Movement Disorder Emergencies 1 4 Robert L. Rodnitzky Abstract Movement disorders can be the source of signifi cant occupational, social, and functional disability. In most circumstances the progression of these disabilities is gradual, but there are circumstances when onset is acute or progression of a known movement disorders is unexpectedly rapid. These sudden appearances or worsening of abnormal involuntary movements can be so severe as to be frightening to the patient and his family, and disabling, or even fatal, if left untreated. This chapter reviews movement disorder syndromes that rise to this level of concern and that require an accurate diagnosis that will allow appropriate therapy that is suffi cient to allay anxiety and prevent unnecessary morbidity. Keywords Movement disorders • Emergencies • Acute Parkinsonism • Dystonia • Stiff person syndrome • Stridor • Delirium severe as to be frightening to the patient and his Introduction family, and disabling, or even fatal, if left untreated. This chapter reviews movement disor- Movement disorders can be the source of signifi - der syndromes that rise to this level of concern cant occupational, social, and functional disabil- and that require an accurate diagnosis that will ity. In most circumstances the progression of allow appropriate therapy that is suffi cient to these disabilities is gradual, but there are circum- allay anxiety and prevent unnecessary morbidity. stances when onset is acute or progression of a known movement disorders is unexpectedly rapid. These sudden appearances or worsening Acute Parkinsonism of abnormal involuntary movements can be so The sudden or subacute onset of signifi cant par- R. L. Rodnitzky , MD (*) kinsonism, especially akinesia, is potentially very Neurology Department , Roy J. and Lucille A. Carver frightening to the affected patient and his/her College of Medicine, University of Iowa , Iowa City , IA , USA family members. Of more concern is the potential e-mail: [email protected] for severe untreated akinesia to lead to serious K.L. Roos (ed.), Emergency Neurology, DOI 10.1007/978-0-387-88585-8_14, 259 © Springer Science+Business Media, LLC 2012 260 R.L. Rodnitzky complications, such as pulmonary embolism, persistent hydrocephalus, or to shunt revision, aspiration, and pneumonia. Seven general etio- levodopa therapy is usually effective both in the logic categories of acute parkinsonism can be short term and chronically [ 2, 4– 6 ] . identifi ed and the likelihood of arriving at the Acute cerebral infarction involving the stria- correct clinical diagnosis can be greatly enhanced tum or the substantia nigra is another structural by systematically considering which one or com- insult that can result in acute parkinsonism. The bination of these etiologies may be at play in a common term “vascular parkinsonism,” as used given acutely parkinsonian patient. The seven today, refers to the gradual appearance of parkin- etiologic categories of acute parkinsonism are as sonian features, usually a parkinsonian gait, due follows (1) structural, (2) toxic, (3) impaired to diffuse, bihemisphere small vessel ischemic levodopa absorption, (4) iatrogenic, (5) infec- disease. Large artery infarctions, on the other tious, (6) surgery, and (7) de novo (spontaneous hand, produce unilateral or bilateral parkinsonism acute parkinsonism). over a matter of days to months. When a striatal infarction is associated with signifi cant hemipa- resis, unilateral parkinsonism typically evolves Structural once the hemiparesis begins to improve [ 7 ] . Striatal infarctions are relatively common, but The two most common structural causes of acute only a small percentage result in parkinsonism parkinsonism are stroke and hydrocephalus, [ 8 ] . Parkinsonism can also develop after infarc- although neither is extremely common in an tion of the substantia nigra [ 9 ] . Infarction of the absolute sense. Parkinsonism due to acute hydro- pedunculopontine nuclei in the brainstem can cephalus is to be distinguished from the gradu- cause acute onset of gait freezing, similar to that ally evolving form of parkinsonism that can seen in Parkinson’s disease [ 10 ] . Therapy of occur in patients with chronic hydrocephalus, infarction-related parkinsonism with levodopa is especially normal pressure hydrocephalus. Acute most effective in those cases where the pathology parkinsonism can occur simultaneously with the is in, or close to, the substantia nigra [ 11 ] . development of acute hydrocephalus [ 1 ] but can Somewhat paradoxically, stroke involving the also occur after shunt placement [ 2, 3 ] or shunt tuberothalamic artery can improve parkinsonian revision [ 4 ] in patients with long-standing tremor, presumably through damage to the vent- hydrocephalus. The rapid onset