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Advanced Neurology POTS with autonomic storms misdiagnosed as FND

extreme nausea that did not lead to vomiting, dizziness, the remaining patient was confirmed to have POTS after
and extreme cold. Her right arm or right leg would start leaving the hospital, at our outpatient neurology clinic.
to twitch and within 2 – 3 min, she experienced full-body Both patients were confirmed to have POTS on receiving
jerks (Video S2). After the events subsided, she claimed positive tilt table testing results. In addition, both patients
being extremely tired and sore. The twitching episodes were advised to start on non-pharmacological treatment
at night were more violent. ED evaluation and hospital and lifestyle modifications, including optimization of
admission revealed a normal MRI of the brain and spine hydration and electrolytes as well as wearing compression
and a negative continuous EEG. Subsequently, she was stockings. Neither patient in our case study had relevant
diagnosed with FND. personal or family history.
The patient was referred to our neurology group for POTS symptoms can be divided into three distinct
her abnormal movements. Her neurological examination grades. Grade 1 includes orthostatic symptoms that are
revealed POTS, hyperreflexia in the patella, small fiber infrequent, and the patients of this grade are able to stand
neuropathy, and frequent myoclonus involving arms and for more than 15 min at a time and perform unrestricted
legs. Her POTS diagnosis was confirmed by a positive tilt daily living. Carrying a higher symptomatic burden,
table test, showing a >30-point increase in heart rate with Grade 2 includes orthostatic symptoms developing at least
standing, and autonomic evaluation. She was treated with once a week, commonly with orthostatic stress; an ability
pyridostigmine and valium and her twitching episodes to stand for at least 5 min at a time; and some limitations in
resolved. daily life. Finally, Grade 3 includes orthostatic symptoms
that are common, an ability to stand for more than 1 but
2.3. POTS symptoms in patients <5 min at a time, being severely incapacitated (being bed
Table 1 presents the list of common POTS symptoms or wheelchair-bound), and syncope when the patient
affecting the patients in our case series. A categorized attempts to stand. 13,14 These three grades track orthostatic
breakdown highlights the typical cardiovascular, symptoms as a means of determining whether a patient has
neurological, and general symptoms of POTS-related POTS. In our case series, both of our patients presented
autonomic storms and their occurrence in our patients. 3 with tachycardia, and one of the patients presented with
hyperthermia and dystonia, which are typical symptoms
3. Discussion associated with POTS-related autonomic storms.
Furthermore, both patients had episodes of myoclonus
In this retrospective case series of two patients affected indicative of POTS (Table 1). At our clinic, we have seen
by POTS, both were incorrectly misdiagnosed with FND tremor, myoclonus, and jerking movements that may
on ED admission for autonomic storms. The patients in be synchronous or asynchronous as manifestations of
our study were both female and young, between 18 and autonomic movement disorders.
24 years old. One patient was previously diagnosed with
POTS approximately 3 years before ED admission while The leading factor in the misdiagnosis of POTS is the
lack of recognition of POTS symptoms by physicians.
Table 1. Presence of clinical symptoms affecting patients Making correct diagnosis of POTS on a patient’s first visit
with POTS at initial diagnosis is very rare, a factor causing delays in reaching a correct
diagnosis, which may take 6 – 72 months from the time
Clinical symptoms Patient 1 Patient 2 of presentation. Among undiagnosed cases of POTS,
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Alterations in level of consciousness No No many occur in the workplace, where patients present with
Increased posturing No No syncopal and pre-syncopal episodes. Workers with POTS
Dystonia Yes No have symptoms that are associated with high occupational
Hypertension No No stress, poor quality of sleep, and disturbances in mental
Hyperthermia No No wellness, indicating the need for timely diagnosis of the
condition.
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Tachycardia Yes Yes
Tachypnea No No Furthermore, the accurate diagnosis of POTS is
Diaphoresis No No challenged due to the lack of universal consensus on
diagnostic criteria. Many non-specific symptoms, such
Agitation No No as myoclonus, fatigue, lightheadedness, and headache,
Tremor Yes No overlap with a broad array of neurological and other
Myoclonus Yes Yes clinical disorders. However, for a female patient presented
Abbreviation: POTS: Postural orthostatic tachycardia syndrome. to the ED or the clinic experiencing orthostatic symptoms

Volume 4 Issue 2 (2025) 125 doi: 10.36922/an.7653