Safety and Usefulness of Lumbar Puncture for the Diagnosis and Management of Young-Onset Cognitive Disorders.

ABSTRACT

BACKGROUND: Young-onset cognitive disorders (YOCD) often manifests with complex and atypical presentations due to underlying heterogenous pathologies. Therefore, a biomarker-based evaluation will allow for timely diagnosis and definitive management. OBJECTIVE: Here, we evaluated the safety and usefulness of cerebrospinal fluid (CSF) sampling through lumbar puncture (LP) in YOCD patients in a tertiary clinical setting. METHODS: Patients with mild cognitive impairment (MCI) and mild dementia with age of onset between 45-64 years were evaluated. Patients underwent magnetic resonance imaging and their medial temporal lobe atrophy (MTA) was rated. LP side-effects and the impact of the CSF findings on diagnosis and management were analyzed. RESULTS: 142 patients (53 (37.32%) MCI, 51 (35.92%) dementia of the Alzheimer's disease [DAT] type, and 38 (26.76%) non-AD type dementia) who underwent LP between 2015 to 2021 were analyzed. Using post-LP results and MTA ratings, 74 (52.11%) patients met the AT(N) criteria for AD. 56 (39.44%) patients (28 out of 53 (50.0%) MCI, 12 out of 51 (21.43%) DAT, and 16 out of 38 (28.57%) non-AD dementia) had a change in diagnosis following LP. 13 (9.15%) patients developed side-effects post-LP (11 (84.62%) patients had headache, 1 (7.69%) patient had backache, and 1 (7.69%) patient had headache and backache). 32 (22.54%) patients had a change in management post-LP, 24 (75.0%) had medication changes, 10 (31.30%) had referrals to other specialists, and 3 (9.40%) was referred for clinical trial with disease modifying interventions. CONCLUSION: LP is well-tolerated in YOCD and can bring about relevant clinical decisions with regards to the diagnosis and management of this complex clinical condition.