Neurological outcome after resection of primary somatosensory cortex

Object: The postoperative neurological outcome has not been well documented after resection of the primary sensory cortex (S1). This study was designed to evaluate the neurological deterioration that follows resection of the S1 and to assess the risk factors associated with these morbidities.

Methods: We reviewed 50 consecutive patients who suffered from pharmacologically intractable epilepsy and underwent the resection of the S1 and/or adjacent cortex with intraoperative cortical stimulation and mapping while under awake anesthesia. The 50 patients were categorized into 4 groups according to the resected area on the postoperative magnetic resonance images: Group 1 (resection of the only S1; n = 6), 2 (resection of the only posterior parietal cortex (PPC); n = 28), 3 (resection of both S1 and PPC; n = 6), and 4 (resection of both S1 and precentral gyrus; n = 10).

Results: After the resection of S1 and/or adjacent cortex, 16 patients (34%) experienced neurological worsening, including 5 permanent deficits (10%) and 11 transient deficits (22%). Permanent deficits included 2 motor dysphasia, 1 dysesthesia, 1 gait disturbance, and 1 fine movement disturbance of hand. The neurological risks were 17% (1/6) in the group 1, 21% (6/28) in the group 2, 50% (3/6) in the group 3, and 60% (6/10) in the group 4. The permanent neurological deficits showed in 0 patients (0%) of the group 1, 1 (4%) of the group 2, 1 (17%) of the group 3, and 3 (30%) of the group 4.

Conclusions: The neurological results of the S1 resection were tolerable, however, the resection of the PPC or the primary motor cortex in addition to S1 was significantly associated with the development of postoperative neurological impairments.