A clinical study on mild cognitive impairment in amyotrophic lateral sclerosis / 中华神经科杂志

ABSTRACT

Objective To explore the cognitive status of amyotrophic lateral sclerosis (ALS) patients, and to explore the involved cognitive domains, subtypes and risk factors of mild cognitive impairment in ALS ( ALS-MCI).Methods Twenty-nine cases of ALS and 58 healthy volunteers were included.The severity of the bulbar and spinal functions of the patients was evaluated by the Improved Norris Scale.According to the Diagnostic and Statistical Manual of Mental Disorders 4th Edition-Revised( DSM-Ⅳ-R) criteria of dementia, ALS cases were classified as demented and non-demented.For non-demented ALS cases, the common cognitive batteries evaluating mental state, verbal memory, executive, attentional and visuospatial abilities were performed.Hamilton Anxiety Scale ( HAMA) and Hamilton Depression Scale (HAMD) were evaluated too.They were further classified into ALS-cognitively normal (ALS-CogNL) and ALS-MCI groups according to Petersen criteria of MCI.Risk factors possibly correlated with ALS-MCI were analyzed by comparing the differences in age, age of onset, duration of the disease, sites of onset, symptoms of bulbar and limb function between ALS-CogNL and ALS-MCI groups.Results Among 29 ALS cases, 14 (48.3% ) cases with cognitively normal( ALS-CogNL), 15 cases (51.7% ) with ALS-MCI,and none with dementia were identified.Among 15 ALS-MCI cases, 12 cases with executive dysfunction, 8 cases with memory deficits,9 cases with attention impairment and none with visuospatial impairment were found.ALSMCI cases could be further classified into three subtypes; 1 case with amnestic MCI (aMCI) ,6 cases with single domain non-memory MCI ( sdMCI), and 8 cases with multiple domains slightly impaired MCI (mdMCI).Between ALS-MCI and ALS-CogNL groups, there were significant differences (t = -2.435,- 2.576, both P ＜ 0.05) in education ((8.7 ± 2.8) years vs (11.3 ± 3.0) years) and Improved Norrisscale (bulbar score (28.4 ± 7.7) scores vs ( 34.0 ± 3.4) scores) , however, no significant differences in sex, age, age of onset, duration,site of onset,HAMA or HAMD scores,and Improved Norris scale( spinal score) were found.Conclusions Cognitive deficits commonly exist in ALS patients.For the involved domains, executive dysfunction is the most common, deficits of attention and memory are also common, and deficit in visuospatial function is not found.The most common subtype of ALS-MCI is mdMCI.Severe bulbar symptoms and lower education may be the risk factors of ALS-MCI.