TICS AND TREMORS
All tremors, whether they occur during muscular repose or muscular activity, are distinguished by the relative restriction of their range and the regularity of their time. The tremors of paralysis agitans, disseminated sclerosis, senility, toxæmia, hysteria, ex-ophthalmic goitre, etc., are not liable to be mistaken for tic.
It is true, of course, that tremor is sometimes combined with choreiform or athetotic movements in patients with psychical stigmata.[190] A proposal, too, has been made to unite hereditary and functional tremor and to describe them as a tremor neurosis.[191]
However simple be the diagnosis between tremor and tic, it is worth while to note in passing the etiology they may have in common. In a case recorded by van Gehuchten an intention tremor of the right arm co-existed with a tic of the right sternomastoid.
A sudden twitch of the whole body Letulle particularises as a "tic of starting," and Noir too thinks that a start of this nature may constitute a tic, but we are inclined to consider it a generalised reflex.