Other clinical examination can include grading of muscle weakness, which is done by asking the patient to stand from a seated position with their hands folded across their chest. Laboratory investigations include evaluating blood calcium and alkaline phosphatase, which are always increased in tertiary hyperparathyroidism. Other common results from laboratory investigations would include decreased vitamin D levels, elevated blood parathyroid hormone and hyperphosphatemia. Etiology
Hyperparathyroidism, in general, is caused by either tumorous growth in one or more parathyroid glands or a prolonged decrease in blood calcium levels or hypocalcaemia which in turn stimulates the production of parathyroid hormone release from the parathyroid gland. The parathyroid gland is located beside the thyroid gland in the neck, below and in front of the larynx and above the trachea. It is composed of four glands in total that monitor blood calcium levels via the calcium sensing receptors, a g-coupled protein receptor. The parathyroid glands main role is calcium homeostasis. Histologically, these glands are composed of chief cells and oxyphil cells with the chief cell primarily responsible for the storing and release of parathyroid hormone. These cells are arranged in a pseudo-follicular pattern similar to the thyroid follicles. Keratin staining is used to image the parathyroid hormone granules. Parathyroid hormone is responsible for the induction of increased calcium absorption in the gastrointestinal tract or gut and in the kidney. It also induces calcium and phosphate resorption from the bone by osteoclasts. Parathyroid hormone also plays a role in activating vitamin D from its pro form to its active form.
Anencephaly
Anencephaly (without brain) is a severe neural tube defect that occurs when the anterior-most end of the neural tube fails to close, usually during the 23rd and 26th days of pregnancy. This results in an absence of a major portion of the brain and skull. Infants born with this condition lack the main part of the forebrain and are usually blind, deaf and display major craniofacial anomalies. The lack of a functioning cerebrum will prevent the infant from even gaining consciousness. Infants are either stillborn or usually die within a few hours or days after birth. For example, anencephaly in humans can result from mutations in the NUAK2 kinase. Encephaloceles
Encephaloceles are characterized by protrusions of the brain through the skull that are sac-like and covered with membrane. They can be a groove down the middle of the upper part of the skull, between the forehead and nose, or the back of the skull. Due to the range in its location, encephaloceles are classified by the location as well as the type of defect it causes. Subtypes include occipital encephalocele, encephalocele of the carnival vault, and nasal encephaloceles (frontoethmoidal encephaloceles and basal encephaloceles), with approximately 80% of all encephaloceles occurring in the occipital area. Encephaloceles are often obvious and diagnosed immediately. Sometimes small encephaloceles in the nasal and forehead are undetected.