Dystonic Storm

Authors:

Ayesha Hameed MBBS,

Tasneem Kousar MBBS,

Adeel Memon MD

Introduction

• Also known as Status Dystonicus

• A rare life-threatening movement disorder emergency, characterized by marked exacerbations of dystonia that requires immediate intervention and ICU admission

Clinical Features

• It usually occurs in patients with severe or poorly controlled dystonia.

• In addition to the development of increasingly frequent and severe episodes of generalized dystonia, signs, and symptoms of Dystonic Storm are included in Table 1.

Signs and Symptoms of Dystonic Storm

• Fever

• Tachypnea

• Sweating

• Dysarthria

• Respiratory failure

• Tachycardia

• Hypertension

• Autonomic instability

• Dysphagia

• Pain

Lab Findings

Differential Diagnosis

• There are several conditions which present with fever, elevated serum CK, with or without muscle rigidity and thus resembling Dystonic Storm.

• As compared to other conditions, dystonic storm is usually present in the pediatric population and develops quickly over hours to several days. Triggers may or may not be present.

Table 3: Differential Diagnosis of Dystonic Storm

Triggers and Clinical Course Triggers

Triggers

• Dystonic Storm is usually triggered, however, one-third of events are unprovoked.

• The main triggers are infection and change in medication (Table 4)

• Less common triggers are trauma, surgical procedures, anaesthesia, ‘metabolic disorder’ decompensation, stress, pain, gastro-oesophageal reflux disease, constipation, and puberty-related deterioration in Cerebral Palsy.

Clinical Course of Dystonic Storm

• Dystonic Storm usually appears after weeks or months in the patients who have already been diagnosed with Dystonia

• In some patients, a prodrome of status dystonicus may be present where dystonia is worse than baseline but has not become as severe as in true storm (Figure 1)

• The true storm usually lasts 2-4 weeks with slow recovery

• The mortality is 10% even with treatment

• Some patients are prone to relapses and patients with a history of Dystonic Storm should be monitored for recurrence

Figure 1: Typical Clinical Course of Dystonic Storm Patient

Management

• Management must be initiated immediately

• Patients should be admitted to ICU

• The initial stabilization measures include intubation, mechanical ventilation, fluid resuscitation, antibiotics, nasogastric or parenteral nutrition and antipyretics

Management in first 24 hours

• Goal during the first 24 hours
• Identify and treat triggers such as infection or medications
• Evaluate if the patient requires Globus Pallidus Interna (GPi) Deep Brain Stimulation or ITB therapy (Figure 2)

Management in 2-4 weeks

• The usual list of medical treatment for the next 2-4 weeks is listed in table 5

• The anti-dystonic drugs are used in combination
• Most successful combination include an anticholinergic (trihexyphenidyl), a dopamine blocker (haloperidol or pimozide), and tetrabenazine

Table 5: Management in next 2-4 weeks

Supportive Treatment

• Includes airway protection, sedation and pain control

• Anesthetic agents such as IV midazolam is generally chosen as a first choice i.e. because of its muscle relaxant effect, rapid onset of action, and short half-life

• For refractory symptoms, propofol is considered as a second line

• Third line agents are pancuronium and barbiturates which are non-depolarizing paralytic agents.

• To prevent dependence or tolerance, attempts to reduce sedative and anesthetics drugs should be made

Invasive therapies

Intrathecal baclofen

• ITB has been used in some patients with refractory status dystonicus

• The risks of using ITB are over-dosage, withdrawal syndrome and migration or breakage of catheter

Deep brain stimulation

• In majority of patients DBS has been an effective treatment

• The anatomical site of choice is globus pallidus interna (bilaterally)

• The effects are usually evident within days or weeks

• It is however challenging to operate on patients with status dystonicus due to higher rate of hardware and other complications present in these patients

Pallidotomy and thalamotomy

• Pallidotomy is rarely used unless DBS is not available

Figure 2: Management in first 24 hours

Complications

• Respiratory compromise/failure, rhabdomyolysis and acute renal failure due to severe generalized muscle spasms

• Secondary complications include dysphagia, thrombosis, injuries, fractures and sepsis

Further Reading

References

• Termsarasab, P., & Frucht, S. J. (2017). Dystonic storm: A practical clinical and video review. Journal of Clinical Movement Disorders, 4(1). https://doi.org/10.1186/s40734-017-0057-z

• Allen, N. M., Lin, J.-P., Lynch, T., & King, M. D. (2013). Status dystonicus: A practice guide. Developmental Medicine & Child Neurology, 56(2), 105–112. https://doi.org/10.1111/dmcn.12339

• R, H. (2021). Intermittent cerebral ischemia as a cause of dystonic storms in hypermobile Ehlers-Danlos syndrome with upper cervical instability, and Prolotherapy as successful treatment: 4 case series. Clinical and Medical Case Reports, 7(07).

• Mayo Foundation for Medical Education and Research. (2020, April 25). Dystonia. Mayo Clinic.https://www.mayoclinic.org/diseases-conditions/dystonia/symptoms-causes/syc-20350480.