Tablee 4.

Mixed lineal regression model that analyses the factors that contribute to the SNh area.

	Estimate	Std. Error	Lower 95%	Upper 95%	P-value
PMA	−0.006	0.029	−0.063	0.051	0.831
PLS	−0.067	0.034	−0.135	0.001	0.055
History of PD or dementia	0.006	0.029	−0.05	0.063	0.824
Age	0.001	0.001	0	0.003	0.163
Male gender	0.036	0.023	−0.009	0.082	0.119
fALS	0.083	0.031	0.021	0.145	0.01*
Left SNh	0.022	0.012	−0.001	0.045	0.066

fALS: familial ALS; PLS: primary lateral sclerosis; PMA: progressive muscular atrophy; PD: Parkinson’s disease; SNh: hyperechogenicity of substantia nigra.