Neurology -- Correspondence for Pharr et al., 56 (7) 957-963

Correspondence published:

Comparison of apraxia in corticobasal degeneration and progressive supranuclear palsy: Gianfranco Denes (25 September 2001)

Comparison of apraxia in corticobasal degeneration and progressive supranuclear palsy 25 September 2001

Gianfranco Denes
Ospedale Civile Venezia Italy
Send Correspondence to journal:
Re: Comparison of apraxia in corticobasal degeneration and progressive supranuclear palsy

denes{at}unive.it Gianfranco Denes

Pharr et al. report the incidence and severity of ideomotor apraxia (IMA) in patients with corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP).
Both patient groups were impaired, but at different degrees: PSP patients impairment was limited only to transitive tasks, while CBD patients were more severely affected, their performance being lower than those of PSP patients in all conditions. In there paper no mention is made about the presence of apraxia in daily living activity and its consistency, the lack of automatic-voluntary dissociation and finally of the scarcity of the most characteristic error type shown by focal (left parietal) IMA patients, the use of hands or fingers to represent an intended object (body-part-as-object). [1]
Apraxia is the neuropsychological hallmark of CBD. However, it must be reminded that CBD apraxia is characterized by its presence in daily living activities, its asymmetry, being limited, at least in the initial phase, to one upper limb, its consistency. [2, 3]
Most typical is a disorder of motor control and specific activation of simple movements, present in the execution of uni-manual and bi-manual dexterity tasks. This pattern is reminiscent of a neglected form of apraxia, the melokinetic or limb-kinetic apraxia (LKA), that, according to Liepmann’s original description consists of “impaired, coarse, mutilate execution of simple movements”, while more complex motion may not even be possible, though the ideational plan is spared. [4] “Even the simplest and more practiced movements, for which we have purely kinetic memory, are coarse and rough, the skill deriving from daily experience being lost.”
The following points seem to characterize the apraxic deficit of CBD patients: the selectivity of involvement of the limbs, in a centripetal fashion, with sparing of oro-facial movements, severity of apraxic deficit, which from the start affect daily life activities, leading in the latest stages to a complete loss of the autonomy, thus in contrast to the usual pattern of apraxia following focal lesions, which in most cases is apparent only in testing conditions.
References:
1) Pharr V, Uttl B, Stark M, Litvan I, Fantie B, Grafman J. Comparison of apraxia in corticobasal degeneration and progressive supranuclear palsy. Neurology 2001;56:957-963.
2) Pillon B, Blin J, Vidailher M. The neuropsycholgocial pattern of corticobasal degeneration. Neurology 1995;45:1477-1483.
3) Denes G, Mantovan MC, Gallana A, Cappelletti JY. Limb kinetic apraxia. Movement Disorders 1998;13:468-477.
4) Liepmann H. Apraxia. (A translation from Ergebnisse der gesamten Medizin, 1920;1:516-543) In Research Bulletin #506. Department of Psychology, The University of Western Ontario, 1980.