Asterixis As a Focal Neurologic Sign: Report of Three Cases and Literature Review
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Caspian Journal of Neurological Sciences http://cjns.gums.ac.ir Asterixis as a Focal Neurologic Sign: Report of Three Cases and Literature Review Sayadnasiri Mohammad (MD) 1* , Altafi Davar (MD) 2 A R T I C L E I N F O A B S T R A C T Article type: Asterixis, firstly described in metabolic encephalopathies, may occur Case Report unilaterally in patients with various focal brain diseases. Although hardly localizing, most reported cases have showed a contralateral thalamic pathology; but Lesions in the medial frontal lobe, parietal lobe, brain stem, basal ganglia, Article history: insular lesions, may also cause unilateral asterixis. In this article, three cases of Received: 16 September 2015 acute cerebral vascular event with unilateral or asymmetrical asterixis were Accepted: 7 January 2016 described: first patient with left sided hemiparesis and asterixis that ultimately Available online: 30 June 2016 diagnosed as right thalamic hemmorrage; second patient with right sided CJNS 2016; 2 (5): 54-58 hemiparesis and asterixis after acute left thalamic infarction and a patient with transient right sided weakness and bilateral asymmetrical asterixis secondary to a transient ischemic attack in left internal carotid territory. We then provided a literature review of published similar cases to emphasize on asterixis as a focal 1. Assistant Professor of Neurology, Department of Clinical Sciences, neurological sign. University of Social Welfare and Rehabilitation Sciences, Tehran, Iran 2. Neurologist, Department of Neurology, Alavi University Hospital, Ardabil, Iran Keywords: Asterixis; Thalamus *Corresponding author: Assistant Professor of Neurology, Copyright © [2016] Caspian Journal of Neurological Sciences. All rights reserved. Department of Clinical Sciences, University of Social Welfare and Please cite this paper as: Rehabilitation Sciences, Tehran, Sayadnasiri M, Altafi D. Asterixis as a Focal Neurologic Sign: Report of Three Cases and Iran Literature Review. Caspian J Neurol Sci 2016; 2(5): 54-58. Email: [email protected] Introduction sterixis, which is traditionally may affect various parts of the body considered a sign of metabolic independently. By electrophysiological study, A cerebral dysfunction, is a form of these myoclonic lapses of posture became involuntary movement characterized by more apprehensible where involuntary 50- to intermittent loss of muscle tone during 200 msec silent periods appeared in both posture maintenance (1). Clinically, it flexors and extensors during downward produces the so-called bilateral flapping (flexor) phase of hand asterixis (2,3). In tremor of asterixis which appears as nearly all cases, asterixis is bilateral and arrhythmic flexion-extension of the wrist and associated with toxic-metabolic fingers, several seconds after holding of the encephalopathies but it may be infrequently upper limbs in an outstretched position but manifested unilaterally so, the possibility of 54 Asterixis as a Focal Neurologic Sign Sayadnasiri M and Altafi D focal cerebral origin for this sign arose. Patient 2, a 62 years old man, presented Reported case series of patients with focal with sudden mild right sided hemiparesis and brain lesions and asterixis opened new sensory loss. At examination, right sided horizon on the pathophysiologic concept of asterixis was evident that recovered after 2 this sign. weeks. Brain MRI showed a small thalamic In this paper, we firstly describe three infarct (Figure 2). cases of unilateral asterixis and continue with a brief literature review to characterize asterixis as a focal neurologic sign. Case Presentation Patient 1, a 62 years old man, was referred with headache and gait abnormality to emergency ward. At first examination, patient showed mild left sided weakness and a tendency to fall leftward when walking. In outstretched upper limb position (performed for muscle force evaluation), he manifested a left-sided flapping tremor. Laboratory tests ruled out any underlying metabolic abnormality. Brain CT scan was performed that revealed a right thalamic hematoma Figure 2. Brain MRI (FLAIR) showed a small hypersignal lesion of left thalamus due to infarction in patient 2 (arrow). (Figure 1). Patient 3, a 59 years old diabetic man, presented with acute confusional state, right sided hemiparesis and bilateral asterixis more prominent at right side. All findings recovered after 12 hours. Brain MRI (including DWI) revealed no abnormality but Doppler ultrasound of carotid arteries revealed more than 70% stenosis of proximal left internal carotid artery. Laboratory tests were normal. Discussion For the identification of studies included or considered unilateral asterixis, detailed search strategies