Background. Proportional motor recovery in the upper limb has been investigated, indicating about 70% of the potential
for recovery of motor impairment within the first months poststroke. Objective. To investigate whether the proportional
recovery rule is applicable for upper-limb somatosensory impairment and to study underlying neural correlates of
impairment and outcome at 6 months. Methods. A total of 32 patients were evaluated at 4 to 7 days and 6 months using
the Erasmus MC modification of the revised Nottingham Sensory Assessment (NSA) for impairment of (1) somatosensory
perception (exteroception) and (2) passive somatosensory processing (sharp/blunt discrimination and proprioception);
(3) active somatosensory processing was evaluated using the stereognosis component of the NSA. Magnetic resonance
imaging scans were obtained within 1 week poststroke, from which lesion load (LL) was calculated for key somatosensory
tracts. Results. Somatosensory perception fully recovered within 6 months. Passive and active somatosensory processing
showed proportional recovery of 86% (95% CI = 79%-93%) and 69% (95% CI = 49%-89%), respectively. Patients with
somatosensory impairment at 4 to 7 days showed significantly greater thalamocortical and insulo-opercular tracts (TCT
and IOT) LL (P < .05) in comparison to patients without impairment. Sensorimotor tract disruption at 4 to 7 days did not
provide significant contribution above somatosensory processing score at 4 to 7 days when predicting somatosensory
processing outcome at 6 months. Conclusions. Our sample of stroke patients assessed early showed full somatosensory
perception but proportional passive and active somatosensory processing recovery. Disruption of both
