Akinetic mutism following stroke

Download Akinetic mutism following stroke

Post on 21-Oct-2016




3 download

Embed Size (px)


<ul><li><p>Clinical study</p><p>Akinetic mutism following strok</p><p>Nages Nagaratnam, Kujan Nagaratnam, Kevin Ng, Patrick D</p><p>Blacktown-Mount Druitt Health, Blacktown, NSW 2148, Australia</p><p>he</p><p>irium</p><p>ent</p><p>r ar</p><p>m</p><p>lin</p><p>bou</p><p>xpl</p><p>frontal subcortical circuits.</p><p>ubc</p><p>This paper will appraise (i) stroke patients with AM selected to</p><p>and non-communicative but seemed to comprehend. Three weeks</p><p>tone was increased in all four limbs. He had a grasp reflex with</p><p>motor, supplementary motor area, prefrontal and anterior part of</p><p>gyrus on the right side and deep in the left parietal region (Fig. 3).Speech output was markedly reduced and whatever words he ut-</p><p>was relatively unimpaired and was able to identify objects, col-</p><p>Journal of Clinical Neuroscience (2004) 11(1), 2530</p><p>0967-5868/$ - see front matter 2003 Elsevier Ltd. All rights reserved.doi:10.1016/j.jocn.2003.04.002</p><p>Accepted 9 April 2003Blacktown, NSW 2148, Australia.25ours, geometric designs, letters and body parts. The voice washypophonic. He remained alert with eyes open and tracking with</p><p>Correspondence to: Nages Nagaratnam, Blacktown-Mount Druitt Health,tered were slurred. Comprehension was possible. He had right-sided weakness and bilateral plantar responses. When seen a weeklater he was alert but had reduced verbal output. ComprehensionReceived 17 October 2002later although she was alert, she was markedly akinetic with noillustrate the variability in the clinical presentation, speech andlanguage characteristics and course of the disease process and (ii)the likely pathophysiological mechanisms that underlie the di-verse locations associated with AM.</p><p>ILLUSTRATIVE CASES</p><p>Right supplementary area and cingulate gyrus</p><p>A 77-year-old right handed woman was seen with left-sidedhemiplegia on day two. She was drowsy and responded poorly toverbal commands. She had a right gaze palsy with total weaknessof the left arm and leg. The tone was decreased and the left plantarwas extensor. She was in atrial fibrillation. On day 8 she was alert</p><p>the cingulate gyrus (Fig. 2).</p><p>Right cingulate gyrus and deep left parietal</p><p>A right-handed 38-year-old male was seen with right-sidedweakness. The CT scan done the following day and a repeat scanfour days later did not reveal any abnormality. He suffered fromdysarthria and at the end of 4 weeks he had largely recovered andwas walking independently. Cerebral angiogram was normal sowas the carotid doppler. Investigations such as echocardiogram,cardiolipin antibodies, procoagulants, ANA, and ds DNA were allnormal. He was seen 10 months later with a recurrence of hisright-sided weakness. The CT scan and MRI showed hypodenseareas abutting the corpus callosum and involving the cingulate 2003 Elsevier Ltd. All rights reserved.</p><p>Keywords: akinetic mutism, abulia, apathy, aphasia, stroke, frontal s</p><p>INTRODUCTION</p><p>Akinetic mutism (AM), abulia and apathy are terms that have beenused to describe behavioural abnormalities relating to reducedactivity and slowness. Several investigators proposed that theseclinical states are simply a continuum of severity of reduced be-haviour and AM may be an extreme form.1</p><p>Following the landmark case report of Cairns et al.,2 the termAM had been used to describe a syndrome characterised bymarked reduction of nearly all motor functions including facialexpression, gestures and speech output but with some degree ofalertness. They described a patient with an epidermoid cyst in thethird ventricle whom after several evacuations of the cyst becamemore alert and responsive. Since then AM had been used in sit-uations with similar clinical picture associated with differentaetiologies and pathologies. There is considerable variation in thepresentation of such patients and the clinical features of AMcorrespond more closely to the functional anatomy of the brainregions affected rather to the pathology.Summary This is an appraisal of the varied clinical presentation and t</p><p>important as akinetic mutism is often misdiagnosed as depression, del</p><p>patients with akinetic mutism following infarction/haemorrhage in differ</p><p>critical areas namely, the frontal (cingulate gyrus, supplementary moto</p><p>the mesencephalon and thalamus. The disorders of speech and com</p><p>inertia, hypophonia, perseveration, softened and at times slurred. The</p><p>(motor, mixed) aphasias. The findings were related to what is known a</p><p>subcortical circuitry in relation to behaviour. Akinetic mutism could be eforced grasping. He spoke with an occasional yes and the voicewas of low volume and showed no emotion. The findings of thespeech assessments at two weeks and a month later were that of ananomic aphasia (Table 1). The CT scan demonstrated an infarctionin the left anterior cerebral artery territory involving the sensory,speech output except for an occasional word. There was somereturn of power to the left arm. There was no grasp reflex orforced grasping. The CT scan of the brain done on day 2 showedan infarction in the territory of the right anterior cerebral artery(Fig. 1). When seen four weeks post-onset she remained mute.