Late Detection of Corpus Callosum Infarction in a 55-Year-Old: Insights from Alien Hand Syndrome

Introduction

Alien hand syndrome (AHS) is a rare neurological disorder characterized by involuntary but apparently intentional limb movements, with partial or absent consciousness [1]. The hypothetical mechanism involves disruption of the structures involved in manual control and appropriate environmental interactions, including the additional motor area, anterior cingulate, medial frontal lobe, corpus callous, and parietal lobe [2].

AHS exists in 3 clinical forms depending on the site of the lesion. Frontal impairment is characterized by a gripping reflex, groping, and compulsive manipulation of tools (grasping of surrounding objects), and sometimes a bimanual coordination disorder; callous impairment is characterized by an intermanual conflict (diagonal dyspraxia), and in some cases, it is associated with ideomatic apraxia, tactile anomia, and agraphy of the non-dominant left hand; posterior or parieto-occipital impairment is characterized by involuntary levitation of the limbs, sometimes with triple ataxia (sensory, optical, cerebellum), hemispatial neglect, and denial of ownership of the non-dominating hand [3,4]. The etiology of AHS is the dysfunction of critical brain regions, secondary to various neurological disorders, such as post-surgical trauma, neoplasms, vascular events, and neurodegenerative diseases [1]. AHS due to a corpus callous infarction is rare and frequently unknown to physicians, due to its various clinical manifestations [5,6]. This report describes a 55-year-old man with an AHS related to a corpus callus infarction of late discovery. This is the first case reported in Côte d’Ivoire, a country located in sub-Saharan Africa.

Case Report

A 55-year-old patient who worked as a computer scientist and was right-handed presented to the Neurology Department on March 5, 2024, with episodes of uncontrolled movements of his left hand. According to him, this phenomenon had been developing for 8 days, preceded by a numbness sensation in his left upper limb 6 days earlier. He described these episodes as follows: his left hand was always in conflict with his right hand; when he went to the bathroom, he felt that his left hand had more difficulty holding the soap than his right hand, but he managed to wash himself properly with his right hand; when he opened a door with his right hand, his left hand bothered him; when he opened the case with his glasses, his left hand interfered with him; and when he crossed his hands behind his back, his left hand became more easily detached. These symptoms made him anxious, and he kept asking the neurologist if this hand behavior would ever stop.

His medical history included high blood pressure and type 2 diabetes for at least 5 years. There was no history of alcohol or tobacco use and no family history of hypertension or diabetes. Neurological examination was normal, blood pressure was 160/100 mmHg, temperature was 37.2°C, pulse was 84 beats per minute and was regular, weight was 93 kg, and height was 1.76 m. A scheduled neuropsychological evaluation could not be performed.

Faced with this unusual symptomatology, clearly evoking a diagonal dyspraxia (intermanual conflict), we prescribed brain imaging, including brain magnetic resonance imaging (MRI; more efficient than a brain scanner), in order to search for an organic origin to this syndrome, including an involvement of the corpus callus, but also to determine the cause. This examination also aimed to rule out differential diagnoses. Cerebral MRI on March 9, 2024, showed signal anomalies within the corpus callous splenium, extending anterior to its trunk, relatively well systematized, with a discrete mass effect on the corpus callous body. These anomalies appeared in hyposignal on the T1 sequence, hypersignal on the T2 sequences, and fluid-attenuated inversion recovery in diffusion 1000, without restriction on the apparent diffusion coefficient and without hemorrhagic stigmata in gradient echo, corresponding to images of a relatively recent corpus callous ischemic stroke in the territories of the left pericallous and posterior cerebral arteries. An old punctuated vascular lesion of the left caudate nucleus and an acquired leukoencephalopathy of old vascular origin were also noted (Figure 1).

Electrocardiogram (ECG) showed sinus tachycardia, associated with an incomplete right branch block with a V5–V6 late S-wave. Holter ECG could not be performed. Transthoracic echocardiography showed mainly concentric hypertrophy of left ventricular walls and no intracavity thrombus. Transoesophageal echocardiography was non-specific. Doppler ultrasound of supra-aortic trunks showed marked bilateral atheromatosis, with the presence of a non-stenotic heterogeneous plaque at the ostium of the right internal carotid artery.

Biologically, complete blood count, erythrocyte sedimentation rate, C-reactive protein, urea, and creatinine were within the reference range. Lipid parameters were normal except for LDL-C, which was abnormally high at 1.37 g/dL. Retroviral serology was negative. Immunological and thrombophilic tests were normal.

On the basis of epidemiological, clinical, and paraclinical arguments, the diagnosis of AHS of the diagonistic dyspraxia type (intermanual conflict), following an infarction of the corpus callosum, was retained. The cause was probably atheromatous.

Management was that of an ischemic stroke. Medications prescribed to the patient included an antidiabetic prescribed by his or her diabetologist, an antihypertensive (perindopril arginine/amlodipine besilate), a statin (Rosuvastatin EG), an antiplatelet aggregator (Aspirin Cardio) and an anxiolytic (prazepam). The medications were well tolerated.

Twenty-one days after the onset of the stroke, the patient noted a significant improvement in the behavior of his left hand, which became less and less troublesome, with the disappearance of the intermanual conflict. On the other hand, the patient reported difficulties in deciding which of the 2 opposite actions to initiate.

