Abstract
Dear sir I read with great interest the article by Dr Yen-Yu Chen et al. (1) on primary cough headache. I think that among the aetiologies of symptomatic cough headache, spontaneous intracranial hypotension (SIH) should also be included. In fact occasionally cough causes SIH associated with an intermittent transient severe headache. We also observed a similar patient in the case histories of 21 patients with SIH. In these cases orthostatic features of headache by SIH are absent and the patients are asymptomatic if they avoided the provoking manouvres. Each headache would last for about 20 min (2).
I think that the brain MRI study reported in the article by Dr Yen-Yu Chen is incomplete because brain MRI is performed without gadolinium administration. In fact only with gadolinium brain MRI it is possible to show the diffuse pachymeningeal enhancement by SIH. Therefore it is very important to perform gadolinium brain MRI. Furthermore the article of Dr Yen-Yu Chen reports that patients with primary cough headache had a significantly lower position of the cerebellar tonsillar tip above the line of foramen magnum than the control subjects. So, it is possible that someone of these patients was afffected by SIH. In fact SIH causes brain descent sometimes provoking cerebellar tonsils ectopy so-called Arnold-Chiari pseudomalformation beacause it is similar type 1 Arnold-Chiari malformation (3).
In conclusion I think that it is very important to perform gadolinium brain MRI in patients with cough headache to exclude symptomatic cough headache by SIH.