71% had bradykinesia (slow movements), 64% showed apraxia, 43% reported limb dystonia, and although more cognitive 36% had dementia. In another study of 36, over half had a useless/alien arm and 27% had a gait impediment[21]. From this, we can see why CBD is hard to diagnose. Even if it can be distinguished as different from one of the other similar diseases, the varying combinations of symptoms create a difficult path to diagnosis. Motor and associated cortical dysfunctions
Some of the most prevalent symptom types in people exhibiting CBD pertain to identifiable movement disorders and problems with cortical processing. These symptoms are initial indicators of the presence of the disease. Each of the associated movement complications typically appears asymmetrically and the symptoms are not observed uniformly throughout the body. For example, a person exhibiting an alien hand syndrome (explained later) in one hand, will not correspondingly display the same symptom in the other hand. Predominant movement disorders and cortical dysfunctions associated with CBD include:
Parkinsonism
Alien hand syndrome
Apraxia (ideomotor apraxia and limb-kinetic apraxia)
Aphasia

Parkinsonism
The presence of parkinsonism as a clinical symptom of CBD is largely responsible for complications in developing unique diagnostic criteria for the disease. Other such diseases in which parkinsonism forms an integral diagnostic characteristic are Parkinsons disease (PD) and progressive supranuclear palsy (PSP). Parkinsonism in CBD is largely present in an extremity such as the arm, and is always asymmetric. It has been suggested that non-dominant arm is involved more often.
Erythema multiforme (EM) is a skin condition that appears with red patches evolving into target lesions, typically on both hands.It is a type of erythema possibly mediated by deposition of immune complexes (mostly IgM-bound complexes) in the superficial microvasculature of the skin and oral mucous membrane that usually follows an infection or drug exposure. It is an uncommon disorder, with peak incidence in the second and third decades of life. The disorder has various forms or presentations, which its name reflects (multiforme, "multiform", from multi- + formis). Target lesions are a typical manifestation. Two types, one mild to moderate and one severe, are recognized (erythema multiforme minor and erythema multiforme major). Erythema multiforme was first described by von Hebra in 1860. Signs and symptoms
The condition varies from a mild, self-limited rash (E. multiforme minor) to a severe, life-threatening form known as erythema multiforme major (or erythema multiforme majus) that also involves mucous membranes. Consensus classification:
Erythema multiforme minor—typical targets or raised, edematous papules distributed acrally
Erythema multiforme major—typical targets or raised, edematous papules distributed acrally with involvement of one or more mucous membranes; epidermal detachment involves less than 10% of total body surface areaStevens–Johnson syndrome and toxic epidermal necrolysis used to be considered part of the erythema multiforme spectrum, but that is no longer the case.The mild form usually presents with mildly itchy (but itching can be very severe), pink-red blotches, symmetrically arranged and starting on the extremities. It often takes on the classical "target lesion" appearance, with a pink-red ring around a pale center.