Protocols Lacking to Assess Cognitive Decline in Niemann-Pick Type C, Review Says

Despite the wide variety of presentations in Niemann-Pick type C (NP-C), there is a common element—early cognitive decline.

However, little is known about the cognitive impairment in patients with NP-C or how their neuropsychological functioning is assessed. A recent review sought to analyze studies to identify a neuropsychological assessment to evaluate cognitive domains and neuropsychological changes.

NP-C, a rare, difficult-to-diagnose condition, is a congenital recessive disease caused by an accumulation of lipids in various organs. It has a wide range of manifestations, including visceral, neurological, psychiatric, and cognitive, that vary in terms of age of onset, severity, and rate of disease progression.

Affected areas, which slowly degrade, include memory, verbal fluency, aphasia, apraxia, and visual-spatial functions. As the disease advances, patients meet the criteria for dementia; the authors noted that adults with NP-C and those with dementia share similarities, such as an apolipoprotein E ε4 genotype, basal forebrain cholinergic system, and chronic neuroinflammation.

Using PubMed and Web of Science, the researchers identified 73 articles and narrowed them down to 25 papers. Of the 25, only 4 focused on neuropsychological assessments and the other 21 examined neuropsychological tools.

Most of the researchers of the other works described the use of tests to assess global cognitive level functioning; other authors used scales of intelligence. One study investigated fine-motor functions. Of the cognitive domains, the one investigated the most was executive functions followed by short-term memory.

Some researchers measured changes in adaptive behavior. Language skills, episodic memory, visuospatial memory, and visuospatial and constructive skills were rarely assessed.

Despite the negative impact this cognitive slide has on the daily lives of patients with NP-C, research is lacking, the authors of the currents study noted.

“The management of NP-C disease should be based on a multidisciplinary approach, to treating symptoms, preserving neurological functions, and guaranteeing the best possible quality of life,” they wrote. “Early identification of neurological and psychological symptoms of the disease is necessary in order to decrease the progression of neurological disease and improve patient care and treatment outcomes.”

Reference

Maresca G, Formica C, Nocito V, et al. Neuropsychological assessment in Niemann-Pick disease type C: a systematic review. Neurol Sci. 2021; 42(8):3167-3175. doi: 10.1007/s10072-021-05337-5.