Rare Diseases Day 2025

Published by ICSEB at 27 February, 2025

At the Institut Chiari de Barcelona, we have worked with conditions related to Filum Disease and Neuro-Cranio-vertebral Syndrome since 2008. Some are considered to be orphan diseases, such as Arnold-Chiari Syndrome Type I and idiopathic Syringomyelia.

The authors of The Lancet Global Health stated last year that, in general, Rare Disease Day 2024 was characterised by both advances and ongoing challenges. They highlighted that still “urgent attention is needed to prioritise early and precise diagnosis as well as effective treatment of rare diseases via specific policies and funding for research and development. A collective approach involving integration of rare diseases into the health-care system, inclusion of mental health considerations in rare disease services, and increased awareness efforts will be essential for fostering progress and addressing the unmet needs of those affected by rare diseases”. (The landscape for rare diseases in 2024, The Lancet, Vol 12, March 2024).

As for the conditions we manage, we fully agree that it is essential and urgent to establish a diagnosis as early as possible.

Firstly, there are imaging characteristics that are often overlooked in radiology and neurosurgery on diagnostic tests (MRI). These include slight cerebellar tonsil descent (which is not recognised as Arnold-Chiari I), cerebellar tonsil impaction within the foramen magnum (which many still fail to diagnose as Arnold-Chiari 0), spinal cord oedema or ischemia (pre-syringomyelia), among others. Other overlooked findings include signs of tense spinal cord, spinal deviations, and a conus medullaris lower than T12-L1. These features are characteristic for Neuro-Cranio-vertebral Syndrome.

Secondly, regarding symptoms and signs, it still seems that the clinical presentation associated with these diagnoses is not yet widely acknowledged to be as diverse as our specialists have described and published (Tables I and II). In fact, many patients continue to face long waits between the initial consultations with their general practitioner and their referral to specialists. Often, they are  surprised that even specialists are sometimes unaware of the broad range of disorders linked to the conditions involved in Filum Disease.

Table I. Frequency of symptoms in 373 patients with FD/NCVS. (The Filum disease and the Neuro-Cranio-vertebral Syndrome: definition, clinical picture and imaging features, Royo et al., BMC Neurology 2020).

Table II. Frequency of clinical signs in 373 Patients with FD/NCVS. (The Filum Disease and the Neuro-Cranio-vertebral Syndrome: Definition, Clinical Picture and Imaging Features, Royo et al., BMC Neurology 2020).

Thirdly, although there is already considerable medical-scientific literature describing the neuropsychological symptoms in these conditions, particularly in Arnold-Chiari I, patients are still frequently referred to mental health services – even when imaging shows abnormalities. However, if these abnormalities are mild, they are usually dismissed as not being responsible for the level of health deterioration they can, in fact, cause.

“Advances in early and precise diagnosis are of key importance, since rapid diagnosis can enhance health outcomes and improve quality of life.” This is precisely why we recommend that patients seek diagnostic guidance at our centre as soon as possible, to detect cerebellar tonsil descent or impaction, scoliosis/kyphosis – even if mild – or small cysts in the spinal cord. All of these findings correspond to the previously described clinical picture, despite the fact that  previously consulted specialists or radiologists may not have considered them significant.

On this International Rare Diseases Day 2025, we emphasise the importance of patients receiving an early opinion and having  access to appropriate, minimally invasive, and personalised treatment. This treatment should  comprehensively addres all the necessary guidelines for managing each developed disorder. Acting as early as possible – as proposed by the Filum System^® method –can significantly improve outcomes, provide relief, facilitate recovery, or at the very least, enable the early detection of neurological deterioration. This, in turn, increases the chances of restoring a satisfactory quality of life.