Best Practices, Exclusives, Patient Care

Weakness Unchecked: A Case of Severe Muscle Weakness

Photo/National Highway Traffic Safety Administration

At 1 p.m., after being on duty for six hours and running all day you, finally get some downtime and place your order at the local burger joint. As always seems to happen, you get another call before your food is ready. “Medic 46 and Engine 49, respond code 3 to 72 MLK Boulevard for an adult female sick.”

Upon entering the home, the BLS engine crew is assessing a middle-aged woman who appears to be very weak. They report her speech is a bit garbled and all of her muscles are extremely weak. Cincinnati Prehospital Stroke Scale revealed some slurring of speech. Arm drift and facial droop were hard to assess. The patient is not able to raise either arm to assess for drift and she is unable to smile. Her face appears symmetric.

The patient’s husband reports that she was recently diagnosed with a neurologic condition, but he wasn’t sure the name of it. The husband is very concerned about her as he’s never seen her like this. He said the last time he saw her in her normal state it was at about 12 p.m. that afternoon.

Upon closer assessment, in addition to diffuse muscle weakness, the patient’s respirations appear very shallow. You decide to start assisting her ventilations with a bag valve mask.

The patient’s initial set of vital signs are:

HR: 92
RR: Assisted at 12 breaths per minute
SpO2: 88% on room air; 100% with assisted ventilations
EtCO2: 55 mmHg with 4-phase waveform
BP: 108/74
BGL: 80

The patient is transported to the local stroke center with a stroke alert due to the change in speech an hour prior to the call. You and your partner debrief the case after the run and realized you’ve never seen a stroke present like that before and question whether it actually was a stroke. Your partner pointed out it was strange that the patient was so profoundly weak on both sides rather than one side as you’ve seen before in stroke patients. When you get back to the station, you and your partner go down the rabbit hole of web searches to try and find out more about cases like this one.

Severe Muscle Weakness/Paralysis

Severe muscle weakness/paralysis is a very complicated chief complaint for any provider. These patients are not the most common ones that you will see, yet they can be some of the most medically complex cases of one’s career. With all of these cases, a good history and physical is paramount to deciphering through the wide variety of diagnoses that can contribute to this chief complaint. Below are several of the causes of severe weakness or paralysis.

Myositis

Myositis is a general term for conditions related to inflammation within the muscles. There are several different types of myositis, though, muscle weakness is the key finding linking the group together. Generally, this presents as a progressive, symmetrical muscle weakness of the proximal arms and legs.1

This is typically a painless condition but can be associated with myalgia (muscle soreness), and eventually, dysphagia and dysarthria. You may notice a history of difficulty with kneeling, climbing stairs, combing hair and/or rising from a seated position. The definitive modality of diagnosis is with a muscle biopsy that demonstrates inflammation within the muscle fibers.

Current treatment for the prehospital provider is limited to supportive care. Although quite rare, respiratory support may be needed in the prehospital environment. Once in the hospital setting, steroids may be initiated as a first line with immunosuppressive therapy, IV immunoglobulin and other specialized therapies.

Myasthenic Crisis

Myasthenic crisis is a life-threatening manifestation of Myasthenia Gravis. This autoimmune disease occurs when antibodies bind to acetylcholine receptors at the postsynaptic neuromuscular junction.2 This leads to the predominant symptom of weakness of skeletal muscles that increases with usage. This pattern is usually symmetric with the exception of the eye muscles that present with unilateral ptosis.3

One complication every prehospital provider should be aware of is respiratory failure. This results from the inability of the diaphragm and intercostal muscles to contract sufficiently. Therefore, it is of the utmost importance that these patients are repeatedly assessed throughout transport and ensured to have adequate respiratory status. End-tidal waveform capnography is an essential monitoring in these cases.

Positive airway pressure, via CPAP, can be beneficial for patients who are not in obvious need of assisted ventilations.4 Two-thirds to 90% of patients with a myasthenic crisis will require intubation at some point in the disease process.5 Overall, respiratory support is the mainstay of prehospital management. In the hospital, additional patients will often receive plasmapheresis and IV Immunoglobulin.

Botulism and Guillain Barre Syndrome (GBS)

Botulism is characterized by a symmetric cranial nerve paralysis followed by a descending, flaccid paralysis of skeletal muscles.6 This is key in differentiating the paralysis from a similar pathology, Guillain Barre syndrome (GBS), which usually presents with an ascending flaccid paralysis that is due to an autoimmune-mediated destruction of the myelin sheath of peripheral nerves.

Botulism is predominantly due to a toxin of bacteria Clostridium botulinum that inhibits acetylcholine release from the presynaptic membrane of motor neurons. There are multiple clinical etiologies of botulism consisting of foodborne botulism, wound botulism, infant botulism and intestinal toxemia.7

Foodborne botulism and infant botulism are both due to ingestion of foods, however they have different pathophysiologies. Foodborne usually occurs due to inappropriately handled home-canned or raw fermented foods. These provide a sufficient environment for germination of C botulinumspores. This in turn produces the preformed botulinum toxin that is then ingested. As a result, providers may notice GI symptoms such as nausea, vomiting, and diarrhea before the typical neurologic manifestations.8

On the other hand, infant botulism develops when C. botulinum is directly ingested through food such as honey. The bacterial spores then germinate and produce botulinum toxin within the GI tracts of the infant.9 The GI tract of children greater than one year of age has a different composition of other bacteria and certain acids which prevent the germination of the spores.