of parkinsonism rolateral thalamic nucleus, similar to the lesion of in acute hydrocephalus is probably due to a therapeutic thalamotomy [ 12 ] , or deep brain direct compression or shearing force on the stimulation of this structure. substantia nigra secondary to changing pressure dynamics of the rapidly enlarging ventricles [5 ] . Parkinsonism due to shunt revision or placement Toxic is due to rapidly shrinking ventricles with subse- quent midbrain distortion [ 2 ] . The simultaneous A variety of nonindustrial toxins can also cause occurrence of other signs of rostral midbrain acute parkinsonism. The more common toxic dysfunction, along with parkinsonism, after exposures that might present to a community shunting supports the notion that the postshunt- Emergency Department are discussed here. ing fi ndings are all due to mechanical distortion Organophosphate insecticides, either through of the midbrain [ 6 ] . In patients whose akinesia inadvertent ingestion on food or exposure in an appears to be related to acute hydrocephalus with agricultural setting, can cause acute, reversible acutely enlarging ventricles, shunting is indi- parkinsonism. In these cases, treatment with cated and could be lifesaving. Parkinsonism levodopa [ 13 ] has been less effective than amanta- might be improved by this intervention, or dine [ 14 ] and dopamine agonists [ 15 ] . Carbon as mentioned above, could be exacerbated. monoxide (CO) poisoning results in subacute par- In parkinsonism related to acute hydrocephalus, kinsonism. In a large series of 242 CO poisoning 14 Movement Disorder Emergencies 261 cases, 10% of the individuals affected developed resultant impaired levodopa absorption should be parkinsonism with a latency of 2–26 weeks strongly suspected. Gastroparesis in PD patients (median 4 weeks) after the acute exposure [16 ] . has also been reported in the presence of acute Imaging of the brain in these patients reveals evi- duodenal ulcer and intestinal volvulus [ 21 ] . In dence of bilateral pallidal necrosis with symmetric addition to treating the primary medical cause of hypodensity on CT scan and high signal intensity delayed gastric emptying, prokinetic agents can on FLAIR and T2-weighted MRI sequences [17 ] . be useful to reduce gastric stasis. Domperidone, a There is, however, not a complete correlation peripheral dopamine receptor antagonist, is use- between the appearance of pallidal necrosis on CT ful for this purpose but is not yet approved in the or MRI and parkinsonism in CO poisoning. Of 17 USA. Administering levodopa with a carbonated patients with CO-related parkinsonism in one and/or caffeinated beverage may enhance pas- series, only 47% had abnormal CT scans [16 ] . In sage of levodopa through the stomach and this series, levodopa and anticholinergic drugs enhance absorption. Replacing an oral dopamine were not effective, but 81% of affected individuals agonist with a transdermal agent, such as rotigo- recovered gradually over a 6-month period of tine [ 22 ] (if available), would be useful. For very time. Initial hyperbaric oxygen therapy of CO poi- severe absorptive dysfunction with signifi cant soning in the acute phase may reduce subsequent akinesia such as after gastrointestinal surgery, neurologic sequelae, but controlled studies of this subcutaneous apomorphine may prove useful therapeutic approach are still lacking [18 ] . [ 23 ] , although in this circumstance, some patients Purposeful or accidental ingestion of ethylene gly- become relatively refractory to all dopaminergic col or methanol can result in acute parkinsonian agents, including apomorphine [ 21 ] . akinesia, often associated with hemorrhagic necro- sis of the basal ganglia [ 19 ] . Levodopa therapy can improve the rigidity and bradykinesia associ- Iatrogenic ated with these two toxic exposures [ 19 ] . The inadvertent or ill-advised use of drugs that are dopamine receptor blocking agents (DRBA) Impaired Levodopa Absorption can rapidly result in a severely exacerbated par- kinsonian state in PD patients. Occasionally, non- Gastric emptying is commonly slightly delayed PD patients or PD patients not yet known to have in PD patients, but superimposed gastrointestinal clinically apparent PD can be rendered acutely or disorders can further delay passage of levodopa subacutely akinetic by the administration of through the pylorus resulting in a signifi cant DRBAs, particularly if used at a high dosage. decrease in levodopa absorption in its main Among DRBAs, the typical antipsychotic agents, absorptive site in the jejunum. The consequence such as haloperidol, have the greatest potential to of such an acute or subacute decrease in levodopa cause signifi cant akinesia, but other classes of absorption is an acute increase in parkinsonian dopamine