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Advanced Neurology Narcolepsy-multiple sclerosis coexistence

3. Discussion alternative neuropathophysiological mechanisms that may
impact hypocretin-1 levels.
We report a rare case of MS coexistence with narcolepsy.
Previous limited studies have demonstrated a genetic When MS coexists with narcolepsy, the complexity of its
association between narcolepsy and MS. However, treatment strategies deepens. Disease-modifying therapy
their interaction and mutual influence still require an (DMT) is an intervention to improve the condition of MS
in-depth exploration. This special case of MS complicated and reduce the relapse rate by regulating the body’s immune
by narcolepsy has prompted many thought-provoking function. At present, the common DMTs for MS include
explorations. siponimod, fingolimod, teriflunomide, dimethyl fumarate,
and ofatumumab . Existing studies have reported that
[11]
Narcolepsy is a chronic neurological disease immune regulation does not affect the sleep quality of MS
accompanied by several defining clinical symptoms, patients and may even result in sleep disorders . Several
[12]
including daytime drowsiness, hypnotic hallucinations, studies have also shown that some DMT treatments, such
and sleep paralysis. Narcolepsy usually starts in as natalizumab, have the potential to alleviate daytime
adolescence and persists throughout an individual’s life drowsiness in patients with narcolepsy . However, in this
[13]
cycle, exerting a significant impact on daily functions . It case, the MS symptoms were alleviated while the narcoleptic
[5]
is estimated that the incidence of narcolepsy in the general condition was significantly improved after ofatumumab
population is about 0.047% . However, studies on the treatment, although the efficacy of other DMTs in treating
[6]
incidence of narcolepsy in MS patients are very scarce. It the coexistence of MS and narcolepsy still needs to be
is well known that the symptoms of narcolepsy are not further explored. The continuous progress in medical
uncommon in patients with MS. Approximately 12% of technology, coupled with extensive research, will likely
narcoleptic cases can be attributed to MS, and a study on promote the emergence of novel DMTs. It is incumbent
the secondary causes of narcolepsy has revealed that MS is upon us to remain abreast of these developments and
the fourth most significant risk factor after genetic diseases, thoroughly investigate their potential value. This endeavor
CNS tumors, and brain damage. The HLA-DR2/DQ6 is will not only enhance patient outcomes but also establish
the most frequently associated HLA haplotype in MS. a more robust groundwork for forthcoming medical
However, it is noteworthy that a considerable percentage research and clinical practice.
of individuals diagnosed with narcolepsy also harbor the
DR2 gene . This observation implies the possibility of a 4. Conclusion
[7]
shared molecular genetic mechanism or potential overlap
between the pathogenesis of these two disorders, providing The coexistence of MS and sleep disorders is common
valuable information for further research on their common in clinical practice and will adversely affect the patient’s
health and quality of life. This case report sheds light
pathophysiological basis.
on how to approach this comorbidity. In the future, we
Hypocretins, also known as orexins, belong a newly should delve into the exploration of the pathophysiological
identified class of excitatory neuropeptides that are mechanisms shared by these two diseases and seek more
primarily synthesized by neurons in the posterolateral effective therapeutic strategies. It is necessary to further
hypothalamus . However, individuals diagnosed with explore comprehensive treatment methods to alleviate the
[8]
narcolepsy suffer from a significant reduction of these symptoms and improve the quality of life of patients with
pivotal neurons and therefore a decline in the concentration this comorbidity.
[7]
of hypocretin-1 in the cerebrospinal fluid . Previous
research has evidenced that individuals diagnosed with MS Acknowledgments
may develop demyelinating lesions in the hypothalamus, None.
which result in a reduction of hypocretin-1 levels in the
cerebrospinal fluid . This condition possibly triggers the Funding
[9]
development of symptomatic hypersomnia or narcolepsy
with cataplexy. In our case, demyelination-like changes in None.
the hypothalamus were not captured by MRI. Nevertheless, Conflict of interest
other possibilities cannot be excluded. According to
pertinent research, the decline in hypocretin-1 levels The authors declare they have no competing interests.
may be linked to inflammation in the CNS, rather than
being exclusively ascribed to demyelination . Therefore, Author contributions
[10]
in our case, despite the absence of evident hypothalamic Conceptualization: Meijuan Zhang
demyelination on MRI scans, it is imperative to consider Data curation: Minkai Zhang, Linjie Yu

Volume 2 Issue 4 (2023) 4 https://doi.org/10.36922/an.1913