Additionally, infant botulism can be acquired by spores that are present within dust such as around a construction site.

While there are four different types of botulism etiologies, the neurological manifestations are the same. The key clinical manifestation is a symmetric descending flaccid paralysis that can lead to respiratory compromise. In infants, a parent may describe poor feeding, weak suck, feeble crying and even an obstructive apnea due to tongue floppiness (“floppy baby syndrome”).10

Visual complaints and difficulty swallowing may be one of the initial complaints noticed. With Guillain Barre, the symptoms are similar but reversed. You may notice decreased muscle tone, strength, and reflexes in the lower extremities that begins with difficulty walking. Regardless of the cause, it is extremely important to prioritize effective airway and ventilation strategies, as in the case of Myasthenic crisis. These patients will usually be admitted to the ICU and treated with various forms of immunoglobulin or antitoxin, depending on the etiology.

Todd’s Paralysis

Todd’s paralysis is a transient paralysis that occurs after convulsive seizures and mimics a stroke-like syndrome. This can complicate patient care especially when there is no significant past medical history of epilepsy. This paresis may be partial (i.e. hand, arm or leg) or complete but usually manifests as a transient hemiparesis (localized to one side).

It is theorized that this is due to a transient brain hypoxia/ischemia that occurs after the termination of a seizure; therefore mimicking the pathophysiology of a stroke.11 For these patients, it is impossible to truly delineate between a Todd’s paralysis and a stroke in the prehospital setting even with a history of a recent convulsive episode.

It must be noted that some strokes can even trigger a focal seizure during the event. Therefore, it is imperative that all of these patients undergo rapid transport to an appropriate stroke center that can perform further workup such as CT and MRI. Most of these individuals will recover over time but there is no established therapy specific to Todd’s paralysis besides rest until the paresis resolves. Any continued seizure activity will be treated with benzodiazepines.

In the Field

As always, management of these cases is going to rely around the assessment and management of ABCs, with a careful attention to reassessment due to the progressive nature of these conditions. Many of these conditions can mimic findings of a stroke, yet in the prehospital environment this differentiation can be very challenging. As such, appropriate transport and treatment of a potential stroke should never be withheld.

Finally, be wary of patients with seemingly mild complaints such as subtle weakness, blurred or double vision. Many of these conditions are progressive over hours to days, so while they may present initially as a very benign complaint, these patients may decompensate. A good assessment, stabilization of the patient and transport to a higher level of care will ensure a better prognosis for patients with severe muscle weakness or paralysis.

Back to the Patient

Later that day you bring another patient back to the same ED and seek out the ED physician to get a follow-up on the stroke alert patient you brought in. The ED doctor said he was able to look up her record in the electronic health record and it turns out she was recently diagnosed with Myasthenia Gravis, and her presentation was a myasthenic crisis. She’s in the ICU on a ventilator at the moment but will likely make a full recovery. The ED physician commends you and your partner on a job well done, particularly recognizing the need for assisted ventilation.

References

  1. Carstens PO, Schmidt J. Diagnosis, pathogenesis and treatment of myositis: recent advances. Clin Exp Immunol. 2014;175(3):349–358. doi:10.1111/cei.12194.
  2.  Longo DL. Myasthenia Gravis. N Engl J Med. 2016; 375:2570-2581.
  3. Gilhus NE, Verschuuren JJ. Myasthenia Gravis: subgroup classification and therapeutic strategies. Lancet Neurol. 2015;14:1023-1036.
  4. Wendell LC, Levine JM. Myasthenic crisis. Neurohospitalist. 2011;1(1):16–22.
  5. Thomas CE, Mayer SA, Gungor Y, Swarup R, Webster EA, Chang I, Brannagan TH, Fink ME, Rowland LP Neurology. 1997 May; 48(5):1253-60.
  6. Sobel SJ Botulism. Clin Infect Dis. 2005;41(8):1167–1173.
  7. Carillo-Marquez MA. Botulism. Pediatrics in Review. 2016; 37(5): 183-192.
  8. Arnon SS, Barzilay E. Clostridial infections: botulism and infant botulism (Clostridium botulinum). In: Kimberlin DW, ed. The Red Book: 2015 Report of the Committee on Infectious Diseases. 30th ed. American Academy of Pediatrics: Elk Grove Village, IL, 294-296, 2015.
  9. Arnon SS. Infant Botulism. In: Cherry J, Demmler-Harrison GJ, Kaplan SL, Steinbach WJ, Hotez BJ, eds. Feigin and Cherry’s Textbook of Pediatric Infectious Diseases. 7th ed. Elsevier Saunders: Philadelphia, PA, 1801-1809, 2014.
  10. Overturf GD. Clostridial Intoxication and Infection. Botulism. In: Cherry JD, Demmler-Harrison GJ, Kaplan SL, Steinbach WJ, Hotez BJ, eds. Feigin and Cherry’s Textbook of Pediatric Infectious Diseases, 7th ed. Elsevier Saunders: Philadelphia, PA, 1791-1794, 2014.
  11. Farrell JS, Gaxiola-Valdez I, Wolff MD, et al. Postictal behavioural impairments are due to a severe prolonged hypoperfusion/hypoxia event that is COX-2 dependent. eLife. 2016;5.