Corticobasal degeneration (CBD)  is a rare neurodegenerative disease involving the cerebral cortex and the basal ganglia. CBD symptoms typically begin in people from 50 to 70 years of age, and the average disease duration is six years. It is characterized by marked disorders in movement and cognition, and is classified as one of the Parkinson plus syndromes. Diagnosis is difficult, as symptoms are often similar to those of other disorders, such as Parkinsons disease, progressive supranuclear palsy, and dementia with Lewy bodies, and a definitive diagnosis of CBD can only be made upon neuropathologic examination. Signs and symptoms
Because CBD is progressive, a standard set of diagnostic criteria can be used, which is centered on the diseases evolution. Included in these fundamental features are problems with cortical processing, dysfunction of the basal ganglia, and a sudden and detrimental onset. Psychiatric and cognitive dysfunctions, although present in CBD, are much less prevalent and lack establishment as common indicators of the presence of the disease.Although corticobasal degeneration has a plethora of symptoms, some are more prevalent than others. In a study of 147 patients with CBD, it was found that all of them had at least one Parkinsonian sign, 95% having two and 93% had some higher order dysfunction (cognitive impairments like acalculia, sensory loss, dementia, neglect, etc.). In a separate study of 14 patients recorded 3 years after the onset of symptoms, many patients had high numbers of motor symptoms.
Parathyroid carcinoma is a rare cancer resulting in parathyroid adenoma to carcinoma progression. It forms in tissues of one or more of the parathyroid glands (four pea-sized glands in the neck that make parathyroid hormone (PTH). PTH helps the body maintain normal levels of serum calcium by promoting calcium reabsorption from bone. It is antagonized by the hormone calcitonin, which prompts calcium storage.). It is rare, and much less common than parathyroid adenoma. It can be difficult to excise. Signs and symptoms
Most patients experience moderate to severe hypercalcemia and high parathyroid hormone levels. A large mass in the neck is often seen, and kidney and bone abnormalities are common. Risk factors
Parathyroid cancer occurs in midlife at the same rate in men and women.Conditions that appear to result in an increased risk of parathyroid cancer include multiple endocrine neoplasia type 1, autosomal dominant familial isolated hyperparathyroidism and hyperparathyroidism-jaw tumor syndrome (which also is hereditary). Parathyroid cancer has also been associated with external radiation exposure, but, most reports describe an association between radiation and the more common parathyroid adenoma. Diagnosis
On Sestamibi parathyroid scan, intense radioactivity greater than submandibular gland on delayed image, no washout between early and delayed images, and high concentration of parathyroid hormone concentration in blood in those who age more than 40 years is suggestive of parathyroid carcinoma. Some authors suggest high levels of HCG as a marker for parathyroid carcinoma in the right context.