CASE REPORT
Case report
A paralysed thumb
Kazumasa Sudo, Riichiro Kishimoto,Yasutaka Tajima, Akihisa Matsumoto, Kunio Tashiro In October, 2002, a right-handed, 67-year-old man presented with complaints of a sudden paralysis of his left thumb that had first occurred 20 days earlier while drinking a glass of beer. Within a few hours, the paralysis had resolved itself completely. 7 days later, again while drinking beer, he had a second attack of isolated left thumb paralysis. As there was no improvement after the second episode, he sought advice from a neurosurgeon, and an orthopaedic surgeon, both of Brain MRI showing infarction of the omega knob. whom suggested that he had damaged FLAIR images (A, B; arrowheads) diffusion-weighted image (C). a peripheral nerve controlling the thumb. We saw him 13 days after the onset of the second endarterectomy on the 27th hospital day. Upon his episode. He had a history of hypertension, and had been discharge, in December, 2002, after 43 days in hospital, taking antihypertensive medication for 15 years, but he he had no complaints of any limitation in the movement had no history of hyperlipidaemia, diabetes mellitus, atrial of the thumb. When last seen in September, 2003, he had fibrillation, or myocardial infarction. On examination, we normal strength and range of motion in his left thumb, found that he had complete paralysis of his left thumb in although he complained that it still took a little longer to all planes, while all other digits, limbs, and the face were button his shirt. unaffected. There was no sensory disturbance, cerebellar ataxia, or impairment of cranial nerves or autonomic Isolated paralysis of the hand has been shown to nervous system. correspond to small cortical lesions1-3 on MRI, and paresis of a lower limb to a small infarction in the contralateral MRI of the brain showed a small infarction restricted to motor leg cortex.4 In comparison to the cases of handthe lateral portion of the omega knob on the right finger paralysis, our patient’s infarct was restricted both precentral gyrus (arrowheads; figures A, B). Diffusionlaterally and inferiorly.5 Decreased thumb flexion can be a weighted MRI, done 5 days later, showed the same lesion residual effect of larger infarcts of the motor cortex,2 but (arrowhead; figure C). We did a carotid angiography and our case shows that a tiny lesion in the thumb area found an 80% stenosis of the right internal carotid artery, according to Penfield’s homunculus5 can cause isolated and attributed his infarction to an intra-arterial embolism. thumb paralysis. The patient was hospitalised for a course of rehabilitation, and intravenous sodium ozagrel and citicoline, which is commonly used for treatment of ischaemic infarction in References Japan. On the 8th hospital day, he began to regain 1 Yousry TA, Schmid UD, Alkadhi H, et al. Localization of the motor hand area to a knob on the precentral gyrus. A new landmark. Brain movement of the thumb, and he had a carotid 2
Lancet 2004; 363: 1364 3
Department of Neurology, Sapporo City General Hospital (K Sudo PhD, R Kishimoto MD, Y Tajima PhD, A Matsumoto PhD) and Hokkaido University Graduate School of Medicine (K Tashiro PhD) Sapporo, 060-8648 Japan Correspondence to: Dr Kazumasa Sudo (e-mail:
[email protected])
1364
4
5
1997; 120: 141–57. Terao Y, Hayashi H, Kanda T, Tanabe H. Discrete cortical infarction with prominent impairment of thumb flexion. Stroke 1993; 24: 2118–20. Tei H. Monoparesis of the right hand following a localised infarct in the left “precentral knob”. Neuroradiology 1999; 41: 269–70. Kohno Y, Ohkoshi N, Shoji S. Pure motor monoparesis of a lower limb due to a small infarction in the contralateral motor cortex. Clin Imaging 1999; 23: 149–51. Waxman SG. Physiology of specialized cortical regions. In: Correlative neuroanatomy. New York: Lange Medical Books/ McGraw-Hill, 2000: 145–47.
THE LANCET • Vol 363 • April 24, 2004 • www.thelancet.com
For personal use. Only reproduce with permission from The Lancet publishing Group.