Short latency afferent inhibition associated with cortical compression and memory impairment in patients with chronic subdural hematoma.

OBJECTIVE

To evaluate the cortical excitability in patients with mild cortical compression.

METHODS

The present study used short interval intracortical inhibition (SICI), intracortical facilitation (ICF), and short latency afferent inhibition (SAI) to evaluate motor cortex excitability in 16 chronic subdural hematoma (CSDH) patients with memory impairment and compared the data with those of 16 healthy controls.

RESULTS

SAI was reduced in patients compared with controls (99±14 vs. 47±11% of the test size; p<0.0001, unpaired t-test). CSDH patients tended to have a high resting motor threshold and less pronounced SICI and ICF than controls, but these differences were not significant. Treatment of hematoma improved memory impairment and SAI in CSDH patients with wide individual variations that ranged from an increase of 74% to 17% of test size.

CONCLUSION

These findings suggest that measuring SAI may provide a means of probing the integrity of cortical cholinergic networks in a compressed human brain.