Cerebral hemispherectomy: sensory scores before and after intensive mobility training

Abstract

Purpose: It is unclear whether sensory modalities can be modified by rehabilitation and if sensory functions vary on the affected side many years after cerebral hemispherectomy. This pilot, proof-of-concept study assessed light touch and proprioception before and after 10 days of intensive mobility training in individuals after hemispherectomy.

Methods: Light touch and proprioception of the upper and lower extremity was measured using the Fugl-Meyer sensory subtest on the paretic side in 18 individuals with hemispherectomy before and after mobility training. Sensory scores and differences related to mobility training were compared with clinical variables.

Results: Patients were 7.1±5.7 years from time of surgery to sensory assessment and mobility training. Light touch scores were 81±22% and proprioception values were 64±23% of normal (p=0.0022). Light touch did not correlate with proprioception scores, and differences comparing after with before mobility training did not correlate. In multivariate analysis, younger age at seizure onset correlated with better light touch scores, and older age at onset correlated with improvements in light touch scores with mobility training. By comparison, proprioception scores were better in individuals with perinatal infarcts compared with Rasmussen encephalitis and Sturge-Weber. Post-training, proprioception scores were better in Sturge-Weber cases.

Conclusion: Light touch was less affected than proprioception on the paretic side after cerebral hemispherectomy. Improvements with mobility training correlated with older age at seizure onset and etiology. These findings suggest that many years after epilepsy surgery sensory functions are not static supporting the notion of existing developmental neuroplasticity of the remaining cerebral cortex along with brain stem and spinal cord pathways.

Figure 1

Scatterplots comparing Light Touch Scores against age at seizure onset (A) and age at surgery (B), and differences in Light Touch Scores post-pre mobility therapy (LT2 – LT1=Δ LT) compared with age at seizure onset (C). R-values and P-values are shown for each graph (from Table 2). Light Touch scores negatively correlated with age at seizure onset (A) and surgery (B). Improved Light Touch Scores post-mobility therapy positively correlated with age at seizure onset (C).

Figure 2

Scatterplots comparing Proprioception Scores against age at seizure onset (A) and epilepsy duration (B), and bar graphs comparing etiology groups with Proprioception Scores, Pro2-Pro1=Δ Pro (C) and differences in post-pre mobility therapy. Proprioception Scores negatively correlated with age at seizure onset (A) and positively correlated with epilepsy duration (B). In addition, Proprioception Scores were greater in patients with Perinatal Infarcts compared with Rasmussen Encephalitis (RE; see *; Post-hoc; p=0.0033; C). Patients with Sturge-Weber (n=2) had greater improvements in Proprioception scores after mobility therapy compared with those with Perinatal Infarcts and RE (see **; Post-hoc; p<0.012; D).