were developed by searching Figure 1. Brain CT scan without contrast showed a right thalamic MEDLINE/PubMed (till 2012). Totally, 26 hematoma in patient 1. articles, as we found, described this sign as case reports or case series (4-29). Adams and 55 Caspian J Neurol Sci 2016 June; 2(5): 54-58 Foley first described asterixis in patients with Authors have proposed several different advanced hepatic encephalopathy in 1949 (1) pathophysiologic mechanisms for asterixis; in but first report of unilateral asterixis was fact, it is postulated that pathologic structures appeared when Young et al reported in reported cases may be a part of the posture unilateral asterixis produced by a discrete maintaining system. Frequent involvement of CNS lesion (4). thalamus or adjacent structures suggested Totally, 125 patients have been reported disruption of thalamo-cortical loops as the with unilateral asterixis, as we found. main pathology (10,12,15,19,20,25,28). Because of not available some papers’ full Sensory (parietal) cortex involvement in some text, 100 patients with defined cause were case reports are also in favour to this afferent analysed and results are as follows: motor dysfunction (12). Nighoghossian et al Of all patients with mentioned definite (21) reported patients with primary motor causes (100 patients), 71 patients (71%) had cortex lesion and recommended asterixis may thalamic lesions; the seconds most common be a disorder of efferent (command signal site was cortical area (11%) especially frontal generator) pathways. lobe (9%). Other involved areas, in order to By finding out other involved structures, frequency, are internal capsule (6%), brain the pathophysiologic ranges were extended to stem (5%), basal ganglia (4%) and cerebellum cerebello-brain stem- thalamus-frontal system (3%). dysfunction (26). However, the exact The most frequent cause for unilateral mechanism underlying asterixis remains asterixis has been reported to be stroke, either elusive. Generally, it can be concluded that ischemic or hemorrhagic (87%). Other postural control of limbs is under influence of reported causes were rare and included many brainstem and spinal pathways that are, tumors (12,15,24), encephalitis (23), post- in turn, are controlled by supratentorial surgical (19), subdural hematoma (11). structures (1) and thalamus (especially Fourteen patients (11%) presented with ventrolateral nucleus) plays a major role in bilateral asterixis despite a focal lesion. connecting these diverse areas, so it’s Only a few patients with non-stroke pathology leads to disruption of these etiology manifested this focal sign; this pathways so greatly that clinical asterixis indicates that on contrary to bilateral asterixis emerges. On the other hand, some cases of resulting from slowly evolving metabolic bilateral asterixis in the presence of a focal disturbances, lateralized asterixis often results lesion emphasize that this posture controlling from an acute disruption of neuronal circuits system is not necessarily unilateral and this and chronic focal lesions rarely produce this bilateral representation is another explanation sign. This susceptibility to acute injury and for transient nature of this symptom. transient nature of this symptom may be Our three reported cases are, also, in explained by wide ranges of neural pathways agreement with previous reports and affecting posture maintenance, as described underlined thalamic vascular accident as below, that leads to rapid brain adjustment major culprit in development of unilateral and recovery but the main cause is not yet axterixis. An interesting part is TIA-like described. nature of bilateral asterixis in third patient 56 Asterixis as a Focal Neurologic Sign Sayadnasiri M and Altafi D that rarely reported as yet. This means 6. Ericson G, Warren SE, Gribik M, Channick M, Steinberg SM. Unilateral Asterixis in a asterixis, in setting of a focal brain lesion, Dialysis Patient. JAMA 1978; 240(7):671. follows the main features of other focal 7. Degos J, Verroust J, Bouchareine A, Serdaru neurological signs in spite of bilateral M, Barbizet J. Asterixis in Focal Brain presentation. Lesions. Arch Neurol 1979; 36(11):705-7. 8. Massey EW, Goodman JC. Unilateral Asterixis. JAMA 1979; 241(2):133-4. Conclusion 9. Massey EW, Goodman JC, Stewart C, Brannon WL. Unilateral Asterixis: Motor Asterixis, bi- or unilateral, may be Integrative Dysfunction in Focal Vascular considered as a focal neurological sign in Disease. Neurology 1979; 29(8):1180-2. specific situations. This is a short-lasting sign 10. Donat JR. Unilateral Asterixis Due to in patients with focal brain lesions and Thalamic Hemorrhage. Neurology 1980; occasionally may present in setting of a TIA. 30(1):83-4. 11. Vallat JM, Rkina M, Bokor J. Unilateral Although not definitely localizing, a Asterixis due to