Unilateral asterixis associated with a mesencephalic syndrome

Hyperkinetic movement disorders during and after acute stroke: the Lausanne Stroke Registry

BACKGROUND AND OBJECTIVE

To study consecutive patients with acute or delayed hyperkinetic movement disorders in the Lausanne Stroke Registry.

METHODS

We have identified 29 patients with acute or delayed movement disorders among 2500 patients who had their first-ever acute stroke in the Lausanne Stroke Registry.

SETTING

Department of Neurology, Lausanne University Hospital.

RESULTS

Our patients presented with hemichorea-hemiballism (11 patients), hemidystonia (5 patients), stereotypias (2 patients), jerky dystonic unsteady hand (3 patients), asterixis (2 patients), initial limb-shaking (2 patients), bilateral tremor (1 patients), bilateral jaw myoclonus (1 patient), hemiakathisia (1 patient) and dysarthria-dyskinetic hand (1 patient). On neuroimaging a lesion was found in 25 of the 29 cases in the territory of the middle cerebral artery (7 deep, 2 superficial and 2 complete), the posterior cerebral artery (11 patients), both middle and posterior cerebral arteries (2 patients) or the anterior cerebral artery (1 patient). The jerky dystonic unsteady hand syndrome was associated with a specific lesion, an infarct in the territory of the posterior choroidal artery. Presumed small-vessel disease was the commonest cause of stroke (15 patients). Only 3 patients had persistent movements (> 6 months).

CONCLUSION

Hyperkinetic movement disorders are uncommon in acute stroke (1%), the commonest types being hemichorea-hemiballism and hemidystonia. These movement disorders are associated with stroke involving the basal ganglia and adjacent white matter in the territory of the middle or the posterior cerebral artery. The jerky dystonic unsteady hand syndrome is specifically associated with a small infarct in the territory of the posterior choroidal artery. The abnormal movements usually regress spontaneously.

Asterixis associated with anatomic cerebral lesions: a study of 45 cases

INTRODUCTION

Asterixis is an uncommon sign in structural central nervous system disorders. When asterixis is present, one cannot rule out the possibility of a focal lesion, but it is almost always due to a metabolic encephalopathy.

PATIENTS AND METHODS

In the last five years all patients with uni- or bilateral neurologic asterixis attended in our hospital have been studied. Cerebral computed tomogram or magnetic resonance imaging was performed in all patients with uni or bilateral asterixis.

RESULTS

We describe 45 patients with different forms of structural cerebral pathology who presented unilateral (37 patients) or bilateral (8 patients) asterixis not associated to either toxic or metabolic disorder. Central nervous system ischemic or hemorrhagic disorders were found to be the most frequent causes of asterixis (95.5%) and the thalamus the most frequent localization for unilateral asterixis to result (54%).

CONCLUSIONS

Bilateral asterixis is not always associated with toxic or metabolic disorders and it may be a sign of some structural neurologic alterations. A good correlation was found between the presence of unilateral asterixis and structural intracranial disease.

Unilateral upper limb asterixis related to primary motor cortex infarction

BACKGROUND

Unilateral upper limb asterixis related to cortical infarct is an unusual clinical picture. We found this association in two patients. Magnetic resonance imaging (MRI), somatosensory evoked potentials (SEPs), and electromyographic recording were performed.

CASE DESCRIPTIONS

Two patients developed an acute upper limb ataxia with asterixis. This consisted of frequent arrhythmic loss of extensor muscle tone on instruction to maintain the wrist and fingers extended. Voluntary electromyographic activity in the left extensor digitorum communis muscle showed abrupt periods of interruption ranging from 90 to 260 milliseconds in duration in the first case and from 60 to 220 milliseconds in the second case. SEPs were normal. MRI disclosed a right cortical infarct within the primary motor cortex in both cases.

CONCLUSIONS

These findings indicate that asterixis was not related to a failure in the processing of proprioceptive input controlling the regulation of postural tone of the distal upper limbs because SEPs were normal. The involvement of primary motor cortex might suggest that asterixis results from an impairment of a centrally generated motor-command signal controlling the postural tone of the distal upper limb.

