Background: While myoclonus and ataxia are considered common in patients with familial Creutzfeld-Jakob disease (fCJD), other movement disorders are less prevalent.

Objectives: To systemically evaluate the frequency of extrapyramidal signs and movement disorders in patients with fCJD.

Methods: A detailed neurological examination, with special emphasis on movement disorders and extrpyramidal signs, was conducted in 43 consecutive symptomatic CJD patients (26 males and 17 females mean age 58.7 ± 8.9 yrs, range 43–77 years) carrying the E200K mutation in the PRNP gene.

Results: Limb or gait ataxia was noted in 38 patients (88%) (37 patients, 86%, had ataxia at presentation). Myoclonus was evident in 25/43 patients (58%) (21 patients, 49%, at presentation). In 95% of the patients (41/43) (37/43, 86% at presentation) at least one extrapyramidal sign throughout the disease course was noted, the most prevalent being rigidity (28/43, 65% of the patients and 22/43, 51% at presentation), followed by the glabellar sign (24/43, 56% of the patients and 22/43, 51% at presentation), bradykinesia (19/43, 44% and 15/43, 35% at presentation), dystonia (15/43, 35% 12/43, 28% at presentation) and tremor (13/43, 30% 12/43, 28% at presentation).

Conclusions: In this unique population of fCJD patients, myoclonus was less prevalent than previously reported while other extrpyramidal signs were common and occurred at a relatively early stage of the disease. The high prevalence of movement disorders can be added to other phenomena characteristic of this familial disorder among Libyan Jews. Whether this is attributable to the E200K mutation itself or to some other mechanism has still to be elucidated.