Urgent considerations
See Differentials for more details
It is important to keep in mind the following situations and conditions that require urgent intervention.
History of drug intake/exposure
Drug-induced dystonia can produce extremely severe dystonia. Onset varies; dystonia may occur shortly after administration of the drug or hours to days later.[82] All the medications the patient has been taking, or exposed to in utero, should be reviewed. The drug most likely to be the offending agent should be immediately discontinued. With respect to intrauterine exposure, the timing and the duration of the dystonia postpartum is variable and depends on the offending drug and the duration of intrauterine exposure.
Drugs most likely to be implicated and their possible mechanisms are:
Antipsychotics, antiemetics: dopamine receptor antagonists[83]
Midazolam (midazolam-withdrawal syndrome): prolonged agonist action on benzodiazepine receptors[84]
Intrauterine cocaine exposure: primary dopaminergic, and complex time- and dose-dependent effects on the serotonergic and adrenergic neurotransmitter systems[85]
Intrauterine metoclopramide exposure: central and peripheral dopamine receptor antagonist[86]
Bethanechol: acetylcholine receptor agonist[87]
Benztropine: anticholinergic and antihistaminic effects[88]
Domperidone: antidopaminergic effect[89]
Metoclopramide: central and peripheral dopamine receptor antagonist, occasionally causing tardive dystonia with high doses[90][91]
Cisapride: serotonin 5-hydroxytryptamine 4 (5-HT4) receptor agonist[92]
General anesthesia using nitrous oxide[93]
Carbamazepine: possible dopamine antagonistic effect.[94]
Cervical instability
It is especially important to recognize cervical instability as a complication of some of the conditions that may cause secondary infantile torticollis (SIT). Emergent diagnosis and treatment are essential because of risk of cervical spinal cord compromise in some of these conditions. An unstable spine requires immobilization and neurosurgical consultation, not physical therapy. The patient may require halo placement for prolonged stabilization. SIT is considered in the differential diagnosis of benign paroxysmal torticollis and congenital torticollis.
SIT may be caused by any of the following conditions:
Vertebral body segmentation anomalies (e.g., Klippel-Feil malformation, spondyloepiphyseal dysplasia, hemivertebra, subluxation of the atlanto-axial or atlanto-occipital joint, hereditary unilateral absence of the sternocleidomastoid [SCM] and trapezius muscles)[95]
Central nervous system abnormalities (e.g., cerebellar tumors, Chiari malformations, cortical dysplasia, cerebral injury or cervical spinal cord tumors)[96]
Ocular abnormalities (e.g., congenital nystagmus, 4th cranial nerve palsy)
SCM tumor of infancy (e.g., infantile desmoid fibromatosis)[97]
Sandifer disease: torticollis and episodic dystonic movements are associated with severe GERD[98]
Traumatic structural abnormalities (e.g., subluxation of cervical vertebrae, fractures, muscular injuries)
Infection in the head and neck region (e.g., cervical osteomyelitis, bacterial meningitis, retropharyngeal abscess)[99][100]
Spasmus nutans: causing nystagmus, head nodding, and torticollis[101]
The inspection and palpation of the SCM is crucial.
