present study was to evaluate whether patients with neurolathyrism (NL) have cognitive abnormalities, and whether the cognitive decline, if found, correlates with the motor deficit.

NL is a neurological syndrome that develops following ingestion of the grass pea (Lathyrus Sativus). These beans have excellent nutritional properties but contain the neurotoxin beta-N-oxalylamino-l-alanine (BOAA), suggested to be responsible for the development of CNL with the main symptom being spastic paraparesis. BOAA is closely related to beta-metyl-amino-alanine (BMA), the putatove phytotoxin involved in the pathogenesis of the ALS-PD complex of Guam. As the latter includes dementia, we investigated the cognitive functions of CNL patients.

NL patients (n=30), all subjects over 65-years old, and 30 aged matched controls underwent a neurological examination including a structured cognitive evaluation diagnosed according to DSM-IV criteria. In addition, all the participants were tested with the Wechsler Memory Scale (WMS). Patients' motor function was divided into five stages according to disease severity. Statistical analysis was performed using Student's t-test.

Only one patient was found to be demented. The 30 CNL patients had a mean total WMS score of 57.2+/-18.2 and a memory quotient (MQ) of 128.9+/-28.5. The corresponding values for controls were 57.1+/-13.2 and 124+/-15.2 and there were no significant statistical differences between the two groups. No correlation was found between the cognitive and motor state of the CNL patients.

The cognitive state of CNL patients does not show a decline.