Discussion

Our case report highlighted an AHS that led to a delay in the diagnosis of a cerebral infarction due to damage to the corpus callus. Indeed, it was only after 2 weeks of development that a brain MRI could be prescribed and carried out, a delay that was certainly due to ignorance of this syndrome. In fact, several symptoms could be assimilated to this syndrome, such as psychiatric disorders, a disturbance of the body pattern due to injury to the hemisphere minor, or abnormal movements. In this case, we recommend that doctors conduct brain imaging without delay in the presence of any unusual clinical manifestation of sudden onset or refer the patient to a neurologist without delay. This clinical case also contributes to the enrichment of sub-Saharan African data on AHS by corpus callous infarction.

AHS is a rare manifestation of stroke [7,8] and not a specific manifestation of corpus callus infarction. It is therefore easy to miss the diagnosis and misdiagnose it at an early stage [9]. However, in the presence of classic signs of stroke, such as hemicorporeal motor deficit, physicians can easily prescribe brain imaging, because they are used to this type of symptom. This is not evident with AHS, especially diagonal dyspraxia. In addition, stroke is an emergency, especially in the case of cerebral infarction, in which the possibility of thrombolysis can be considered. El Nahas et al, in Egypt, performed intravenous thrombolysis in a 66-year-old patient who abruptly lost control of his upper right limb, which was moving without his control. These involuntary movements lasted 30 min, followed by right hemiplegia and dysarthria. Brain imaging revealed a left parietal infarction involving the postcentral gyrus [10]. The imaging was performed because the hemiplegia was obvious. This was not the case in our situation, in which there was no motor deficit. The diagnosis of AHS by infarct of the corpus callus was made on the basis of the clinical presentation, characterization of the movement, and localization, in correlation with the results of the neuroimaging.

Several cases of AHS have been reported and are variable depending on lesion sites. In 2016, Gao et al [11] reported a case similar to ours in a 56-year-old woman with an involuntary movement of the right hand. In the same study, they also reported 31 cases of AHS by infarctus of the corpus callous through a review of the extensive literature from 1990 to 2014, with diagonal dyspraxia observed in 19 cases (61.3%) [11]. In contrast, in 2014, Yang et al reported 1 case of inter-manual conflict (4%) out of 25 cases of AHS admitted between 2012 and 2013 [9]. Also, Qureshi et al reported, in an 84-year-old woman, an AHS characterized by unilateral and involuntary movements of the left arm that were uncontrolled, with repetitive grip. This syndrome was related to damage of the left frontal lobe and corpus callous by cerebral hemorrhage [12]. Although the corpus callous was affected, there was no intermanual conflict. Panikkath et al reported acute infarctions in both parietal lobes that externalized through uncontrolled involuntary movements without intermanual conflict [13].

AHS can be a source of anxiety and stress for patients, as in our case [4,13,14]. Indeed, the uncontrolled hand takes on an unusual character and could give rise to all sorts of interpretations and qualifications, such as “my arm was possessed by the devil” [12], “my left hand did not belong to me but to my grandson, my left hand was controlled by someone other than me, my two hands were always fighting each other during bi-manual coordination” [15], and “my left hand was stupid, stupid, indiscreet and reckless, useless and uncontrollable” [16]. Moreover, people with AHS often feel a loss of control and ownership over their affected limb, and many describe it as having “its own mind” [13,17]. However, as reported by Yuan et al, in some cases, patients show no signs of anxiety [15].

The causes of ischemic stroke of the corpus callus are dominated by vascular causes (66%). Cardiac causes account for 13.6%, rare causes for 1.7%, and undetermined causes for 18.6% [6]. In addition, splenic infarction is more frequently due to embolism, while atherothrombotic infarctions are more frequent in the knee and the callous body [18]. In our case, at the current stage of our investigations, the etiology remains undetermined, although we suspect an atheromatous origin.

Regarding the treatment of AHS, there is no approved or recommended therapy, and its management is based on anecdotal reports of pharmacological interventions based on botulinum toxin and clonazepam, as well as behavioral interventions [1,2]. In general, the prognosis is good, with partial or complete recovery [1]. For our patient, in addition to the usual treatment of cerebral infarction, we instituted an anxiolytic (prazepam), due to anxiety. The outcome was favorable 21 days after the onset of symptoms. Clonazepam and prazepam belong to the same therapeutic group and have similar actions, which may explain the improvement observed in our patient. In addition, patients can also improve spontaneously.

Although AHS can occur anywhere in the world, including in Africa, it is considered a very rare neurological disease, meaning that cases in Africa are likely to be rare due to its low prevalence globally and the need for specialized neurological care to diagnose it. However, cases of AHS in Africa have been identified, particularly in regions with access to advanced medical facilities, where accurate diagnosis is possible.

The strength of this study lies in its ability to bring AHS to the to the attention of physicians, given its very specific nature. In addition, it will enrich publications in sub-Saharan Africa, which, to the best of our knowledge, are extremely rare or virtually non-existent. The limitations of this study are related to the neuropsychological assessment and Holter ECG, which we were not able to do. These examinations would have helped in the etiological diagnosis and would have enriched the clinical signs in this context.

Conclusions

This was a case of AHS of diagonal dyspraxia type associated with cerebral infarction. We hope, by updating this syndrome, to attract the attention of physicians, to avoid diagnostic delays. Thus, we recommend brain imaging in case of unusual clinical manifestation or the prompt referral of the patient to a neurologist. In addition, this case report could contribute to enriching data on AHS in sub-Saharan Africa.