Status dystonicus (dystonic storm)
Status dystonicus is:[104]
A life-threatening condition seen in dystonic patients, particularly in certain types (e.g., patients with post-traumatic dystonia or nonfatal drowning)[105]
Characterized by severe generalized muscle contractions that are extremely painful
Triggered by infection, stress, trauma, surgery, fever, zinc or penicillamine therapy in Wilson disease, abrupt introduction, withdrawal, or change in medical treatment, including lithium, tetrabenazine, and clonazepam
Managed promptly in the intensive care unit
Complicated by hypercreatine kinasemia, rhabdomyolysis, hyperpyrexia, muscle exhaustion, pain, dehydration, acute renal failure, and respiratory insufficiency
One of the differential diagnoses of neuroleptic malignant syndrome and malignant hyperthermia
Treated with basic supportive therapy that includes adequate fluid balance, analgesia, antipyretics, ventilatory support; hemodynamic monitoring is vital[106][107]
At times, an indication for deep sedation under muscle paralysis and assisted ventilation. Even though it may be controlled by midazolam and propofol in a child with static encephalopathy, it may require a more aggressive approach, such as the combination of intrathecal baclofen infusion and bilateral pallidal deep brain stimulation in a patient with pantothenate kinase-associated neurodegeneration.[108][109][110]
Difficulty in breathing and swallowing
May occur during status dystonicus or at any time in the course of all types of dystonia. Prompt intervention is required. Treatment includes: maintenance of fluid and electrolyte balance by intravenous fluid hydration, nasogastric feeding, or total parenteral nutrition; and good tissue oxygenation, which may necessitate endotracheal intubation and mechanical ventilation.
Acute encephalopathic crisis and acute metabolic decompensation
Recognizing these acute conditions and managing them appropriately is crucial in the treatment of inherited dystonias due to metabolic diseases, where neurotoxic metabolites can cause permanent neurologic injury or "metabolic stroke". These conditions include glutaric aciduria type I and methylmalonic acidemia. Dystonia can also occur during acute crisis in other organic acidemias (e.g., maple syrup urine disease) and urea cycle disorders with ammonia toxicity. In these disorders, emergency treatment is indicated for any conditions with increased catabolic state (such as recurrent vomiting, diarrhea, other nonfebrile illness, fever, or decreased oral intake) or any evidence of new encephalopathy (such as irritability, poor feeding, hypotonia, new dystonia, or lethargy).
Disease-specific guidelines for outpatient and inpatient emergency treatment are available.[40][111] General principles of acute management are:[40][112]
Reversing catabolism through high-calorie nutrition with glucose and electrolytes (enterally or parenterally as needed, with or without lipids/total parenteral nutrition); any persistent hyperglycemia is corrected by insulin infusion, not by decreasing glucose infusion
Reducing production of neurotoxic metabolites by temporarily (24 hours) holding or decreasing natural protein; in some patients disease-specific amino acid mixtures may be given
Supplementing carnitine to amplify physiologic detoxifying mechanisms and prevent secondary carnitine depletion
Treating severe hyperammonemia (if present, can occur in organic acidemias) with dialysis or ammonia scavengers; severe leucinosis in maple syrup urine disease may also need dialysis
Treating any fever with antipyretics
Treating dehydration and acidosis by rehydration, which may include cautious use of bicarbonate
Empirically treating patients with possible vitamin-responsive disorders, such as hydroxocobalamin for B12-responsive methylmalonic acidemia, and biotin with thiamine for DYT-SLC19A3 (biotin-thiamine-responsive basal ganglia disease).
Acute encephalopathic crises require prompt diagnosis and aggressive treatment, which will have an impact on the degree of basal ganglia degeneration and determine the eventual functional outcome.[40]
In methylmalonic acidemia, early diagnosis and appropriate long-term treatment are essential to improve prognosis. The mainstay of long-term treatment is a low-protein, high-energy diet, supplemented with specific mixtures free of propiogenic substrates, with added vitamins and trace elements. Nasogastric or gastrostomy feeding is often used to maintain a satisfactory nutritional status. Carnitine is supplemented to prevent deficiency. Vitamin B12 is used in the responsive forms of methylmalonic acidemia.[111]
Acute bilirubin encephalopathy
Characterized by lethargy, decreased feeding, variable or fluctuating tone (hypo- and hypertonia), high-pitched cry, retrocollis and opisthotonus, impaired upward gaze, fever, and seizures. Acute bilirubin encephalopathy needs to be treated immediately by phototherapy or exchange transfusion because outcome is related to the duration of exposure to excessive bilirubin.
Neonates with hyperekplexia have "board-like" rigidity, which can result in apnea and sudden death. Episodes respond well to head and leg flexion and to clonazepam.[113]
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