Methotrexate (MTX) is commonly used in intrathecal chemotherapy for patients with acute lymphocytic leukemia (ALL) to prevent central nervous system (CNS) involvement. However, the use of MTX-based chemotherapy can lead to rare yet severe complications, such as MTX-induced myelopathy. Here we report the case of MTX-induced myelopathy initially misdiagnosed as Guillain-Barre syndrome, leading to a delay in diagnosis and treatment. We present a case of a 39-year-old male with a history of B-cell acute lymphoblastic leukemia (B-ALL) who experienced bilateral foot paresthesia and progressive lower extremity weakness after intrathecal methotrexate (MTX) treatment. Initially suspected as Guillain-Barre syndrome (GBS) due to similar clinical features and nerve conduction studies. The patient received intravenous immunoglobulin (IVIG) treatment, but his condition worsened. A subsequent spine MRI revealed MTX-induced myelopathy. This case highlights the diagnostic challenge posed by the similarity in clinical presentation between MTX-induced myelopathy and GBS. Differentiating between these conditions is critical for appropriate management. Prompt recognition and treatment with folate metabolism compounds may mitigate neurological sequelae.

Choroid plexus insufficiency or glymphatic stasis are often classified as prequels to harmful accretion of toxic proteins in neurodegenerative disease. Cognitive decline and memory loss subsequently become cardinal features of Alzheimer’s disease (AD), typically progressing with amyloid-ß and tau protein accumulation. For Parkinson’s disease (PD), α-synuclein deposits and dopamine depletion are linked to impaired movement, resting tremor, and rigidity. Importantly, both diagnoses are accompanied by hyperinflammation and intrathecal cytokine changes. Thus far, numerous clinical trials for investigational drugs have produced nothing effective for AD or PD, yet the anti-inflammatory and regenerative potential of platelet-rich plasma (PRP) remains largely unexamined in this context. This report explores a proposed Phase I study on intrathecal condensed plasma growth factors processed from autologous thrombin-activated PRP as monotherapy for AD or PD. The concept gains support from related work where cytokines of platelet origin successfully lowered inflammation, corrected background fibrosis, deactivated abnormal cells, and recovered local tissue function—all desirable outcomes in AD and PD. PRP-mediated effects on membrane potentials, electrolyte balance, and water clearance are less well characterized, but experimental evidence suggests these pathways could likewise influence glymphatic drainage to ameliorate proteinopathies. As a well-tolerated ‘orthobiologic’ with no hypersensitivity risk, intrathecal PRP and its derivatives bring advantages distinct from synthetic pharmaceuticals. If age-associated neuroinflammation in AD and PD is an upstream event contributing to neural disruption, then dampening local oxidative stress by a patient’s own platelet cytokines (as already proven in other tissues) could offer therapeutic relevance to these neurodegenerative conditions as well.