Cognitive performance of neuromyelitis optica patients: comparison with multiple sclerosis

Abstract

Neuromyelitis optica (NMO) is an uncommon disease that affects the optic nerves and spinal cord 1 . The recent identification of a specific antibody for aquaporin 4 (AQP4) water channel at the blood-brain barrier in NMO patients (IgG-NMO) makes it the first central nervous system autoimmune channelopathy 2 .Little is known about cognitive dysfunction in NMO, its frequency, and its relationship with clinical variables. Blanc et al. 3 reported impairment of attention, speed of information processing, and word generation in NMO patients. Nilsson et al.4 also found cognitive impairment (CI) in patients diagnosed with isolated optic neuritis (ON) from 24 to 31 years earlier. Finally, He et al. 5 evidenced cognitive alterations in NMO patients after an acute relapse, and encountered an association between neuropsychological performance and routine activities 6 . During the past 20 years, numerous researches have indicated frequent CI in multiple sclerosis (MS) patients. Working memory, attention, verbal fluency, and speed of information processing are often affected [7][8][9] . The differences between MS and NMO neuropathology suggest distinct cognitive patterns, but only one previous study compared these patients and found no significant variations in cognitive measures ABSTRACTThe aim of the present research was to investigate cognitive pattern of patients with neuromyelitis optica (NMO) and to compare it with multiple sclerosis (MS) patients' performance. Methods: Fourteen NMO, 14 relapsing remitting multiple sclerosis (RRMS), and 14 healthy control patients participated in the investigation. Neuropsychological functions were evaluated with the Brief Repeatable Neuropsychological Battery for MS; Symbol Digit Modalities Test; Digit Span; and Semantic Fluency. Results: Fifty-seven percent of NMO patients and 42.85% of the MS ones had abnormal performance in at least two cognitive tests. The NMO Group showed abnormal performance in verbal fluency, verbal and visual memories, with greater attention deficits. NMO patients outperformed healthy control in the paced auditory serial addition test (PASAT). However, no difference was found between NMO and RRMS patients. Conclusions: The NMO Group showed more dysfunction in attention and verbal fluencies than in verbal and visual memories. When compared with the MS patients, a similar dysfunction pattern was found.Key words: neuropsychology, neuromyelitis optica, depression, multiple sclerosis, autoimmune diseases. RESUMOO objetivo da presente pesquisa foi investigar o padrão cognitivo de pacientes com neuromielite óptica (NMO) e compará-lo com o desempenho de pacientes com esclerose múltipla (EM). Métodos: Quatorze pacientes com NMO, 14 com esclerose múltipla recorrente remitente (EMRR) e 14 participantes do Controle saudáveis participaram da presente investigação. As funções neuropsicológicas foram avaliadas com a Bateria Breve de Testes Neuropsicológicos de Rao, Teste Símbolo Digit e a Fluência Semântica. Resultados: Cinquenta e sete por cento dos pacientes com NMO e 42,...

Gray Matter Volume Reduction Is Associated with Cognitive Impairment in Neuromyelitis Optica

“…These impaired cognitive domains have frequently been reported in patients with NMO. 10,18,[21][22][23][24] However, inconsistent with previous studies that reported deficits in immediate memory, attention, and executive abilities, 10,17,18,21,23,24 we did not find any significant changes in these 3 cognitive domains in the patients with NMO. This discrepancy may be related to variations in the sample size, demographic and clinical features, and cognitive scales used.…”

“…We found that the intergroup GMV differences were similar before and after excluding these patients (On-line Fig 3), suggesting that the impact of comorbidities on the intergroup GMV comparisons was not significant. Consistent with prior findings, 10,17,18,[21][22][23][24] we also found cognitive impairment in the patients with NMO. The cognitive impairments in NMO were deficits in short-and long-term memory, speed of information processing, and verbal fluency on semantic stimuli.…”

“…Cognitive impairment has been repeatedly reported in patients with NMO 10,17,18,[21][22][23][24] and is characterized by deficits in multiple cognitive domains, including memory, attention, and speed of information processing. The neural correlates of the cognitive impairment in NMO have been attributed to focal reductions in white matter volume and integrity.…”

Neuropsychiatry of Neuromyelitis Optica

“…This fi nding was subsequently confi rmed by others [ 17 -22 ]. Cognitive impairment is present in more than half of NMO patients: 57 % of NMO patients for Vanotti et al [ 19 ] and also for Saji et al [ 20 ] and 54 % in our cohort [ 23 ].…”

Treatment of Neuromyelitis Optica Spectrum Disorder: Acute, Preventive, and Symptomatic

“…Cognitive problems in NMOSD may be due to depression, fatigue, and medication but may occasionally be due to primary involvement of the subcortical or cortical brain matter. Research in cognition of NMO patients is ongoing, and specific therapies have not yet been developed [64, 65]. …”