Movement disorders following lesions of the thalamus or subthalamic region

Reports of 62 cases with a movement disorder associated with a focal lesion in the thalamus and/or subthalamic region were analyzed. Thirty-three cases had a lesion confined to the thalamus. Sixteen cases had a thalamic lesion extending into the subthalamic region and/or midbrain. Thirteen cases had a lesion in the subthalamic region or a subthalamic lesion extending into the midbrain. Nineteen cases with dystonia, 18 with asterixis, 17 with ballism-chorea, three with paroxysmal dystonia, and five with clonic or myorhythmic movements have been described. No case with isolated tremor has been described. In 53 cases with unilateral thalamic or subthalamic lesions, all but one with bilateral blepharospasm (associated with right posterior thalamic, pontomesencephalic, and bilateral cerebellar lesions) had dyskinesias in the limbs contralateral to the lesion. The other nine cases had bilateral paramedian thalamic lesions; seven developed bilateral dyskinesias, and the remaining two had unilateral dyskinesias. Regarding the 19 patients with dystonia, the two with bilateral blepharospasm had thalamic and upper brainstem lesions, and one with hemidystonia and torticollis had a subthalamic lesion. The other 16 patients all had a unilateral thalamic lesion with contralateral dystonia (10 hemidystonia, five focal dystonia affecting a hand and/or and one segmental dystonia involving face, arm, and hand). The exact location of the thalamic lesion was mentioned in 10 cases; the posterior or posterolateral thalamus was involved in six and the paramedian thalamus in four. These areas are more posterior or medial to the ventrolateral and ventroanterior thalamic nuclei, which receive pallido-thalamic and nigro-thalamic afferents. Two cases developed dystonia immediately after thalamotomy, and one case developed it 4 days after head trauma. The others initially had a hemiplegia and developed dystonia 1-9 months after the acute insult. Fifteen of the 17 patients with chorea had a unilateral lesion in the subthalamic nucleus or subthalamic region (eight due to infarcts, one to hemorrhage, five to mass lesions, and one to multiple sclerosis). All had contralateral hemichorea or hemiballism. One other case had bilateral chorea of the hands and tongue due to paramedian thalamic infarction. Another case with generalized chorea and thalamic atrophy was complicated by stereotaxic surgery. Thirteen of the 18 cases with asterixis had lesions confined to the thalamus. Eight were associated with thalamotomy, and five others had a stroke (four infarction and one hemorrhage) affecting the contralateral thalamus.(ABSTRACT TRUNCATED AT 400 WORDS)

Asterixis induced by carbamazepine therapy

There are very few reports about asterixis as a side effect of treatment with psychopharmacologic agents. In this report we present four patients treated with a combination of different psychotropic drugs, in whom asterixis was triggered either by adding carbamazepine (CBZ) to a treatment regimen, or by increasing its dosage. Neither dosage nor serum levels of CBZ were in a higher range. We consider asterixis to be an easily overlooked sign of neurotoxicity, which may occur even at low or moderate dosage levels, if certain drugs as lithium or clozapine are used in combination with CBZ.

Cortical activity-associated negative myoclonus

A patient with myoclonus epilepsy had 2 types of negative myoclonus as well as positive myoclonus at rest. One type followed a large EMG discharge at the end of continuous contraction and the other did not. Both types of negative myoclonus and positive myoclonus were preceded by EEG activity, predominantly distributed in the contralateral central region. It is suggested that an abnormal activity around the motor cortex suppresses a voluntary contraction as well as induces myoclonus. Clonazepam was markedly effective on both positive and negative myoclonus.

Transient myoclonic state with asterixis in elderly patients: a new syndrome?

We report 7 patients who developed acute co-occurrences of fragmentary generalized myoclonus and asterixis. All patients were elderly and had other chronic diseases. This condition appeared acutely, progressed over several hours and then disappeared in 2-3 days with diazepam administration. No sequelae were noted, although most cases developed recurrences. The myoclonus occurred spontaneously and was slightly enhanced by action. The myoclonus was widely distributed but predominated in the neck, shoulder girdle, and upper extremities. Opsoclonus was not noted. Clinically apparent myoclonus was not evoked by sensory stimuli. Asterixis was observed in the upper extremities in all cases. Asterixis-like movements of the protruded tongue were also observed. Neurological findings other than the myoclonus and asterixis were unremarkable. Neither metabolic nor organic abnormalities clearly responsible for this condition were identified. Cerebral potentials preceding the myoclonic jerks recorded in one case suggested that the myoclonus may have been a spontaneous cortical myoclonus. We named this condition a transient myoclonic state with asterixis (TMA). Awareness of this syndrome is clinically important because of its benign nature, although it can recur.

Synchronous positive and negative myoclonus due to pontine hemorrhage

We report a case of synchronous positive and negative myoclonus following pontine hemorrhage. Constant synchronous jerking of the eyes, tongue, face, mandible, larynx, pharynx, and diaphragms persisted during sleep. Jerking of limb muscles occurred during volitional activities, but not at rest. Inability to sustain glottic adduction during phonation contributed to severe dysarthria. Electromyography (EMG) revealed positive myoclonus of the branchial musculature with synchronous negative myoclonus in a generalized distribution. Treatment with trazodone reduced the ocular myoclonus but worsened the dysphagia. We suggest that a single neural rhythm generator may produce both positive and negative myoclonus.

Unilateral asterixis due to ipsilateral lesions in the pons and medulla

Unilateral asterixis was ipsilateral to the brainstem lesions in 2 patients. The finding of unilateral asterixis has been consistently associated with structural neurological disease, but contrary to previous reports it is not a reliable localizing or lateralizing finding.

Asterixis due to pontine hemorrhage

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Hyperammonemia in asterixis induced by carbamazepine: two case reports

Two patients developed asterixis while they were taking carbamazepine at "therapeutic" levels. The only laboratory abnormality was slight hyperammonemia. It occurred with normal hepatic function as a dose-related effect. In fact, the blood ammonia level decreased and asterixis ceased when carbamazepine was stopped or reduced in dosage. The relationship between asterixis and hyperammonemia during carbamazepine therapy is discussed.

Rhythmic alternating asterixis

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Midbrain asterixis

Asterixis is usually a manifestation of metabolic encephalopathy. It was the only skeletal motor sign in a patient with ophthalmoplegia caused by midbrain infarction; no metabolic abnormality was present. The asterixis was accompanied by signs of damage to the mesencephalic reticular formation. We propose that episodic lapses of postural control by the reticular formation are responsible for midbrain asterixis and suggest that this asterixis is a segmental form of drop attack.