</p><p>Left supplementary motor area cingulate gyrus andpremotor area</p><p>A 75-year-old right handed man was seen in hospital with a right-sided hemiparesis and inability to talk. He was alert and hadweakness of his right arm and leg, leg more than arm (subtle). Thee</p><p>iu</p><p>neural substrate for akinetic mutism following stroke. The diagnosis is</p><p>and locked-in-syndrome.This is a descriptive study of eight selected</p><p>regions of the brain with characteristic syndromes. They involved the</p><p>ea and dorso-lateral border zone), basal ganglia (caudate, putamen),</p><p>unication took different forms. The speech disorder included verbal</p><p>guistic disturbances were fluent, non-fluent, anomia and transcortical</p><p>t the neuroanatomic location of the lesions and the role of the frontal-</p><p>ained by damage to the frontal lobe and or interruption of the complex</p><p>ortical circuitry</p></li><li><p>26 Nagaratnam et al.generalised slowness but able to communicate, though poorly. Hedied suddenly two weeks later and no autopsy was done.</p><p>Caudate nucleus</p><p>A right handed 72-year-old English speaking man of Polish ex-traction was seen in hospital for not talking over three days withnumbness and weakness of his right side of less than a day. He had</p><p>Fig. 1 CT scan showing infarction in the right anterior cerebral artery territory.</p><p>Table 1 Results of the Western Aphasia Battery test</p><p>19.04.98 15.5.98</p><p>Spontaneous speech Severe impairment</p><p>Information content (10) 0 8</p><p>Fluency (10) 0 9</p><p>Comprehension Moderate impairment</p><p>Yes/no questions (60) 39 59</p><p>Auditory word recognition (60) 32 54</p><p>Sequential commands (80) 16 72</p><p>Repetition (100) Severe 2 96</p><p>Naming Severe impairment</p><p>Object naming (60) 0 60</p><p>Word fluency (20) 0 8</p><p>Sentence sequence (10) 4 10</p><p>Responsive speech (10) 0 10</p><p>Aphasia quotient 9.4 89.3</p><p>Reading and writing were severely impaired initially and reassessment.</p><p>( ) Maximum score.</p><p>Journal of Clinical Neuroscience (2004) 11(1), 2530been well till three days earlier when the wife noticed him sittingand apparently in deep thought and never spoke. Two days laterhe had weakness of the right arm and was unsteady on his feet.These symptoms had largely resolved by the time he was seen inhospital. He was a hypertensive. On examination he was alert. Thespeech output was markedly reduced and expression was limitedto single words when actively spoken to. An Aphasia LanguagePerformance Scale was completed but detailed aphasia assessmentwas not possible. The rest of the nervous system was normal. TheCT scan of the brain showed a hypodense area in the region of theleft caudate nucleus (Fig. 4).</p><p>Putamen</p><p>This case had been reported in detail earlier.3 This is a 79-year-oldman who was seen with slurred speech and had difficulty inproviding responses to questions with prolonged delay. His voli-tional swallowing was slow chewing was effortful and keptremnants of food in the mouth. He had subtle weakness of hisright side but could walk only with two people. On the BostonDiagnostic Aphasia Examination he was slow with longer in-structions, correct naming of objects and expression were 75%and 50%, respectively, with perseveration on previous response.The findings were consistent with abulia and this lasted for morethan 12 weeks. The CT scan done on day 1 revealed an extensivehaemorrhage in the region of the left putamen and extending to-wards the internal capsule. On day 18 a repeat CT scan showed a</p><p> 2003 Elsevier Ltd. All rights reserved.</p></li><li><p>Akinetic mutism following stroke 27hypodense area in the left putamen. On day 60 proton-density-weighted image demonstrated haemosiderin rim in the externalcapsule and a slit extending towards the thalamus (Fig. 5).</p><p>Border zones</p><p>A 73-year-old man had combined coronary artery bypass and rightcarotid endarterectomy. He had subtle residual weakness on theleft side following an earlier stroke. Post-operatively, he went intocardiogenic shock. Two days later he was alert but was unable tospeak with weakness of the left arm and leg and reluctant to movehis limbs. The tone was increased in all four limbs but the reflexeswere normal. The plantars could not be elicited. Finger dexteritywas poor bilaterally.</p><p>He could hardly talk and that to in single words when ac-tively spoke to with a low voice, he understood what was said.</p><p>However, he was slow and reluctant to carry out simple verbacommands. The speech output over the next two weeks re-mained markedly reduced, hypophonic and slurred with a ten-dency to perseverate and hardly exhibited any emotion. He hada grasp reflex in his right hand but no forced grasping. Eighweeks post-onset speech assessment revealed the expression tobe restricted but able to produce personal information reason-ably accurately and repetition skills were good and was able toidentify object functions. Yes/no responses were unreliable andwas able to follow commands at the two-word level. A weeklater the speech output was somewhat improved and showedmore emotion and was able to stand and walk with minimaassistance.