Ischaemic stroke of the cortical „hand knob“ area: pathomechanisms and clinical course

Background: Cortical ischaemic stroke affecting the precentral “hand knob“ area is a rare but well known stroke entity. To date, little is known about the underlying pathomechanisms and the clinical course.

Methods: Thirty patients admitted to our service between 2003 and 2007 were included in the study on the basis of an acute ischaemic infarct of the cortical “hand knob“ area confirmed by diffusion-weighted magnetic resonance imaging (MRI) with contralateral hand paresis. Retrospective analysis of the following data at the time point of admission was performed: clinical and epidemiological data, MRI parameters (including MR-angiography), Doppler-/Duplexsonography findings of extra- and intracranial vessels as well as cardial diagnostics. Furthermore, follow-up data on all patients was obtained.

Results: Of the thirty patients (21 male/9 female, mean age 71,0 + 9,2 years), seventeen (57%) had an acute ischaemic infarct of the right, and thirteen (43%) of the left cortical “hand knob“ area. The majority (n=22; 73%) of patients had an isolated infarct of the cortical “hand knob“ area. For 22 (73%) patients it was a first ever stroke. Ten (33%) patients had ipsilateral extracranial internal carotid artery (ICA) stenosis and 5 (17%) a cardiac embolic source. All but two patients (93%) had clear atherosclerotic alterations of the ICA. Ischaemic white matter lesions were observed in only eight (27%) patients. Hypertension was the most prevalent vascular risk factor (n=24; 80%).

Follow-up data was obtained for all patients, with a mean follow-up period of 24.2 months (range 0.4–47.4 months). Under standard treatment according to current guidelines, no patient deceased and only one (3%) experienced a second stroke. Twenty-three (77%) patients reported improvement of hand paresis, 18 (60%) were asymptomatic at follow-up (modified Rankin score=0). Nine (30%) patients had mild disability (modified Rankin Score=1), only one patient was significantly disabled due to a second stroke.

Conclusion: Ischaemic infarcts affecting the cortical “hand knob“ area are frequently associated with arterial hypertension and atherosclerotic disease of the ICA, suggesting a thrombembolic pathomechanism. It mostly reflects first ever ischaemic stroke, and follow-up data suggest a rather benign course.