# Does Lumbar Puncture Still Have Clinical Value for Patients with Amyotrophic Lateral Sclerosis?

## TL;DR

This study explores whether lumbar puncture provides useful clinical information for amyotrophic lateral sclerosis patients.

## Contribution

The study identifies Aβ42 as a potential prognostic marker for predicting ALS survival and progression.

## Key findings

- About 25% of ALS patients had elevated CSF protein, albumin, and QAlb, but these were not linked to clinical outcomes.
- Neurodegeneration markers like p-tau/t-tau ratio and Aβ42 correlated with ALS progression and survival.
- Aβ42 was the strongest prognostic marker for survival in ALS patients.

## Abstract

Background: The relationship between routine cerebrospinal fluid (CSF) testing and clinical and prognostic data in amyotrophic lateral sclerosis (ALS) remains unclear. Additionally, biochemical data have never been correlated with markers of neurodegeneration. The purpose of this study is to determine whether lumbar puncture may still have clinical utility in ALS. Methods: We collected the CSF profiles of 140 ALS subjects. CSF protein, albumin, IgG, IgG index, albumin quotient (QAlb), t-tau, p-tau, and Aβ42 were analyzed. Results: Approximately one-quarter of ALS patients had elevated levels of protein, albumin, and QAlb in the CSF, but these were not associated with clinical or survival data. Among the neurodegeneration markers, the percentage of patients with abnormal values ranged from 26.3% to 35.4%. The p-tau/t-tau ratio and Aβ42 were correlated with both the ALS progression rate and the time from diagnosis to death. Aβ42 was the prognostic marker most strongly associated with survival. Conclusions: The lack of correlation between biochemical CSF findings and the clinical and/or prognostic status of ALS suggests that these markers have no clinical value. However, neurodegeneration markers that are easily measurable in clinical laboratories, particularly Aβ42, may be useful at the time of diagnosis for predicting ALS survival and progression rate.