Hand vs Hand: The Strange World of Alien Limb

Medscape

8 hours ago

A 55-year-old patient who was right-handed consulted a neurologist for episodes of inter-manual conflict due to uncontrolled movements of his left hand, marked by involuntary movements of his left hand that interfered with the right hand. Each time he reached for a door handle with his right hand, his left hand counteracted the movement. He reported similar interference during other manual tasks. The patient was anxious and feared the persistence of these movements. A brain MRI prescribed by the neurologist allowed the diagnosis of infarction of the corpus callosum.
This rare case of alien hand syndrome reported by Léonard Kouamé Kouassi, MD, and colleagues at Félix Houphouët-Boigny University in Abidjan, Côte d'Ivoire, recommends brain imaging in case of unusual clinical manifestation or prompt referral of the patient to a neurologist.
The Patient and His History
The right-handed patient had 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 is right-handed. Whenever he moves his right hand to perform an activity, his left hand interferes. He has the impression that his left hand is being controlled by someone else, preventing him from performing his activities. These symptoms made him anxious, and he kept asking the neurologist if this hand behaviour 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.
Findings and Diagnosis
On admission, neurologic examination was normal, blood pressure was 160/100 mm Hg, temperature was 37.2 °C, pulse was 84 beats/min and was regular, weight was 93 kg, and height was 1.76 m. A scheduled neuropsychological evaluation could not be performed.
Complete blood cell count, erythrocyte sedimentation rate, C-reactive protein, urea, and creatinine levels were within the reference range. Only low-density lipoprotein cholesterol was elevated at 1.37 g/dL. The retroviral serology results were negative. The immunological and thrombophilia test results were normal.
Cerebral MRI showed well-systematised signal anomalies within the corpus callosum splenium, extending anteriorly to its trunk, with a discrete mass effect on the corpus callosum 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 haemorrhagic stigmata in gradient echo, corresponding to images of a relatively recent corpus callosum ischaemic stroke in the territories of the left pericallosal and posterior cerebral arteries. An old punctuated vascular lesion of the left caudate nucleus and acquired leukoencephalopathy of old vascular origin were also noted.
ECG showed sinus tachycardia associated with an incomplete right branch block with a V5-V6 late S-wave. A Holter ECG could not be performed. Transthoracic echocardiography showed concentric hypertrophy of the 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.
On the basis of these findings, the patient was diagnosed with alien hand syndrome. The management was that of ischaemic stroke. Medications prescribed to the patient included an antidiabetic by a diabetologist, an antihypertensive (perindopril arginine/amlodipine besylate), a statin (Rosuvastatin EG), an antiplatelet aggregator (aspirin), and an anxiolytic (prazepam). Around 21 days after the onset of the stroke, the patient noted a significant improvement in the behaviour of his left hand, which became less and less troublesome, with the disappearance of the inter-manual conflict. However, the patient reported difficulties in deciding which of the two opposite actions to initiate.
Discussion
Alien hand syndrome is a rare manifestation of stroke. The diagnostic workup followed standard stroke protocols. There is no approved or recommended therapy, and its management is based on anecdotal reports of pharmacological interventions using botulinum toxin and clonazepam, as well as behavioural interventions. In this case, in addition to the usual treatment of cerebral infarction, prazepam is an anxiolytic. Clonazepam and prazepam belong to the same therapeutic group and have similar actions, which may explain the improvement seen in our patient. 'We hope, by updating this syndrome, to attract the attention of physicians to avoid diagnostic delays. In addition, this case report could contribute to enriching data on alien hand syndrome in sub-Saharan Africa,' the authors wrote.