Regional estimates of cortical thickness in brain areas involved in control of surgically restored limb movement in patients with tetraplegia

Figures & data

Table 1 Demographics, clinical characteristics and surgical procedures included among the tetraplegic individuals.

Patient	Age	Time since surgery	Cause of injury	BR function (0–5)^1	International Classification^2	Level of injury	Surgical procedures
1	31	1	Diving	5	4	C7	tf, ff, ir, fpl-epl, elk, ecu, cmcI
2	41	10	Fall	5	3/4	C6	tf, ff, ir, fpl-epl, cmcI
3	48	5	Work-related	5	4	C7	tf, ff, ir, fpl-epl, ecu, cmcI
4	39	7	Sport	5	2	C6	tf, fpl-epl, elk, cmcI
5	41	10	Traffic	5	2	C6	tf, ff, fpl-epl, ir
6	43	7	Diving	5	4	C7	tf, ff, ir, fpl-epl, cmcI, ecu

BR = brachioradialis; tf = thumb flexion reconstruction; ff = finger flexion reconstruction; ir = intrinsic reconstruction; elk = Extensor Pollicis Longus-loop-knot; fpl-epl = Split FPL–EPL tenodesis; ecu = Extensor Carpi Ulnaris tenodesis; cmcI = arthrodesis of carpometacarpal (CMC) joint I.

¹Classified according to the Medical Research Council (MRC) system.

²Description of motor groups according to the International Classification for Surgery (ICSHT) of the Hand in Tetraplegia.

Figure 1 Gray matter thickness in (A) functionally and (B) anatomically defined areas of the primary motor cortex. Bar charts show cortical thickness in patients and control participants. The scatter plot shows patients’ cortical thickness as a function of time since reconstructive surgery, while controlling for age. Error bars indicate standard deviations, and the dotted lines show the 95% confidence bounds. Abbreviations: n.s., not significant; SCI, spinal cord injury.

Table 2 Cortical thickness in individuals with tetraplegia and control participants.

Cortical region	Cortical thickness (mm)		P
	Individuals with tetraplegia (n = 6)	Controls (n = 6)
Pinch grip area	2.64 (0.18) [2.41–2.90]	2.70 (0.47) [2.26–3.22]	0.591
Brodmann Area 4	2.44 (0.12) [2.28–2.53]	2.68 (0.22) [2.38–2.95]	0.013

P values refer to one-tailed non-parametric Wilcoxon rank sum tests for the comparison between Individuals with tetraplegia and controls.

Table 3 Individual cortical thicknesses for individuals with tetraplegia and control participants.

		Cortical thickness (mm)
		Pinch grip area	Brodmann Area 4
Individuals with tetraplegia	1	2.754	2.529
	2	2.572	2.519
	3	2.503	2.510
	4	2.411	2.277
	5	2.901	2.503
	6	2.696	2.283
Controls	1	2.263	2.643
	2	2.899	2.922
	3	3.224	2.945
	4	3.201	2.627
	5	2.285	2.379
	6	2.300	2.539