Annals of Indian Academy of Neurology
EDITORIAL COMMENTARY
Year
: 2022  |  Volume : 25  |  Issue : 5  |  Page : 790--791

Movement disorders in demyelinating disorders: How important is this historical link today?


Salil Gupta 
 Department of Internal Medicine, King Hamad University Hospital, Al Sayh, Bahrain

Correspondence Address:
Salil Gupta
Consultant Neurologist, Department of Internal Medicine, King Hamad University Hospital, Al Sayh
Bahrain




How to cite this article:
Gupta S. Movement disorders in demyelinating disorders: How important is this historical link today?.Ann Indian Acad Neurol 2022;25:790-791


How to cite this URL:
Gupta S. Movement disorders in demyelinating disorders: How important is this historical link today?. Ann Indian Acad Neurol [serial online] 2022 [cited 2022 Dec 1 ];25:790-791
Available from: https://www.annalsofian.org/text.asp?2022/25/5/790/351856


Full Text



Jean-Martin Charcot (1825–1893) was a French neurologist and anatomical pathologist. Born in Paris, he was trained by the famous neurologist Duchenne. Charcot worked and taught at the famous Hôpital de la Salpêtrière for more than 3 decades. His name has been associated with at least fifteen medical eponyms including Charcot joint (diabetic arthropathy), Charcot's artery (lenticulostriate artery), Charcot's disease (amyotrophic lateral sclerosis), Charcot's triad of acute cholangitis (right upper quadrant pain, jaundice, and fever), and Charcot's neurologic triad for multiple sclerosis (MS) (nystagmus, intentional tremor, and scanning or staccato speech), to name a few.[1] Reviewing and summarizing previous reports and adding his own clinical and pathological observations, Charcot was the first to identify MS and called the disease sclérose en plaques. He identified three signs of MS, nystagmus, intention tremor, and scanning or staccato speech (dysarthria). These are known as Charcot's neurologic triad. They were originally described by Charcot to distinguish it from Parkinson's Disease.[2] We know now that these clinical signs suggesting underlying movement disorder are neither unique to MS nor are they the most common features seen in this disease as we know it today. However, this unique and historically important link of movement disorder signs in demyelinating disease has been explored further in a very well-researched article published in this issue of the journal.[3]

Singh et al.,[3] through a meticulous review process, have described the association of various movement disorders in demyelinating diseases. Their task was difficult as the association is a highly complex one due to several reasons. Firstly, the spectrum of diseases constituting demyelinating disorders ranges from chronic conditions such as MS and neuromyelitis optic spectrum disorders (NMOSDs) to potentially fulminant situations such as acute disseminated encephalomyelitis (ADEM) and osmotic demyelination (OD). Secondly, each of the demyelinating diseases considered is inherently heterogeneous in course. MS and NMOSD can have a varying course from relapsing to progressive, whereas ADEM and OD are generally monophasic.[4] Thirdly, the nature of each of these diseases can vary. MS may be relatively benign or have a more aggressive nature with several relapses and accumulating deficits in a short period.[5] NMOSD patients may be either aquaporin 4 antibody-positive, myelin oligodendrocyte glycoprotein (MOG)-positive, or double seronegative with variations in the phenotype of each one of them and outcomes.[6] There are certain MOG-positive patients who do not satisfy the criteria of NMOSD and may present like ADEM.[7] Presentation of ADEM may be fulminant or relatively benign. Fourthly, although demyelinating diseases have the potential to occur anywhere along the entire neuraxis, individually, each of them may have a predilection for certain anatomical areas. For example, aquaporin 4 positive NMOSD may involve the cervical and dorsal cord more, whereas MOG positive disease is more likely to involve the caudal area. ADEM has cortical involvement with seizures being one of the manifestations, whereas OD may be pontine or extra-pontine, especially in basal ganglia presenting as locked-in state or parkinsonism.[8] Fifthly, from the time of Charcot, due to the therapeutic armamentarium available, the course of these diseases has been altered and the spectrum of clinical findings seen then may have somewhat changed. Lastly, movement disorders per se are a basket of clinical manifestations and include hyperkinetic and hypokinetic disorders. Depending on the circuit disrupted in the same anatomical area, the presentation can vary. As a result of the above, the theoretical possibilities of various permutations and combinations possible are phenomenal. However, in clinical practice, neither are movement disorders commonly seen in demyelinating diseases nor are the full spectrum seen. For example, tremor may occur in patients with MS, but parkinsonism is more likely to be an incidental finding. This has been well highlighted in the review by the authors.

After a PubMed search using key Medical Subject Heading (MeSH), they identified 199 articles, which they summarize systematically covering hyperkinetic and hypokinetic disorders. Although much of the published literature is on MS, they have done well to cover other relevant demyelinating diseases as well. Not surprisingly, tremor is the most common movement disorder seen in MS. Paroxysmal dyskinesias occur most commonly in NMOSD, whereas parkinsonism dominates in OD. In this review, two of the original three Charcot's triad of MS have been covered particularly well. It is well known that tremor in MS can be disabling, and treatment can be difficult. Therapeutic options range from drugs to neuro-stimulation, but response is less than satisfactory. It has also been reported with other demyelinating diseases. Evaluation of movement of the eyes, especially saccades, provides a host of important information such as localization of lesion and cognitive involvement. Patients with MS can have different types of nystagmus, but central positional nystagmus and opsoclonus are rarely reported.

There are other non-autoimmune conditions which affect myelin and may potentially cause movement disorders, and this link is relevant to them also. These include vasculopathy causing Binswanger disease (parkinsonism, especially lower body), toxic exposure (carbon monoxide, mercury, etc.), and leukodystrophies. For today's practicing neurologists, how important is the link between movement disorders and demyelinating diseases? The presence of a particular movement disorder may not be the sole reason to diagnose a demyelinating disease, but its identification and specific treatment along with the primary disease therapy is important to improve the quality of life.

References

1Pedro MKF, De Souza TFS. “Stat Rosa Pristina Nomine, Nomina Nuda Tenemus”: The many syndromes, diseases, and anatomic structures bearing Jean-Martin Charcot's name. Eur Neurol 2020;83:550-3.
2Charcot J-M. Diagnostic des formes frustes de la sclérose en plaque. Prog Med 1879;7:97-9.
3Singh R, Pandey S. Movement disorder in demyelinating disease: Tracing the Charcot's foot print. Ann Ind Acad Neurol 2022. doi: 10.4103/aian.aian_64_22.
4Guimarães MPM, Nascimento ACB, Alvarenga RMP. CLINICAL course of acute disseminated encephalomyelitis in adults from Rio de Janeiro: Retrospective study of 23 cases and literature review. Mult Scler Relat Disord 2020;46:102424. doi: 10.1016/j.msard. 2020.102424.
5Mathey G, Pisché G, Soudant M, Pittion-Vouyovitch S, Guillemin F, Debouverie M, et al. Long-term analysis of patients with benign multiple sclerosis: New insights about the disability course. J Neurol 2021;268:3817-25.
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7Hamid SHM, Whittam D, Saviour M, Alorainy A, Mutch K, Linaker S, et al. Seizures and encephalitis in myelin oligodendrocyte glycoprotein igg disease vs aquaporin 4 IgG disease. JAMA Neurol 2018;75:65-71.
8Pandit L, Sato DK, Mustafa S, Takahashi T, D'Cunha A, Malli C, et al. Serological markers associated with neuromyelitis optica spectrum disorders in South India. Ann Indian Acad Neurol 2016;19:505-9.