Hemiparkinson–hemiatrophy syndrome Mentioned here is a rare syndrome described by Klawans and elaborated in a series of 30 patients by Wijemanne and Jankovic. The typical case shows atrophy in one or more body parts, including at times the face, often since childhood, and usually quite subtle. Signs of progressive parkinsonism or dystonia begin in midlife on the atrophic side and, for the most part, are responsive to l-dopa, but some, such as Klawans’ patients, are resistant. Several types of early life cerebral injury underlie the syndrome, but half of patients have no such lesion evident. Understanding of the idiopathic cases is limited. Those with deep brain lesions may be experiencing a slow degeneration of basal ganglia pathways.
The 2 main difficulties are to distinguish typical Parkinson disease from the many parkinsonian syndromes caused by other degenerative conditions and by medications or toxins, and to distinguish the Parkinson tremor from other types, especially essential tremor. It is worth noting that Parkinson disease is far more common than any of the degenerative syndromes that resemble it but the accuracy of diagnosis, especially early in the course of disease has been poor when compared with pathologic verification as noted just below. Much of this discrepancy in our view has been due simply to inadequate examination and follow up. Bradykinesia and rigidity of the limbs and axial musculature are symptoms shared with other forms of parkinsonism, but it is mainly in Parkinson disease that one observes an early sign of “resting” alternating tremor that is more prominent in one arm. A response of the main symptoms to dopaminergic medication (as noted below and see further on) has been the most dependable feature for accurate diagnosis in several series.
If one adheres to the standard definition of
Parkinson disease—bradykinesia, hypokinesia “resting” tremor, postural changes and instability, cogwheel rigidity, and response to l-dopa—errors in diagnosis are, in our experience, few. Yet in a series of 100 cases, studied clinically and pathologically by Hughes and associates, the diagnosis was inaccurate in 25 percent (see also Adler et al). The ostensible explanation for this difficulty is that approximately one-quarter of Parkinson patients fail to display the characteristic tremor and approximately 10 percent are said to not respond to l-dopa. These authors noted that early dementia and autonomic disorder and the presence of ataxia or corticospinal signs were reliable guides to an alternate diagnosis.
When not all the typical signs are evident, there is no alternative but to reexamine the patient at several-month intervals until it is clear that Parkinson disease is present or until the characteristic features of another degenerative process become evident; these include early falls and vertical gaze impairment in progressive supranuclear palsy; dysautonomia with fainting, bladder, or vocal cord dysfunction in multiple system atrophy; early and rapidly evolving dementia or intermittent psychosis in Lewy body disease; or apraxia in corticobasal ganglionic degeneration. Very symmetrical findings, particularly tremor, suggest an alternative to idiopathic Parkinson disease but quantifying how much asymmetry is too much is not possible. Also, the constellation of features termed “lower half parkinsonism” consisting of difficulty purely with gait and stability, as discussed below and in Chap. 6, suggest a process other than Parkinson disease.