</p><p>The CT scan of the brain showed hypodense areas at the levelsof the centrum semiovale and corona radiata in the central borderzones (right) and in the cortical border zones dorsolateral (left)</p><p>Fig. 2 CT scan showing in the territory of the left anterior cerebral artery involving the sensory, motor, supplementary motor area, prefrontal and anterior part of</p><p>the cingulate gyrus.</p><p>Fig. 3 MRI scan showing hypodense areas abutting the corpus callosum and involving the cingulate gyrus on the right side and deep in the left parietal region</p><p> 2003 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2004) 11(1), 2530l</p><p>t</p><p>l</p><p>.</p></li><li><p>the left thalamus and midbrain bilaterally. Over the next three</p><p>28 Nagaratnam et al.Fig. 4 CT scan showing a hypodense area in the region of the left caudate</p><p>nucleus.and posterolateral (right) consistent with bilateral watershed in-farctions (Fig. 6).</p><p>Thalamus</p><p>A 50-year-old right-handed man and a known hypertensive wasadmitted with left-sided weakness, gaze palsy and was mute.There was apathy with limited responses after long delay. The CTscan of the brain showed a primary right thalamic haemorrhage.On day 3 he developed haemocephalus with mass effect and anexternal ventricular drain was inserted. He remained mute forseveral days with return of speech which was slow, hypophonicand slurred. His mood fluctuated, he was impulsive with denial.</p><p>Mesencephalothalamic</p><p>A 64-year-old right handed man following a left thalamo-me-sencephalic infarction lacked spontaniety with perseveration ofmovements had been described in an earlier article written by theauthor.4 The CT scan demonstrated an infarction in the regions of</p><p>period soon after dorsal frontal and cingulate lesions. In a study of</p><p>Fig. 5 On MRI a proton-density-weighted image demonstrating</p><p>haemosiderin rim in the external capsule and a slit extending towards the</p><p>thalamus.</p><p>Journal of Clinical Neuroscience (2004) 11(1), 2530the 10 patients with ACA infarction with involvement of thecingulate gyrus and of them six had AM with four on the right sideand the remaining two in the left, even though five out of the sixand three out of the four had cingulate gyrus involvement.12 It isvery likely the ones that did not show AM at the time of exami-nation could have had AM which had been short-lived. Unilaterallesions are said to give rise to transient akinetic mutism. Inthe case that we have described here (Case 1) AM had continuedfor more than four weeks during the time the patient was underobservation.months he remained hypokinetic and his ability to communicatefluctuated from reduced speech to mutism and hypophonia. Healso exhibited disinhibition, incontinence and gait dyspraxiasuggestive of frontal lobe dysfunction. His language deficitsfluctuated with impairment of comprehension, non-fluency, ano-mia with retention of the ability to repeat and the findings wereconsistent with mixed transcortical aphasia.</p><p>Table 2 summarises the neurological, neurobehavioural andradiological findings. None of the patients in this study had do-pamine agonists.</p><p>DISCUSSION</p><p>Eight patients with AM involving different anatomical sites and ofmaximal importance the frontal lobe (supplementary motor area,cingulate gyrus), basal ganglia (caudate, putamen/globus pallidus)and the mesencephalothalamic regions were selected for consid-eration. The diagnosis of AM requires certain criteria for this isnot only important scientifically but also for use in clinicalpractice and in research. Furthermore the heterogeneity among thepatients with akinetic mutism may raise the possibility of suchvaried conditions as advanced Alzheimers Disease, Picks Dis-ease, Creutzfeld-Jakobs Disease and may complicate certainpsychiatric disorders including catatonic schizophrenia, severedepression or conversion reaction. AM is erroneously diagnosedas depression, delirium or locked-in-syndrome which are not un-commonly associated with stroke. Depression is a significantproblem in stroke patients. The blunted emotional expression to-gether with apathy and in some patients psychomotor retardationsuch as slurring of speech and body movements may mimic AM.Distinguishing between them is important as treatment differs. Inlocked-in-syndrome the patient is awake and aware but is unableto communicate due to paralysis in all parts of the body but for eyemovements and this is the only way he can communicate. It arisesfrom a lesion in the basis pontis with involvement of the spinaland corticobulbar tracts. Case 3 in this study may be mistaken forlocked-in-syndrome. The pathologies in AM have ranged frommeningitis, encephalitis, hydrocephalus, trauma, tumours, thirdventricular cysts to vascular lesions namely ruptured aneurysmsand infarction. Depending on the clinical picture AM had beensubdivided into two types based on the anatomical location of thelesion. One is related to the mesencephalic region and described asapathetic akinetic mutism or somnolent mutism. The other isknow as hyperpathic akinetic mutism and is associated withbilateral frontal damage.5 In th...</p></li></ul>