title: Isolated hand paresis: a case series.
abstract: BACKGROUND
  Hand knob infarction is a well-known stroke entity. Based on very limited data, embolic stroke mechanism has been considered the most frequent cause; however, prognosis is considered good. We wanted to shed more light on this phenomenon by assessing a cohort of patients referred to a general hospital stroke unit.
  
  
  METHODS
  Every subject admitted to our stroke unit with an acute isolated hand paresis in the period from 2007 to 2012 was identified prospectively. Patients who had suffered from a stroke in the hand motor cortex or an adjacent area explaining the acute loss of hand function were included in the study. The Trial of Org 10172 in Acute Stroke Treatment criteria were used to classify subtypes of stroke according to etiology. The patients were followed up during autumn 2012.
  
  
  RESULTS
  Seventeen subjects were admitted, but in 2 of them symptoms were transitory and magnetic resonance imaging was negative. Two patients were excluded due to persisting sensory deficits. The remaining 13 (11 males and 2 females) patients with an average age of 62.9 (± 13.4) years were included, representing 1.5% of all ischemic strokes diagnosed at the stroke unit in the given period. All patients were right-handed, and the dominant hand was affected only in 4 (31%). The average Medical Research Council's scale score was 3.1 (± 1.4) on admission, and classified as bad. On follow-up, which occurred on average 29.8 (± 19.8) months after the stroke, the score was 4.6 (± 0.4) and was classified as fair to good. No patient experienced a new stroke. The outcome was good to excellent in 10 patients (77%). Two patients died (15%), 1 of probable cardiac arrest and 1 of unknown cause. One patient did not participate in the follow-up. The majority of patients had evidence of both small artery (77%) and large artery (85%) disease. On average, there were 1.6 (± 0.4) new ischemic lesions per patient. Six patients had a solitary lesion (46%). In 5 of them, small artery occlusion was considered the probable stroke mechanism. In 4 cases, the stroke was of undetermined etiology. Three patients had atrial fibrillation, and in 2 of them cardioembolism was the probable stroke mechanism. Two patients with definite large artery atherosclerosis underwent carotid endarterectomy, and 1 of them had comorbid atrial fibrillation.
  
  
  CONCLUSIONS
  Strokes causing isolated hand paresis seem to have a heterogeneous etiology. Prognosis regarding hand function is good, but long-term outcome depends on stroke etiology and secondary prophylaxis.
authors.affiliation: Department of Neurology, Nordland Hospital Trust, Bodø, Tromsø, Norway ; Institute of Clinical Medicine, University of Tromsø, Tromsø, Norway.
authors.forename: Karl B
authors.initials: KB
authors.lastname: Alstadhaug
authors.forename: Ane
authors.initials: A
authors.lastname: Sjulstad
keywords: Cortical hand; Hand knob; Hand motor cortex; Monoparesis; Stroke; Stroke mechanism