Correlation of Neurocortical Atrophy Scores on Imaging with Mini-Mental Status Examination

Abstract

Introduction: The term “Cognitive impairment” is used for decline of memory and behaviour, depicting its progressive nature, of which the most common cause is Alzheimer’s followed by vascular injury. Magnetic Resonance Imaging (MRI) and Mini-Mental State Examination (MMSE) together have an established role to identify aetiology and also to distinguish normal ageing from demented patients. Final diagnosis by brain biopsy is an invasive method, hence structural MRI scores are used to differentiate and characterise the course and prognosis of disease. Aim: This study was done to correlate the various imaging scores of dementia like Schelten’s, Davies-Mattis-Kipps, Fazekas, Pasquier and Koedam scores with the severity of cognitive impairment on MMSE scores. Materials and Methods: It was a cross-sectional study done on 100 patients based on purposive sampling techniques of exclusion and inclusion criteria. All patients above 18 years of age referred for the evaluation of cognitive impairment were included after taking informed and written consent. Magnetic Resonance Imaging (MRI) Brain was performed using a 1.5 T MRI scanner (PHILIPS ACHIEVA 16 channel system) as per the department protocol. The axis was taken perpendicular to long axis of hippocampus on sagittal, and perpendicular to the commissures intersecting the mamillary bodies on coronal. The MMSE and lobar cortical atrophy scores (Schelten’s, Davies- Mattis-Kipps, Fazekas, Pasquier and Koedam) were recorded for each patient and imaging diagnosis was made. The data was then analysed for statistics. Frequency percentage distribution of range of MMSE, Pearson Coefficient of Correlation and Fisher’s exact test, Chi-squared Test and Sig. (2-tailed) correlation were used. Statistical measurement was done using Statistical Package for Social Sciences (SPSS), version 21. Results: There was statistically significant association (p<0.05) between Schelten’s and Mattis imaging scores with MMSE. This determines that there exists relationship between degree of cognitive impairment and neurodegeneration predominantly temporal lobe. However, linear coefficient of correlation (r>0.3) was noted between MMSE severity and Schelten’s, Davies-Mattis-Kipps and Fazekas grading. This determines that there is a moderately positive linear relationship between the two variables. Conclusion: MRI Brain is the investigation of choice in patients with cognitive impairment to categorise the patients based on aetiology and stage the disease that could be misdiagnosed on clinical assessment alone. MRI also diagnoses stage of dementia that affects the prognosis and outcome of the patient. Patients with cognitive impairment irrespective of MMSE score severity need to undergo neuroimaging that helps in improvising patient management at the earliest.

Role of Magnetic Resonance Imaging in Dementia

“…MTL atrophy and parietal lobe atrophy are specific for AD, whereas symmetric atrophy of frontal and temporal lobe favors frontotemporal dementia. [14] Another similar Indian study by Chatra et al, 2021, showed statistically significant association between Scheltens et al's imaging scores with MMSE. There is a moderately positive linear relationship between the two.…”

“…This feature can be used as a screening tool in patients with subclinical dementia for early diagnosis and management. [16,17] MRI has many advantages as it is easy to perform, specific features help in diagnosing specific type of dementia which is crucial for the management, whereas molecular studies which are available for the diagnosis of AD are practically not available and cannot be used for the routine diagnosis in all patients because of logistical challenges. [18] MRI gives high resolution with excellent tissue contrast.…”